Isolation and identification of an endophytic fungus of Polygonatum cyrtonema and its antifungal metabolites

Abstract:

Abstract: [Objective] Endophytic fungi in medicinal plants produce a variety of bioactivity compounds. In this study, an endophytic fungus zjqy610 with antifungal activity was isolated from Polygonatum cyrtonema in Zhejiang Qingyuan Baishanzu Mountain nature reserve. [Methods] Strain zjqy610 was identified as Penicillium canescens based on the morphology and its rDNA sequence analysis. Three antifungal compounds were isolated from the fermentation broth of zjqy610 through normal-phase silica gel column chromatography and gel (Sephadex LH-20) column chromatography, traced by ultraviolet light or iodine vapor with bioassay-guided fractionation. [Results] These three compounds were elucidated as o-acetylbenzeneamidinocarboxylic acid (zjqy610B-g-3), griseofulvin (zjqy610D-4) and naphtho [1,2-b] furan-3 -carboxylic acid, 4-hydroxy-5-methoxy-2-methyl-(zjqy610F-2) based on mass spectrometry and nuclear magnetic resonance spectroscopy. The antifungal activity assays showed that the three compounds had inhibitory to variety of plant pathogenic fungi. Compound zjqy610D-4 had strong antifungal activity against Botrytis cinerea, Colletotrichum orbiculare, Didymella bryoniae and Sclerotinia sclerotiorum. EC50 was 0.68, 0.38, 0.91 and 0.61 mg/L, respectively. [Conclusion] Zjqy610D-4 is deserved to develop an agricultural antibiotics.