Isolation and Structure Elucidation of Secondary Metabolites From an Endophytic Fungus Annulohypoxylon ilanense

Abstract

Fractionation of the EtOAc-soluble fraction of the liquid fermentation of an endophytic fungus Annulohypoxylon ilanense associated with the wood of medicinal plant Cinnamomum species resulted in the isolation of 1 new α-pyrone, ilanpyrone (1), along with 3 previously identified compounds, 2 to 4. Their structures were elucidated by means of spectroscopic and mass-spectrometric analyses, especially 1D and 2D nuclear magnetic resonance (NMR) spectroscopy as well as high-resolution electrospray ionization mass spectrometry. The isolated compounds were tested for their cytotoxicity against MCF-7, NCI-H460, and SF-268 cell lines using the MTT assay. Among them, compounds 1 and 4 were found to have moderate-to-weak cytotoxic effects against these 3 cell lines in vitro.