Beta-Peltoboykinolic acid

Bioorg Med Chem Lett. 2006 Jun 15;16(12):3273-6.

Protein tyrosine phosphatase 1B inhibitory activity of triterpenes isolated from Astilbe koreana.[Pubmed: 16580200]

METHODS AND RESULTS:
Bioassay-guided fractionation of a MeOH extract of the rhizomes of Astilbe koreana (Saxifragaceae), using an in vitro protein tyrosine phosphatase 1B (PTP1B) inhibitory assay, resulted in the isolation of a new triterpene, 3alpha,24-dihydroxyolean-12-en-27-oic acid (4), along with four triterpenes, 3-oxoolean-12-en-27-oic acid (1), 3beta-hydroxyolean-12-en-27-oic acid (Beta-Peltoboykinolic acid; 2), 3beta-hydroxyurs-12-en-27-oic acid (3), and 3beta,6beta-dihydroxyolean-12-en-27-oic acid (astilbic acid; 5). Compounds 1-5 inhibited PTP1B with IC50 values of 6.8+/-0.5, 5.2+/-0.5, 4.9+/-0.4, 11.7+/-0.9, and 12.8+/-1.1 microM, respectively. Our results indicate that 3-hydroxyl group and a carboxyl group in this type of triterpenes may be required for the activity, while addition of one more hydroxyl group at C-6 or C-24 may be responsible for a loss of activity.
CONCLUSIONS:
Thus, compounds 2 and 3 which possess only one hydroxyl group at C-3 and a carboxyl group at C-27 could be potential PTP1B inhibitors.

Pharmaceutical Biology,2008,5 (2):141-3.

Cytotoxic Principles from Chrysosplenium flagelliferum[Reference: WebLink]

METHODS AND RESULTS:
Two cytotoxic principles were isolated from a MeOH extract of Chrysosplenium flagelliferum (Saxifragaceae), and identified as ß-peltoboykinolic acid (Beta-Peltoboykinolic acid,1), cucurbitacin B (2), ß-sitosterol-ß-D-glucopyranoside (3), penduletin (4), pendulin (5) and d-catechin (6). The 13 C-NMR of compounds 4 and 5 are reported here.