Biopesticide Activities Screening, Structure Identification And Evaluation On Development Prospects Of New Agricultural Antibiotics

In the present paper, guided by the bioassay results, through semi-preparation and fraction bioassay, the active parts were located. Based on HPLC-MS data of crude extracts and Natural Products Dictionary, by means of comparison with published papers, the active compounds were identified rapidly. Twelve kinds of antibiotics with top activities and frequently isolated compounds were characterized and evaluationed.1. Nucleoside antibiotics. Their features were water soluble and abroad activities such as pesticide, herbicide, fungicide, and anti-virus. In the converse phase HPLC system, the retention time was very short. The UV absorption wavelengthes were different from one another. These kinds of compounds were suitable for development of agro-antibiotics, because of the broad spectrum, and strong activities. But, mere are many antibiotics of this kind of compounds marketed in China, such as Ninnanmycin, agro-antibiotic120, and Wuyimycin etc. So the ratios of known compounds were higher relatively.2. Polyene antibiotics. The features of these compounds were strong fungicidal activities. They were classified from triene to heptaene based on the conjugated double bonds in the structure. The similarity were the UV spectrum, three finger shaped peak of absorption. These kinds of compounds were sensitive to sunlight, and decomposed easily, so they were not fit for the development of agro-antibiotics.3. Indole-carbazoles. These kinds of antibiotics, such as staurosporine and rebeccamycin, possess strong fungicidal activities. May be fit for agro-antibiotics, but one of them are developing for anti-tumor drugs. 4. Elaiophylins. The UV absorption spectrum was obvious and recognized easily. The toxicity was acceptable, with strong fungicidal, herbicidal, and pesticidal activities, and maybe worth of developing.5. Cinerubins. The UV absorption spectrum was obvious and recognized easily. The toxicity was too strong, so they should be eliminated as early as possible.6. Actinomycins. The UV absorption spectrum was obvious and recognized easily. Because of high toxicity, these compounds should be eliminated as early as possible.7. Concanamycins. The UV absorption spectrum was obvious and recognized easily. They were very toxic, so should be eliminated as early as possible.8. Oligomycins. The UV absorption spectrum was obvious and recognized easily. These compounds exhibited strong pesticidal and fungicidal activities, but they were very toxic, so should be eliminated as soon as possible.9. Quinomycins. The UV absorption spectrum was obvious and recognized easily. The characters were high molecular weight, strong pesticidal and fungicidal activities, but high toxicity, should be eliminated as soon as possible.10. Piericidins. The UV absorption spectrum was obvious and recognized easily. Because of high toxicity, should be eliminated as soon as possible.11. Antimycins. With strong fungicidal and pesticidal activity, the UV absorption spectra were not apparent.12. Cycloheximides. With strong fungicidal and herbicidal activity, the UV absorption spectra were not apparent. Because of side effect to crops, these compounds should be eliminated as early as possible. During the year of2008to2010, about17113Actinomyces strains were fermented with two medium, some34226crude extracts were bioassayed with different targets. About34novel compouns were obtained, and the ratio was0.2%, and99.8%of them were known compounds.Of all the strains,6346producing compounds with pesticidal activity, and2106strains producing active compounds in both media.The proportion of active compounds with insectcidal, herbicidal, and fungicidal activities were7.2%,3.9%and19.2%respectively, and the total ratio was24.7%. Rapid identificaction were conducted with100top pesticidal activities based on HPLC-MS data of crude extracts and Natural Products Dictionary. The sequences in file were elaiophylins, polyenes, indole-carbazols, oligomycins, dianemycin, toyocamycin and9-methylstreptimidone, on the basis of frequency occurred. For insecticidal activities,128top crude extracts were identified. They were antimycins, oligomycins, borrelidin, actinomycins, indole-carbazols, piericidins, and dianemycin.For herbcidal activities,50top crude extracts were identified. They were toyocamycin, cycloheximide, elaiophylins, geldanamycin and9-methylstreptimidone.For fungicidal activities,100top crude extracts were identified. They were polyenes, elaiophylins,9-methylstreptimidone, oligomycins, indole-carbazols, geldanamycin, dianemycin, antimycins, and piericidins.Another seven antibiotics were identified on the basis of UV spectrum and HPLC-MS data. Five of them were known compounds, strains identification and fermentation features were tested, and pot tests were carried out.One strain HBERC-20821produce a series of novel antibiotics.1. Dianemycin. It was a polyether antibiotic, with strong anti-coccidiosis activities, in our lab, it exhibited strong pesticide and fungicide activities. By tank fermentation and HPLC analysis, the metabolite peak time were84hours, its toxicity was lower relatively, was worth of developing.2.9-methylstreptimidone. It possesses antivirus and fungicide activities. Its toxicities was lower than that of cycloheximide. The producing strain growth quickly and cultivate easily. So there was some possibility to development this antibiotic.3. Borrelidin. It possesses broad biological activities such as antivirus, anti-tumor and fungicide activities. The producing strain growth well, and fit for fermentation, so it is possible to developed to agricultural antibiotic.4. Ikarugamycin.lt possesses pesticide and partly anti-fungus activity, and the acute toxicity by orally were lower relatively, the producing strain growth well, and fit for fermentation. So it was worth of developing.5. Geldanamycin. It exhibited insecticide and fungicide activities. The strain growth well, and productivity was high, and was easy to get purified compound by simple procedures. It was fit for agro-antibiotic development if no consider of medicinal application.6. Strain HBERC-25376.The strain producing three kinds of antibiotics, capsimycin, bundlin A and nodusmicin. It exhibited strong insecticidal activities especially plutella xylostell (Diamond back moth).These antibiotics were stable in acid, alkali, UV light and heat. It was possible to develop them as new agro-antibiotics.7. Strain HBERC-20821.The extract exhibited strong anti-tumor and anti-fungi activities, the active compounds were a series of macro molecular compounds. Their structures were elucidated by means of HR-MS and NMR analysis. They are new32-membered macrolide compounds with strong anti-tumor and anti-fungi activities.These compounds were worth of developing.