海洋放线菌Y12-26中抗真菌活性代谢产物的分离纯化与结构鉴定

Purification and structure elucidation of antifungal bioactive metabolites from marine actinomycete Y12-26

目的研究海洋放线菌Y12-26发酵液中对几种植物病原真菌具有抑制作用的次生代谢活性物质。方法发酵离心上清液用等体积正丁醇萃取,得到发酵液浸膏。浸膏采用正相硅胶柱色谱、制备TLC和半制备HPLC等方法进行分离纯化该菌株活性次级代谢产物,并运用MS、~1H NMR和^(13)C NMR等波谱技术并结合文献比对鉴定所分离的单体化合物。结果从28g正丁醇萃取物中分离纯化并鉴定了3个单体活性化合物,分别为:salicylamide(1)、iturin A-2(2)、daidzein-4',7-di-α-L-rhamnoside(3)。结论海洋放线菌Y12-26能代谢产生具有多种生物活性的化合物。化合物1对Botriytis cinerea和Pyricularia oryzae的最低抑菌浓度(minimal inhibitory concentration,MIC)为125μg/mL,化合物2有强烈的抗真菌活性,其对Rhizoctonia solani的MIC为12.5μg/mL,化合物3对Botriytis cinerea的MIC为125μg/mL。本文首次报道大豆素类化合物3抗植物病原真菌活性。

Objective To study the antifungal constituents of a marine actinomycete Y12-26. Methods The fermentation centrifugal supernatant was extracted with an equal volume of butanol. The extracts was isolated and repeatedly purified by column chromatography on silica gel, preparative TLC arid semi-preparative HPLC. Their structures were elucidated by MS, ^1H-NMR, ^13C-NMR spectral analysis and compared with the data of literature. Results Three compounds were isolated and identified as salicylamide （1）, iturin A-2 （2）, daidzein-4＇,7-di-α-L-rhamnoside （3） from 28g butanol extracts. Conclusion The marine actinomycete Y12-26 can produce the compounds with many biological activities. The MIC of compound 1 against Botrytis cinerea and Pyricularia oryzae is 125μg/mL, compound 2 shows significant antifungal bioactivity against Rhizoctonia solaniis 12.5μg/mL, compound 3 against Botrytis cinereais 125μg/mL. Compound 3 is reported firstly for the inhibitory activities against plant-pathogenic fungus.