Cyclohexenone Derivative and Drimane Sesquiterpenes from the Seagrass-Derived Fungus Aspergillus insuetus

One new cyclohexenone derivative (1), and two undescribed drimane sesquiterpenes (2 and 3), together with another seven known drimane sesquiterpenes were isolated from a seagrass-derived fungus Aspergillus insuetus SYSU6925. Structures of these metabolites were elucidated by comprehensive spectroscopic analysis, including NMR analysis, mass spectrometry, and ECD calculations. Compounds 1-3, 5 and 7 displayed weak to moderate antifungal activities towards four phytopathogenic fungi, with Minimum inhibition concentration (MIC) values range from 50 to 200 mu g/mL. Compound 1, a rare cyclohexenone derivative with n-propyl group exhibited more potent inhibitory activities (MIC, 50 mu g/mL) against F. oxysporum than positive control (Triadimefon). Compounds 2 and 3 also exhibit potent anti-inflammatory activities by inhibiting the production of nitric oxide (NO) in RAW264.7 cells with IC50 values of 21.5 +/- 1.1 and 32.6 +/- 1.16 mu M, respectively.

Automated summary

One new cyclohexenone derivative (1) and two undescribed drimane sesquiterpenes (2 and 3), along with seven known drimane sesquiterpenes, were isolated from a seagrass-derived fungus Aspergillus insuetus SYSU6925. The structures of these metabolites were determined through comprehensive spectroscopic analysis. Compounds 1-3, 5, and 7 exhibited weak to moderate antifungal activities against four phytopathogenic fungi, with MIC values ranging from 50 to 200 mu g/mL. Compound 1, a rare cyclohexenone derivative with an n-propyl group, showed more potent inhibitory activities (MIC, 50 mu g/mL) against F. oxysporum compared to the positive control (Triadimefon). Compounds 2 and 3 also demonstrated potent anti-inflammatory activities by inhibiting nitric oxide (NO) production in RAW264.7 cells with IC50 values of 21.5 +/- 1.1 and 32.6 +/- 1.16 mu M, respectively.