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The aim of the present study was to identify potentially useful natural compounds for the development of novel therapeutic agents to inhibit metastasis. A phytochemical investigation of Pachysandra terminalis resulted in the isolation of seven new pregnane alkaloids, terminamines A-G (1-7), and seven known alkaloids (8-14). The structures of 1-7 were elucidated by 1D- and 2D-NMR spectroscopic and mass spectrometric methods. Compounds 1-5 and 8-14 inhibited the migration of MB-MDA-231 breast cancer cells induced by the chemokine epithelial growth factor. In addition, compound 1 inhibited phosphorylation of integrin β(1), which plays an important role in MB-MDA-231 cell adhesion and metastasis.

The inhibitory effects of procyanidine, one of the components from the bark of Pinus massoniana Lamb, on the P-glycoprotein (P-gp) function of the blood-brain barrier (BBB) were studied using in vitro rat brain microvessel endothelial cells (RBMECs) and nude mice transplanted with human cerebroma. Quantitative accumulation and efflux of rhodamine 123 (Rh123), a P-gp substrate, were determined using a fluorescence spectrophotometer as a measure of P-gp function. Procyanidine markedly increased the accumulation of Rh123 by inhibiting its efflux in a dose-dependent manner. A 5-fold increase in cellular Rh123 was observed for procyanidine at 10 micromol/L. The verapamil-stimulated ATPase activity in plasma membrane vesicles from the RBMECs was estimated by measuring inorganic phosphate liberation. Procyanidine significantly inhibited the verapamil-induced P-gp ATPase activity by 78% when pretreated with 10 micromol/L in a concentration-dependent manner. The inhibition of P-gp by procyanidine was suggested to be at least partly due to its inhibition of P-gp ATPase. Procyanidine markedly improved the therapeutic effects of adriamycin (ADM) on nude mice transplanted with human cerebroma, compared with solitary treatment of ADM. The combination of 80 mg/kg procyanidine with 2 mg/kg ADM significantly elevated the days of survival with an increase in life span of 76%. The findings suggested that procyanidine was a potent inhibitor of P-gp on BBB and could improve the therapeutic effects on cerebral tumors of some drugs which are difficult to accumulate in the brain.

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A chemical investigation of marine sponge Jaspis stellifera, collected from the South China Sea, led to the isolation of four new isomalabaricane-type triterpenoids, jaspiferins C-F (1-4). The structures of those compounds were elucidated by extensive spectroscopic methods. Jaspiferin C (1), which has the six-membered carbon ring at the side chain, was discovered for the first time from the isomalabaricane-type triterpenoids. The hypothesis of a biogenetic pathway to generate jaspiferin C (1) was depicted.