Chemical constituents from plant endophytic fungus <i>Alternaria alternata</i>

Abstract

Five new natural compounds (<b>1</b>-<b>5</b>) along with four known ones, involving dibenzo-<i>α</i>-pyrone derivatives, a benzo-<i>γ</i>-pyrone derivative and an amide-type compound were obtained from <i>Alternaria alternata</i>, an endophyte isolated from <i>Paeonia lactiflora.</i> The structures of these isolates were elucidated by intensive analysis of spectroscopic data including NMR, HRMS (ESI and EI), UV and IR spectra. Compounds (<b>1</b>-<b>4</b>) were evaluated for their cytotoxicities against five selected human tumourtumour cell lines (A-549, MDA-MB-231, MCF-7, KB and KB-VIN), and compound <b>3</b> exhibited activities against MDA-MB-231and MCF-7 with IC₅₀ values of 20.1 <i>μ</i>M and 32.2 <i>μ</i>M.