Rare β-Resorcylic Acid Derivatives from a Halophyte-Associated Fungus Colletotrichum gloeosporioides JS0419 and Their Antifungal Activities.

Six new β-resorcylic acid derivatives ( 1 - 5 and 7 ) were isolated from a halophyte-associated fungus, Colletotrichum gloeosporioides JS0419, together with four previously reported β-resorcylic acid lactones (RALs). The relative and absolute stereochemistry of 1 was completely established by a combination of spectroscopic data and chemical reactions. The structures of the isolated compounds were elucidated by analysis of HRMS and NMR data. Notably, compounds 1 - 3 had a β-resorcylic acid harboring a long unesterified aliphatic side chain, whereas the long aliphatic chains were esterified to form macrolactones in 4 - 9 . Among the isolated compounds, monocillin I and radicicol showed potent antifungal activities against Cryptococcus neoformans , comparable to clinically available antifungal agents and radicicol showed weak antifungal activity against Candida albicans . These findings provide insight into the chemical diversity of fungal RAL-type compounds and their pharmacological potential.