Conformational Changes in the β-Glycyrrhetinic Acid Skeleton. Microenvironmental Effects of Solvent Polarity and Amphiphilic Effects of the Polyethylene Glycol Side Chain.

Abstract

The circular dichroism (CD) of the inflammatory drug β-glycyrrhetinic acid (β-GA) with tripenoidal skelton showed considerable variation in the CD amplitude with change in solvent polarity, due primarily to the high conformational flexibility of the enone portion of the β-GA skeleton. No such variation was observed for α-GA. β-GA with a polyethylene side chain exhibited enhanced selectivity toward Li⁺ over Na⁺ or K⁺.