WO2001023384A1 - Antitumor agents - Google Patents

Abstract

Antitumor agents containing as the active ingredient phenanthroindolizidine alkaloids represented by general formula (1) which originate in Ideopsis similis, wherein X represents hydrogen or methoxy CH3O.

Description

 Description Antitumor agent Technical field

 TECHNICAL FIELD The present invention relates to an antitumor agent and a novel phenanthroindrididine alkyloid compound having a cancer cytotoxic activity. Background art

 There are many steps in transforming a normal cell into a cancer cell, and a wide variety of factors are involved. In particular, the induction of cancer cell-damaging activity in pre-cancerous cells and cancer cells has important significance in preventing cancer development, preventing cancer recurrence, and in treating cancer. Therefore, there has been a demand for the development of a compound having a high effect in an antitumor test.

Many compounds have been used for antitumor tests. For example, chemically synthesized compounds and natural components of various origins were tested. The antitumor effect of many natural components extracted from mold plants was confirmed. However, there are few reports on the antitumor activity of components derived from insects. In order to find compounds with completely different structures that exhibit antitumor activity, it is significant to look at natural ingredients that have not been tried before. For example, a compound that has a different origin from a compound that has been developed so far may lead to a compound that can be expected to be effective against drug-resistant tumors. Disclosure of the invention An object of the present invention is to provide an antitumor agent containing an insect-derived natural ingredient as an active ingredient. Alternatively, an object of the present invention is to provide a novel compound having an insect-derived cancer cytotoxic activity, and a medicament containing the compound as an active ingredient.

The present inventors have conducted intensive studies to detect useful substances from natural products. As a result, the extract of Ideopsis (Ideopsis) belonging to the family Amarantidae, which feeds on Tylophora tanakae, a potato family plant, has been found. And a remarkable cancer cytotoxic activity at a dilution of 100,000.Furthermore, by purifying the fractions of the extract, a novel compound having a cancer cytotoxic activity, fenanthroindolizidine alkyloid, was obtained. Compound (3-demethyltylophorinine; 3-demethyltylophorinin e) and phenanthroindolizidine alkyloid compound of known structure (3-demethyl-14-hydroxyisotylocreclin; 3-demethy: i-14 (Hydroxyisoty locrebrine) was isolated and 3-demethyltyrophorinine was derived from Ideopsis. The present inventors have completed the present invention by confirming that the herbaceous plant, Tylophora ia / ia e, cannot be detected.The extract of the leaves of rilmomuka (ylophomia / za e) exhibits antitumor activity. (Koyajna K. et. Al., Proc. Jpn. Acad. 1999, 75B, 7-9) ₀ However, the compounds constituting the present invention are clearly derived from insects, Specifically, the present invention relates to the following antitumor agents, novel compounds having antitumor activity, and pharmaceutical compositions containing the compounds as active ingredients.

 [1] An antitumor agent comprising, as an active ingredient, a phenanthroindolizidine alkyloid compound represented by the following general formula (1).

General formula (1)

(Wherein, X represents a hydrogen atom or a methoxy group CH ₃ 0,.) [2] represented by the following structural formula (1) 3-demethyl Ciro Huo linin ₍₍₁₎

[3] a pharmaceutical composition c containing the compound according to [2] as a main component The present invention also relates to the use of the compound represented by the general formula (1) in the production of an antitumor agent. Alternatively, the present invention relates to the use of a compound represented by the general formula (1) in the treatment of a tumor. Furthermore, the present invention relates to the use of 3-demethyltyloforinine represented by the structural formula (1) in the production of a pharmaceutical composition.

 The compound used as an active ingredient in the antitumor agent of the present invention is an organic solvent extract of Ryukyu Asagi Madara of the family Paragonidae. As an example of a method for producing these compounds, a production method using Ryukyu Asagi Madara pupas as a starting material is shown below. Ryukyu Asagi cod pupae are ground or powdered prior to extraction. Ultrasonic treatment or the like can be used for pulverization. This is extracted with an organic solvent such as methanol. The extraction method may be a commonly used method, for example, a method of immersing a crushed Ryukyu Asagida pupa in an organic solvent for a long time, heating and stirring at a temperature below the boiling point of the organic solvent, and performing extraction. There is a method of obtaining an extract by filtration. The obtained extract is concentrated under reduced pressure to obtain an organic solvent extract. The organic solvent extract is dissolved in water, extracted with a hydrophobic organic solvent such as hexane and defatted. The aqueous layer is made acidic (pH 2) by adding concentrated hydrochloric acid, and washed with an organic solvent such as ethyl acetate. Further, the aqueous layer is made basic (pH 9) with aqueous ammonia and extracted with an organic solvent such as ethyl acetate.

