[go: up one dir, main page]

US20080176748A1 - Novel herbicides and methods for preparation thereof - Google Patents

Novel herbicides and methods for preparation thereof Download PDF

Info

Publication number
US20080176748A1
US20080176748A1 US12/055,384 US5538408A US2008176748A1 US 20080176748 A1 US20080176748 A1 US 20080176748A1 US 5538408 A US5538408 A US 5538408A US 2008176748 A1 US2008176748 A1 US 2008176748A1
Authority
US
United States
Prior art keywords
compound
phenyl
weeds
alkyl
independently
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
US12/055,384
Inventor
Sheng Qiang
Shiguo Chen
Chunlong Yang
Xinbin Dai
Yunfa Dong
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
NANTONG JIANGSHANG AGROCHEMICAL & CHEMICAL Ltd LLC
Nantong Jiangshan Agrochemical and Chemical Ltd LLC
Nanjing Agricultural University
Original Assignee
Nantong Jiangshan Agrochemical and Chemical Ltd LLC
Nanjing Agricultural University
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Nantong Jiangshan Agrochemical and Chemical Ltd LLC, Nanjing Agricultural University filed Critical Nantong Jiangshan Agrochemical and Chemical Ltd LLC
Assigned to NANTONG JIANGSHANG AGROCHEMICAL & CHEMICAL LIMITED LIABILITY CO., LTD., NANJING AGRICULTURAL UNIVERSITY reassignment NANTONG JIANGSHANG AGROCHEMICAL & CHEMICAL LIMITED LIABILITY CO., LTD. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: DONG, YUNFA, CHEN, SHIGUO, DAI, XINBIN, YANG, CHUNLONG, QIANG, SHENG
Publication of US20080176748A1 publication Critical patent/US20080176748A1/en
Priority to US13/414,711 priority Critical patent/US8921274B2/en
Priority to US14/548,289 priority patent/US9468209B2/en
Abandoned legal-status Critical Current

Links

Classifications

    • A—HUMAN NECESSITIES
    • A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
    • A01N—PRESERVATION OF BODIES OF HUMANS OR ANIMALS OR PLANTS OR PARTS THEREOF; BIOCIDES, e.g. AS DISINFECTANTS, AS PESTICIDES OR AS HERBICIDES; PEST REPELLANTS OR ATTRACTANTS; PLANT GROWTH REGULATORS
    • A01N43/00—Biocides, pest repellants or attractants, or plant growth regulators containing heterocyclic compounds
    • A01N43/34—Biocides, pest repellants or attractants, or plant growth regulators containing heterocyclic compounds having rings with one nitrogen atom as the only ring hetero atom
    • A01N43/36—Biocides, pest repellants or attractants, or plant growth regulators containing heterocyclic compounds having rings with one nitrogen atom as the only ring hetero atom five-membered rings
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07D—HETEROCYCLIC COMPOUNDS
    • C07D207/00—Heterocyclic compounds containing five-membered rings not condensed with other rings, with one nitrogen atom as the only ring hetero atom
    • C07D207/02—Heterocyclic compounds containing five-membered rings not condensed with other rings, with one nitrogen atom as the only ring hetero atom with only hydrogen or carbon atoms directly attached to the ring nitrogen atom
    • C07D207/30—Heterocyclic compounds containing five-membered rings not condensed with other rings, with one nitrogen atom as the only ring hetero atom with only hydrogen or carbon atoms directly attached to the ring nitrogen atom having two double bonds between ring members or between ring members and non-ring members
    • C07D207/34—Heterocyclic compounds containing five-membered rings not condensed with other rings, with one nitrogen atom as the only ring hetero atom with only hydrogen or carbon atoms directly attached to the ring nitrogen atom having two double bonds between ring members or between ring members and non-ring members with hetero atoms or with carbon atoms having three bonds to hetero atoms with at the most one bond to halogen, e.g. ester or nitrile radicals, directly attached to ring carbon atoms
    • C07D207/36—Oxygen or sulfur atoms
    • C07D207/38—2-Pyrrolones

