Stabilization of ampicillin analogs in aqueous solution. IV. Effect of addition of furfural on the degradation of ampicillin in the presence of various carbohydrates in aqueous solution.

Abstract

It is well known that the degradation of ampicillin is accelerated by various kinds of carbohydrates in neutral and alkaline aqueous solutions. Thus, the kinetics of ampicillin degradation in the presence of carbohydrate and furfural were investigated to determine how the rate-accelerating effect of carbohydrate is inhibited by furfural. The rate accelerating effect of carbohydrates increased with increasing molecular weight of the carbohydrates. However, the accelerating effects of sucrose, glucose, maltose and dextran 40 were all inhibited by the addition of furfural at pH 7-9. This inhibition is due to the resistance of the Schiff base, which is formed between ampicillin and furfural, to the action of carbohydrate, presumably because of steric hindrance.