(3β,18β,20β)-N-Ethoxycarbonylmethyl-3-nitrato-11-oxoolean-12-ene-29-carboxamide methanol monosolvate

Abstract

The title compound, C34H52N2O7·CH4O, is the methanol solvate of a difunctionalized derivative of the therapeutic agent 18β-glycyrrhetinic acid, a pentacyclic triterpene. The five six-membered rings of the glycyrrhetinic acid moiety show normal geometries, with four rings in chair conformations and the unsaturated ring in a half-chair conformation. This moiety is substituted by a nitrate ester group and anO-ethylglycine group. In the crystal, the nonsolvent molecules are packed parallel to (010) in a herringbone fashion with the nitrato, ethylglycine and methanol-O atom being proximate. The methanol solvent molecule is anchoredviaa donated O—H...Oacyland an accepted N—H...O hydrogen bond, giving rise to infinite zigzag chains of hydrogen bonds parallel to [100]. Two weak intermolecular C—H...O interactions to the methanol and to an acyl oxygen establish links along [100] and [010], respectively.