Definitions

  • This invention relates to the application of chemicals and biochemicals to weed control in agriculture and, more specifically to pyrrolidineone derivatives of herbicidal tenuazonic acid (3-acetyl-4-hydroxy-5-tert-butylpyrroline-2-ketone), and to their use as herbicides.
  • Tenuazonic acid (formula name: 3-acetyl-4-hydroxy-5-sec-butylpyrroline-2-ketone) is a strong phytotoxin, isolated, purified and identified from metabolites of Alternaria Alternata by Qiang Sheng et al. It is isolated from the crude mixture of metabolites by the extraction of the fermentation fluid. Due to the low yield (0.0005%) and high cost of fermentation, it is very important to develop a synthetic process. Through a rational design, more potent compounds can be made that are also easy to manufacture. Environmentally safe herbicides can be developed with low toxicity. This is the main direction of the current herbicide development.
  • 3-Acetyl-4-hydroxy-5-tert-butylpyrroline-2-ketone is a heterocyclic compound containing carbonyl and hydroxyl functional groups.
  • the lactam that is part of the heterocyclic ring is the most important functional group.
  • the hydrophobic side chain also plays an important role in its herbicidal activity.
  • the compound is very effective at killing monocotyledon weeds (such as common crabgrass and barnyardgrass) and dicotyledonous weeds including Crofton weeds at a concentration of 50 ⁇ g/mL. It has the potential to become a biological herbicide (CN Pat. Appl. No. 200510038263.2; CN Pat. No. 1644046. However, the low yield and high cost associated with the fermentation process prevents large-scale production of this compound.
  • A1994 patent (WO1994/01401) discloses 3-benzoylpyrrolidine-2,4-dione derivatives and their herbicidal activity.
  • toxin interacts with D1 protein by competing with Q B for the binding site and thus inhibits the electron transfer. Therefore, it is an inhibitory phytotoxin of photosystem II. Based on the discovery of this mechanism, the molecular structure of tenuazonic acid has heretofore been and new herbicidal molecules discovered.
  • CN Appl. Nos. 200510094521.9 and 200610038765.X, and CN Pat Pub No CN1752075 disclose certain compounds and methods of their synthesis.
  • photosystem II inhibitors have successfully become commercial herbicides, such as s-triazines, triazinones and phenols, etc., and have become major players in the field of herbicides.
  • photosystem II inhibitors There are two advantages associated with photosystem II inhibitors: first, since photosynthesis is a common phenomenon among plants, and inhibition is specific to the plants, the toxicity to animals is low, thus this type of herbicides possesses the characteristics of high efficacy and low toxicity.
  • transgenic technology there are 67,700,000 hectares of farm land that grow transgenic crops globally and greater than 80% of these crops are herbicide-resistant transgenic (based on Monsanto's 2003 data).
  • the photosynthetic inhibitors herbicides have a growing share of the herbicides market. With combination of new herbicides and transgenic agricultural products, the chemical pollution to the environment has been greatly reduced. Since the photosynthetic inhibition is the only effect for 3-acetyl-4-hydroxy-5-sec-butylpyrroline-2-ketone on the plant cells, this type of herbicide with high potency, quick action, broad-spectrum, simple structure and easy synthesis will have a bright future.
  • photosystem II inhibitors There are many types of photosystem II inhibitors according to their chemical structures such as ureas, pyridines, triazinones, pyridazinones, dinitrophenols and cyanophenols, etc. They can be divided into two main groups such as ureas/triazine and phenol.
  • the first type (classical photosystem II inhibitors) can be represented as N—C ⁇ X (X stands for O or N atom, not sulfur atom), i.e. atrazine, metribuzin, phemedipham, terbutryand, N-(3,4-dichlorophenyl)-N′-methylurea (DCMU) et al.
  • the second type is phenolic herbicide, including ioxynil, dinoseb and 2-iodo-4-nitro-6-isobutylphenol, etc.
  • the common feature of the second type of herbicide is that the molecules contain at least one carbonyl oxygen, or a hydroxy oxygen and a long hydrophobic hydrocarbon side-chain. Most of these herbicides form a hydrogen bond between the carbonyl hydrogen and the D1 protein of photosystem II, which enables them to successfully compete with plastoquinone Q B (secondary electron acceptor), thus block electron transfer from Q A to Q B , and lead to the inhibition of photosynthetic process of the plant.
  • Q B secondary electron acceptor
  • 3-Acetyl-4-hydroxy-5-sec-butylpyrroline-2-ketone has moderate toxicity of 200 mg/kg to rat and moderate level phytotoxicity, which is acceptable in light of its high biological activity. However, its toxicity level may be reduced through modification of its chemical structure.
  • the invention is directed to compounds represented by the general formula (I), or (II), or a salt thereof
  • R 1 independently and at each occurrence represents H; or —C k H 2k+1 , —OC k H 2k+1 , —(C ⁇ O)C k H 2k+1 , —COOC k H 2+1 , —C k H 2k ⁇ 1 , —OC k H 2k ⁇ 1 , —(C ⁇ O)C k H 2k ⁇ 1 , or —COOC k H 2k ⁇ 1 , each unsubstituted or substituted by one or more substituents selected from a heterocycle, an aryl, a phenylalkyl, a heterocycloalkyl phenyl, a heterocycloalkyl, a heterocycloalkoxyl, a phenoxyl; a phenoxy phenyl; a halogen, a cyano, a nitro, an alkoxyalkyl, an alkoxycarbonyl, and/or an amido.
  • R 2 , and R 3 each independently and at each occurrence represent H, C n H 2n+1 , C n H 2n ⁇ 1 , a halogen, —CN, a phenyl, a halogenated alkyl, a cyano-alkyl, a phenylalkyl, a halogenoalkenyl, a cyanoalkenyl, or a phenylalkenyl.
  • R 2 and R 3 each independently and at each occurrence represent H, —CH 3 , —C 2 H 5 , —CH 2 CH 2 CH 3 , —CH(CH 3 ) 2 , —(CH 2 ) 3 CH 3 , —C(CH 3 ) 3 , —CH 2 CH(CH 3 )CH 3 , —CH(CH 3 )CH 2 CH 3 , —(CH 2 ) 4 CH 3 , —CH(CH 3 )CH 2 CH 2 CH 3 , —CH 2 CH(CH 3 )CH 2 CH 3 , —CH 2 CH 2 CH(CH 3 ) 2 , —CH(CH 2 CH 3 ) 2 , —C(CH 2 ) 2 C 2 H 5 , —(CH 2 ) 5 CH 3 , —CH(CH 3 )(CH 2 ) 3 CH 3 , —CH 2 CH(CH 3 )(CH 2 ) 2 CH 3 , —CH 2 CH 2 CH(CH 3 ) 3 ,
  • R 2 and R 3 each independently and at each occurrence represent —CN or a phenyl group substituted at positions 1-3 by a substituent selected from: —CHClCH 3 , —CHClCH 2 CH 3 , —CHClC 3 H 7 , —CHClC 4 H 9 , —CHClC 5 H 11 , —CHClC 6 H 13 , —CHClC 7 H 15 , —CHFCH 3 , —CHFCH 2 CH 3 , —CHFC 3 H 7 , —CHFC 4 H 9 , —CHFC 5 H 11 , —CHFC 6 H 13 , —CHFC 7 H 15 , —CHCNCH 3 , —CHCNCH 2 CH 3 , —CHCNC 3 H 7 , —CHCNC 4 H 9 , —CHCNC 5 H 11 , —CHCNC 6 H 13 , —CHCNC 7 H 15 , —CH(
  • X is CN, a C 1 to C 5 amido, a benzyl, a naphthalenyl, a phenyl, a pyrrolyl, a furyl, a thiazolyl, a heterocyclic alkyl phenyl; each phenyl or heterocycle being unsubstituted or substituted by a substituent selected from a C 1 to C 6 alkyl, a C 1 to C 4 alkoxy, a halogenated C 1 to C 5 alkyl, a halogen, a C 1 to C 5 amido, a nitro, a cyano, an alkoxycarbonyl, and/or a C 1 to C 5 sulfonyl group.
  • the compounds are calcium, magnesium, copper, iron, nickel, sodium, potassium, magnesium, zinc or ammonium salts.
  • k represents an integer from 1 to 8.
  • n represent an integer from 1 to 15.
  • the invention is directed to compounds represented by the general formula (III), (IV) or (V)
  • X independently and at each occurrence represents H; or —C m H 2m+1 , or —OC m H 2m+ , each unsubstituted or substituted by one or more substituents selected from a heterocyclic alkyl, a heterocyclic aryl, an aryl, a phenylalkyl, a heterocycloalkyl phenyl, a heterocycloalkyl, a heterocycloalkoxyl, a phenoxyl; a phenoxy phenyl; a halogen, a cyano, a nitro, an alkoxyalkyl, an alkoxycarbonyl, and/or an amido.
  • R 2 and R 3 each independently and at each occurrence represents H, C n H 2n+1 , C n H 2n ⁇ 1 , a halogen, —CN, a phenyl, a halogenated alkyl, a cyano-alkyl, a phenylalkyl, a halogenoalkenyl, a cyanoalkenyl, or a phenylalkenyl.
  • n represents an integer from 1 to 7.
  • the invention is directed to a method for preparation of a compound of claim 1 comprising the following steps:
  • X independently and at each occurrence represents H; or —C m H 2m+1 , or —OC m H 2m+1 , each unsubstituted or substituted by one or more substituents selected from a heterocyclic alkyl, a heterocyclic aryl, an aryl, a phenylalkyl, a heterocycloalkyl phenyl, a heterocycloalkyl, a heterocycloalkoxyl, a phenoxyl; a phenoxy phenyl; a halogen, a cyano, a nitro, an alkoxyalkyl, an alkoxycarbonyl, and/or an amido.
  • n represents an integer from 1 to 7.
  • Y is Cl or Br.
  • the steps are carried out in situ without purification of intermediates.
  • the invention is directed to a method of eradicating weeds, comprising applying to the weeds compounds described herein.
  • the compound is applied in a solution having a concentration of between 10 and 800 ⁇ g of the compound per 1 g of the solution.
  • the weeds are broadleaf plants, grassy weeds, or sedge weeds.
  • the compound is applied under exposure to sun light.
  • the compound inhibits photosynthesis and metabolism of the plant cell, which causes a rapid accumulation of large amounts of reactive oxygen species in cells of the weeds and subsequent death of the cells.
  • This invention provides a pyrrolidineone-type herbicide, which was developed through a modification of tenuazonic acid, a patented herbicidal compound (chemical name: 3-acetyl-4-hydroxy-5-sec-butylpyrroline-2-ketone).
  • the modification provided us a quick and effective way of developing the new herbicides.
  • the synthetic pathway is as follows:
  • n represents from 1 to 7 carbon atoms
  • R 2 , and R 3 each independently and at each occurrence represent H, —CH 3 , —C 2 H 5 , —CH 2 CH 2 CH 3 , —CH(CH 3 ) 2 , —(CH 2 ) 3 CH 3 , —C(CH 3 ) 3 , —CH 2 CH(CH 3 )CH 3 , —CH(CH 3 )CH 2 CH 3 , —(CH 2 ) 4 CH 3 , —CH(CH 3 )CH 2 CH 2 CH 3 , —CH 2 CH(CH 3 )CH 2 CH 3 , —CH 2 CH 2 CH(CH 3 ) 2 , —CH(CH 2 CH 3 ) 2 , —C(CH 2 ) 2 C 2 H 5 , —(CH 2 ) 5 CH 3 , —CH(CH 3 )(CH 2 ) 3 CH 3 , —CH 2 CH(CH 3 )(CH 2 ) 2 CH 3 , —CH 2 CH 2 CH(CH 3 )CH 2
  • 3-Acetyl-4-hydroxy-5-sec-butylpyrroline-2-ketone analogs were dissolved in a small amount of methanol and diluted with water to a concentration of 5-100 ⁇ g/g.
  • a pathogenic test was conducted by placing the toxic liquid on the slightly wounded leaf of Crofton weed with a needle. The test has shown that the pathogenic capability of 3-Acetyl-4-hydroxy-5-sec-butylpyrroline-2-ketone analogs with respect to Crofton weed increases with the increase of concentration.
  • the spot diameter caused on the leaf of Crofton weed after 24 hours was 2 mm at 50 ⁇ g/g.
  • the mechanism of action of 3-acetyl-4-hydroxy-5-sec-butylpyrroline-2-ketone analogs on weeds is the effect on plant photosynthesis; significantly reducing the photosynthetic oxygen evolution rate and the apparent quantum efficiency.
  • the main action site of the compounds is the thylakoid membrane, inhibiting the electron transfer reaction of two photosystems, especially photosystem II, but no effect has been observed on the structure and synthesis of the membrane protein.
  • the active oxygen content significantly increased 3 hours after the leaf was treated with 3-acetyl-4-hydroxy-5-sec-butylpyrroline-2-ketone analogs. This may be the cause of cell death and appearance of the brown spots on the leaf. Moreover, it may also block the synthesis of protein in the ribosome.
  • the main advantages and positive effects of the invention include: modification of 3-acetyl-4-hydroxy-5-sec-butylpyrroline-2-ketone was carried out, based on (1): its inhibitory activity to photosystem II and its binding mode to D1 protein; and (2): its inhibitory activity and its action sites, combined with chemical synthetic route of 3-acetyl-4-hydroxy-5-sec-butylpyrroline-2-ketone. Focus was placed on the carbonyl oxygen (a few hydroxyl oxygens), which played essential role in the protein binding. The structure of D1 protein from algae was carefully analyzed and of various factors including hydrophobicity, electronegativity and stereo hindrance were considered when designing and selecting the target molecules. It is obvious that such rational design has advantage over the traditional chemical herbicide screening.
  • a series of herbicidal molecules was prepared through the modification of 3-acetyl-4-hydroxy-5-sec-butylpyrroline-2-ketone, a metabolic phytotoxin of Alternaria alternata . These compounds kill weeds quickly; the weeds treated with the herbicidal agents clearly show symptoms after 24 hours, and the weeds can be killed in about 3 to 5 days.
  • the method of biocontrolling weeds using the analogues of tenuazonic acid and their salts effectively controls and eradicates the main gramineous weeds in the farmland, such as common crabgrass, barnyardgrass, goosegrass, green foxtail, equal alopecurus, Japanese alopecurus, Beckmannia syzigachne Fern, wild oat, annual bluegrass, keng stiffgrass, common polypogon, and rabbitfoot polypogon; broad leaf weeds, such as Crofton weed, Copperleaf, Yerbadetajo, Redroot pigweed, Tender catchweed bedstraw, Narrowleaf vetch, Sheathed monochoria, Indian rotala, Water ammannia, Purslane, Flixweed tansymustard, Shepherdspurse, Common dayflower, Wild cress, Wormseed mustard, Pennsylvania bittercress, Geminate speedwell, Mouse-ear chickweed; and sedges, such as Needle spike
  • the compounds of the invention have high activity at concentration as low as from 5 to 50 ⁇ g/g. At a concentration of 10 to 800 ⁇ g/g (close to 45-360 g/hectare), the compounds can kill a variety of broad-leaf weeds, grassy weeds and sedge weeds. They are highly potential herbicides.
  • the analogues disclosed herein have comparable herbicidal activity to the original tenuazonic acid. These molecules are easy to make, thus reducing the manufacturing cost. Because these compounds were obtained through modification of the metabolite of a fungus, a natural product, these analogs have some desirable characteristics of bio-based herbicides: low pollution, few byproducts, high rate of decomposition and high environmental safety.
  • the new synthetic process can be carried out in one pot without isolation and purification of the intermediates. This process can reduce the manufacturing cost.
  • the study results showed different herbicidal activities of the above compounds.
  • the different compounds also effect the Hill reaction rate and fluorescence of the chlorophyll.
  • 3-Acetyl-4-hydroxy-5-sec-butylpyrroline-2-ketone analogue (Table 3, compounds 10-57) was dissolved in small amount of methanol. The solution was then diluted with distilled water to a concentration of 50 ⁇ g/mL. Methanol solution with same concentration and pure distilled water were used as control of the experiment. A pathogenic test was conducted by placing the toxic liquid on the slightly wounded leaf of Crofton weed with a needle. The experiment was carried out at 25° C. under the natural light and each test was repeated 6 times. It was measure the diameter of the spot after 24 h. The experimental results are listed in Table 4. The data indicated that most of the 3-acetyl-4-hydroxy-5-sec-butylpyrroline-2-ketone analogs have high herbicidal activity. The size of the side chain also has an effect on their activity.
  • Compound 10-57 were dissolved in small amount of methanol. The solutions were then diluted with distilled water to a concentration of 50 ⁇ g/mL. A mixture of methanol and water in the same ratio as the sample solution was also prepared and used as control in the experiment. The healthy leaves of Crofton weed were washed in water for 30 minutes and then rinsed with distilled water. The clean and tissue dried leaves were placed in petri dish with the back-side of the leaves facing up. Wet filter paper was also placed in the in petri dish for moisture control. Water, methanol and chemical solutions of the analogues were applied to the back-side of each leaf. Test sample was then placed in vacuum chamber at 25° C.
  • the salt form of these compounds is much more herbicidal.
  • the ammonium salt, the sodium salt, the potassium salt, the magnesium salt and the zinc salt have higher activity than the calcium, magnesium and copper salts.
  • results listed in the table 10 suggest that eight compounds (7, 14, 15, 16, 40, 44, 48, and 53) have potential to be used to control or kill grassy weed such as Common crabgrass, Bbarnyardgrass, Difformed galingale, broadleaf weeds, Yerbadetajo, Copperleaf, Chenopodium serotinum, Commelina communis, Alligator weed, Redroot pigweed, Japanese false bindweed, Sonchus oleraceus etc.
  • grassy weed such as Common crabgrass, Bbarnyardgrass, Difformed galingale, broadleaf weeds, Yerbadetajo, Copperleaf, Chenopodium serotinum, Commelina communis, Alligator weed, Redroot pigweed, Japanese false bindweed, Sonchus oleraceus etc.
  • Compound 1, 2, 3 and 40 were dissolved in small amount of methanol and diluted with distilled water to concentration of 50 ⁇ g/mL. The solution was sprayed to the soil sample until the soil was wet but not overflows. After standing at room temperature for 3 hours, the soil sample was washed with water and methanol. The wash solution was collected and concentrated. Such process was repeated three times. The concentrated solutions were used for herbicidal activity test using the method of needle puncture on Crofton weed. Methanol water solution and pure water were used as control. The experiment for every sample was repeated six times. The spot diameters were measured with vernier caliper after the plant was kept under natural light at 25° C. for 24 hours (Table 11).

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Dentistry (AREA)
  • Wood Science & Technology (AREA)
  • Plant Pathology (AREA)
  • Health & Medical Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Agronomy & Crop Science (AREA)
  • General Health & Medical Sciences (AREA)
  • Pest Control & Pesticides (AREA)
  • Zoology (AREA)
  • Environmental Sciences (AREA)
  • Agricultural Chemicals And Associated Chemicals (AREA)
  • Nitrogen Condensed Heterocyclic Rings (AREA)
  • Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
  • Pyrrole Compounds (AREA)
  • Plural Heterocyclic Compounds (AREA)

Abstract

A series of herbicidal molecules derived from 3-acetyl-4-hydroxy-5-sec-butylpyrroline-2-ketone, a natural substance, and their potential use in agriculture for weed control. Through the modification of the 5-sec-butyl hydrocarbon chain and 3-acetyl group and the analysis of their biological functioning, newly designed molecules are superior to the original compound in herbicidal activity. These molecules inhibit the photosynthesis of the plants. The treated plants show significant damage in 24 hours and die within 3-5 days after the chemical treatment. In addition, the new molecule has relatively simple structure, they are easy to make and they have better physical properties. They are broad-spectrum, high potency herbicides.