Examples of the hydrophobic organic solvent used in the degreasing step include hydrocarbons such as pentane, hexane, heptane, and cyclohexane. Organic solvents used in the extraction step include lower fatty acid esters such as methyl acetate, ethyl acetate, and butyl acetate; lower alcohols such as methanol, ethanol, and isopropanol; and methyl ether, ethyl ether, tetrahydrazine, and dioxane. Ethers, ketones such as acetone and methyl ethyl ketone, or aromatic hydrocarbons such as toluene and benzene, or halogenated hydrocarbons such as dichloromethane and chloroform. A solvent and a mixed solvent of a hydrophilic solvent and a hydrophobic solvent can also be used. The target compound is contained in this basic fraction. From the fraction extracted with the organic solvent, the compound is separated and purified by high performance liquid chromatography (hereinafter abbreviated as HPLC). In HPLC, a reversed-phase chromatography filler such as 0DS, octyl, phenyl, and cyanoprobe, and an adsorption chromatography filler such as silica gel can be used. As the conditions that can be used, general conditions using 0DS as a carrier and a water-soluble organic solvent such as acetonitrile, methanol, tetrahydrofuran and water, or a mixed solvent of a buffer solution can be used. It is preferable to use a mixed solvent. The fraction of the column containing the target compound can be further purified by repeating preparative HPLC using a 0DS column and aqueous acetonitrile. In this way, the compound described as the general formula of claim 1 which finally gives a single peak in the analysis by HPLC can be isolated. The HPLC profile of each compound is as shown in the examples.

 Alternatively, a compound having an antitumor activity revealed by the present invention can also be chemically synthesized based on its structural information. For example, diarylhexahydroindolizines (3) have been synthesized through the reaction of benzoylacetic acid (1) derived from phenylalanine with topiroline (2). This compound has been reported to be a biosynthetic precursor for tylophorin (R. B. Herbert, et al., J. Chem. Soc. Perkin I, 1984, 825-831 .; R. B. Herbert, et al., J. Chem. Soc. Chem. Co., 1977, 955-956 .;

DS Bhakuni, et al., Tetrahedron, 37, 401-407, 1981) ₀ Further, it is possible to synthesize phenanthroindolizines according to the biosynthetic pathway. Equation (2) shows a series of synthesis steps. In the formula, R, Rl, and R2 each represent a hydroxyl group or a methoxy group bonded to one or more substitutable positions, and R3 represents a hydroxyl group or a hydrogen atom.

(2)

上記の方法によつて得られた本化合物のガン細胞傷害活性は、 公知の方法によ つて測定することができる。 たとえば、 ヒト胃ガン細胞 TMK-1を用い、 WST- 1ァ ッセィ （同仁化学株式会社製） により細胞傷害性効果を測定することができる。 そして、 同様の手法によって公知の抗腫瘍剤の細胞障害性効果を測定することに より、 本発明によつて提供される抗腫瘍剤の細胞障害活性を評価することができ る。 本発明の抗腫瘍剤の細胞障害性効果は、 たとえば、 現在実用化されている癌 の化学療法剤である Taxolに匹敵する。 すなわち、 本発明の抗腫瘍剤の抗癌活性 は、 たいへん優れていると言うことができる。 また実施例に示すとおり、 本発明 において抗腫瘍活性を確認することができた化合物は、 幅広い腫瘍細胞に対して 有効性を示した。 したがって、 これらの化合物は、 作用スペクトルの広い抗腫瘍 剤として期待できる。

The cancer cytotoxic activity of the present compound obtained by the above method can be measured by a known method. For example, the cytotoxic effect can be measured by WST-1 assay (manufactured by Dojindo Co., Ltd.) using human gastric cancer cells TMK-1. Then, by measuring the cytotoxic effect of a known antitumor agent by the same method, the cytotoxic activity of the antitumor agent provided by the present invention can be evaluated. The cytotoxic effect of the antitumor agent of the present invention is comparable to, for example, Taxol, a cancer chemotherapeutic agent currently in practical use. That is, it can be said that the antitumor activity of the antitumor agent of the present invention is extremely excellent. In addition, as shown in the examples, the compounds that could be confirmed to have antitumor activity in the present invention showed efficacy on a wide range of tumor cells. Therefore, these compounds can be expected as antitumor agents having a broad action spectrum.

In the present invention, the following compounds are novel among the compounds derived from Ryukyu Asagi-dara, whose antitumor activity has been confirmed. That is, the present invention has the following structure The present invention relates to a novel 3-demethyltylophorinine represented by the formula (1). Furthermore, the present invention relates to a pharmaceutical composition containing 3-demethyltyrofurinine as an active ingredient (1)

 The compound found to have antitumor activity in the present invention can be made into an antitumor agent or a pharmaceutical composition by using a known formulation technique. That is, an antitumor agent or a pharmaceutical composition can be obtained by blending these compounds with a pharmaceutically acceptable excipient.

 The compounds of the present invention can be administered to animals and humans as they are or together with conventional pharmaceutical carriers. The administration form is not particularly limited, and is appropriately selected and used as needed. Specific examples include oral preparations such as tablets, capsules, granules, fine granules and powders, and parenteral preparations such as injections and suppositories.

Oral preparations are manufactured according to a conventional method using excipients such as starch, lactose, sucrose, mannitol, carboxymethylcellulose, corn starch, and inorganic salts. In addition, binders, disintegrants, surfactants, lubricants, fluidity promoters, flavoring agents, coloring agents, fragrances, and the like can be used. The compounds of the present invention can also be administered as suspensions, emulsions, syrups, and elixirs. These various forms may contain flavoring agents and coloring agents.

 Parenteral preparations are manufactured according to the usual methods, and are generally used as diluents such as distilled water for injection, physiological saline, aqueous solution of pudose, vegetable oil for injection, sesame oil, laccase oil, soybean oil, corn oil, propylene glycol, and polyethylene glycol. Etc. can be used. If necessary, bactericides, preservatives and stabilizers may be added. Other parenteral preparations include liquid preparations for external use, ointments such as ointments, suppositories for rectal administration, and the like, and are produced according to a conventional method.

 The content of the active ingredient in the antitumor agent or the pharmaceutical composition according to the present invention can be appropriately adjusted so as to give a required dose by a selected administration route. . Specifically, the usual dosage is 0.01 g to lmg, preferably 0.01 g to 0.1 mg, more preferably 0.1 g to 0.1 mg / kg of body weight. 0 lm can be indicated. The final dose is appropriately adjusted in consideration of the weight, age, sex, symptoms, etc. of the patient to be administered. BRIEF DESCRIPTION OF THE FIGURES

 FIG. 1 is a diagram showing the steps of obtaining extracts from Ryukyu Asagi Madara pupae, and the ratio of cancer cytotoxic activity of each extract.

 FIG. 2 is a view showing an HPLC profile of a basic fraction of an extract from Ryukyu Asagi Madara pupae, an adult, and a turmoulinka. The horizontal axis represents the retention time (minutes), and the vertical axis represents the HPLC signal (absorbance at 254 nm). BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited thereto. [Example 1] Cancer cytotoxicity activity test

 (1) Preparation of each extract

 The Ryukyu Asagi Madara pupa used was collected from Ishigaki Island and purchased from Hiroshima Mikado Co., Ltd. Five Ryukyu Asagi Madara pupae (2.8 g) were homogenized, sonicated three times for 20 minutes at room temperature, and extracted with methanol (40 ml). The solution was concentrated under reduced pressure to obtain 0.2 g of a methanol extract. The residue was dissolved in water and extracted with n-hexane. Subsequently, concentrated hydrochloric acid was added to the aqueous layer (pH 2), and the mixture was extracted with 10 ml of ethyl acetate. The aqueous layer was made alkaline (pH 9) with aqueous ammonia and extracted three times with ethyl acetate. Original methanol extract (0.2 g), n-hexane extract (67.0 mg), acidic ethyl acetate extract (13.7 mg), basic ethyl acetate extract (2.4 mg), and water extract The cancer cytotoxic activity was examined.

 Similarly, nineteen adults of Ryukyu Asagida (1.0 g) were extracted with methanol (250 ml × 3), and a basic fraction (5.1 mg) was obtained in the same manner.

 (2) Method of cytotoxicity test

For the cytotoxicity test, human gastric cancer cell TMK-1 was used. Cells in a confluent state were collected after trypsinization and diluted to 5 × 10 ⁴ cells / ml in Eagle's medium (Gibco BRL, Gaithersburg, MD) containing 10% fetal calf serum. 100 1 of the cell suspension was dispensed into gels on a 96-well plate and diluted extract samples were added. After incubation for 96 hours at 37 ° C in the presence of 5¾ carbon dioxide, the cytotoxic effect was measured using WST-1 (2- (4-iodophenyl) -3- (4-nitrophenyl) -5- (2,4-disul fophenyl) -2H-tetrazolium, manufactured by Dojin Chemical)

 (3) Measurement results

The IC5 _{) value of the methanol extract was 107 ng / ml. 87% of the cancer cytotoxic activity was enriched in the basic fraction. Isolated compound A (wherein X is a hydrogen atom in the formula of the general formula (1) described in the claims; hereinafter abbreviated as compound A); In the formula of the general formula (1), X is a methoxy group; hereinafter, abbreviated as compound B) has a cancer cytotoxic activity of IC ₅ . The values were 0.5 and 0.7 ng / ml, respectively.

 [Example 2] Identification of compound having cancer cytotoxic activity

 After treating the methanol extract with acid and base, each fraction was evaluated for cancer cytotoxicity. The basic fraction showing the cancer cytotoxic activity was analyzed on a 0DS column (Shiseido Capsell Pak C18, 4.6 × 250) with a gradient solvent system of acetonitrile in 20 mM potassium dihydrogen phosphate buffer. Separated by HPLC on Shiseido Co., Ltd. (linear gradient of 10 to 25% from 0 to 80 minutes) (flow rate: 1 ml / min, UV: 254 im). Significant cancer cytotoxicity was observed in the fraction with a retention time of 30-34 minutes (Peak I) and 34-38 minutes (Peak I I). The respective cancer cytotoxic activities corresponding to peaks I and II were 34 and 34%, respectively, of the total cancer cytotoxicity by HPLC hair ply. To prepare larger amounts of cancer cytotoxic compounds from 50 pupae, sonication was performed three times for 20 minutes at room temperature and extracted with 200 ml of methanol. The methanol extract was treated with n-hexane, acid, and base as described above. The basic fraction (38.7 nig) was purified by HPLC on the same gradient solvent system. Compounds A (2.2 mg) and B (3.7 mg) were isolated by selecting peaks I and a fraction containing II in the HPLC profile (FIG. 2). FIG. 1 shows the extraction process and the ratio of the cancer cytotoxic activity of each extract.

With the above gradient system, remarkable cancer cytotoxicity was observed in compounds A and B showing retention times of 33.0 minutes and 37.0 minutes, respectively. Similarly, 15% § Se Tonitoriru - compound in 20 mM KH ₂ P0 ₄ A, and the retention time of B was 18.2 min, and 23.6 min, respectively.

Furthermore, in order to confirm that these antitumor active compounds are not derived from edible plants, the above-mentioned homogenate of Tylophora tanakae was extracted under the same conditions and subjected to HPLC analysis. Was. The results are also shown in FIG. As is evident from FIG. 2, the extract of the turmolinka (Tylo.hora ia / za) A small peak corresponding to compound B was observed. However, no beak corresponding to compound A could be confirmed.

 [Example 3] Analysis of compound structure

Compound A was isolated as fine, colorless crystals, and was estimated to have a phenolic hydroxyl group by TLC test using iron (II) chloride. The UV spectrum of Compound A showed the absorbance of 259, 285, and 314 dishes attributable to the phenanthroindolizidine scaffold. Compound A cation EI-MS showed a molecular ion peak at m / z 365 (M) +. In addition, the m / z 296 (M-69) ⁺ fragment ion peak generated by the retro Diels Alder reaction, which is characteristic of the phenanthroindolizidine alkaloids, and the m / z 70 reference peak corresponding to the pyrrolidine ring It was observed. These fragments suggested the presence of a hydroxyl group at C14. By high resolution MS analysis of the molecule I Onpiku (M) ^+, molecular formula of Compound A was found to be C ₂₂ H ₂₃ N0 _4. The A-NMR spectrum of compound A showed a signal indicating the presence of the 3,6,7-phenanthroindolizidine alkyloid skeleton and two methoxy groups (53.91 and 3.99). Considering the molecular formula, the existence of one phenolic hydroxyl group and benzyl hydroxyl group was estimated. In the N0ESY (nuclear Overhauser and exchange spectroscopy) spectrum, a correlation was seen between: H-1 (58.13) and H-14 (54.90)

