Two new alkaloids from the endophytic fungus Schizophyllum sp. HM230 isolated from Vincetoxicum mongolicum Maxim

Abstract

Endophytic fungi is an important source for the discovery of bioactive natural compounds. A chemical investigation of the ethyl acetate extract of the endophytic fungus Schizophyllum sp. HM230 derived from stems of the herb Vincetoxicum mongolicum Maxim led to isolation of five alkaloids, including two new compounds, schizophyllins M (1) and N (2), along with three known ones (3–5). The planar structures of two new compounds were elucidated by extensive spectroscopic methods including MS, 1D and 2D NMR. Their absolute configurations were determined by Mosher’s method and comparison of the ECD data. All the isolates were evaluated for their cytotoxicity and antioxidant activities. Compounds 1–4 showed middle cytotoxicity against MCF-7 cells with IC50 values range of 68.1 ∼ 87.32 μM. Compounds 1–5 displayed obvious antioxidant activity with the IC50 values range of 0.86 ∼ 5.78 mg/mL.