Meroterpenoids and Steroids from the Marine-Derived Fungus Trametes sp. ZYX-Z-16

Marine fungi can metabolize structurally diverse active components, and have become an important source of drug lead molecules. In the present study, the chemical investigation on the EtOAc extract of the fermentation broth of the marine-derived fungus Trametes sp. ZYX-Z-16 led to the isolation of eight meroterpenoids (1–8), including two undescribed ones, together with ten ergostane steroid analogues (9–18). The structures of two new spiromeroterpenoids, asnovolin H (1) and asnovolin I (2), were determined based on 1D, 2D NMR, and HRESIMS spectroscopic data along with ECD spectra calculations. All compounds were tested for antibacterial and α-glucosidase inhibitory activity. Among them, compound 12 showed definite antibacterial activities against Staphylococcus aureus ATCC 6538 (MIC 32 μg/mL) and Bacillus subtilis ATCC 6633 (MIC 16 μg/mL). In addition, compounds 9 and 10 showed superior inhibitory activity, with IC₅₀ values of 104.1 and 111.3 μM, respectively, to the positive control acarbose (304.6 μM).