Description

    CROSS-REFERENCE TO RELATED APPLICATIONS
  • This application is a continuation of International Patent Application No. PCT/CN2006/001315 with an international filing date of Jun. 13, 2006, designating the United States, now pending, and further claims priority benefits to Chinese Patent Application No. 200510094521.9 filed Sep. 26, 2005. The contents of the aforementioned specifications are incorporated herein by reference.
    • BACKGROUND OF THE INVENTION
  • 1. Field of Invention
  • This invention relates to the application of chemicals and biochemicals to weed control in agriculture and, more specifically to pyrrolidineone derivatives of herbicidal tenuazonic acid (3-acetyl-4-hydroxy-5-tert-butylpyrroline-2-ketone), and to their use as herbicides.
  • 2. Description of the Related Art
  • Tenuazonic acid (formula name: 3-acetyl-4-hydroxy-5-sec-butylpyrroline-2-ketone) is a strong phytotoxin, isolated, purified and identified from metabolites of Alternaria Alternata by Qiang Sheng et al. It is isolated from the crude mixture of metabolites by the extraction of the fermentation fluid. Due to the low yield (0.0005%) and high cost of fermentation, it is very important to develop a synthetic process. Through a rational design, more potent compounds can be made that are also easy to manufacture. Environmentally safe herbicides can be developed with low toxicity. This is the main direction of the current herbicide development.
  • 3-Acetyl-4-hydroxy-5-tert-butylpyrroline-2-ketone is a heterocyclic compound containing carbonyl and hydroxyl functional groups. The lactam that is part of the heterocyclic ring is the most important functional group. The hydrophobic side chain also plays an important role in its herbicidal activity.
  • The compound is very effective at killing monocotyledon weeds (such as common crabgrass and barnyardgrass) and dicotyledonous weeds including Crofton weeds at a concentration of 50 μg/mL. It has the potential to become a biological herbicide (CN Pat. Appl. No. 200510038263.2; CN Pat. No. 1644046. However, the low yield and high cost associated with the fermentation process prevents large-scale production of this compound.
  • A1994 patent (WO1994/01401) discloses 3-benzoylpyrrolidine-2,4-dione derivatives and their herbicidal activity.
  • Chinese Pat. No. 1676515A made claims based on the fact that some triketones inhibit 4-hydroxyphenylpyruvate dioxygenase (HPPD), which is a key enzyme responsible for biosynthesis of plastoquinone and α-tocopherol. If the biosynthesis of plastoquinone and α-tocopherol is blocked, it will impact the biosynthesis of carotenoids. Therefore both HPPD inhibitor and carotenoid preventing inhibitors have similar function. Taking advantage of similar structural modification and synthesis, a key characteristic of this type of compounds is the existence of N-substituent. The major representative of this type of herbicides is sulfentrazone, including isoxazole herbicide, and pyridine type herbicides. It is reported that tenuazonic acid copper salt has a slight inhibition to HPPD (Meazza et al., 2002). With only hydrogen attached to nitrogen, no other substituents, it is obvious that 3-acetyl-4-hydroxy-5-tert-butylpyrroline-2-ketone has a totally different mechanism of action.
  • Study on the mechanism of action of 3-acetyl-4-hydroxy-5-tert-butylpyrroline-2-ketone has shown that the phytotoxin clearly inhibits plant's photosynthesis. Its inhibition to Hill reaction is much higher than the typical photosynthetic inhibitor (herbicide), such as 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU). In addition, there is no adverse effect to other parts of the cells. The compound blocks electron flow from QA to QB in the photosystem II, but has no effect on the donor of photosystem II, photosystem I and other parts of chloroplasts, which was the first time such effects were observed among known phytotoxins produced by fungus Alternaria alternata.
  • It is believed that the toxin interacts with D1 protein by competing with QB for the binding site and thus inhibits the electron transfer. Therefore, it is an inhibitory phytotoxin of photosystem II. Based on the discovery of this mechanism, the molecular structure of tenuazonic acid has heretofore been and new herbicidal molecules discovered. CN Appl. Nos. 200510094521.9 and 200610038765.X, and CN Pat Pub No CN1752075 disclose certain compounds and methods of their synthesis.
  • Many photosystem II inhibitors have successfully become commercial herbicides, such as s-triazines, triazinones and phenols, etc., and have become major players in the field of herbicides. There are two advantages associated with photosystem II inhibitors: first, since photosynthesis is a common phenomenon among plants, and inhibition is specific to the plants, the toxicity to animals is low, thus this type of herbicides possesses the characteristics of high efficacy and low toxicity. Secondly, with the development of transgenic technology, there are 67,700,000 hectares of farm land that grow transgenic crops globally and greater than 80% of these crops are herbicide-resistant transgenic (based on Monsanto's 2003 data).
  • The photosynthetic inhibitors herbicides have a growing share of the herbicides market. With combination of new herbicides and transgenic agricultural products, the chemical pollution to the environment has been greatly reduced. Since the photosynthetic inhibition is the only effect for 3-acetyl-4-hydroxy-5-sec-butylpyrroline-2-ketone on the plant cells, this type of herbicide with high potency, quick action, broad-spectrum, simple structure and easy synthesis will have a bright future.
  • There are many types of photosystem II inhibitors according to their chemical structures such as ureas, pyridines, triazinones, pyridazinones, dinitrophenols and cyanophenols, etc. They can be divided into two main groups such as ureas/triazine and phenol. The first type (classical photosystem II inhibitors) can be represented as N—C═X (X stands for O or N atom, not sulfur atom), i.e. atrazine, metribuzin, phemedipham, terbutryand, N-(3,4-dichlorophenyl)-N′-methylurea (DCMU) et al. The second type is phenolic herbicide, including ioxynil, dinoseb and 2-iodo-4-nitro-6-isobutylphenol, etc.
  • The common feature of the second type of herbicide is that the molecules contain at least one carbonyl oxygen, or a hydroxy oxygen and a long hydrophobic hydrocarbon side-chain. Most of these herbicides form a hydrogen bond between the carbonyl hydrogen and the D1 protein of photosystem II, which enables them to successfully compete with plastoquinone QB (secondary electron acceptor), thus block electron transfer from QA to QB, and lead to the inhibition of photosynthetic process of the plant.
  • Only a small number of herbicides form hydrogen bond between hydroxyl oxygen and D1 protein and successfully blocking photosynthetic process. The structure of the hydrophobic hydrocarbon side-chain (number of carbon and chain length) also influences herbicidal activity. Obviously, the binding site, binding manner and possible binding region of herbicides to D1 protein determines the strength of herbicidal activity. Based on the chemical structure, 3-acetyl-4-hydroxy-5-sec-butylpyrroline-2-ketone belongs to the group of photosystem II inhibitor (containing N—C═O). Unlike the classical herbicides mentioned earlier, there are no literature reports that describe the mechanism of action of this compound to photosynthesis. Therefore, it might be a new type of photosystem II inhibitor.
  • 3-Acetyl-4-hydroxy-5-sec-butylpyrroline-2-ketone has moderate toxicity of 200 mg/kg to rat and moderate level phytotoxicity, which is acceptable in light of its high biological activity. However, its toxicity level may be reduced through modification of its chemical structure.
    • SUMMARY OF THE INVENTION
  • In one embodiment, the invention is directed to compounds represented by the general formula (I), or (II), or a salt thereof
  • Figure US20080176748A1-20080724-C00001
  • In a class of this embodiment, R1 independently and at each occurrence represents H; or —CkH2k+1, —OCkH2k+1, —(C═O)CkH2k+1, —COOCkH2+1, —CkH2k−1, —OCkH2k−1, —(C═O)CkH2k−1, or —COOCkH2k−1, each unsubstituted or substituted by one or more substituents selected from a heterocycle, an aryl, a phenylalkyl, a heterocycloalkyl phenyl, a heterocycloalkyl, a heterocycloalkoxyl, a phenoxyl; a phenoxy phenyl; a halogen, a cyano, a nitro, an alkoxyalkyl, an alkoxycarbonyl, and/or an amido.
  • In another class of this embodiment, R2, and R3 each independently and at each occurrence represent H, CnH2n+1, CnH2n−1, a halogen, —CN, a phenyl, a halogenated alkyl, a cyano-alkyl, a phenylalkyl, a halogenoalkenyl, a cyanoalkenyl, or a phenylalkenyl.
  • In another class of this embodiment, R2 and R3 each independently and at each occurrence represent H, —CH3, —C2H5, —CH2CH2CH3, —CH(CH3)2, —(CH2)3CH3, —C(CH3)3, —CH2CH(CH3)CH3, —CH(CH3)CH2CH3, —(CH2)4CH3, —CH(CH3)CH2CH2CH3, —CH2CH(CH3)CH2CH3, —CH2CH2CH(CH3)2, —CH(CH2CH3)2, —C(CH2)2C2H5, —(CH2)5CH3, —CH(CH3)(CH2)3CH3, —CH2CH(CH3)(CH2)2CH3, —CH2CH2CH(CH3)CH2CH3, —(CH2)3CH(CH3)2, —CH(CH2CH3)CH2CH2CH3, —CH2CH(CH2CH3)2, —C(CH3)2(CH2)2CH3, —C(CH3)CH2CH3)2, —(CH2)6CH3, —CH(CH2CH2CH3)2, —CH2CH2CH(CH2CH3)2, —CH(CH2CH3)(CH2)3CH3, —CH2CH(CH2CH3)CH2CH2CH3, —CH(CH3)(CH2)4CH3, —CH2CH(CH3)(CH2)3CH3, —(CH2)2CH(CH3)(CH2)2CH3, —(CH2)3CH(CH3)CH2CH3, —(CH2)7CH3, —CH2CH(CH2CH2CH3)2, —CH(CH2CH2CH3)(CH2)3CH3, —CH(CH3)(CH2)5CH3, —CH2CH(CH3)(CH2)4CH3, —(CH2)2CH(CH3)(CH2)3CH3, —(CH2)3CH(CH3)(CH2)2CH3, —(CH2)4CH(CH3)CH2CH3, —CH(CH2CH3)(CH2)4CH3, —(CH2)3CH(CH2CH3)2, —CH2CH(CH2CH3)(CH2)3CH3, —(CH2)2CH(CH2CH3)(CH2)2CH3, —CH═CH2, —CH═CHCH3, —CH2CH═CH2, —CH═CHCH2CH3, —CH2CH2CH═CH2, —CH2 CH═CHCH3, or —CH═CH—CH═CH2.
  • In another class of this embodiment, R2 and R3 each independently and at each occurrence represent —CN or a phenyl group substituted at positions 1-3 by a substituent selected from: —CHClCH3, —CHClCH2CH3, —CHClC3H7, —CHClC4H9, —CHClC5H11, —CHClC6H13, —CHClC7H15, —CHFCH3, —CHFCH2CH3, —CHFC3H7, —CHFC4H9, —CHFC5H11, —CHFC6H13, —CHFC7H15, —CHCNCH3, —CHCNCH2CH3, —CHCNC3H7, —CHCNC4H9, —CHCNC5H11, —CHCNC6H13, —CHCNC7H15, —CH(C6H5)CH3, —CH(C6H5)CH2CH3, —CH(C6H5)C3H7, —CH(C6H5)C4H9, —CH(C6H5)C5H11, —CH(C6H5)C6H13, —CH(C6H5)C7H15, —CHClCH═CH2, or —CHClCH2CH═CH2, or a corresponding isomeric halogenate.
  • In another class of this embodiment, X is CN, a C1 to C5 amido, a benzyl, a naphthalenyl, a phenyl, a pyrrolyl, a furyl, a thiazolyl, a heterocyclic alkyl phenyl; each phenyl or heterocycle being unsubstituted or substituted by a substituent selected from a C1 to C6 alkyl, a C1 to C4 alkoxy, a halogenated C1 to C5 alkyl, a halogen, a C1 to C5 amido, a nitro, a cyano, an alkoxycarbonyl, and/or a C1 to C5 sulfonyl group.
  • In another class of this embodiment, the compounds are calcium, magnesium, copper, iron, nickel, sodium, potassium, magnesium, zinc or ammonium salts.
  • In another class of this embodiment, k represents an integer from 1 to 8.
  • In another class of this embodiment, n represent an integer from 1 to 15.
  • In another embodiment, the invention is directed to compounds represented by the general formula (III), (IV) or (V)
  • Figure US20080176748A1-20080724-C00002
  • In a class of this embodiment, X independently and at each occurrence represents H; or —CmH2m+1, or —OCmH2m+, each unsubstituted or substituted by one or more substituents selected from a heterocyclic alkyl, a heterocyclic aryl, an aryl, a phenylalkyl, a heterocycloalkyl phenyl, a heterocycloalkyl, a heterocycloalkoxyl, a phenoxyl; a phenoxy phenyl; a halogen, a cyano, a nitro, an alkoxyalkyl, an alkoxycarbonyl, and/or an amido.
