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

The title compound, CHO, is a penta-cyclic triterpene isolated from the Cameroonian medicinal plant and known as quafrinoic acid. The mol-ecule is composed of five fused six-membered rings, four of which adopt a chair conformation and one a half-chair conformation. Intra-molecular C-H⋯O hydrogen-bond inter-actions exist, which generate 6 and 8 rings. In the crystal, mol-ecules are linked by pairs of O-H⋯O hydrogen bonds, linking (8) rings into chains running parallel to the axis; these chains are further connected into layers parallel to the 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%) inter-actions.