SYNTHESES AND PHARMACOLOGICAL ACTIVITIES OF THE DERIVATIVES OF FURANOSESQUITERPENES FROM LIGULARIA-VIRGAUREA

Four benzofuranosesquiterpenes, 1-hydroxy-2-(3'-pentenyl)-3,7-dimethyl benzofuran (1), 1-hydroxy-2-(3'-pentenyl)-3,7-dimethylbenzofuran (2), cacalol (13), and 1,2-dehydrocacalohastin (14) were isolated from the rhizomes of Ligularia virgaurea (Compositae). A lipophilic group and a n aqueousfavoring group were introduced to the compounds 1 and 13 to a fford twelve new derivatives. Their structures were elucidated by spec troscopic methods. The results of the pharmacological test indicated t hat some of them can block Ca++ influx by occupying binding sites of d ihydropyridine.