Hydrolysis penicillin

Under approximately neutral conditions, where the degradation rate is independent of pH for a range of pH values characteristic of the individual penicillin, hydrolysis appears to occur through a general base-catalyzed attack of a water molecule (77JPS861) on the /3-lactam carbonyl. 

Pectin, 20 345, 346 Peltier cooling, 22 209, 224 Penicillins, hydrolysis of, catalytic action of cycloheptaamylose on, 23 231 Pentacarbonylmethylmanganese, reaction on alumina, 35 195... 

Interference with cell Lactams Penicillins Hydrolysis... 

In conclusion, estimations of q indicate that there are no diffusional limitations as long as the substrate concentration is high. This is the case under the starting conditions of technical penicillin hydrolysis as long as only the substrate is taken into consideration. At lower substrate concentrations pore diffusion leads to low efficiency. 

M. A. Schwarts, Catalysis of penicillin hydrolysis by catechol and 3,6-bis(dimethylaminomethyl)catechol,... 

Kinetics of penicillin hydrolysis of penicillin G with penicillin acylase has been extensively studied. An example of reactor design and performance evaluation based on such kinetics was presented in section 5.4.4. 

Schneider CH, de Week AL (1970) Evaluation of intrinsic and extrinsic penicilloyl-specific immunogenicity of penicillins. The use of penicillin hydrolysis catalyzed by 3,6-bis-(di-methylaminomethyl)catechol. