Two new triterpenoids from the resin of Boswellia carterii

Two new triterpenoids, 3-oxotirucalla-7,9(11),24-trien-21-oic acid (1) and 18H,3,20-ursanediol (2), along with 15 known triterpenes, -amyrin, -boswellic acid, -boswellic acid, acetyl -boswellic acid, acetyl -boswellic acid, 9,11-dehydro--boswellic acid, 9,11-dehydro--boswellic acid, acetyl 11-methoxy--boswellic acid, 11-keto--boswellic acid, acetyl 11-keto--boswellic acid, acetyl -elemolic acid, 3-hydroxytirucalla-8,24-dien-21-oic acid, elemonic acid, 3-hydroxytirucalla-7,24-dien-21-oic acid, and 3-hydroxytirucall-24-en-21-oic acid, were isolated from the resin of Boswellia carterii Birdw.