Expansinine, a novel indole alkaloid–ergosteroid conjugate from the endophytic fungus Penicillium expansum of Aconitum carmichaelii†

Abstract

The endophytic fungus Penicillium expansum WTJP1 was isolated from Aconitum carmichaelii Debeaux, a famous traditional Chinese medicine known as aconite. Chemical investigation of this aconite-derived fungus led to the isolation of one previously undescribed compound, expansinine (1), which represents the first example of an indole alkaloid–ergosteroid conjugate found in nature. The assignments of the structure of 1 were determined by extensive spectroscopic and spectrometric ECD and DP4+ probability analyses. In addition, compound 1 was evaluated for its cytotoxic activities against five human cancer cell lines.