STRUCTURES AND SPASMOLYTIC ACTIVITIES OF DERIVATIVES FROM SESQUITERPENES OF ALPINIA-SPECIOSA AND ALPINIA-JAPONICA

Sesquiterpenes isolated from Alpinia speciosa and Alpinia japonica, an d their derivatives were found to inhibit histamine- or barium chlorid e-induced contraction of excised guinea pig ileum when tested by the M agnus method, Major spasmolytic principles contained in those extracts were the sesquiterpenes, beta-eudesmol, nerolidol, humulene epoxide I I and 4 alpha-hydroxydihydroagarofuran. Relationships between the chem ical structures of the sesquiterpenes and their derivatives, and their spasmolytic activities were discussed.