CN106135205A - A kind of purposes of isoflavan class natural products DTMI - Google Patents

Abstract

The invention discloses the use of DTMI, a natural product of isoflavanes, which is used in the preparation of novel botanical pesticides. The invention provides the possibility for the application of DTMI and a new approach for the development of new pesticides.

Description

Application of a kind of isoflavane natural product DTMI

technical field

The present invention relates to the use of a natural product of isoflavanes, in particular to the use of a natural product of isoflavanes, DTMI.

Background technique

For a long time, chemical pesticides have played an important role in the antibacterial and bactericidal aspects of crops, but they are prone to drug resistance, leading to the deterioration of natural ecosystems. Issues such as pollution have been questioned. Especially for foods that directly affect people's health, countries around the world have implemented "green trade barriers" to limit the amount of chemical pesticide residues. Therefore, seeking alternatives to chemical pesticides for plant protection has become a frontier topic for scientific researchers around the world. The more successful alternatives are biopesticides, and botanical pesticides are a very important research direction for biopesticides.

The main purpose of the research on botanical pesticides at home and abroad is, firstly, through the screening and structural identification of the active ingredients of pesticides in plants, the active ingredients of botanical pesticides are synthesized as commercial pesticides by means of organic synthesis, or the active ingredients are used as lead compounds to obtain Reasonable structural modification, simulated synthesis of new commercial pesticides. The second is to directly apply plant resources to develop new plant-derived pesticides through the extraction, separation and screening of pesticide active substances in plants. Most foreign pesticide companies focus on the former, because this approach must be based on strong manpower, capital, technology and good research conditions, and the research cycle is too long; while in my country, because of the rich plant resources, the research and development of botanical pesticides The cycle is short, the cost is relatively small, and the technical level is low, and the latter is the main reason.

Wheat stripe rust is one of the wheat rust diseases. Wheat rust, commonly known as "jaundice", is divided into three types: stripe rust, stem rust, and leaf rust. It is an important disease with wide distribution, fast spread and large damage area in China's wheat production. Among them, wheat stripe rust is the most common and serious. It mainly occurs in Hebei, Henan, Shaanxi, Shandong, Shanxi, Gansu, Sichuan, Hubei, Yunnan, Qinghai, Xinjiang and other places. Wheat stripe rust is routinely treated with the commercial fungicide triamcinol. However, due to the continuous use of triazole fungicides such as Triadimefon for many years, the resistance of crop pathogenic fungi to them is increasing year by year, which greatly affects the effectiveness of chemical control.

Isoflavan natural product 7,5'-dihydroxy-2',3',4'-trimethoxyisoflavan (7,5'-dihydroxy-2',3',4'-trimethoxyisoflavan; DTMI) It was first isolated from high-quality leguminous forage alfalfa (name: Medicagosativa L., English name alfalfa), see literature: Phytochemistry, 1991, 30 (12), 4147-4149. However, so far there is no report about the inhibitory effect of DTMI on pathogenic fungi in crops, nor any report about other biological activities of DTMI.

Contents of the invention

The purpose of the present invention is to provide a new application of DTMI, a natural product of isoflavanes, which provides a possibility for the application of DTMI and a new way for the development of new pesticides.

The technical solution adopted by the present invention to solve its technical problems is:

A use of DTMI, a natural product of isoflavanes, which is used in the preparation of novel botanical pesticides.

The chemical structure of DTMI is as follows:

Preferably, DTMI is applied to the preparation of novel botanical pesticides for inhibiting wheat fungal diseases. Preferably, the wheat fungal disease is a fungal disease caused by wheat stripe rust (Puccinia striiformis. f. sp. tritici).

The prior art has not seen any activity reports of DTMI, and the present invention provides a method for preparing botanical pesticides with DTMI, thereby inhibiting crop pathogenic fungi. The inventor unexpectedly discovered that DTMI has a good antibacterial effect on the pathogenic fungus of wheat stripe rust (Stripe rust), and developed its new use as a pesticide, which provides a new way for the development of new pesticides.

The beneficial effect of the invention is that it provides the possibility for the application of DTMI and provides a new approach for the development of new pesticides.

detailed description

The technical solution of the present invention will be further specifically described below through specific examples.

In the present invention, unless otherwise specified, the raw materials and equipment used can be purchased from the market or commonly used in this field. The methods in the following examples, unless otherwise specified, are conventional methods in the art.

Example:

The DTMI pure strain used in the present invention is extracted from the alfalfa that has been infected with rust (Uromyces striatus), and its extraction process is as follows:

After pulverizing 6kg of the alfalfa aerial parts infected with rust collected from Qingyang City, Gansu Province, soak and extract 3 times with 95% ethanol at room temperature, each time for 7 days, concentrate under reduced pressure to obtain 264g of total extract, dissolve in water, and then Extract with ethyl acetate. Ethyl acetate was partially concentrated under reduced pressure to obtain 117.6g of extract; the extract was dissolved in ethanol and then depigmented by macroporous resin column chromatography. After equilibrating with pure water, ethanol/water system 30%, 50%, and 80% were sequentially eluted , three parts were obtained in total; 80% of the part (12.4g) was dissolved in methanol and segmented by MCI column chromatography, and the methanol/water system 10%-90% was eluted sequentially, and a total of nine parts of Fr.1-Fr.9 were obtained ; Fr.6 (1.552g) was subjected to silica gel column chromatography (petroleum ether/acetone 10:1,5:1,2:1,1:1 sequential elution) and Sephadex LH- 20; pure methanol elution) was purified to obtain the compound (27.3 mg), which was confirmed to be DTMI by structural identification, and its structural identification was as follows:

