Seco- and isopimarane diterpenoids from Kaempferia marginata rhizomes and their NO inhibition activities.

Three undescribed 9,10-seco-isopimarane diterpenoids, marginols I-K, and an unprecedent isopimara-8(9),15-diene diterpene, 14-epi-boesenberol F, together with a known 9,10-seco-isopimarane diterpenoid, kaemgalangol A, were isolated from the rhizomes of Vietnamese Kaempferia marginata. Marginols I and J contained a naturally very rare 6-oxabicyclo[3.2.