A New Guaiane Sesquiterpene from the Cultured Lichen Mycobiont of Diorygma sp.

Abstract

The cultured mycobiont of the Vietnamese crustose lichen Diorygma sp. was subjected to chemical investigation, which led to the isolation and characterization of a new guaiane sesquiterpene, diorygmone F (1), along with three known compounds, pruinosone, β-sitosterol, and methyl 4-hydroxybenzoate. Structural elucidation was achieved through extensive spectroscopic methods, including NMR, HR-ESI-MS, and ECD. Compound 1 displayed modest inhibitory activity against α-glucosidase, with an IC₅₀ value of 131 ± 1.4 μM, and showed no cytotoxicity against the HepG2 cancer cell line.