Isolation, Structural Modification, and HIV Inhibition of Pentacyclic Lupane-Type Triterpenoids from Cassine xylocarpa and Maytenus cuzcoina

As a part of our investigation into new anti-HIV agents, we report herein the isolation, structure elucidation, and biological activity of six new (1-6) and 20 known (7-26) pentacyclic lupane-type triterpenoids from the stem of Cassine xylocarpa and root bark of Maytenus cuzcoina. Their stereostructures were elucidated on the basis of spectroscopic and spectrometric methods, including 1D and 2D NMR techniques. To gain a more complete...