Parviflorene A, a novel cytotoxic unsymmetrical sesquiterpene–dimer constituent from Curcuma parviflora

A novel natural sesquiterpene–dimer-type compound, named parviflorene A ( 1 ), was isolated from the extract of a tropical Zingiberaceous plant, Curcuma parviflora, collected in Thailand, and its structure was elucidated by spectral data. Parviflorene A ( 1 ) possesses an unprecedented unsymmetrical bis-cadinane skeleton and exhibited cytotoxic activity against murine leukemia P388 and B16 melanoma cells.