Kaempulchraols A-H, Diterpenoids from the Rhizomes of Kaempferia pulchra Collected in Myanmar

Eight new diterpenoids, kaempulchraols A-H (1-8), along with five known analogues were isolated from the CHCl₃-soluble extract of rhizomes of Kaempferia pulchra of Myanmar. The structures of these compounds were elucidated using extensive spectroscopic techniques including X-ray diffraction analysis. All the isolates were tested for their antiproliferative activity against a panel of five human cancer cell lines (A549, human lung cancer; HeLa, human cervix cancer; PANC-1 and PSN-1, human pancreatic cancer; MDA-MB-231, human breast cancer) and TIG-3, normal human primary fibroblast cells. Kaempulchraol F (6) exhibited weak activity against the human pancreatic PSN-1 cell line with an IC₅₀ value of 12.3 M.