  • In another class of this embodiment, R2 and R3 each independently and at each occurrence represents H, CnH2n+1, CnH2n−1, a halogen, —CN, a phenyl, a halogenated alkyl, a cyano-alkyl, a phenylalkyl, a halogenoalkenyl, a cyanoalkenyl, or a phenylalkenyl.
  • In another class of this embodiment, m represents an integer from 1 to 7.
  • In other aspects, the invention is directed to a method for preparation of a compound of claim 1 comprising the following steps:
      • (a) reacting an aminoacid of formula:
  • Figure US20080176748A1-20080724-C00003
  • with an alcohol under acidic reaction conditions;
      • (b) neutralizing with sodium ethoxide; and
      • (c) adding a compound of formula XCOCH2COY or cyclobutane-1,3-dione in the presence of a sodium alkoxide.
  • In a class of this embodiment, X independently and at each occurrence represents H; or —CmH2m+1, or —OCmH2m+1, each unsubstituted or substituted by one or more substituents selected from a heterocyclic alkyl, a heterocyclic aryl, an aryl, a phenylalkyl, a heterocycloalkyl phenyl, a heterocycloalkyl, a heterocycloalkoxyl, a phenoxyl; a phenoxy phenyl; a halogen, a cyano, a nitro, an alkoxyalkyl, an alkoxycarbonyl, and/or an amido.
  • In another class of this embodiment, m represents an integer from 1 to 7.
  • In another class of this embodiment, Y is Cl or Br.
  • In another class of this embodiment, the steps are carried out in situ without purification of intermediates.
  • In other aspects, the invention is directed to a method of eradicating weeds, comprising applying to the weeds compounds described herein.
  • In a class of this embodiment, the compound is applied in a solution having a concentration of between 10 and 800 μg of the compound per 1 g of the solution.
  • In another class of this embodiment, the weeds are broadleaf plants, grassy weeds, or sedge weeds.
  • In another class of this embodiment, the compound is applied under exposure to sun light.
  • In another class of this embodiment, the compound inhibits photosynthesis and metabolism of the plant cell, which causes a rapid accumulation of large amounts of reactive oxygen species in cells of the weeds and subsequent death of the cells.
    • DETAILED DESCRIPTION OF THE INVENTION
  • This invention provides a pyrrolidineone-type herbicide, which was developed through a modification of tenuazonic acid, a patented herbicidal compound (chemical name: 3-acetyl-4-hydroxy-5-sec-butylpyrroline-2-ketone). The modification provided us a quick and effective way of developing the new herbicides.
  • It was decided to keep the major functional carbonyl group of 3-acetyl-4-hydroxy-5-sec-butylpyrroline-2-ketone and modify the hydrophobic 5-sec-butyl chain and the 3-acetyl group. A large number of derivatives were synthesized using phosphorous ylides and halogenated amino acids as precursors. Recently, a new synthetic route was developed, which no longer uses phosphor ylides and halogenated amino acids as starting materials. The new process starts from an amino acid and the 4 step reaction sequence is carried out in one pot without isolation and purification of any intermediates.
  • The synthetic pathway is as follows:
  • Figure US20080176748A1-20080724-C00004
  • wherein
  • X═H; —CmH2m+1 substituted or unsubstituted; —OCmH2m+1 substituted or unsubstituted; —CmH2m−1 substituted or unsubstituted, —OCmH2m−1 substituted or unsubstituted; a substituted heterocyclic, an aryl, a phenylalkyl, a heterocycloalkyl-phenyl, a heterocycloalkyl, a heterocycloalkoxy, a phenoxy, or a phenoxyphenyl; the substituent groups being a halogen, a cyano, a nitro, an alkyoxyalkyl, an alkyoxycarbonyl, and/or an amido;
  • m represents from 1 to 7 carbon atoms; and
  • R2, and R3 each independently and at each occurrence represent H, —CH3, —C2H5, —CH2CH2CH3, —CH(CH3)2, —(CH2)3CH3, —C(CH3)3, —CH2CH(CH3)CH3, —CH(CH3)CH2CH3, —(CH2)4CH3, —CH(CH3)CH2CH2CH3, —CH2CH(CH3)CH2CH3, —CH2CH2CH(CH3)2, —CH(CH2CH3)2, —C(CH2)2C2H5, —(CH2)5CH3, —CH(CH3)(CH2)3CH3, —CH2CH(CH3)(CH2)2CH3, —CH2CH2CH(CH3)CH2CH3, —(CH2)3CH(CH3)2, —CH(CH2CH3)CH2CH2CH3, —CH2CH(CH2CH3)2, —C(CH3)2(CH2)2CH3, —C(CH3)CH2CH3)2, —(CH2)6CH3, —CH(CH2CH2CH3)2, —CH2CH2CH(CH2CH3)2, —CH(CH2CH3)(CH2)3CH3, —CH2CH(CH2CH3)CH2CH2CH3, —CH(CH3)(CH2)4CH3, —CH2CH(CH3)(CH2)3CH3, —(CH2)2CH(CH3)(CH2)2CH3, —(CH2)3CH(CH3)CH2CH3, —(CH2)7CH3, —CH2CH(CH2CH2CH3)2, —CH(CH2CH2CH3)(CH2)3CH3, —CH(CH3)(CH2)5CH3, —CH2CH(CH3)(CH2)4CH3, —(CH2)2CH(CH3)(CH2)3CH3, —(CH2)3CH(CH3)(CH2)2CH3, —(CH2)4CH(CH3)CH2CH3, —CH(CH2CH3)(CH2)4CH3, —(CH2)3CH(CH2CH3)2, —CH2CH(CH2CH3)(CH2)3CH3, —(CH2)2CH(CH2CH3)(CH2)2CH3, —CH═CH2, —CH═CHCH3, —CH2CH═CH2, —CH═CHCH2CH3, —CH2CH2CH═CH2, —CH2 CH═CHCH3, —CH═CH—CH═CH2, —CN, phenyl, —CHClCH3, —CHClCH2CH3, —CHClC3H7, —CHClC4H9, —CHClC5H11, —CHClC6H13, —CHClC7H15, —CHFCH3, —CHFCH2CH3, —CHFC3H7, —CHFC4H9, —CHFC5H11, —CHFC6H13, —CHFC7H15, —CHCNCH3, —CHCNCH2CH3, —CHCNC3H7, —CHCNC4H9, —CHCNC5H11, —CHCNC6H13, —CHCNC7H15, —CH(C6H5)CH3, —CH(C6H5)CH2CH3, —CH(C6H5)C3H7, —CH(C6H5)C4H9, —CH(C6H5)C5H11, —CH(C6H5)C6H13, —CH(C6H5)C7H15, —CHClCH═CH2, or —CHClCH2CH═CH2.
  • When X is a methyl group, the following synthetic method can also be used:
  • Figure US20080176748A1-20080724-C00005
  • 3-Acetyl-4-hydroxy-5-sec-butylpyrroline-2-ketone analogs were dissolved in a small amount of methanol and diluted with water to a concentration of 5-100 μg/g. A pathogenic test was conducted by placing the toxic liquid on the slightly wounded leaf of Crofton weed with a needle. The test has shown that the pathogenic capability of 3-Acetyl-4-hydroxy-5-sec-butylpyrroline-2-ketone analogs with respect to Crofton weed increases with the increase of concentration. The spot diameter caused on the leaf of Crofton weed after 24 hours was 2 mm at 50 μg/g.
  • The mechanism of action of 3-acetyl-4-hydroxy-5-sec-butylpyrroline-2-ketone analogs on weeds is the effect on plant photosynthesis; significantly reducing the photosynthetic oxygen evolution rate and the apparent quantum efficiency. The main action site of the compounds is the thylakoid membrane, inhibiting the electron transfer reaction of two photosystems, especially photosystem II, but no effect has been observed on the structure and synthesis of the membrane protein. In addition, the active oxygen content significantly increased 3 hours after the leaf was treated with 3-acetyl-4-hydroxy-5-sec-butylpyrroline-2-ketone analogs. This may be the cause of cell death and appearance of the brown spots on the leaf. Moreover, it may also block the synthesis of protein in the ribosome.
  • The main advantages and positive effects of the invention include: modification of 3-acetyl-4-hydroxy-5-sec-butylpyrroline-2-ketone was carried out, based on (1): its inhibitory activity to photosystem II and its binding mode to D1 protein; and (2): its inhibitory activity and its action sites, combined with chemical synthetic route of 3-acetyl-4-hydroxy-5-sec-butylpyrroline-2-ketone. Focus was placed on the carbonyl oxygen (a few hydroxyl oxygens), which played essential role in the protein binding. The structure of D1 protein from algae was carefully analyzed and of various factors including hydrophobicity, electronegativity and stereo hindrance were considered when designing and selecting the target molecules. It is obvious that such rational design has advantage over the traditional chemical herbicide screening.
  • A series of herbicidal molecules was prepared through the modification of 3-acetyl-4-hydroxy-5-sec-butylpyrroline-2-ketone, a metabolic phytotoxin of Alternaria alternata. These compounds kill weeds quickly; the weeds treated with the herbicidal agents clearly show symptoms after 24 hours, and the weeds can be killed in about 3 to 5 days.
  • The method of biocontrolling weeds using the analogues of tenuazonic acid and their salts effectively controls and eradicates the main gramineous weeds in the farmland, such as common crabgrass, barnyardgrass, goosegrass, green foxtail, equal alopecurus, Japanese alopecurus, Beckmannia syzigachne Fern, wild oat, annual bluegrass, keng stiffgrass, common polypogon, and rabbitfoot polypogon; broad leaf weeds, such as Crofton weed, Copperleaf, Yerbadetajo, Redroot pigweed, Tender catchweed bedstraw, Narrowleaf vetch, Sheathed monochoria, Indian rotala, Water ammannia, Purslane, Flixweed tansymustard, Shepherdspurse, Common dayflower, Wild cress, Wormseed mustard, Pennsylvania bittercress, Geminate speedwell, Mouse-ear chickweed; and sedges, such as Needle spikesedge, Difformed galingale, Rice galingale, and Dichotomous dimbristylis.
  • The compounds of the invention have high activity at concentration as low as from 5 to 50 μg/g. At a concentration of 10 to 800 μg/g (close to 45-360 g/hectare), the compounds can kill a variety of broad-leaf weeds, grassy weeds and sedge weeds. They are highly potential herbicides.
  • The analogues disclosed herein have comparable herbicidal activity to the original tenuazonic acid. These molecules are easy to make, thus reducing the manufacturing cost. Because these compounds were obtained through modification of the metabolite of a fungus, a natural product, these analogs have some desirable characteristics of bio-based herbicides: low pollution, few byproducts, high rate of decomposition and high environmental safety.
  • The new synthetic process can be carried out in one pot without isolation and purification of the intermediates. This process can reduce the manufacturing cost.
    • EXAMPLES
  • The following examples illustrate the products of this invention and the methods for preparing them. However, the examples are not intended in any way to otherwise limit the scope of the invention. The number of compounds that were synthesized and evaluated is far exceeding the number of examples.
    • Example 1
  • List of compounds having formula (I) and (II) (Table 1) and their herbicidal activities (Table 2).
  • Synthesis of compound 1: A 100 mL three-neck flask was charged with anhydrous alcohol (30 mL), hydrogen chloride (0.055 mol, 2 g) and Isoleucine (0.05 mol, 6.56 g). The mixture was heated to reflux and stirred for 3 h and then left overnight. Ethanol was removed by distillation and the residue was mixed with sodium ethoxide (0.05 mol, 2.6 g, freshly prepared) solution in ethanol. The mixture was stirred for 0.5 h. Cyclobutane-1,3-dione (0.055 mol, 4.62 g) was added over 1 h, with the temperature kept below 10° C., and the reaction was stirred for 2 h. Benzene (20 ml) and sodium ethoxide (0.0575 mol, 3 g, freshly prepared) solution in ethanol were added, and the mixture was stirred at reflux for 3 h and allowed to stand at room temperature overnight. The reaction mixture was poured into 30 mL of water and acidified with 10% sulfuric acid (0.055 mol, 55 g), then extracted with ethyl acetate and dried over sodium sulfate. Ethyl acetate was removed under vacuum and the residue was mixed with concentrated sulfuric acid and toluene. The mixture was refluxed in toluene for 2 h. Compound 1 was obtained as a brown solid after column chromatography in a 55.6% yield.
  • Synthesis of compound 9: A 100 mL three-neck flask was charged with anhydrous alcohol (30 mL), hydrogen chloride (0.055 mol, 2 g) and Isoleucine (0.05 mol, 6.56 g). The mixture was heated to reflux and stirred for 3 h and then left overnight. Ethanol was removed by distillation and the residue was mixed with sodium ethoxide (0.05 mol, 2.6 g, freshly prepared) solution in ethanol and stirred for 0.5 h. 2-Propionamidoacetyl chloride (0.055 mol, 8.22 g) was added over 1 h and the reaction was stirred for 2 h. Benzene (20 ml) and sodium ethoxide (0.0575 mol, 3 g, freshly prepared) solutions were added, and the mixture was stirred at reflux for 3 h and allowed to stand at room temperature overnight. The reaction mixture was poured into 30 mL of water and acidified with 10% sulfuric acid (0.055 mol, 55 g), then extracted with ethyl acetate and dried over sodium sulfate. Removal of ethyl acetate under vacuum gave crude product which was purified with column chromatography, providing compound 9 as a pale brown oil in a 47.1% yield.
