A pair of sulfonated diarylheptanoid epimers from Kaempferia galanga

AimTo discover new bioactive constituents from Kaempferia galanga L. (Zingiberaceae).MethodsThe extract of K. galanga was divided into the chloroform and water-soluble portions. The latter fraction was successively subjected to column chromatography over a D101 macroporous adsorption resin, MCI, Sephadex LH-20, and preparative HPLC to obtain two compounds.ResultsTwo novel sulfonated diarylheptanoid epimers, namely kaempsulfonic acids A (1) and B (2), were isolated from the rhizomes of K. galanga. Their structures were established by analysis of spectroscopic data. The absolute configurations of 1 and 2 were determined by the comparison of experimental electronic circular dichroism (ECD) spectroscopy and the computational calculation method, combined with Mo2(OAc)4 induced circular dichroism (ICD).ConclusionThe isolates 1 and 2 are new compounds and their absolute configurations were determined for the first time.