The levo-enantiomer of an orally bioavailable polyphenolic aldehyde, derived primarily from unrefined cottonseed oil, with potential antineoplastic activity. Mimicking the inhibitory BH3 (Bcl-2 homology 3) domain of endogenous antagonists of Bcl-2, L-gossypol binds to and inhibits various anti-apoptotic Bcl-2 proteins, which may result in the inhibition of tumor cell proliferation and the induction of tumor cell apoptosis. This agent has greater affinity for Bcl-2 proteins than racemic gossypol. Check for active clinical trialsusing this agent.