Publications by authors named "Alain Wembe Ngouonpe"
Two new seco-lanostane-type triterpenes, named mayomlactones A (1) and B (2) were isolated from the fruits of Leplaea mayombensis together with 10 known compounds (3-12). Structures of the new compounds were elucidated by extensive spectroscopic studies. Except compounds 11 and 12, all the other chemical compounds are newly reported from Leplaea genus.
View Article and Find Full Text PDFThe stem bark of Polyalthia oliveri was screened for its chemical constituents using liquid chromatography high resolution mass spectrometry resulting in the isolation of three indolosesquiterpene alkaloids named 8α-polyveolinone (1), N-acetyl-8α-polyveolinone (2) and N-acetyl-polyveoline (3), together with three known compounds, dehydro-O-methylisopiline (4), N-methylurabaine (5) and polycarpol (6). The structures of the compounds were elucidated by means of high resolution mass spectrometry and different NMR techniques and chemical transformations. Their absolute configurations were assigned by ab-initio calculation of CD and ORD data (for 2 and 3) and X-ray diffraction analysis (for 2).
View Article and Find Full Text PDFArticle Synopsis
- A new iridoid compound named 6-oxo-genipin was isolated from Canthium multiflorum alongside twelve previously known compounds, with most being reported from this plant for the first time.
- The structures of these compounds were determined using advanced NMR techniques and mass measurements, drawing comparisons to known substances.
- The isolated compounds exhibited antimicrobial activities, particularly 6-oxo-genipin, which was highly effective against both Gram-positive and Gram-negative bacteria, while some compounds also showed antiplasmodial effects against malaria-causing Plasmodium falciparum.