Antifungal Activity of Tetra-Substituted Tetrahydrofuran Lignan, (−)-Virgatusin, and Its Structure-Activity Relationship

Abstract

Antifungal activities of the optically pure (>99%ee) (−)- and (+)-virgatusin, a tetra-substituted tetrahydrofuran lignan, were tested. (−)-Virgatusin, which is a natural product, showed highest antifungal activity against Colletotrichum lagenarium. Research on its structure-activity relationship was also performed. It was shown that two methoxy groups on 9 and 9′ positions and a 3,4-methylenedioxyphenyl group on the 7 position of virgatusin were essential for high fungal growth inhibition. The part on 7′-phenyl group was not essential for activity. The 7′-(4-methoxyphenyl) derivative showed higher activity than that of (−)-virgatusin.