Crystal structure of betulinic acid methanol monosolvate

The title compound [systematic name: 3β-hy­droxy­lup-20(29)-en-28-oic acid methanol monosolvate], C₃₀H₄₈O₃·CH₃OH, is a solvent pseudopolymorph of a naturally occurring plant-derived lupane-type penta­cyclic triterpenoid, which was isolated from the traditional Chinese medicinal plant Syzygium jambos (L.) Alston. The dihedral angle between the planes of the carb­oxy­lic acid group and the olefinic group is 12.17 (18)°. The A/B, B/C, C/D and D/E ring junctions are all trans-fused. In the crystal, O—H...O hydrogen bonds involving the hy­droxy and carb­oxy­lic acid groups and the methanol solvent mol­ecule give rise to a two-dimensional network structure lying parallel to (001).