Diterpenoids from the rhizomes of Alpinia calcarata
Kong, L.Y.; Qin, M.J.; Niwa, M.
Journal of Natural Products 63(7): 939-942
ISSN/ISBN: 0163-3864 PMID: 10924169 DOI: 10.1021/np9904962
Four new labdane-type diterpenoids, calcaratarins A-D (1-4), along with six known labdane-type diterpenoids, a known elemane-type sesquiterpenoid, and a known coumarin, were isolated from the rhizomes of Alpinia calcarata. The structures of 1-4 were elucidated on the basis of spectroscopic studies.