Bioactive constituents of Leptadenia arborea

The aerial part of Leptadenia arborea has been shown to contain pinoresinol (1), syringaresinol (2), leucanthemitol (3) and E-ferulaldehyde (4). These known compounds are being reported for the first time from this plant. Among them, syringaresinol has shown an inhibitory effect against acetylcholinesterase. The IC(50) (the concentration of 50% enzyme inhibition) value of this compound was 200 microg/ml.

New steroids from Solenostemma argel leaves

Two new pregnane ester glycosides, named stemmoside A (1) and stemmoside B (2) and a third new polyhydroxy pregnane, named stemmin C (3), were isolated from Solenostemma argel leaves. The structures were achieved by extensive one- and two-dimensional NMR and MS spectroscopic analysis.

A new trinortriterpenoid from Cleome chrysantha

A new trinortriterpenoid, 1-epibrachyacarpone, was isolated from aerial parts of Cleome chrysantha. Its structure was elucidated as 1 by NMR investigations and X-ray crystallographic studies.