4-Arylcoumarins from endophytic Streptomyces aureofaciens CMUAc130 and their antifungal activity

Abstract

Streptomyces aureofaciens CMUAc130 was isolated from the root tissue of Zingiber officinale Rosc. (Zingiberaceae). It was an antagonist of Colletotrichum musae and Fusarium oxysporum, the causative agents of anthracnose of banana and wilt of wheat, respectively. The culture filtrate and crude extract from S. aureofaciens CMUAc130 were all inhibitory to tested phytopathogenic fungi. The major active ingredients from the culture filtrate were purified by silica gel column chromatography and identified to be 5,7-dimethoxy-4-p-methoxylphenylcoumarin (compound 1) and 5,7-dimethoxy-4-phenylcoumarin (compound 2) by NMR and mass spectral data, respectively. Bioassay studies showed that compounds 1 and 2 had antifungal activities against tested fungi, and its minimum inhibitory concentrations were found to be 120 mu g/ml and 150 mu g/ml, respectively. This is the first report of compounds I and 2 from microorganisms as active ingredients for the control of phytopathogenic fungi.