White amorphous powder, mass spectrometry (ESI-MS) gives its molecular ion peak [M+H] ⁺ m/z=333, combined with ¹³ C NMR and DEPT, it can be determined that the molecular formula of the compound is C ₁₈ H ₂₀ O ₆ , Unsaturation is 9. The ¹ H NMR of this compound shows five characteristic proton signals of isoflavanes δ _H 2.89(2H,m),3.57(1H,m),3.99(1H,dd,J=10.0,10.8Hz),4.28 (1H,dd,10.4,3.2,2.4Hz) and an ABX spin-coupled system δ _H 6.37(1H,d,J=2.4Hz),6.41(1H,dd,J=8.0,2.4Hz),6.95( 1H, d, J=8.0Hz), 1 singlet proton signal δ _H 6.47 (1H, s), 3 methoxy signals δ _H 3.82 (3H, s), 3.94 (3H, s), 3.95 (3H ,s) and 2 hydroxyl active hydrogen signals δ _H 4.85(1H,s), 5.53(1H,s), it is speculated that the compound is an isoflavane compound with 2 hydroxyl groups and 3 methoxy groups in the molecule, And it may be substituted at the 7,2',3',4',5'positions; ¹³ C NMR shows 3 characteristic carbon signals of isoflavanes δ _C 70.33(C-2), 31.73(C -3), 31.39 (C-4), there are 12 aryl carbon signals and 3 methoxy carbon signals, further confirming the previous speculation; by consulting the literature, it is found that the spectral data of the compound is consistent with that of 7,5 The spectral data of '-dihydroxy-2',3',4'-trimethoxyisoflavan (7,5'-dihydroxy-2',3',4'-trimethoxyisoflavan) were completely consistent. So far, the structure of the product has been determined (white amorphous powder, ¹ H NMR and ¹³ C NMR data are shown in Table 1).

Table 1. ¹ H NMR and ¹³ C NMR data of compound DTMI (400MHz, CDCl ₃ )

.

Determination of Compound DTMI's Inhibitory Activity to Plant Pathogens:

1. The plant pathogenic bacteria tested: wheat stripe rust (Puccinia striiformis.f.sp.tritici); the potted experimental wheat variety is Mingxian 169.

2. Test method: The in vivo assay of compound DTMI’s inhibitory effect on plant pathogens adopts the greenhouse pot experiment method. Reference: The inhibitory effect of dinbu on wheat stripe rust. [J] China Agricultural Science Bulletin, 2006, 22 (6), 324 -326.

Disinfect, soak and accelerate germination of wheat seeds for testing, and plant about 15 strains in each pot; DTMI is prepared into a concentration of 0.5 mg/ml (adding 0.1% Tween20) with sterile water; simultaneously, clear water and fenoxin are treated as controls ( Add 0.1% Tween20), each treatment was repeated 3 times.

When the first leaf of the wheat seedlings was fully unfolded, the resistance test was carried out. When measuring the protective effect, after spraying for 24 hours, use the sweeping method to inoculate and moisturize for 24 hours, and then transfer to routine management. , When measuring the therapeutic effect, inoculate the bacteria first, and then apply the medicine after moisturizing for 24 hours.

Grading standards for severity of wheat stripe rust: Grade 0 = no disease on wheat leaves; Grade 1 = 1% to 5%; Grade 3 = 6% to 25%; Grade 5 = 26% to 50%; Grade 7 = 51% to 75% %; Grade 9 = more than 75%.

References: State Bureau of Quality and Technical Supervision. National Standards: Guidelines for Field Efficacy Tests of Pesticides

(1) [M]. Beijing: China Standard Press, 2000: 437-440.

3. Test results: See Table 2 for the control effect of the compound DTMI on wheat stripe rust at the seedling stage. The blank control is clear water, and the positive control is fenxining.

Table 2. The control results of the compound DTMI on wheat stripe rust at the seedling stage

The results of indoor pot experiments showed that at a concentration of 0.5 mg/ml, the compound DTMI had obvious protective and therapeutic effects on wheat stripe rust at the seedling stage, and the protective effect was greater than the therapeutic effect, but the control effect was not as good as the commercial fungicide fenxining. However, due to the continuous use of triazole fungicides such as Triadimefon for many years, the resistance of crop pathogenic fungi to them is increasing year by year, which greatly affects the effectiveness of chemical control. In this context, isoflavane compounds with certain antibacterial effects such as DTMI can provide ideas for the development of new botanical fungicides.

The embodiment described above is only a preferred solution of the present invention, and does not limit the present invention in any form. There are other variations and modifications on the premise of not exceeding the technical solution described in the claims.

Claims (3)

1. A use of isoflavane natural product DTMI, characterized in that: DTMI is applied to the preparation of novel botanical pesticides. 2. The use according to claim 1, characterized in that: DTMI is applied to the preparation of novel botanical pesticides for inhibiting wheat fungal diseases. 3. The use according to claim 2, characterized in that: the wheat fungal disease is a fungal disease caused by wheat stripe rust.