A pair of sulfonated diarylheptanoid epimers from Kaempferia galanga

AIM:To discover new bioactive constituents from Kaempferia galanga L.(Zingiberaceae).METHODS:The 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.RESULTS:Two 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).CONCLUSION:The isolates 1 and 2 are new compounds and their absolute configurations were determined for the first time.