Medicinal flowers. II. Inhibitors of nitric oxide production and absolute stereostructures of five new germacrane-type sesquiterpenes, kikkanols D, Dmonoacetate, E, F, and F monoacetate from the flowers of Chrysanthemum indicum L.

The methanolic extract and ethyl acetate-soluble portion from the flowers o f Chrysanthemum indicum L., Chrysanthemi Indici Flos, were found to show in hibitory activity against nitric oxide (NO) production in lipopolysaccharid e-activated macrophages. Five new germacrane-type sesquiterpenes, kikkanols D, D monoafetate, E, F,and F monoacetate, were isolated from the ethyl ace tate-soluble portion. Their absolute stereostructures were elucidated on th e basis of chemical and physicochemical evidence, which included applicatio n of the modified Mosher's method. The effects of fifteen principal compone nts from the ethyl acetate-soluble portion of this medicinal flower against NO production were examined and, among them, acetylenic compounds and flav onoids were found to show potent inhibitory activity.