  • TABLE 1
    Physical properties of 3-acetyl-4-hydroxy-5-sec-butylpyrroline-2-ketone
    analogs with formula (I) and (II)
    Com-
    pound Type R1 R2 R3 Appearance
    1 II H sec-C4H9 H Brown solid
    2 II H C3H7CHCl H Brown solid
    3 I H sec-C4H9 H Light brown
    viscous liquid
    4 I CH3CH2 sec-C4H9 H Light brown
    viscous liquid
    5 I C2H5O sec-C4H9 H Light brown
    viscous liquid
    6 I C6H5CH2CH2 sec-C4H9 H Light brown
    viscous liquid
    7 I NH2COCH3CH2 sec-C4H9 H Light brown
    viscous liquid
    8 I Cl(CH2)3NH sec-C4H9 H Light brown
    viscous liquid
    9 I C2H5CONH sec-C4H9 H Light brown
    viscous liquid
  • TABLE 2
    Comparison of the toxicity of 3-acetyl-4-hydroxy-5-sec-
    butylpyrroline-2-ketone analogs with formula (I) and (II)
    Time of disease spot Average diameter of
    Treatment to occur (h) the spot after 24 h (mm)
    Water control / 0.23 ± 0.02
    Methanol / 0.27 ± 0.14
    control
    1 22.3 ± 0.77 1.97 ± 0.04
    2 22.0 ± 2.30 2.96 ± 0.01
    3 20.9 ± 1.01 2.31 ± 0.09
    4 18.5 ± 1.55 2.97 ± 0.01
    5 20.7 ± 0.75 2.35 ± 0.14
    6 21.2 ± 3.85 2.12 ± 0.08
    7 14.9 ± 2.65 4.45 ± 0.22
    8 20.0 ± 1.51 2.53 ± 0.18
    9 21.9 ± 2.00 2.80 ± 0.33
    • Example 2
  • Herbicidal activity evaluation of compounds 10-57 with formula (III), (IV) and (V) (Table 3).
  • Synthesis of compound 24: A100 mL three-neck flask was charged with anhydrous alcohol (30 mL), hydrogen chloride (0.055 mol, 2 g) and 2-amino-2-methylbutanoic acid (0.05 mol, 5.85 g). The mixture was heated to reflux and stirred for 3 h and then left for overnight. Ethanol was removed by distillation and the residue was mixed with sodium ethoxide (0.05 mol, 2.6 g, freshly prepared) solution in ethanol and stirred for 0.5 h. Cyclobutane-1,3-dione (0.055 mol, 4.62 g) was added over 1 h maintaining the temperature of the reaction mixture below 10° C., and the reaction was stirred for 2 h. Benzene (20 ml) and sodium ethoxide (0.0575 mol, 3 g, freshly prepared) solution in ethanol were added, and the mixture was stirred at reflux and then allowed to stand for 3 h at room temperature overnight. The reaction mixture was mixed with 30 mL of water and acidified with 10% sulfuric acid (0.055 mol, 55 g), then extracted with ethyl acetate and dried over sodium sulfate. Removal of ethyl acetate under vacuum gave crude product, which was purified with column chromatography, providing compound 24 as a pale brown oil in a 53% yield.
  • Synthesis of Compound 53: A 100 mL of three-neck flask was charged with anhydrous alcohol (30 mL), hydrogen chloride (0.055 mol, 2 g) and 2-amino-3-cyanohexanoic acid (0.05 mol, 7.81 g). The mixture was heated to reflux and stirred for 3 h and then left overnight. Ethanol was removed by distillation and the residue was mixed with sodium ethoxide (0.05 mol, 2.6 g, freshly prepared) solution in ethanol, and stirred for 0.5 h. Cyclobutane-1,3-dione (0.055 mol, 4.62 g) was added over 1 h and maintaining the temperature of the reaction mixture below 10° C., and the reaction was stirred for 2 h. Benzene (20 mL) and sodium ethoxide (0.0575 mol, 3 g, freshly prepared) solution in ethanol were added, and the mixture was stirred at reflux for 3 h and then to allowed to stand at room temperature overnight. The reaction mixture was mixed with 30 mL of water and acidified with 10% sulfuric acid (0.055 mol, 55 g), extracted with ethyl acetate and dried over sodium sulfate. Removal of ethyl acetate under vacuum gave crude product, which was purified with column chromatography, providing compound 53 as a brown oil in 45% yield.
  • TABLE 3
    Physical properties of 3-Acetyl-4-hydroxy-5-sec-butylpyrroline-2-ketone
    analogues with formula of (III), (IV) and (V).
    Com-
    pound Type X R2 R3 Appearance
    10 III CH3 H H Light yellow
    solid
    11 III CH3 CH3 H Pale needle
    crystal
    12 III CH3 CH3CH2 H Light brown
    solid
    13 III CH3 CH3CH2CH2 H Light brown
    viscous liquid
    14 III CH3 n-C4H9 H Light brown
    viscous liquid
    15 III CH3 n-C5H11 H Light brown
    viscous liquid
    16 III CH3 n-C6H13 H Light brown oil
    17 III CH3 n-C7H15 H Light brown oil
    18 III CH3 n-C8H17 H Light brown oil
    19 III CH3 C6H5CH2 H Light yellow
    solid
    20 III CH3 (1-C6H5)C4H8 H Light yellow
    solid
    21 III CH3 H3C—CH:CH H Brown viscous
    liquid
    22 III CH3 CH3 CH3 Light yellow
    solid
    23 III CH3 CH3CH2 CH3CH2 Light brown
    viscous liquid
    24 III CH3 CH3CH2 CH3 Light brown
    viscous liquid
    25 III CH3 CH3CH2CH2 CH3CH2CH2 Light brown
    viscous liquid
    26 III CH3 CH3CH2CH2 CH3 Light brown
    viscous liquid
    27 III CH3 CH3CH2CH2 CH3CH2 Light brown
    viscous liquid
    28 III CH3 n-C4H9 n-C4H9 Light brown
    viscous liquid
    29 III CH3 n-C4H9 CH3 Light brown
    viscous liquid
    30 III CH3 n-C4H9 CH3CH2 Light brown
    viscous liquid
    31 III CH3 sec-C5H11 H Light yellow
    liquid
    32 III CH3 tert-C5H11 H Light yellow
    liquid
    33 III CH3 iso-C5H11 H Light yellow
    liquid
    34 III CH3 OOCCH2 H Light yellow
    solid
    35 III CH3 OOCCH2CH2 H Light yellow
    solid
    36 III CH3 (NH2)OCCH2 H Light yellow
    solid
    37 III CH3 (NH2)OCCH2CH2 H Light yellow
    solid
    38 III CH3 C3H7CHCN H Light brown
    viscous liquid
    39 III CH3 iso-C3H7 H Light brown
    solid
    40 III CH3 C3H7CHCl H Light brown
    viscous liquid
    41 III CH3 CH3SCH2CH2 H Light brown
    solid
    42 III C2H5 sec-C4H9 H Light brown
    viscous liquid
    43 III ClC2H4 sec-C4H9 H Light brown
    viscous liquid
    44 III FC2H4 sec-C4H9 H Light brown
    viscous liquid
    45 III C2H5OC2H5 sec-C4H9 H Light brown
    viscous liquid
    46 III PhCH2CH2O S6C-C4H9 H Light brown
    viscous liquid
    47 III PhOCH2CH2 sec-C4H9 H Light brown
    viscous liquid
    48 III (m-diCl)PhCH2CH2 sec-C4H9 H Light brown
    viscous liquid
    49 III PhCH2NH sec-C4H9 H Light brown
    viscous liquid
    50 III THF-CH2CH2 sec-C4H9 H Light brown
    viscous liquid
    51 III PhCH2 sec-C4H9 H Light brown
    viscous liquid
    52 III p-NO2PhCH2 sec-C4H9 H Light brown
    viscous liquid
    53 IV CH3 C3H7CHCN H Brown viscous
    liquid
    54 IV CH3 C5H11CHCN H Brown oil liquid
    55 IV CH3 C7H13CHCN H Brown oil liquid
    56 IV CH3 C7H13CHF H Brown oil liquid
    57 V CH3 CH3 H Yellow needle
    crystal
  • The study results showed different herbicidal activities of the above compounds. The different compounds also effect the Hill reaction rate and fluorescence of the chlorophyll.
    • Example 3
  • 3-Acetyl-4-hydroxy-5-sec-butylpyrroline-2-ketone analogue (Table 3, compounds 10-57) was dissolved in small amount of methanol. The solution was then diluted with distilled water to a concentration of 50 μg/mL. Methanol solution with same concentration and pure distilled water were used as control of the experiment. A pathogenic test was conducted by placing the toxic liquid on the slightly wounded leaf of Crofton weed with a needle. The experiment was carried out at 25° C. under the natural light and each test was repeated 6 times. It was measure the diameter of the spot after 24 h. The experimental results are listed in Table 4. The data indicated that most of the 3-acetyl-4-hydroxy-5-sec-butylpyrroline-2-ketone analogs have high herbicidal activity. The size of the side chain also has an effect on their activity.
  • TABLE 4
    Comparison of the toxicity of 3-acetyl-4-hydroxy-5-sec-
    butylpyrroline-2-ketone analogs with formula (III), (IV), (V)
    Time of Disease spot Average diameter of
    Treatment (h) spot after 24 h (mm)
    H2O Control / 0.23 ± 0.02
    Methanol / 0.27 ± 0.14
    control
    10   29 ± 6.30 1.11 ± 0.16
    11 21.5 ± 0   1.80 ± 0.41
    12 15.2 ± 0.35 2.77 ± 0.23
    13 16.70 ± 0.21  5.21 ± 0.44
    14 13.80 ± 0.54  6.37 ± 0.04
    15  9.5 ± 1.26 9.61 ± 1.20
    16 13.80 ± 0.54  7.61 ± 0.11
    17  9.5 ± 2.36 7.94 ± 1.30
    18 12.00 ± 0.48  8.27 ± 0.61
    19   24 ± 4.00 1.24 ± 0.10
    20 21.1 ± 3.56 1.57 ± 0.04
    21 16.5 ± 1.30 2.89 ± 0.14
    22 20.0 ± 1.63 1.76 ± 0.24
    23 18.3 ± 2.17 2.23 ± 0.12
    24 16.21 ± 3.55  2.43 ± 0.07
    25 15.22 ± 2.00  2.44 ± 0.10
    26 13.61 ± 1.35  3.31 ± 0.07
    27 14.2 ± 4.15 3.18 ± 0.93
    28 16.9 ± 2.25 2.40 ± 0.11
    29 12.1 ± 3.75 5.77 ± 1.15
    30 13.3 ± 2.00 4.53 ± 1.03
    31 10.8 ± 2.00 5.93 ± 1.35
    32 12.5 ± 3.75 4.82 ± 1.44
    33 13.5 ± 0.75 4.17 ± 1.15
    34 24.0 ± 0.02   1 ± 0.86
    35 26.4 ± 0.12 1.27 ± 0.02
    36 21.9 ± 0.23 1.54 ± 0.07
    37   24 ± 0.08 1.64 ± 0.25
    38 13.6 ± 0.50 9.82 ± 0.02
    39 16.5 ± 2.15 4.89 ± 0.37
    40 11.93 ± 0.66  8.10 ± 0.90
    41 20.8 ± 3.00 2.45 ± 0.24
    42 19.4 ± 2.50 2.24 ± 0.45
    43 20.1 ± 1.15 2.30 ± 0.28
    44 12.0 ± 1.33 4.07 ± 0.51
    45 20.3 ± 0.57 2.73 ± 0.73
    46 22.1 ± 1.35 2.31 ± 0.44
    47 21.2 ± 1.88 2.12 ± 0.09
    48 13.5 ± 2.77 4.33 ± 0.54
    49 23.2 ± 2.86 2.47 ± 0.08
    50 22.6 ± 0.69 2.66 ± 0.46
    51 15.1 ± 1.82 3.28 ± 1.12
    52 15.3 ± 1.72 3.83 ± 1.03
    53 12.90 ± 0.27  7.334 ± 0.845
    54 11.30 ± 0.73  8.211 ± 0.101
    55 9.81 ± 0.33 8.931 ± 0.086
    56 14.00 ± 1.09  6.927 ± 0.317
    57 20.4 ± 0   1.98 ± 0.51
    • Example 4
  • Compounds 1, 2, 3 and 40 were separately dissolved in a small amount of methanol. The solutions were then diluted with distilled water to a concentration of 50 μg/mL. A mixture of methanol and water in the same ratio as the sample solution was also prepared and used as control in the experiment. The solutions were sprayed on leaves and stems of three-leaf-stage Crofton weed seedlings. All the plants were grown in pot in a greenhouse. The leaves were properly wet by the solutions for consistency and the treatment was repeated 3 times. The plant damage assessment was conducted two days later and the results were listed in Table 5. The measurement of the plant damage was calculated by the formula: Damage Index=Σ(damage level×number of plants)×100/4/number of plants in each treatment. The calculated results are listed in Table 6.
  • TABLE 5
    Standard of evaluation of weed damage
    Damage Level Description
    4 Plant completely dead
    3 Two thirds of the plant stems and leaves dried out
    2 Half of the plant stems and leaves dried out
    1 One third of the plant stems and leaves dried out
    0 No damage at all
  • TABLE 6
    Weed damage assessment results
    Treatment Damage Level
    H2O control 0
    Methanol control 0
    1 2
    2 2
    3 1
    40  4
  • The data in the Table 6 suggests that the analogs of 3-acetyl-4-hydroxy-5-sec-butylpyrroline-2-ketone have good herbicidal activity against Crofton weed. Substitution of chlorine on the side chain increases their activity.
    • Example 5
