Study On Identification And Secondary Metabolites Of Two Endophytic Fungi From Dongxiang Wild Rice

Dongxiang wild rice(Oryza rufipogon Griff.)is the northernmost wild rice in the world.As an important resources,it has excellent properties with cold-resistant,insect-resistance as well as disease-resistant.Endophytic fungi refers to a class of fungi that live in healthy plants in part or all of life history of the host plants without causing symptoms.Due to the rich diversity of endophytic fungi,it is an important source of biologically active and novel lead compounds.The diversity of endophytic fungi in Dongxiang wild rice was studied by our laboratory,and a large number of endophytic fungi strains were isolated.In this study,two strains of endophytic fungi L99 and R57 were selected to study on identification and secondary metabolites of them which aimed to look for antibacterial or anticancer active lead compounds.The endophytic fungi L99 and R57 were identified by traditional morphology and molecular biology.The phylogenetic trees based on ITS rDNA showed that strain L99 and R57 were respectively clustered with Sarocladium oryzae and Eupenicillium javanicum.In combination with the morphological characteristics of strains L99 and R57 on different media,strain L99 was identified as Sarocladium oryzae L99 and strain R57 was identified as Eupenicillium javanicum R57.In this paper,5 secondary metabolites,Di-2-ethylhexyl phthalate(1),Dibutyl phthalate(2),Helvolic acid(3),6?,16?-Diacetoxy-25-hydroxy-3,7-dioxo-29-nordammara-1,17(20)-dien-21,24-lactone(4)and a new compound,16?-Acetoxy-25-hydroxy-3,7-dioxo-29-nordammara-1,17(20)-dien-21,24-lactone(5),were isolated from strain L99,and 4 secondary metabolites,Di-2-ethylhexyl phthalate(1),1-Nonadecene(6),Anhydromevalonolactone(7)and Lignoceric acid methyl ester(8),were isolated from strain R57 by column chromatography(CC)on silica gel and Sephadex LH-20,as well as by HPLC.All compounds 1-8 were screened for their antibacterial activities.