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

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.