[Kinetics of hydrolysis of acylderivatives of stobadine, prodrug forms of free oxygen radical scavengers. Part 2: alkaline hydrolysis].

: Stobadin, (-)-cis-2,8-dimethyl-2,3,4,4a,5,9b-hexahydro-1H-pyridol[4,3b]- indol is a compound with a potential antiarrhythmic, antihistamine, anaesthetic, antiulcerous, and marked antioxidative effect. N5-acylsubstitution of stobadin yielded derivatives, which represent prodrug forms of the active principle--stobadin, and it is assumed that they will be hydrolysed in the organism and the active principle will be released in higher concentrations in various biological tissues. The present paper deals with the investigation of the kinetics of hydrolysis of 13 stobadin acylderivatives in a medium of 0.1 mol/l of sodium hydroxide at 70 degrees C, employing spectrophotometry in the UV region of the spectrum. The determined rate constants were correlated with the length of the side acyl chain and the pKa values of the compounds under study.