Crystal structure and Hirshfeld surface analysis of 3-oxours-12-ene-27a,28-dioic acid (quafrinoic acid)

Abstract

The title compound, C30H44O5, is a pentacyclic triterpene isolated from the Cameroonian medicinal plant Nauclea Pobeguinii and known as quafrinoic acid. The molecule is composed of five fused six-membered rings, four of which adopt a chair conformation and one a half-chair conformation. Intramolecular C—H...O hydrogen-bond interactions exist, which generate S6 and S8 rings. In the crystal, molecules are linked by pairs of O—H...O hydrogen bonds, linking R 2 2(8) rings into chains running parallel to the a axis; these chains are further connected into layers parallel to the ab plane by C—H...O hydrogen bonds. The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H...H (79.4%) and O...H (20.4%) interactions.