  • Compound 10-57 were dissolved in small amount of methanol. The solutions were then diluted with distilled water to a concentration of 50 μg/mL. A mixture of methanol and water in the same ratio as the sample solution was also prepared and used as control in the experiment. The healthy leaves of Crofton weed were washed in water for 30 minutes and then rinsed with distilled water. The clean and tissue dried leaves were placed in petri dish with the back-side of the leaves facing up. Wet filter paper was also placed in the in petri dish for moisture control. Water, methanol and chemical solutions of the analogues were applied to the back-side of each leaf. Test sample was then placed in vacuum chamber at 25° C. for 15 min followed by exposure to the strong light (400 μM m−2 s−1) for 12 hours. The leaf sample went through a series of test, and the Hill reaction rate, the electron transfer activity and fluorescence of chlorophyll were measured. Four leaves were used for each treatment and each test was repeated three times.
  • The experiment results indicate that compound 10 to 57 can slow the Hill reaction and inhibit the electron transfer of photosystem II, but has no effect in photosystem I. As the experimental data in Table 7 indicated that compounds having chlorinated side-chain have more inhibitory effect on the activity of Hill reaction and electron transfer in photosystem II than the compounds whose side chain are not substituted by halogen.
  • TABLE 7
    Effects to the photosynthesis of Crofton weed
    PSII Activity of
    Activity of Hill oxygen The t1/2 of
    Reaction evolution of fluorescence
    Treatment (μMO2/mgChlh) (μMO2/mgChlh) Fv/Fm rise (ms)
    H2O control 130.11 65.34 0.83 1339
    Methanol 124.38 60.89 0.81 1382
    control
    1 98.76 50.89 0.82 1184
    2 69.41 37.02 0.84 1055
    3 62.21 32.14 0.83 1172
    4 51.13 28.01 0.83 791
    5 52.31 24.10 0.82 826
    6 50.04 27.11 0.81 773
    7 52.41 29.17 0.82 809
    8 49.05 24.65 0.79 725
    9 50.12 23.33 0.83 733
    10 84.32 47.55 0.79 1176
    11 80.00 46.41 0.82 1181
    12 70.32 34.54 0.83 925
    13 78.19 41.35 0.85 1000
    14 67.37 34.01 0.79 910
    15 62.77 31.26 0.78 946
    16 61.43 30.00 0.83 880
    17 57.13 27.04 0.82 917
    18 67.27 39.98 0.80 913
    19 63.43 40.07 0.79 962
    20 57.23 43.40 0.82 876
    21 62.34 42.25 0.77 879
    22 56.16 38.05 0.82 828
    23 63.28 38.24 0.79 855
    24 71.37 43.01 0.83 921
    25 97.55 57.12 0.82 1197
    26 89.15 58.01 0.82 1211
    27 91.45 53.24 0.81 1232
    28 75.03 31.76 0.82 1124
    30 47.33 22.78 0.79 747
    32 63.42 32.13 0.82 905
    33 51.94 26.54 0.79 791
    34 65.73 35.11 0.81 922
    38 64.69 40.41 0.81 871
    39 62.72 33.79 0.80 884
    40 46.20 24.00 0.82 720
    41 59.07 41.32 0.83 901
    43 63.35 47.80 0.83 880
    44 59.15 40.75 0.79 839
    45 41.00 27.04 0.79 713
    46 58.78 43.67 0.82 899
    47 67.99 49.01 0.82 844
    51 52.23 32.15 0.81 798
    52 53.13 36.86 0.82 814
    53 42.72 32.12 0.79 739
    54 43.65 31.98 0.81 741
    55 42.72 28.63 0.79 727
    56 42.72 29.02 0.79 719
    57 63.42 35.13 0.82 955
    • Example 6
  • Fourteen salts of 3-acetyl-4-hydroxy-5-sec-butylpyrroline-2-ketone analogs were dissolved in small amount of methanol and diluted with distilled water to a concentration of 50 μg/mL. Methanol/water mixture was also prepared and used as control. Needle puncture method was used for the test on the small pieces of Crofton weed. Each treatment was repeated six times or more. The test samples were kept under natural light at 25° C. for 24 hours. The diameters of damaged spot of the plant leaves were measured by vernier caliper. These fourteen compounds are:
    • (a) Sodium salt of 4-Hydroxy-3-acetyl-pyrroline-2-ketone
  • Figure US20080176748A1-20080724-C00006
    • (b) Sodium salt of 4-Hydroxy-3-acetyl-5-methylpyrroline-2-ketone
  • Figure US20080176748A1-20080724-C00007
    • (c) Sodium salt of 4-Hydroxy-3-acetyl-5-ethylpyrroline-2-ketone
  • Figure US20080176748A1-20080724-C00008
    • (d) Sodium salt of 4-Hydroxy-3-acetyl-5-benzylpyrroline-2-ketone
  • Figure US20080176748A1-20080724-C00009
    • (e) Sodium salt of 4-Hydroxy-3-acetyl-5-propenylpyrroline-2-ketone
  • Figure US20080176748A1-20080724-C00010
    • (f) Potassium salt of 4-Hydroxy-3-acetyl-5-ethylpyrroline-2-ketone
  • Figure US20080176748A1-20080724-C00011
    • (g) Calcium salt of 4-Hydroxy-3-acetyl-5-ethylpyrroline-2-ketone
  • Figure US20080176748A1-20080724-C00012
    • (h) Magnesium (II) salt of 4-Hydroxy-3-acetyl-5-ethylpyrroline-2-ketone
  • Figure US20080176748A1-20080724-C00013
    • (i) Manganese salt of 4-Hydroxy-3-acetyl-5-ethylpyrroline-2-ketone
  • Figure US20080176748A1-20080724-C00014
    • (j) Zinc salt of 4-Hydroxy-3-acetyl-5-ethylpyrroline-2-ketone
  • Figure US20080176748A1-20080724-C00015
    • (k) Iron salt of 4-Hydroxy-3-acetyl-5-ethylpyrroline-2-ketone
  • Figure US20080176748A1-20080724-C00016
    • (l) Copper salt of 4-Hydroxy-3-acetyl-5-ethylpyrroline-2-ketone
  • Figure US20080176748A1-20080724-C00017
    • (m) Sodium salt of 4-Hydroxy-3-acetyl-5-(iso-pentanyl)pyrroline-2-ketone
  • Figure US20080176748A1-20080724-C00018
    • (n) Zinc salt of 4-Hydroxy-3-acetyl-5,5′-dimethylpyrroline-2-ketone
  • Figure US20080176748A1-20080724-C00019
    • (o) Ammonium salt of 4-Hydroxy-3-acetyl-5-ethylpyrroline-2-ketone
  • Figure US20080176748A1-20080724-C00020
  • TABLE 8
    Herbicidal activity of 14 salts to Crofton weed
    Average diameter of
    the damage spot after
    Treatment time (h) 24 h (mm)
    H2O control / 0.227 ± 0.002
    Methanol / 0.273 ± 0.014
    control
    a   26 ± 7.30 1.34 ± 0.08
    b 19.5 ± 0.5  2.21 ± 0.18
    c 14.5 ± 1.8  3.11 ± 0.54
    d 10.2 ± 2.50 5.07 ± 0.11
    e 16.8 ± 1.85 2.42 ± 0.05
    f 14.2 ± 2.00 3.72 ± 0.28
    g 18.7 ± 3.00 2.29 ± 0.19
    h 17.5 ± 1.50 2.88 ± 0.10
    i 14.3 ± 3.15 3.24 ± 0.33
    j 15.1 ± 4.00 2.91 ± 0.02
    k 17.2 ± 0.95 1.72 ± 0.15
    l 21.6 ± 3.05 1.22 ± 0.25
    m  8.5 ± 2.00 8.27 ± 1.72
    n 18.2 ± 2.50 2.63 ± 0.06
    o 10.3 ± 1.50 4.97 ± 1.01
  • Compared with the no-salt form (data are listed in Table 2 and Table 4), the salt form of these compounds is much more herbicidal. In addition, the ammonium salt, the sodium salt, the potassium salt, the magnesium salt and the zinc salt have higher activity than the calcium, magnesium and copper salts.
    • Example 7
  • Compounds 7, 14, 15, 16, 40, 45, 48 and 53 were dissolved individually in small amount of methanol, and diluted with distilled water to concentration of 50 μg/mL. Methanol water solution and pure water were used as control. A piece of 5 mm leaf was taken from the second leaf of weed sample and was treated with the solution three times. 5 pieces of the leaf were prepared for each treatment. The damage data were collected 4 days later. The measurement of damage level is described in the Table 9.
  • TABLE 9
    Standard of evaluation of weed damage
    Damage level Description
    4 The leaf completely dead
    3 Two third of the leaf withered
    2 One half of the leaf withered
    1 Only edge of the leaf withered
    0 Not damage at all
  • The measurement of the plant damage was calculated by the formula: Damage Index=Σ(damage level×number of plants)×100/4/number of plants in each treatment. The calculated results are listed in Table 10.
  • TABLE 10
    Weed damage assessment results
    Meth-
    Family Plant species H2O anol 7 14 15 16 40 44 48 53
    Gramineae Goosegrass 0 0 4 3 3 3 4 3 3 4
    Wild oats 0 0 4 3 3 3 3 3 3 3
    Equal 0 0 4 3 3 3 3 3 4 4
    alopecurus
    Japanese 0 0 4 3 3 3 3 4 4 3
    alopecurus
    Keng stiffgrass 0 0 4 3 3 4 3 3 4 4
    Common 0 0 3 3 3 3 3 4 4 4
    polypogon
    Green foxtail 0 0 4 3 4 3 3 4 4 3
    (Setaria viridis)
    Crabgrass 0 0 4 4 4 4 4 4 4 4
    (Digitaria
    sanguinalis)
    Leptochloa 0 0 4 4 4 4 4 4 4 4
    chinensis
    Barbyardgrass 0 0 4 4 4 4 4 4 4 4
    Echinochloa
    crusgalli
    Big Bristlegass 0 0 3 2 2 3 3 2 3 3
    Amaranthaceae Redroot pigweed 0 0 3 2 2 3 3 2 2 3
    (Amaranthus
    retroflexus)
    Alligator weed 0 0 3 3 2 3 3 4 4 3
    (Alternanthera
    philoxeroides)
    Pigweed 0 0 3 2 2 2 2 3 3 3
    (Amaranthus
    spinosus)
    Malvaceae Malvaceae 0 0 3 2 2 2 2 2 2 3
    Abutilon 0 0 2 2 2 3 3 2 3 3
    theophrasti
    Polygonaceae Polygonum 0 0 2 2 2 2 2 2 2 3
    lapathifolium
    Rumex 0 0 2 1 2 2 2 3 2 3
    japonicus
    Polygonum 0 0 3 2 2 3 3 3 3 3
    perfoliatum
    Polygonum 0 0 3 2 2 3 2 3 3 3
    hydropiper
    Rumex dentatus 0 0 2 2 2 2 2 3 3 2
    Euphorbiaceae Acalypha 0 0 3 2 2 2 3 3 3 2
    australis
    Cannabinaceae Humulus 0 0 3 2 2 3 3 2 3 2
    scandens
    Labiatae Perilla 0 0 2 2 3 2 2 3 2 2
    frutescens
    Galeopsis bifida 0 0 3 2 2 2 3 3 2 3
    Lamium 0 0 3 2 3 2 3 3 2 2
    amplexicaule
    Mosla scabra 0 0 2 2 2 2 2 2 2 2
    Scrophulariaceae Veronica 0 0 2 3 2 2 2 3 3 3
    didyma
    Veronica 0 0 3 2 2 2 3 3 3 3
    persica
    Commelinaceae Commelina 0 0 4 2 2 3 3 2 4 3
    communis
    Commelina 0 0 4 3 3 3 3 3 4 3
    bengalensis
    Convolvulaceae Japanese false 0 0 4 3 3 4 3 4 4 4
    bindweed
    (Calystegia
    hederacea)
    Dichondra 0 0 3 2 2 3 3 2 3 2
    repens
    Pharbitis nil 0 0 2 2 3 2 2 3 3 3
    Compositae Lapsana 0 0 4 3 2 3 3 3 4 3
    apogonoides
    Xanthium 0 0 3 2 2 2 2 2 3 3
    sibiricum
    Conyza 0 0 4 3 3 3 3 4 4 3
    canadensis
    Eclipta prostrata 0 0 4 3 4 3 3 4 4 4
    Sonchus 0 0 4 3 3 3 3 3 4 4
    oleraceus
    Aster 0 0 4 3 3 4 3 4 4 4
    ageratoides var.
    scaberulus
    Youngia 0 0 3 3 3 3 3 3 3 4
    japonica
    Sonchus asper 0 0 4 3 3 3 3 3 4 3
    Cirsium 0 0 3 3 3 3 3 3 4 4
    setosum
    Erigeron annuus 0 0 3 3 4 3 3 4 4 3
    Ambrosia 0 0 3 3 2 3 3 4 3 3
    artemisiifolia
    Carpesium 0 0 3 2 2 2 3 3 4 2
    abrotanoides
    Eupatorium 0 0 4 3 4 4 4 4 4 4
    adenophorum
    Trifolium 0 0 3 3 3 3 3 4 4 4
    pratense
    Rosaceae Duchesnea 0 0 2 2 3 2 2 3 3 3
    indica
    Vitaceae Cayratia 0 0 2 2 2 2 2 3 3 3
    japonica
    Parthenocissus 0 0 2 2 3 2 2 3 3 3
    tricuspidata
    Chenopodiaceae Chenopodium 0 0 3 2 2 2 2 3 3 3
    serotinum
    Oxalidaceae Oxalis 0 0 4 4 3 4 4 4 4 4
    corniculata
    Plantaginaceae Plantago 0 0 3 2 3 2 3 3 2 2
    asiatica
    Cyperaceae Cyperus 0 0 2 2 2 2 2 2 2 2
    rotundus
    Cyperus 0 0 4 3 3 3 3 3 4 3
    difformis
    Fimbristylis 0 0 3 2 2 3 3 2 3 2
    miliacea
  • The results listed in the table 10 suggest that eight compounds (7, 14, 15, 16, 40, 44, 48, and 53) have potential to be used to control or kill grassy weed such as Common crabgrass, Bbarnyardgrass, Difformed galingale, broadleaf weeds, Yerbadetajo, Copperleaf, Chenopodium serotinum, Commelina communis, Alligator weed, Redroot pigweed, Japanese false bindweed, Sonchus oleraceus etc.
    • Example 8
  • Compound 1, 2, 3 and 40 were dissolved in small amount of methanol and diluted with distilled water to concentration of 50 μg/mL. The solution was sprayed to the soil sample until the soil was wet but not overflows. After standing at room temperature for 3 hours, the soil sample was washed with water and methanol. The wash solution was collected and concentrated. Such process was repeated three times. The concentrated solutions were used for herbicidal activity test using the method of needle puncture on Crofton weed. Methanol water solution and pure water were used as control. The experiment for every sample was repeated six times. The spot diameters were measured with vernier caliper after the plant was kept under natural light at 25° C. for 24 hours (Table 11).
  • TABLE 11
    Evaluation compound toxicity after they were treated with soil
    Average diameter of the spot after 24 h (mm)
    Treatment H2O wash Methanol wash
    H2O control 0.234 ± 0.045
    Methanol 0.288 ± 0.024
    control
    1 0.223 ± 0.077 0.292 ± 0.041
    2 0.280 ± 0.030 0.362 ± 0.012
    3 0.273 ± 0.062 0.334 ± 0.082
    40  0.336 ± 0.050 0.416 ± 0.024
  • Based on data listed in Table 11, it is clear that the herbicidal activity of all 4 compounds were completely lost after the soil treatment.

