Seven derivatives of pentacyclic triterpene acids (1-7) were isolated from the bark of Alnus viridis ssp. viridis using a combination of column chromatography and semipreparative HPLC. Compounds 1-3, 6, and 7 were determined to be new after spectroscopic data interpretation and were assigned as 27-hydroxyalphitolic acid derivatives (1-3), a 27-hydroxybetulinic acid derivative (6), and a 3-epi-maslinic acid derivative (7), respectively. Pentacyclic triterpenoids with a C-27 hydroxymethyl group have been found in species of the genus Alnus for the first time. These compounds were subjected to cytotoxicity testing against a number of cancer cell lines. Also, selected pentacyclic triterpenoids were selected as potential inhibitors of topoisomerases I and IIα for an in silico investigation.
Novakovic, M., Nikodinovic-Runic, J., Veselinovic, J., Ilic-Tomic, T., Vidakovic, V., Tesevic, V., & Milosavljevic, S. (2017). Bioactive Pentacyclic Triterpene Ester Derivatives from Alnus viridis ssp. viridis Bark. Journal of Natural Products, 80(5), 1255–1263. https://doi.org/10.1021/acs.jnatprod.6b00805