Tumor inhibitors XL. The isolation and structural elucidation of elephantin and elephantopin, two novel sesquiterpenoid tumor inhibitors from Elephantopus elatus.

Kupchan SM, Aynehchi Y, Cassady JM, Schnoes HK, Burlingame AL. Tumor inhibitors XL. The isolation and structural elucidation of elephantin and elephantopin, two novel sesquiterpenoid tumor inhibitors from Elephantopus elatus. J Org Chem. 1969 Dec; 34(12):3867-75.