Claims (13)

1. A compound represented by the general formula (I), or (II), or a salt thereof
Figure US20080176748A1-20080724-C00021
wherein
R1 independently and at each occurrence represents H; or —CkH2k+1, —OCkH2k+1, —(C═O)CkH2k+1, —COOCkH2k+1, —CkH2k−1, —OCkH2k−1, —(C═O)CkH2k−1, or —COOCkH2k−1, each unsubstituted or substituted by one or more substituents selected from a heterocycle, an aryl, a phenylalkyl, a heterocycloalkyl phenyl, a heterocycloalkyl, a heterocycloalkoxyl, a phenoxyl; a phenoxy phenyl; a halogen, a cyano, a nitro, an alkoxyalkyl, an alkoxycarbonyl, and/or an amido;
R2, and R3 each independently and at each occurrence represent H, CnH2n+1, CnH2n−1, a halogen, —CN, a phenyl, a halogenated alkyl, a cyano-alkyl, a phenylalkyl, a halogenoalkenyl, a cyanoalkenyl, or a phenylalkenyl;
k represents an integer from 1 to 8; and
n represent an integer from 1 to 15.
2. A compound of claim 1, represented by the general formula (III), (IV) or (V)
Figure US20080176748A1-20080724-C00022
wherein
X independently and at each occurrence represents H; or —CmH2m+1, or —OCmH2m+1, each unsubstituted or substituted by one or more substituents selected from a heterocyclic alkyl, a heterocyclic aryl, an aryl, a phenylalkyl, a heterocycloalkyl phenyl, a heterocycloalkyl, a heterocycloalkoxyl, a phenoxyl; a phenoxy phenyl; a halogen, a cyano, a nitro, an alkoxyalkyl, an alkoxycarbonyl, and/or an amido;
R2, and R3 each independently and at each occurrence represent H, CnH2n+1, CnH2n−1, a halogen, —CN, a phenyl, a halogenated alkyl, a cyano-alkyl, a phenylalkyl, a halogenoalkenyl, a cyanoalkenyl, or a phenylalkenyl; and
m represents an integer from 1 to 7.
3. The compound of claim 1, wherein R2 and R3 each independently and at each occurrence represent H, —CH3, —C2H5, —CH2CH2CH3, —CH(CH3)2, —(CH2)3CH3, —C(CH3)3, —CH2CH(CH3)CH3, —CH(CH3)CH2CH3, —(CH2)4CH3, —CH(CH3)CH2CH2CH3, —CH2CH(CH3)CH2CH3, —CH2CH2CH(CH3)2, —CH(CH2CH3)2, —C(CH2)2C2H5, —(CH2)5CH3, —CH(CH3)(CH2)3CH3, —CH2CH(CH3)(CH2)2CH3, —CH2CH2CH(CH3)CH2CH3, —(CH2)3CH(CH3)2, —CH(CH2CH3)CH2CH2CH3, —CH2CH(CH2CH3)2, —C(CH3)2(CH2)2CH3, —C(CH3)CH2CH3)2, —(CH2)6CH3, —CH(CH2CH2CH3)2, —CH2CH2CH(CH2CH3)2, —CH(CH2CH3)(CH2)3CH3, —CH2CH(CH2CH3)CH2CH2CH3, —CH(CH3)(CH2)4CH3, —CH2CH(CH3)(CH2)3CH3, —(CH2)2CH(CH3)(CH2)2CH3, —(CH2)3CH(CH3)CH2CH3, —(CH2)7CH3, —CH2CH(CH2CH2CH3)2, —CH(CH2CH2CH3)(CH2)3CH3, —CH(CH3)(CH2)5CH3, —CH2CH(CH3)(CH2)4CH3, —(CH2)2CH(CH3)(CH2)3CH3, —(CH2)3CH(CH3)(CH2)2CH3, —(CH2)4CH(CH3)CH2CH3, —CH(CH2CH3)(CH2)4CH3, —(CH2)3CH(CH2CH3)2, —CH2CH(CH2CH3)(CH2)3CH3, —(CH2)2CH(CH2CH3)(CH2)2CH3, —CH═CH2, —CH═CHCH3, —CH2CH═CH2, —CH═CHCH2CH3, —CH2CH2CH═CH2, —CH2 CH═CHCH3, or —CH═CH—CH═CH2.
4. The compound of claim 1, wherein R2 and R3 each independently and at each occurrence represent —CN or a phenyl group substituted at positions 1-3 by a substituent selected from: —CHClCH3, —CHClCH2CH3, —CHClC3H7, —CHClC4H9, —CHClC5H11, —CHClC6H13, —CHClC7H15, —CHFCH3, —CHFCH2CH3, —CHFC3H7, —CHFC4H9, —CHFC5H11, —CHFC6H13, —CHFC7H15, —CHCNCH3, —CHCNCH2CH3, —CHCNC3H7, —CHCNC4H9, —CHCNC5H11, —CHCNC6H13, —CHCNC7H15, —CH(C6H5)CH3, —CH(C6H5)CH2CH3, —CH(C6H5)C3H7, —CH(C6H5)C4H9, —CH(C6H5)C5H11, —CH(C6H5)C6H13, —CH(C6H5)C7H15, —CHClCH═CH2, or —CHClCH2CH═CH2, or a corresponding isomeric halogenate.
5. The compound of claim 2, wherein X is CN, a C1 to C5 amido, a benzyl, a naphthalenyl, a phenyl, a pyrrolyl, a furyl, a thiazolyl, a heterocyclic alkyl phenyl; each phenyl or heterocycle being unsubstituted or substituted by a substituent selected from a C1 to C6 alkyl, a C1 to C4 alkoxy, a halogenated C1 to C5 alkyl, a halogen, a C1 to C5 amido, a nitro, a cyano, an alkoxycarbonyl, and/or a C1 to C5 sulfonyl group.
6. The compound of claim 1 being a calcium, a magnesium, a copper, an iron, a nickel, a sodium, a potassium, a magnesium, a zinc or an ammonium salt.
7. A method for preparation of a compound of claim 1 comprising the following steps:
(a) reacting an aminoacid of formula:
Figure US20080176748A1-20080724-C00023
with an alcohol under acidic reaction conditions;
(b) neutralizing with sodium ethoxide; and
(c) adding a compound of formula XCOCH2COY or cyclobutane-1,3-dione in the presence of a sodium alkoxide, wherein
X independently and at each occurrence represents H; or —CmH2m+1, or —OCmH2m+1, each unsubstituted or substituted by one or more substituents selected from a heterocyclic alkyl, a heterocyclic aryl, an aryl, a phenylalkyl, a heterocycloalkyl phenyl, a heterocycloalkyl, a heterocycloalkoxyl, a phenoxyl; a phenoxy phenyl; a halogen, a cyano, a nitro, an alkoxyalkyl, an alkoxycarbonyl, and/or an amido;
m represents an integer from 1 to 7; and
Y is Cl or Br.
8. The method of claim 7, wherein the steps are carried out in situ without purification of intermediates.
9. A method of eradicating weeds, comprising applying to the weeds a compound of claim 1.
10. The method of claim 9, wherein the compound is applied in a solution having a concentration of 10-800 μg of the compound per 1 g of the solution.
11. The method of claim 9, wherein the weeds are broadleaf weeds, grassy weeds, or sedge weeds.
12. The method of claim 9, wherein the compound is applied under exposure to sun light.
13. The method of claim 9, wherein said compound inhibits photosynthesis and metabolism of the plant cell, which causes a rapid accumulation of large amounts of active oxygen in cells of the weeds and subsequent death of the cells.
US12/055,384 2005-09-26 2008-03-26 Novel herbicides and methods for preparation thereof Abandoned US20080176748A1 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
US13/414,711 US8921274B2 (en) 2005-09-26 2012-03-07 Method for eradicating weeds with derivatives of 3-acetyl-5-sec-butyl-4-hydroxy-3-pyrrolin-2-one
US14/548,289 US9468209B2 (en) 2005-09-26 2014-11-20 Method for eradicating weeds with derivatives of 3-acetyl-5-sec-butyl-4-hydroxy-3-pyrrolin-2-one

