Studies on topical antiinflammatory agents. II. Synthesis and vasoconstrictive activity of 21-substituted...

As part of the search for new topical antiinflammatory agents, various 21-substituted corticosteroids having sulfur-containing moieties were prepared and tested for vasoconstrictive activity in humans. A structure-activity relationship study revealed that substitution of the 21-hydroxy group with a lower alkyl-thio group enhanced the activity. The activities of the 21-methylthio (3Ad) and the 21-ethylthio (3Ae) compounds were more potent than that of 9 alpha-fluoro-11 beta,21-dihydroxy-16 beta-methyl-17 alpha-valeroyloxy-1,4- pregnadiene-3,20-dione (betamethasone 17-valerate, BV).