Structurally Diverse Secondary Metabolites from a Deep‐sea Derived Cladosporium sp. SCSIO 41318 and Their Biological Evaluation

Abstract Four new compounds, including one drimane sesquiterpene lactone ( 1 ), one isocoumarin ( 2 ), one coumarin ( 3 ), and a new natural product ( 4 ), as well as fourteen known compounds were obtained from a deep‐sea derived Cladosporium sp. SCSIO 41318. The structures of the new compounds were determined using extensive NMR and HRESIMS spectroscopic analysis, electronic circular dichroism calculations, and single‐crystal X‐ray diffraction measurements. Biological assays showed that compounds ( 1 , 6 , 7 , 9 – 12 , 14 , 15 , 17 , 18 ) exhibited varying degrees of antimicrobial activity against the tested human pathogenic bacteria and plant pathogenic fungi. Besides, penicitrinone A ( 11 ) and penicitrinol A ( 12 ) displayed weak antitumor activities against the 22Rv1 cell line.