2β,24-Dihydroxy­urs-12-en-27-oic acid methanol solvate from the rhizome of Astilbe chinensis

The title compound, a novel triterpenoid, C30H48O4·CH4O, was isolated from the rhizome of Astilbe chinensis (Maxim.) Franch. et Sav. It contains five fused six-membered rings, which adopt half-chair conformations. In the crystal structure, inter­molecular O—H⋯O hydrogen bonds link the mol­ecules, forming an extensive network, which may be effective in the stabilization of the structure.