Phenylacetic Acid → 6-Aminopenicillanic acid

Participants

Reaction Conditions

Reaction Steps

An amount of penicillin acylase enzyme, either free or immobilized on the carrier, sufficient to contain about 50 I.U. of activity, was suspended in 60 ml of 7.5-pH phosphate buffer. The mixture was maintained at 28° C. in a vessel connected to a pH controller which electrometrically determined the pH and metered in sufficient 0.8 N sodium hydroxide solution to maintain the pH at approximately 8.0. A solution containing 5 g of penicillin G potassium salt in phosphate buffer, also at 28° C., was added to the vessel, and the rate of formation of phenylacetic acid by the enzyme-catalyzed hydrolysis of the penicillin G was determined from the rate of addition of sodium hydroxide solution to maintain the pH. The liquid in the vessel was sampled upon addition of the penicillin G salt and after 10 and 30 minutes. These samples (0.5 ml) were immediately mixed with 3 ml of a solution of 1 ml of 0.05 M sodium hydroxide, 2 ml of 20% acetic acid and 0.5% (weight-volume) p-dimethylaminobenzaldehyde/methanol, and were allowed to stand for 10 minutes. The amount of 6-aminopenicillanic acid formed was determined by spectrophotometrically measuring the light absorption of the mixture at a wave length of 415 nm.

Provenance & Evidence