Antispasmodic activity of beta-damascenone and E-phytol isolated from Ipomoea pes-caprae.

The crude extract (IPA) of the plant Ipomoea pes-caprae (L.) R. Br. has previously been shown to antagonize smooth muscle contractions induced by several agonists via a non-specific mechanism. Bioassay-guided fractionation of IPA resulted in isolation of the antispasmodically acting isoprenoids beta-damascenone and E-phytol. Their antispasmodic potencies were found to be in the same range as that of papaverine, a general spasmolytic agent. This effect was suggested to play a role in the previously observed anti-inflammatory activity of IPA by interfering with the contraction of endothelial cells. Severe vascular contraction has been shown to be involved in the dermatitis caused by toxic jellyfishes. It is possible that beta-damascenone and E-phytol, by interfering with the contraction of vascular smooth muscle cells, are partly responsible for the previously reported effectiveness of IPA in the treatment of such dermatitis.