Kaemgalangol A: Unusual seco-isopimarane diterpenoid from aromatic ginger ce:italic>Kaempferia galanga/ce:italic>

摘要

A new unusual seco-isopimarane, kaemgalangol A (1) and 12 usual analogs (2?13) were isolated from the rhizomes ofKaempferia galanga(Family: Zingiberaceae). KaemgalangolA (1) represented a rarely isolated 9,10-seco-isopimarane skeleton. The chemical structures of the isolated compounds were mainlyinvestigated by spectroscopic techniques such as 1D, 2D NMR, and HRMS. The absolute configuration of1–3was studied by X-ray diffraction analysis as well as experimental and TDDFT-calculated electronic circular dichroism. Among the isolated diterpenoids,5,6and9exhibited cytotoxic activity against HeLa (IC5075.1, 74.2 and 76.5?μM, respectively) and HSC-2 (IC5069.9, 53.3 and 58.2?μM, respectively) cancer cells.