Antitubercular dihydroagarofuranoid sesquiterpenes from the roots of Microtropis fokienensis

Four new dihydroagarofuranoid sesquiterpenes (1-4) and a new hydroxybenzylsalicylaldehyde, forkienin (5), together with nine known compounds have been isolated from the roots of Microtropis fokienensis. The structures of the new compounds were determined through analyses of physical data. Compounds 3, 4, 7, and 8 exhibited potent antitubercular activities (MICs <= 26.0 mu M) against Mycobacterium tuberculosis 90-221387 in vitro.