抄録
Water-soluble prednisolone 21-hemisuccinate (I), prednisolone 21-hemiphthalate (II), and prednisolone 21-hemimaleate (III) were synthesized, and hydrolysis of I, II, III, and prednisolone 21-phosphate (IV) in aqueous solution was kinetically examined. Alkaline hydrolysis of I, II, and III progresses by the apparent first-order reaction, and these reactions were found to be catalyzed by a hydroxyl ion from the examination of pH profile of their decomposition rate constants. Effect of ionic strength and temperature on the hydrolysis rate constant of I, II, and III was examined. Hydrolysis of IV progresses by the apparent first-order reaction and, from the pH profile of its decomposition, IV was found to be more stable in the alkaline than in acid region. Further examinations were made on the effect of ionic strength, temperature, and buffer concentration on the hydrolysis rate constant of IV.
