Isoflavonoid glycosides from the roots of Baphia bancoensis.

Chemical investigation of the methanol extract of the roots of Baphia bancoensis led to the isolation and characterization of three new isoflavonoid glycosides (1-3). Their structures were determined on the basis of spectroscopic studies andchemical evidence. Antibacterial activity of isolated compounds was evaluated against Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, and Pseudomonas aeruginosa.

Five labdane diterpenoids from the seeds of Aframomum zambesiacum.

Five labdane diterpenoids, (3-5), zambesiacolactone A (7) and zambesiacolactone B (8), were isolated from the seeds of Aframomum zambesiacum (Baker) K. Schum., along with five known labdanes and a linear sesquiterpene, nerolidol.

Four new dammarane saponins from Zizyphus lotus.

Five dammarane-type saponins were isolated by means of centrifugal partition chromatography from the leaves of Zizyphus lotus. Their structures were elucidated using a combination of 1D and 2D 1H and 13C NMR spectra and mass spectroscopy. One of these glycosides is the known jujuboside B (5).

Antiplasmodial activity of alkaloids from various strychnos species.

The in vitro antiplasmodial activities of 69 alkaloids from various Strychnos species were evaluated against chloroquine-resistant and chloroquine-sensitive lines of Plasmodium falciparum. The compounds, comprising mainly indolomonoterpenoid alkaloids, exhibited a wide range of biological potencies in the antiplasmodial assays. The most active alkaloids were also tested for cytotoxicity against HCT-116 colon cancer cells to determine their antiplasmodial selectivity.

Flow Thermolysis Rearrangements in the Indole Alkaloid Series: Strictamine and Akuammicine Derivatives. The Absolute Configurations of Ngouniensine and epi-Ngouniensine.

Flow thermolysis of strictamine (1) generated two of the predictable rearrangement products, resulting from [1,5]-sigmatropic shifts: akuammicine (2) and indolenine 9. Besides formation of these two compounds, a quite different pathway gave rise to a novel rearrangement leading to indole 6, with the framework of the natural alkaloid ngouniensine (19). Rearrangement to the ngouniensine skeleton became the major pathway when the akuammicine derivatives 10, 12, and 17 were submitted to thermolysis, generating compounds 11, 13 + 15, and 18, respectively.