Biotransformation of Ursonic Acid by and to Discover Anti-Neuroinflammatory Derivatives.

Biotransformation of ursonic acid () by two fungal strains CGMCC 3.5324 and CGMCC 3.407 yielded thirteen new compounds (, , -, and -), along with five recognized ones. The structural details of new compounds were determined through spectroscopic examination (NMR, IR, and HR-MS) and X-ray crystallography. Various modifications, including hydroxylation, epoxidation, lactonization, oxygen introduction, and transmethylation, were identified on the ursane core. Additionally, the anti-neuroinflammatory efficacy of these derivatives was assessed on BV-2 cells affected by lipopolysaccharides. It was observed that certain methoxylated and epoxylated derivatives (, , and ) showcased enhanced suppressive capabilities, boasting IC values of 8.2, 6.9, and 5.3 μM. Such ursonic acid derivatives might emerge as potential primary molecules in addressing neurodegenerative diseases.