Bioactive constituents of Chinese natural medicines. I. New sesquiterpene ketones with vasorelaxant effect from Chinese moxa, the processed leaves of Artemisia argyi Levl. et Vant.: moxartenone and moxartenolide

Two new sesquiterpene ketones, moxartenone and moxartenolide, and three octadecadienoic acids were isolated from Chinese moxa, the processed leaves of Artemisia argyi LEVL. et VANT., together with two Sesquiterpenes, five Triterpenes, two phenyl propanoids and three polyoxyflavones. The chemical structures of new Sesquiterpenes, moxartenone, moxartenolide, and octadecadienoic acids were determined on the basis of chemical and physiochemical evidence. Moxartenolide was found to inhibit the contractions induced by a high concentration of K+, by norepinephrine, and by serotonin in isolated aortic strips of rat, while moxartenone showed little activity.