Pseudo-first-order rate constants were observed for the reaction of corticosteroid or corticosteroid esters with blue tetrazolium. The data indicate that the reactivity of corticosteroids in, in part, a function of their geometry in that corticosteroid reactivity toward blue tetrazolium increases with increasing planarity of the steroid molecule and that corticosteroid esters must be hydrolyzed as a necessary prerequisite to reaction with blue tetrazolium. Evidence is presented indicating that free radicals are not involved in the blue tetrazolium reaction with corticosteroids. Certain pharmaceutically important compounds such as pyrocatechol derivatives and hydroquinone appear to reduce blue tetrazolium by the anion free radical mechanism proposed previously. A spectrophotometric method for determining the number of reduction units transferred to blue tetrazolium per molecule is described.
Keyphrases 0 Blue tetrazolium-reduction by corticosteroids, pseudo-fist-order rate constants, mechanism discussed 0 Corticosteroids-reduction of blue tetrazolium, pseudo-first-order rate constants, mechanism discussed Steroids-reaction of corticosteroid and corticosteroid esters with blue tetrazolium, mechanism Cary model 15. Cahn model G-2. Digital Equipment Corp. PDP/& and IBM 360 model 25. Varian model 4502-13. Eastman 6060 silica gel with fluorescent indicator. Eastman Organic Chemicals. Dajac Laboratories.