Chaetosemins A–E, new chromones isolated from an Ascomycete Chaetomium seminudum and their biological activities

Abstract

Fifteen polyketide chromones, including four new ones, chaetosemins B–E (<bold>2–5</bold>), with <bold>4</bold> bearing a new skeleton, and two new natural products, chaetosemin A (<bold>1</bold>) and (+)-(<italic>S</italic>)-chaetoquadrin J (<bold>14</bold>), were isolated from cultures of <italic>Chaetomium seminudum</italic>.