Sg17-1-4, a novel isocoumarin from a marine fungus Alternaria tenuis Sg17-1

One novel isocoumarin, named Sg17-1-4, along with two known isocoumarins AI-77-B and AI-77-F were obtained from a marine fungus Alternaria tenuis Sg17-1. Their structures were elucidated based on detailed NMR analysis. The cytotoxicities of these compounds were evaluated in vitro.