A pair of novel bisindole alkaloid enantiomers from marine fungus <i>Fusarium</i> sp. XBB-9

Abstract

A preliminary research on the marine fungus <i>Fusarium</i> sp. XBB-9 resulted in a pair of novel bisindole alkaloid enantiomers, (+)- and (-)-fusaspoid A (<b>1a</b>/<b>1b</b>) and 12 diverse compounds. One strain many compound (OSMAC) method was used to enhance as many biosynthetic pathways as possible. The structures of the compounds were elucidated by spectroscopic analysis, and the absolute configuration of <b>1a</b> was determined by X-ray single-crystal diffraction analysis. Compounds <b>1a</b> and <b>1b</b> were tested for cytotoxic activity against HCT-15, RKO cell lines, but were inactive. Compounds <b>1a</b> and <b>1b</b> were the first example of bisindole alkaloids isolated from fungus <i>Fusarium</i> sp. XBB-9.