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
CN200510094521.9 2005-09-26
CNA2005100945219A CN1752075A (en) 2005-09-26 2005-09-26 Structure modified product of biosource compound and its use in weed control
PCT/CN2006/001315 WO2007033544A1 (en) 2005-09-26 2006-06-13 A technique for modification of a bio-product molecule and application of weed control

Related Parent Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2006/001315 Continuation WO2007033544A1 (en) 2005-09-26 2006-06-13 A technique for modification of a bio-product molecule and application of weed control

Related Child Applications (1)

Application Number Title Priority Date Filing Date
US13/414,711 Division US8921274B2 (en) 2005-09-26 2012-03-07 Method for eradicating weeds with derivatives of 3-acetyl-5-sec-butyl-4-hydroxy-3-pyrrolin-2-one

Publications (1)

Publication Number Publication Date
US20080176748A1 true US20080176748A1 (en) 2008-07-24

Family

ID=36679090

Family Applications (3)

Application Number Title Priority Date Filing Date
US12/055,384 Abandoned US20080176748A1 (en) 2005-09-26 2008-03-26 Novel herbicides and methods for preparation thereof
US13/414,711 Active US8921274B2 (en) 2005-09-26 2012-03-07 Method for eradicating weeds with derivatives of 3-acetyl-5-sec-butyl-4-hydroxy-3-pyrrolin-2-one
US14/548,289 Active US9468209B2 (en) 2005-09-26 2014-11-20 Method for eradicating weeds with derivatives of 3-acetyl-5-sec-butyl-4-hydroxy-3-pyrrolin-2-one

Family Applications After (2)

Application Number Title Priority Date Filing Date
US13/414,711 Active US8921274B2 (en) 2005-09-26 2012-03-07 Method for eradicating weeds with derivatives of 3-acetyl-5-sec-butyl-4-hydroxy-3-pyrrolin-2-one
US14/548,289 Active US9468209B2 (en) 2005-09-26 2014-11-20 Method for eradicating weeds with derivatives of 3-acetyl-5-sec-butyl-4-hydroxy-3-pyrrolin-2-one

Country Status (5)

Country Link
US (3) US20080176748A1 (en)
EP (1) EP1997803B1 (en)
JP (1) JP2009509944A (en)
CN (3) CN1752075A (en)
WO (1) WO2007033544A1 (en)

Families Citing this family (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1752075A (en) * 2005-09-26 2006-03-29 南京农业大学 Structure modified product of biosource compound and its use in weed control
CN101715785B (en) * 2009-11-26 2012-04-25 李翠兰 Special growth inhibitor for Eupatorium adenophorum
CN102050776A (en) * 2010-12-07 2011-05-11 南京农业大学 5-substituted methylpyrrolidine-2, 4-diketone compound and use thereof
CN103404536B (en) * 2013-08-21 2015-11-25 南京农业大学 A kind of compound biological herbicide and using method thereof
JP6403865B2 (en) * 2014-07-03 2018-10-10 シャンハイ インスティテュート オブ ファーマシューティカル インダストリー Method for producing dabigatran etexilate intermediate and intermediate compound
CN105130871B (en) * 2015-07-29 2018-11-09 南京农业大学 A kind of sulfur derivatives and its preparation method and application of pyrrolin ketone
CN105145577B (en) * 2015-07-29 2018-03-09 南京农业大学 A kind of application of the sulfur derivatives of pyrrolin ketone
CN111808008B (en) * 2019-04-11 2023-09-19 南京农业大学 biogenic herbicides
CN113214130A (en) * 2021-04-09 2021-08-06 南京农业大学 Herbicidal use of chiral pyrrolidone derivatives
CN114009452B (en) * 2021-11-01 2022-12-09 新疆农业科学院植物保护研究所 Application of fermentation broth of alternaria alternata JTF001 in inhibition of germination of seeds of orobanum cucurbitacearum
CN114672421A (en) * 2022-03-02 2022-06-28 陕西海斯夫生物工程有限公司 Method for cultivating and screening microalgae with high tocopherol content

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2692882A (en) * 1952-04-01 1954-10-26 Upjohn Co (5-benzyloxy-3-indole)-alkanoylamides and preparation thereof
US4876343A (en) * 1988-06-15 1989-10-24 Warner-Lambert Company Process for statine and statine analogs
US5008402A (en) * 1988-09-06 1991-04-16 Lonza Ltd. Process for production of 5-alkyl tetramic acids
US5061808A (en) * 1988-06-15 1991-10-29 Warner-Lambert Company 2-oxo-1-pyrrolidine carboxylic acid esters
US6215016B1 (en) * 1996-03-27 2001-04-10 Toray Industries, Inc. Ketone derivatives and medical application thereof

Family Cites Families (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS4931823A (en) * 1972-08-02 1974-03-22
JPS5210266A (en) * 1975-07-14 1977-01-26 Nippon Soda Co Ltd Pyrrolidine series herbicides
AU1044088A (en) * 1986-12-17 1988-07-15 Nippon Soda Co., Ltd. Heterocyclic compounds having triketo skeleton
JPH01313488A (en) * 1988-06-13 1989-12-18 Toray Ind Inc Novel platinum-containing compound and remedy for malignant tumor
ES2063108T3 (en) * 1989-01-07 1995-01-01 Bayer Ag DERIVATIVES OF 3-ARYL-PIRROLIDIN-2,4-DIONA.
DE4223015A1 (en) * 1992-07-13 1994-01-20 Bayer Ag Substituted 3-benzoyl-pyrrolidine-2,4-dione derivatives
EP0825982B1 (en) * 1995-05-09 2002-11-27 Bayer CropScience AG Alkyl dihalogenated phenyl-substituted ketoenols useful as pesticides and herbicides
CN100426963C (en) * 2005-01-28 2008-10-22 南京农业大学 Method for controlling weeds using alternaria tenubilis cupric acid, alternaria heterotennis cupric acid and salts thereof
CN100486965C (en) * 2005-03-17 2009-05-13 南开大学 3-acyl-pyrrolidine-2,4-diketo compound and herbicidal activity
CN1752075A (en) * 2005-09-26 2006-03-29 南京农业大学 Structure modified product of biosource compound and its use in weed control
CN100361972C (en) * 2006-03-10 2008-01-16 南京农业大学 A method for synthesizing alternarinic acid and isoalternarinic acid

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2692882A (en) * 1952-04-01 1954-10-26 Upjohn Co (5-benzyloxy-3-indole)-alkanoylamides and preparation thereof
US4876343A (en) * 1988-06-15 1989-10-24 Warner-Lambert Company Process for statine and statine analogs
US5061808A (en) * 1988-06-15 1991-10-29 Warner-Lambert Company 2-oxo-1-pyrrolidine carboxylic acid esters
US5008402A (en) * 1988-09-06 1991-04-16 Lonza Ltd. Process for production of 5-alkyl tetramic acids
US6215016B1 (en) * 1996-03-27 2001-04-10 Toray Industries, Inc. Ketone derivatives and medical application thereof

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
Kawai et al (1997): STN International HCAPLUS database, (Columbus, Ohio), Accession number: 1997:650253. *
Sato et al (1973): STN International HCAPLUS database, (Columbus, Ohio), Accession number: 1973:533658. *

Also Published As

Publication number Publication date
EP1997803B1 (en) 2018-02-14
JP2009509944A (en) 2009-03-12
US20150141254A1 (en) 2015-05-21
US20120172226A1 (en) 2012-07-05
CN101228124A (en) 2008-07-23
WO2007033544A1 (en) 2007-03-29
US8921274B2 (en) 2014-12-30
CN103922990B (en) 2017-11-07
CN1752075A (en) 2006-03-29
CN103922990A (en) 2014-07-16
US9468209B2 (en) 2016-10-18
EP1997803A4 (en) 2010-11-24
EP1997803A1 (en) 2008-12-03

Similar Documents

Publication Publication Date Title
US9468209B2 (en) Method for eradicating weeds with derivatives of 3-acetyl-5-sec-butyl-4-hydroxy-3-pyrrolin-2-one
JP6949730B2 (en) Substituted cyclic amides and their use as herbicides
DK170439B1 (en) 4-Benzoyl-5-hydroxypyrazole derivatives and herbicides comprising the same
KR100203826B1 (en) Uracil derivatives
DE4109208A1 (en) 3-HYDROXY-4-ARYL-5-OXO-PYRAZOLINE DERIVATIVES
KR920003628B1 (en) Method for preparing thiadiazabicyclononane derivatives
JPH05294953A (en) 3-aryl-4-hydroxy-delta3-dihydrofuranone and 3-aryl-4-hydroxy-delta3-dihydrothiophenone derivatives
DE19516785A1 (en) Substituted aminophenyluracils
JP4966194B2 (en) Selective insecticides based on substituted cyclic ketoenols and safeners.
UA74835C2 (en) Phenyl-substituted 5,6-dihydropyrone derivatives as pesticides and herbicides, agent based thereon and an intermediary compound
FR2590570A1 (en) TRIAZINES, HERBICIDE COMPOSITIONS CONTAINING THESE TRIAZINES AND METHOD FOR COMBATING WEEDS
DE69204909T2 (en) Amino-urazil derivatives, their preparation and use.
EP0415185B1 (en) 4-Alkoxy- and 4-(substituted)amino-3-arylpyrrolinones derivatives
KR0163591B1 (en) Uracil derivatives and herbicides containing the same as active ingredients
CA1163634A (en) Tetrahydrophthalimides and herbicidal composition
KR20160051889A (en) Heterocyclic amide compound and herbicide
CN102939007B (en) Insecticidal and/or herbicidal compositions with improved activity based on spiroheterocyclic substituted tetramic acid derivatives
EP1849361A1 (en) Biological control of weeds using the metabolites of alternaria alternata
LU84914A1 (en) ALCOYLAMINO N-PHENYL PYRAZOLE AND N-PHENYL PYRAZOLE LACTAMES HERBICIDES
JPH069621A (en) Insecticide
KR100338856B1 (en) Novel pyrimidine derivatives, herbicides and plant growth regulators
JP2666380B2 (en) Condensed heterocyclic derivative, production method and herbicide
RU2050356C1 (en) Iminothiazolines, methods of their synthesis, herbicide composition and a method of weeds suppression
WO1994001401A1 (en) Herbicidal and insecticidal 3-benzoyl-pyrrolidin-2,4-dione derivates
CS247077B2 (en) Herbicide and microbicide agent and production method of effective substances

Legal Events

Date Code Title Description
AS Assignment

Owner name: NANTONG JIANGSHANG AGROCHEMICAL & CHEMICAL LIMITED

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:QIANG, SHENG;CHEN, SHIGUO;YANG, CHUNLONG;AND OTHERS;REEL/FRAME:020701/0323;SIGNING DATES FROM 20080305 TO 20080312

Owner name: NANJING AGRICULTURAL UNIVERSITY, CHINA

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:QIANG, SHENG;CHEN, SHIGUO;YANG, CHUNLONG;AND OTHERS;REEL/FRAME:020701/0323;SIGNING DATES FROM 20080305 TO 20080312

STCB Information on status: application discontinuation

Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION