JPS6331196B2 - - Google Patents

Description

[Detailed description of the invention]

[Technical field] The present invention provides novel antibiotics RK-120A and RK-
120B and its manufacturing method, RK−120A, RK−
This invention relates to an agricultural and horticultural fungicide containing 120B or its complex as an active ingredient. In addition, this antibiotic RK-120A and RK-120B
are the same substances referred to as "antibiotics SP-120A and SP-120B", respectively, in the Chinese patent application corresponding to the present application. [Background of the Invention] Conventionally, heavy metal compounds such as copper agents, mercury agents, and arsenic agents, as well as organochlorine agents and organic phosphate agents, have been used as disinfectants for agriculture and horticulture. These drugs are harmful to the human body, contaminate the soil, and remain in nature and act on animals and plants for long periods of time.Environmental pollution caused by these drugs has become a serious social problem, and their use is currently prohibited or restricted. . However, various plant diseases, including major diseases of rice, are showing an increasing trend due to the decrease in target drugs and the emergence of resistant bacteria. There is a strong desire for the development of new high-performance agricultural chemicals. [Object of the Invention] An object of the present invention is to provide antibiotics RK-120A and RK-120B that are effective against various plant diseases and a method for producing the same. A further object of the present invention is to provide an agricultural and horticultural fungicide containing the above-mentioned antibiotic RK-120A, RK-120B, or a complex thereof as an active ingredient. [Configuration of the invention] Antibiotics RK-120A and RK-120B of the present invention
is a new antibiotic described in the literature that has the physicochemical properties described below, and in the spray test described below.
It has excellent control effects against various plant diseases such as major rice diseases such as rice sheath blight and rice blast, as well as cucumber gray mold, cucumber anthracnose, pear black spot, and grape late rot. It is an excellent agricultural and horticultural fungicide that does not cause any phytotoxicity to plants and has no effect on the human body when used. The present invention will be explained in detail below. <Production of antibiotics RK-120A and RK-120B> (Microorganisms used) The microorganism that produces antibiotics RK-120A and RK-120B of the present invention is antibiotic RK-120A belonging to the genus Streptomyces.
and RK-120B. One example is Streptomyces sp. RK-120.
(FERM P-7713) (hereinafter referred to as “RK-120 strain”. This RK-120 strain is the same as the strain referred to as “Streptomyces sp. sp-120” in the Chinese patent application corresponding to this application. The microorganism has the above-mentioned characteristics and is a strain of the antibiotic RK-120A and RK-120A of the present invention.
This method can advantageously produce RK-120B and can be effectively used in the manufacturing method of the present invention. The above RK-120 strain was isolated at the Shanghai Pesticide Research Institute in the People's Republic of China, and the microbial accession number of the Institute of Microbial Technology, Agency of Industrial Science and Technology is FERM P- 7713). RK
Strain -120 belongs to the genus Streptomyces, and its growth status on a medium and various physiological characteristics according to the Japan Patent Office's industry-specific examination standards are as follows. Morphological characteristics This strain is grown on oatmeal agar medium, starch
It grows extremely well on yeast agar medium (composition below), and has abundant aerial mycelia and spores.
Aerial hyphae are white to light gray in color. Growth on sucrose nitrate agar medium and yeast malt agar medium was good, and aerial mycelium and spore settlement were good. Glucose/asparagine grows on other glucose/asparagine agar, glycerin/asparagine agar, starch/mineral salt agar, tyrosine agar, nutrient agar, peptone/yeast/iron agar, but not sufficiently. On agar medium, nutrient agar medium, and peptone yeast iron agar medium, the growth of aerial mycelia is weak or not observed.
In general, the production of soluble pigments is weak and a slight yellowish brown pigment is observed to be produced, but no melanin-like pigments are produced by tyrosine agar medium and peptone yeast iron agar medium. The basal hyphae do not exhibit a distinctive color on the underside, and are slightly yellow to slightly brown. Aerial hyphae grow in a straight line, and those that branch out form a strong spiral, which becomes a long spore chain. The spores are elliptical, almost spherical, less than 1μ in length and about 0.5μ in width, and have a smooth surface. In the carbon source assimilation test using sugar, L-arabinose, D-fructose, raffinose, lactose, and meliose were well assimilated, and growth was good. D-glucol, sucrose,
With inositol and D-mannitol, the growth is slightly inferior, but it grows. Growth on D-xylose and L-rhamnose is poor, and in particular, no formation of aerial mycelium is observed on L-rhamnose. It grows on glucose-peptone-gelatin medium, but does not liquefy gelatin. Skimmed milk is completely peptonized and becomes a nearly transparent liquid. It was observed that starch hydrolysis on the starch/inorganic salt agar medium was strong. The cell wall was hydrolyzed with hydrochloric acid and L-diaminopimelic acid was detected by paper chromatography to detect amino acids constituting the cell wall, indicating that this bacterium belongs to the genus Streptomyces. Properties on various media Various media were prepared according to the Japan Patent Office industry-specific examination standards, and the results observed 3 weeks after inoculation are described below. Color tones are described using Descriptive Color Names.
This is based on the color names dictionary (4th edition). 1 Growth on sucrose nitrate agar medium Good growth of hyphae in aerobic condition Good color of hyphae in aerobic condition 2ba Color of pearl basal hyphae 3lc Amber soluble pigment 3ga Melon yellow 2 Growth on glucose-asparagine agar medium Poor hyphal attachment in aerobic condition Live None Color of aerial hyphae Unknown Color of basal hyphae 5Ca Shell pink soluble pigment 6Ca Shell pink 3 Growth on glycerin/asparagine agar medium Good Epiphytion of hyphae during aeration Poor Color of aerial hyphae 7cb Cloud pink of basal hyphae Color 5Pa Terra Kotsuda Soluble Pigment 6 1/2gc Dusty Coral 4 Growth on Starch/Inorganic Salt Agar Medium Normal Growth of Hyphae during Aeration Medium Color of Hyphae during Aeration a Color of White Basal Hyphae 3Ca Pearl Pink Soluble Dye None 5 Growth on tyrosine agar medium Normal Epiphytion of hyphae during aeration Normal Color of hyphae during aeration b Light gray color of basal hyphae 4Pi Oak brown soluble pigment 5ie Katsupatan 6 Growth on nutrient agar medium Fair Epiphytion of hyphae during aeration None Aerial hyphae Color Unknown Color of basal hyphae 2ea Light maze soluble pigment 2ea Light maize 7 Growth on yeast/malt agar medium Good Adhesion of hyphae in aerobic environment Good Color of aerobic hyphae a White Color of basal hyphae 2ea Light maize soluble pigment None 8 Growth on oatmeal agar medium Good Growth of hyphae in aerobic environment Abundant Mycelia color in aerobic environment c Light gray color of basal hyphae 3ba Pearl soluble pigment None 9 Growth in peptone/yeast/iron agar medium Good Mycelia in aerobic environment Epiphytion None Aerial hyphal color Unknown Basal hyphal color 2ea Light maize soluble pigment None 10 Starch yeast agar medium ^* Growth Good Aerobic hyphal epiphytion Abundant Aerial hyphal color a White basal Mycelia color 3Pc Amber Soluble pigment 3Ca Pearl pink * Starch yeast agar medium composition Soluble starch 10g Yeast extract 1g NZ amine A 1g Agar 15g Water 1 PH7.4 Carbon source utilization (Pridham-Gottlieb agar medium) Carbon source Growth Status ^* L-arabinose ++ D-xinose ± D-glucose + D-fructose ++ Sucrose + inositol + L-rhamnose ± raffinose ++ D-mannitol + lactose +++ Melbiose ++ * Growth status +++ Very well developed ++ Well developed + Growth ± Slight growth − No growth Other physiological properties Optimal temperature 25-30℃ Liquefaction of gelatin (glucose/peptin/gelatin medium) Hydrolysis of starch without liquefaction (starch/inorganic salt agar medium) Hydrolysis Liquefaction of skimmed milk Production of melanin-like pigments that completely liquefy (on tyrosine agar and peptone
(yeast/iron agar medium) Not produced The search for Streptomyces species with the above characteristics was based on Mr. Nonomura's report. Namely, Mr. Nonomura's Journal of Fermentation Technology.
Technology) Vol. 52, No. 2, Streptomyces 1SP458 Species Taxonomy In-ISP (Key
for classification and identification
of458species of the Streptomyces included in
ISP)]. This fungus belongs to the white or gray group, the aerial hyphae are spiral-shaped, and the spore surface is smooth and does not form melanin pigment. Further, both the back surface and the soluble dye do not exhibit a noticeable color tone. Sugars are rhamnose and D
-The use of xylose is bad, but most other things are used. Those that meet the above conditions are Streptomyces albofaciens.
albofaciens), and S. albofaciens is thought to be a species closely related to this bacterium. (Culture method and purification method) To obtain the antibiotics RK-120A and 120B of the present invention, the above-mentioned antibiotic-producing bacteria belonging to the genus Streptomyces can be cultured by a conventional method for producing antibiotics. . The form of culture may be liquid culture or solid culture, and for industrially advantageous culturing, a spore suspension or culture solution of the above-mentioned producing bacteria may be inoculated into a medium and culture with aeration and stirring may be performed. The nutrient source of the medium is not particularly limited, and the medium may contain carbon sources, nitrogen sources, and other sources commonly used for culturing microorganisms. Carbon sources include starch, dextrin, glycerin, glucose, sucrose, galactose, isinotol, mannitol, etc. Nitrogen sources include peptone, soybean flour, meat extract, rice bran, urea, cornstap liquor, and ammonium salts. , nitrates and other organic or inorganic nitrogen compounds are used. In addition, inorganic salts such as common salt, phosphates, metal salts such as potassium, calcium, zinc, manganese, iron, etc. may be added as appropriate, and if necessary, as an antifoaming agent,
Animal, vegetable, mineral oil, etc. may be added. culture temperature,
Culture conditions such as culture time are selected to be suitable for the growth of the bacteria used and to maximize the production of RK-120A and RK-120B. For example, the pH of the medium should preferably be between 4 and 9, especially around neutrality, and the optimum culture temperature should be around 25°-35°C. However, these culture conditions such as culture composition, hydrogen ion concentration of the medium, culture temperature, and stirring conditions should be adjusted as appropriate to obtain favorable results depending on the type of bacterial strain used and external conditions. Needless to say, it is. From the culture thus obtained, RK-
120A and RK-120B can be obtained by appropriately using any means commonly used to collect substitute products. For example, RK-120A and RK-
Any of the methods of utilizing the solubility difference between 120B and impurities, the means of utilizing the difference of ionic binding force, the means of utilizing the difference of adsorption affinity, and the means of utilizing the difference of molecular weight may be used alone or in appropriate combinations. hand,
Or used repeatedly. Specifically, R.K.
Most of -120A and RK-120B are present in the culture solution, but after repeated extraction with butanol from this culture solution or adsorption using a synthetic adsorbent such as Diaion HP10, 50% Elute with acetone to obtain a concentrate. The obtained concentrate is repeatedly subjected to column chromatography using silica gel. The preferred solvent is a butanol-methanol-water system, and by changing these ratios, the desired chromatography can be achieved. The active category is divided into a category rich in RK-120A and a category rich in RK-120B.
Perform column chromatography using -20 or the like. As the solvent, it is preferable to use the same solvent system as above. By gel filtration, RK-120A and RK-120B
are each further purified and obtained as white powders. After this, by performing high performance liquid chromatography, RK-120A and RK-120B can be completely decomposed. As a filler,
The preferred solvent for Nucleosil 5 _C18 is isopropanol-methanol-water with some acetic acid added. RK-120A and RK-120B thus obtained
are new antibiotics that have the physicochemical properties described below. [Physical and chemical properties of RK-120A and RK-120B] (1) Melting point: A: Turns brown and decomposes at 235-255°C. B: Turns brown and decomposes at 235-265°C. (2) Elemental analysis A: Carbon 50.98%, Hydrogen 7.11%, Nitrogen 16.42%, Sulfur 3.55% B: Carbon: 50.91%, Hydrogen 6.95%, Nitrogen 16.12%, Sulfur 3.39% (3) Specific optical rotation: A: [ α] ²⁵ _D = -90° (C = 0.05, dimethyl sulfoxide) B: [α] ²⁵ _D -59 (C = 0.03, dimethyl sulfoxide) (4) Ultraviolet absorption spectrum: A: λ ^{0.1N-HCl-MeOH} _nax 220nm (E1% 1cm293) shoulder (see Figure 1) B: λ ^{0.1N-HCl-MeOH} _nax 220nm (E1% 1cm293) shoulder (see Figure 2) (5) Infrared absorption spectrum: A: 3300 by KBr method; 2903, 2850, 1655, 1520, 1460,
1395, 1382, 1320, 1280, 1250, 1215, 1163,
1100, 1020, 1002, 900, 840, 760cm ^-1 (see Figure 3) B: 3300, 2900, 2850, 1650, 1520, 1435,
1392, 1370, 1342, 1322, 1285, 1212, 1185,
1168, 1100, 1024, 1004, 958, 903, 846, 825,
765cm ^-1 (See Figure 4) (6) Solubility: Both RK-120A and RK-120B are insoluble in organic solvents such as methanol, ethanol, acetone, ethyl acetate, chloroform, benzene, hexane, and ether, and poorly soluble in water. Soluble in a mixture of butanol, methanol and water (7) Molecular weight: Based on FAB mass spectrum) A: 911 B: 923 (8) Color reaction: For both RK-120A and RK-120B,
Positive for potassium permanganate, anisaldehyde-sulfuric acid, and iodine (9) Color of substance: Both RK-120A and RK-120B are white powders. (10) Thin layer chromatography (Thin layer plate 0.25 m/m manufactured by Merck, USA): Cellulose (solvent, butanol: methanol: water = 4:
1:2) Rf value A: 0.60 B: 0.66 Silica gel (solvent, butanol: methanol: water = 4:
1:2) Rf value A: 0.51 B: 0.51 (11) Acid hydrolysis: When hydrolyzed by heating in 6N-HCl at 105℃ for 20 hours, RK-120A becomes glycine,
Each amino acid of leucine was detected, RK−120B
Glycine and valine were detected. (12) Antibacterial spectrum: Tested using the standard agar plate dilution method and expressed as minimum inhibitory concentration (MIC). Bacteria on bouillon agar medium, mold on bouillon agar medium,
The test was carried out using a potato-sucrose agar medium.

【table】

[Table] Comparing the antibiotics RK-120A and RK-120B of the present invention with known antibiotics, it is found that the antibiotics RK-120A and RK-120B of the present invention contain 3 to 4
Bottromycin, Enshumycin, Actinoleukin, Kobenomycin, Zorbomycin, Phleomycin, etc. are known as peptide antibiotics containing % sulfur. However, RK−120A
and RK-120B substances are clearly different from the above-mentioned antibiotics in ultraviolet absorption spectrum and antibacterial activity. Therefore, the antibiotic RK-120A of the present invention and
It was concluded that RK-120B is a new antibiotic described at the end of the literature. (Agricultural and horticultural fungicide containing RK-120A, RK-120B, or a complex thereof as an active ingredient) Here, the complex of RK-120A and RK-120B refers to a compound obtained by adsorbing the culture solution to a synthetic adsorbent. rear,
Elute with aqueous acetone, at least RK-120A and
It means a concentrate containing the RK-120B substance, and since both substances can be obtained simultaneously from the same culture, this complex can be used as it is as an active ingredient, which is extremely advantageous in terms of economy. is attracting attention. When the active ingredient of the present invention is used as a fungicide for agriculture and horticulture, it is usually prepared into granules using a suitable solid carrier, liquid carrier, emulsifying dispersant, etc. in the same way as agricultural chemical formulations known in the art. , powder, emulsion,
It can be formulated and applied in any dosage form such as wettable powders, tablets, oil solutions, sprays, and aerosols. These carriers include clay, kaolin, bentonite, acid clay, diatomaceous earth, calcium carbonate, solid carriers such as nitrocellulose, starch, gum arabic, etc., and liquid carriers such as water, methanol, ethanol, acetone, etc. , dimethylformamide, ethylene glycol and the like. In addition, adjuvants commonly used in formulations, such as
Higher alcohol sulfate ester, polyoxyethylene, alkyl allyl ether, alkyl allyl polyethylene glycol ether, alkyl allyl sorbitan monolaurate, alkyl allyl sulfonate, alkyl allyl sulfonate, quaternary Grade ammonium salts, polyalkylene oxides, etc. can be appropriately blended. The appropriate blending ratio of the active ingredient is approximately 10 to 90% for emulsions and wettable powders, and approximately 0.1 to 10% for powders, oils, etc., but these may vary depending on the purpose of use. The concentration may be increased or decreased as appropriate. In addition, the drug of the present invention may be used with other fungicides, herbicides,
It can be used by appropriately mixing with pesticides, fertilizer substances, and soil conditioners. The present invention will be specifically explained below using production examples, working examples, and test examples, but the present invention is not limited thereto. In addition, "parts" in the examples represent parts by weight. Production example: 2% glucose, 1% solubilized starch, meat extract
0.1%, dry yeast 0.4%, soy flour 2.5%, salt 0.2%,
The RK-120 strain (Microorganism accession number: Microorganism Research Institute No. 7713) is inoculated into a medium containing 0.005% dibasic potassium phosphate, and cultured with shaking at 28° C. for 96 hours. Add this culture solution 25 to Diaphone HP-10.
(manufactured by Mitsubishi Kasei Corporation) No. 4 column, the active fraction is adsorbed. Elute with 50% acetone 40 and concentrate under reduced pressure. Concentrate to 2, separate the precipitate and wash with water. After this, a silica gel column with a diameter of 50 mm and a length of 40 cm was prepared with a solvent of butanol-methanol-water (8:1:1), and a 0.1N-
Pour the sample dissolved in HCl-MeOH (1:8) and develop. Butanol-methanol-water, the mixing ratio is changed from (8:1:1) to (5:1:1) and finally to (4:1:1). The fraction volume is 55 ml, and the first fraction Nos. 57 to 100 contain a large amount of RK-120B, and the first fractions No. 101 to 123 contain a large amount of RK-120A. Each active fraction was concentrated under reduced pressure and finally freeze-dried to obtain 990 mg and 170 mg, respectively. Powder containing a large amount of RK-120A was prepared with butanol-methanol-water (4:1:2) and had a diameter of 50 mm and a length of
90cm Sefadex LH-20 (Sweden)
RK-
Fractions containing 120A as the main component were obtained in fractions No. 28-35.
It becomes a white powder when concentrated under vacuum and lyophilized.
mg is obtained. Thereafter, RK-120A and RK-120B are separated by performing high performance liquid chromatography. Column is Nucleosil 5C ₁₈ : diameter 20
mm, length 30 cm, and the solvent was acetic acid in isopropanol-methanol-water (2:2:6).
System with 0.15% added, flow rate 6.0ml/min, pressure 180Kg/
When done in cm ² , RK-120B has a development time of 30 minutes and 42 minutes.
RK-120A appears. This RK-120A portion was collected, concentrated under reduced pressure until the isopropanol and methanol disappeared, and lyophilized to produce a white powder of 27
mg obtained. Further, when the powder containing RK-120B as the main component was similarly subjected to column chromatography using Sephadex LH-20 and high performance liquid chromatography using Nucleosil 5C ₁₈ , a single form of RK-120B was obtained. This product was collected, concentrated under reduced pressure, and lyophilized to obtain 14.8 mg of RK-120B. After this, desalting was performed by the following method. RK-120A is dissolved in 250 ml of a solvent of butanol-methanol-water (2:1:2) with 0.15% acetic acid added, and insoluble matter is removed. Distill the butanol and water under reduced pressure while adding water so that the acetic acid concentration does not exceed 0.15%. After this, the solution is lyophilized and
Butanol-methanol-water (2:1:2) again
Dissolve in 200 ml of water and concentrate under reduced pressure until the volume is about 10 ml. RK-120A will precipitate, so separate it.
After thorough washing with water, further washing with acetone and ether, and drying in a desiccator, pure RK-
12.8 mg of 120A was obtained as a powder. RK-120B was similarly desalted and 4.2 mg of pure powder was obtained. Example 1 (Hydrating agent) RK-120A (or RK-120B, or composite) 10
1 part, 5 parts of sodium lauryl sulfate, 2 parts of dinaphthylmethane disulfonic acid sodium formalin condensate, and 83 parts of clay were mixed and ground to obtain 100 parts of a wettable powder. Example 2 (Emulsion) RK-120A (or RK-120B, or composite) 8
10 parts of ethylene glycol, 20 parts of dimethylformamide, 10 parts of alkyl dimethylbenzyl ammonium chloride and 52 parts of methanol are mixed and dissolved to obtain 100 parts of an emulsion. Example 3 (Powder) RK-120A (or RK-120B, or composite) 0.2
1 part, 0.5 parts of calcium stearate, 50 parts of talc, and 49.3 parts of clay were mixed and ground to obtain 100 parts of a powder. Example 4 (Granules) RK-120A (or RK-120B, or composite) 10
15 parts of starch, 72 parts of bentonite, and 3 parts of sodium salt of lauryl alcohol sulfate were mixed and ground to obtain 100 parts of granules. Practical example 1 (Control test against Botrytis botrytis) Seedlings of cucumber (variety: Sagami Hanshiro) grown for 15 days after sowing were treated with a wettable powder prepared according to Example 1 diluted to a specified concentration. After spraying, it was air-dried. Botrytis cinerea was cultured on a potato-glucose agar plate medium,
Spores induced by irradiation with BLB light were suspended in a 1% solution of 10% glucose and yeast extract. After the chemical solution dries, transfer the cucumber to the inoculation box,
The suspension was sprayed onto young cucumber seedlings using a spray gun.
10 c.c. spray inoculation was carried out per 10 plants. After inoculation, the cucumber seedlings were left under constant temperature and humidity conditions, and the degree of disease onset was examined 4 days later. In addition, the control value was calculated by the following method. (Incidence index) (Severity of onset) 0 No onset of disease 1 Slight lesions observed. 2 The diseased area is less than 10%. 3. The diseased area is 10% or more and 20% or less. 4 The diseased area is 20% or more and 30% or less. 5 The diseased area is 30% or more and 40% or less. 6 40% or more of the diseased area is observed. Control value (%) = (1 - sum of disease indexes in treated plots/sum of disease indexes in non-treated plots) x 100 The results are shown in Table 1.

