Isolation and characterization of triterpenoids from the stem barks of Pinus massoniana.

Tree barks, residues in forestry and the pulp industry, could be a rich source of novel biologically or pharmaceutically active substances. In the current work, chemical constituents of extracts obtained from stem barks of Pinus massoniana have been analyzed. A novelty is the isolation of a new ursane-type triterpene saponin, which was characterized as ursolic acid 3-O-[β-d-glucopyranosyl (1" ╺ 6')]-β-d-glucopyranoside-28-O-β-d-glucopyranoside (IV). Moreover, three already known triterpenoid compounds ursolic acid (I), oleanolic acid (II) and oleanolic acid 3-O-β-d-glucopyranoside (III) are described. The elucidation of chemical structures of the isolated extractives was carried out mainly by a combination of 1D 1H, 13C and various 2D NMR experiments as well as by IR, UV and MS spectroscopic techniques. It is the first report about four triterpenoids found in bark of P. massoniana. [ABSTRACT FROM AUTHOR]