Synthesis of polyhydroxylated piperidines and evaluation as glycosidase inhibitors

A series of 16 new chiral nonracemic polyhydroxylated piperidines was synthesized utilizing several chiral beta-amino-alcohols. They act as a nitrogen source, chirality inducer and iminium stabilizer, in the desymmetrization of meso-trihydroxylated glutaraldehyde. The biological activity of these compounds towards several glycosidases (alpha-D-glucosidase, alpha-D-mannosidase, alpha-L-fucosidase) has been evaluated.     

Three quinicine derived alkaloids from Guettarda trimera

Three alkaloids, isolated from the trunk bark of Guettarda trimera have been identified as derivatives of quinicine on the basis of mass spectrometry, ¹H and ¹³C NMR data.     

Alcaloïdes minoritaires de Capuronetta elegans (Apocynaceae)

Two monomeric and three dimeric new indole alkaloids derived from cleavamine have been isolated from the leaves and stem barks of Capuronetta elegans. Structural determination was made by physical and chemical correlations with the known major alkaloids of the plants.