[Table] Test Example 2 (Control test against cucumber anthracnose) An emulsion prepared according to Example 2 was diluted to a specified concentration and sprayed on seedlings of cucumber (cultivar: Sagami Hanshiro) grown for 15 days after sowing. After that, it was air-dried. Colletotrichum (Colletotrichum)
lagenarium) was cultured on a potato agar plate medium, and the grown spores were made into a suspension [spore concentration was about 200 per field of view (microscopic magnification x 150)]. After the chemical solution dried, the young cucumber seedlings were transferred to an inoculation box, and 10 c.c. of the suspension was sprayed and inoculated per 10 young cucumber seedlings using a spray gun. After inoculation, the cucumber seedlings were left in an inoculation box with 100% humidity for 24 hours, then transferred to a greenhouse with natural light, and the number of lesions was examined 4 days later. Ten cucumber seedlings were used in each chemical treatment area. In addition, the control value was calculated by the following method. Control value (%) = (1 - total number of lesions in treated area/total number of lesions in untreated area) x
100 The results are shown in Table 2.

[Table] Test Example 3 (Control test against rice sheath blight) Plant seeds in pots in advance (7 plants per pot,
(10 pots for each area) A wettable powder prepared according to the method of Example 1 was diluted with methanol and water to a predetermined concentration, and sprayed on rice (cultivar: Jukoku) at the 5th leaf stage grown in a greenhouse using a spray gun. 40 ml per pot was sprayed using the same method, and then, after 2 hours, a bacterial colony of the rice sheath blight fungus (Pellularia sasakii) (punched to a diameter of 8 mm) was placed between the new shoots of the rice plants, and the above bacteria was inoculated. . After covering the basal leaf with a vinyl sheet and keeping it in a greenhouse for 7 days, the total length of diseased lesions on rice was measured, and the control value (%) was calculated using the following formula. Control value (%) = (1 - total lesion length in treated area/total lesion length in untreated area) x
100 The results are shown in Table 3.

【table】

[Table] (Effects of the present invention) From the above test results, the agricultural and horticultural fungicide of the present invention exhibits an extremely high control value against various plant diseases, has no phytotoxicity, and is safe. It has been revealed that it can provide a high level of pesticides.

