Two new tricycloalternarene acids from the marine-derived fungus Alternaria alternata ICD5-11

Abstract Two new meroterpenoids, named tricycloalternarenes K ( 1 ) and L ( 2 ), together with one known analog ( 3 ) were isolated from the marine-derived fungus Alternaria alternata ICD5-11, which was obtained from marine isopod Ligia exotica . Their structures and relative/absolute configurations were elucidated by extensive spectroscopic methods, including 1D/2D NMR, CD, and mass spectra and by comparison with literature data. The antimicrobial activities of two new compounds were also tested.