Angiogenesis-Inhibitory Piperidine Alkaloids from the Leaves of Microcos paniculata

Eight new 2,6-disubstituted piperidin-3-ol
alkaloids (1–8), featuring a C10 unsaturated alkyl
side chain, together with three previously reported analogues (9–11) were isolated from the leaves of
medicinal plant Microcos paniculata. Their structures and absolute configurations were elucidated unambiguously
by means of 1D and 2D NMR spectroscopic data analysis, modified Mosher’s
method, Snatzke’s method, and quantum chemical electronic circular
dichroism (ECD) calculations, as well as single-crystal X-ray crystallography.
The isolates were evaluated for their antiangiogenic effects on human
umbilical vein endothelial cells (HUVECs). Compound 2 displayed an inhibitory effect on tube formation of HUVECs in a
concentration-dependent manner.