Biotransformation of lithocholic acid by Mucor racemosus and the anti-neuroinflammatory activity of products.

The biotransformation of lithocholic acid (LCA) by Mucor racemosus CGMCC 3.20 resulted in the formation of four novel derivatives (compounds 1-4), characterised by 6β and/or 12β hydroxylation and acetylation, in addition to four previously recognised compounds. Comprehensive structural characterisation was achieved through detailed NMR spectroscopy and high-resolution elec-trospray ionisation mass spectrometry (HR-ESI-MS) analyses. M. racemosus exhibited catalytic proficiency in facilitating the structural modification of LCA, enabling the production of both 6β, 12β-hydroxylated and 6β, 12β-acetylated variants, as well as 24-methylated derivatives. Moreover, the majority of these deri-vatives demonstrated enhanced anti-neuroinflammatory activity compared to the parent compound in lipopolysaccharide (LPS)-stimulated BV-2 microglial cells. These findings underscore biotransformation as a potent approach for diversifying the structural landscape of LCA and identifying promising anti-inflammatory candidates.