H-1 ((58.13) and H-2 (57.09)

H-5 (d7.91) and H-4 (57.92)

H-5 (57.91) and 0 (¾-6 (53.99)

H-8 ((57.16) and 0 (¾-7 (53.91)

H-8 (57.16) and H-9 ((54.50)

0CH ₃ -6 (3.99) and 0 (¾-7 (53.91)

This suggested a 3,14-dihydroxy-6,7-dimethoxy substitution. Corresponds to the C-14-configured methine hydrogen (H.90 couples to the hydroxyl group (J = 9.6 Hz), and since the coupling constant with C-13a hydrogen is almost 0, this hydrogen and C-13a water The dihedral angle with the element was shown to be about 90 degrees.

 Based on the above results, Compound A was determined to be 3-demethyltyrofurinine (3,14-dihydroxy-6, 7-dimethylthioxyphenanthroindo 1 izidine) having the following structural formula (1). This compound is a new compound.

 (1)

Compound B was isolated as pale yellow fine crystals, and was estimated to have a phenolic hydroxyl group by TLC test using iron (II) chloride. The UV spectrum of Compound B showed absorbance at 261 and 319 nm and was very similar to Compound A. Compound B cation EI-MS showed a molecular ion peak at m / z 395 (M) ⁺ . In addition, an m / z 326 (M-69) + fragment ion peak and an m / z 70 reference peak were observed. These fragments characterized the phenanthroindolizidine skeleton and suggested the presence of a C-14 hydroxyl group. By high resolution MS analysis of the molecular ion peak (M) ^+, molecular formula of compound B was found to be C ₂₃ H ₂₅ N0 _5. In the ¹ H-NMR spectrum of Compound B, 3,4,6,7- Signals indicating the presence of the alkaloid structure and the presence of three methoxy groups were found (53.84, 4.04 and 4.08). Considering the molecular formula, the presence of one phenolic hydroxyl group and another oxygen was estimated. The ¹ H-NMR spectrum of compound B was similar to that of compound A, but the H-4 proton disappeared and the H-5 proton moved to the low magnetic field region due to the influence of the methoxy group at the C-5 position. And shifted. The molecular formula deduced by cation EI-MS indicated that Compound B was a compound in which the H-4 proton of Compound A was changed to a methoxy group. From the above results, it was found that compound B was 3-demethyl-14-dihydroxy-4,6,7-trimethoxyphenanthroindolizidine. The structure of this compound is known (Abe F., Iwase Y., Yajnauchi T., Honda K., and Hayashi N., Phytochemistry ₅ 39, 695-699, 1995; Abe F., Hirokawa M., Yamauchi T., Honda K., Hayashi N., Ishn M., Imaga a S., and Iwahana M., Chem. Pharm. Bull., 46, 767-769, 1998). In the previous report, 3-demethyl-14-hydroxy-isotylocreculin was isolated from the potato family Turmolinka from Hateruma Island, and was subjected to ordinary physical methods such as NMR and IR, or chemical methods. Was used to determine the structure. However, this does not suggest that an antitumor compound having this structure exists in insects.

 The physicochemical and spectral properties of the compound of the present invention are as follows.

 • 3-demethyltyrofluorinine:

Color · Properties: colorless fine crystals

Optical rotation: [Hi]!) ²⁷ +20.8. (c = 0.1, CHCl ₃ -MeOH)

_{UV A max: CH 3 CN-} KH 2 P0 4 buffer (pH5): 259, 285, 314 nm

High resolution cation EI-MS:

Theoretical _{C 22 H 23 N0 4 (M} +): 365.1627

Found: 365.1617

Cation EI-MS: 365 (17.5), 326 (3.2), 296 (56.2), 148 (8.0), 70 (100) Table 1 ! H- MR (600 MHz, DMSO- d6) δ: 1.75-1.85 (2H, m, H-12), 1.82 and 2.17 (1H each, m, H-13), 2.36 and 3.30 (1H each, m, H-11), 2.39 (1H, m, H-13a), 3.43 and 4.50 (1H each d, J = 15.0 Hz, H-9), 3.91 (3H, s, OCH3 at C-7), 3.99 (3H , s, OCH3 at C-6), 4.59 (1H, d, J = 9.6 Hz, OH at C-14) 4.90 (1H, d, J = 9.6 Hz, H-14), 7.09 (1H, dd, J = 9.0, 1.8 Hz, H-2), .16 (1H, s, H-8), 7.91 (1H, s, H-5), 7.92 (1H, d, J = 1.8 Hz, H-4), 8.13 (1H, d, J = 9.0 Hz, H-1), 9.63 (1H, s, OH at C-3).

