The Secondary Metabolites And Their Antimicrobial Activity From Endophytic Nigrospora Sp. LM003of Moringa Oleifera Lam

In this paper, the medicinal plant Moringa oleifera Lam was selectedas research source. A fungal strain LM003with higher antifungalactivities and wider antifungal spectrum was isolated from the medicinalplant. The strain LM003was identified as Nigrospora sp. by fungalmorphology and molecular biology methods. The strain Nigrospora sp.LM003was selected for further study because of its higher and broaderspectrum of antifungal activities. In order get more metabolite, the culturecondition of the strain LM003was optimized. Bioactive-guided isolationand purification of the metabolites of the strain LM003obtained6compounds.4compounds were determined to be griseofulvin （1）,dechlorogriseofulvin （2）,8-dihydroramulosin （3） and mellein （4） on thebasis of spectroscopic analyses. Compound2,3and4were isolated fromNigrospora sp. for the first time.The antimicrobial activities antagonized8plant pathogenic fungi and2plant pathogenic bacteria of the four compounds were analysed invitro. The results showed that griseofulvin displayed clear inhibition ofthe growth of8plant pathogenic fungi, in particular inhibited Botrytiscinerea, the50%inhibition concentration (IC₅₀) was0.20μg/ml.Dechlorogriseofulvin and mellein exhibited moderate antifungal activities,whereas8-dihydroramulosin displayed no antifungal activities.Our study therefore underscores that the probability of screening thebiological activity endophytic fungi from the medicinal plant is higherand their secondary metabolites with diverse biological activities.Endophytic fungi of the medicinal plant are promising sources of newdrug.