[Brief explanation of the drawing]

Figure 1 is a diagram showing the ultraviolet absorption spectrum of antibiotic RK-120A of the present invention, Figure 2 is a diagram showing the ultraviolet absorption spectrum of antibiotic RK-120B, and Figure 3 is a diagram showing the ultraviolet absorption spectrum of antibiotic RK-120A of the present invention. FIG. 4 is a diagram showing an infrared absorption spectrum of RK-120A, and FIG. 4 is a diagram showing an infrared absorption spectrum of antibiotic RK-120B.

Claims (1)

[Scope of Claims] 1. An antibiotic selected from the group consisting of novel antibiotics RK-120A, RK-120B, and complexes thereof, having the following physicochemical and biological properties. RK-120A (1) Melting point: Turns brown and decomposes at 235-255℃. (2) Elemental analysis: Carbon 50.98%, Hydrogen 7.11%, Nitrogen
16.42%, sulfur 3.55% (3) Specific rotation: [α] ²⁵ _D = -90° (C = 0.05, dimethyl sulfoxide) (4) Ultraviolet absorption spectrum: λ ^{0.1N-HCl-MeOH} _nax 220n
m
(E1% 1cm186) Shoulder (5) Infrared absorption spectrum: (KBr method) 3300,
2903, 2850, 1655, 1520, 1460, 1395, 1382,
1320, 1280, 1250, 1215, 1163, 1100, 1020,
1002, 900, 840, 760 cm ^-1 (6) Solubility: Insoluble in methanol, ethanol, acetone, ethyl acetate, chloroform, benzene, hexane, ether, sparingly soluble in water, soluble in a mixture of butanol, methanol, and water ( 7) Molecular weight (according to FAB mass spectrum): 911 (8) Color reaction: Positive for potassium permanganate, anisaldehyde-sulfuric acid, and iodine (9) Color of substance: White powder (10) Acid hydrolysis: Acid hydrolysis By leucine,
Give glycine. (11) Antibacterial spectrum: Gram-positive bacteria, acid-fast bacteria,
Shows antibacterial activity against negative bacteria and plant pathogenic bacteria. RK-120B (1) Melting point: Turns brown and decomposes at 235-265℃. (2) Elemental analysis: Carbon 50.91%, Hydrogen 6.95%, Nitrogen
16.12%, sulfur 3.39% (3) Specific rotation: [α] ²⁵ _D = -59° (C = 0.03, dimethyl sulfoxide) (4) Ultraviolet absorption spectrum: λ ^{0.1N-HCl-MeOH} _nax 220n
m
(E1% 1cm293) Shoulder (5) Infrared absorption spectrum: (KBr method) 3300,
2900, 2850, 1650, 1520, 1435, 1392, 1370,
1342, 1322, 1285, 1212, 1185, 1168, 1100,
1024, 1004, 958, 903, 846, 825, 765 cm ^-1 (6) Solubility: Insoluble in methanol, ethanol, acetone, ethyl acetate, chloroform, benzene, hexane, ether, slightly soluble in water, butanol, methanol and water Soluble in a mixture of (7) Molecular weight (according to FAB mass spectrum): 923 (8) Color reaction: Potassium permanganate, anisaldehyde-sulfuric acid, positive for iodine (9) Substance color: White powder (10) Acid Hydrolysis: Acid hydrolysis gives valine and glycine. (11) Antibacterial spectrum: Gram-positive bacteria, acid-fast bacteria,
Shows antibacterial activity against negative bacteria and plant pathogenic bacteria. 2. Cultivate antibiotic RK-120A and RK-120B-producing bacteria belonging to the genus Streptomyces, and use the culture to generate a new antibiotic RK-120B.
1. A method for producing a novel antibiotic, which comprises separating and collecting an antibiotic selected from the group consisting of 120A, RK-120B and complexes thereof. 3 The antibiotic RK-120A and RK-120B producing bacteria is Streptomyces sp. RK-120
(Streptomyces sp. RK-120). 4. An agricultural and horticultural fungicide characterized by containing as an active ingredient an antibiotic selected from the group consisting of antibiotics RK-120A, RK-120B, and complexes thereof.