13 _C -NMR (150 MHz, DMSO -¾) δ: 21.6, 23.9, 53.6, 54.9, 55.5, 55.5, 63.6, 64.9, 103.8, 103.9, 106.0, 116.2, 123.3, 124.0., 124.2, 125 * 3, 126.4 , 129, h, 130.6, 148.5, 149.1, 155.3.

• 3-demethyl-14-hin:

Color · Properties: pale yellow fine crystals

Optical rotation: [Hi] _D ²⁷ + 24.0 ° (c = 0.1, CHCl ₃ -MeOH)

_{UV A Bax: CH 3 CN-} KH 2 P0 4 buffer (pH 5): 261, 319 nm

High resolution cation EI-MS:

Theoretical _{C 23 H 25 N0 5 (M} +): 395.1732

Found: 395.1730

Cation EI-MS: 395 (24.5), 379 (4.1), 326 (58.6), 311 (14.8), 296 (5.6), 255 (4.3), 149 (7.3), 70 (100) Table 2

 ! H-NMR (270 MHz, CDCI3) 8: 1.96 (2H, m, H-12), 2.35 and 2.50 (1H each, m, H-13), 2.61 and 3,41 (1H each, t like, H -11), 2.90 (1H, br d, J = 9 Hz, H-13a), 3.59 and 4.46 (1H each, d, J = 1S Hz, H-9), 3.84, 4.04 and 4.08 (3H each, s , OCH3), 5.10 (1H, br d, J = 9 Hz, H-14), 7.07 (1H, s, H-8), 7.34 (1H, d, J = 9 Hz, H-2), 8.15 ( 1H, d, J = 9 Hz, H-1), 9.00 (1H, s, H-5).

[Example 4]

Three types of human cancer cell lines, A549 (lung cancer cell line), DLD-1 (colorectal cancer cell line) and K556 (leukemia cell line) were obtained from the American Type Culture Collection (Rockville, MD, USA). Hela cervical cancer cell line was obtained from RIKEN Cell Bank (Tsukuba, Japan). A floating cells K562 10% © Shi calf serum (Gibco BL, Gaither sburg, MD , USA) cell suspension 100 1 containing 2.5 × 10 ³ cells in addition RPMI-1640 medium, 96 © El plate Dispensed to each tube. Immediately after adding the sterilized test compound to each well, the cells were treated at 37 ° C for 96 hours in the presence of 5% carbon dioxide. For adherent cells, A549, DLD-1, Hela, and TMK-1, 100 μl of cell suspension containing 1 × 10 ³ cells in the same medium was distributed to each well of a 96-well plate. After 24 hours, the medium was replaced, a sterilized test compound was added to each cell, and the cells were treated at 37 ° C for 96 hours in the presence of 5% carbon dioxide. After these treatments, the cytotoxic effect was reduced by WST-1 {2- (4-iodophenyl) -3- (4-nitrophenyl) -5- (2,4-disulfophenyl) -2H-tetrazolium, Dojindo Labor atories, Kumamoto, Japan} Measured by Atsushi.

IC ₅ when compound A was used as test compound. (ng / ml) values were 0.4 for A549 (lung cancer cell line), 0.5 for DLD-1 (colorectal cancer cell line), 0.8 for Hela (cervical cancer cell line), and 0.4 for K562 (leukemia cell line). Indicated. On the other hand, IC _{5 of} compound B. (ng / ml) values were 0.5 for A549 cancer cells, 0.8 for DLD-1, 1.0 for Hela, and 0.5 for K562. Industrial applicability

 The present invention has provided a novel antitumor agent containing, as an active ingredient, a compound derived from an insect, for which an attempt has not been made to search for an antitumor compound. The present invention is novel in that it has found an antitumor activity in a new structure, and has great significance in reporting a new structure in which antitumor activity can be expected.

Claims

Scope 1. An antitumor agent comprising a fenansroindolizidine alkyloid compound represented by the following general formula (1) as an active ingredient. General formula (1)  Eleven

(Wherein, X represents a hydrogen atom or a main butoxy group CH ₃ 0,.) 2. 3-Demethyltylophorinine ₍ Structural formula (1) shown below)  (1)

3. Pharmaceutical composition c containing the compound according to claim 2 as a main component