Casein kinase II inhibitors isolated from two Brazilian plants Hymenaea parvifolia and Wulffia baccata.

Two dihydroflavonol rhamnosides (1 and 2) isolated from the bark of Hymenaea parvifolia and two pentacyclic triterpenoids (3 and 6) obtained from the leaves of Wulffia baccata have been found to exhibit inhibitory effects of casein kinase II (CK-II) dose-dependently, suggesting that at higher doses more than 10 microM, these four compounds may act as potent CK-II suppressors of the CK-II-mediated activation of 60S acidic ribosomal P proteins in vitro.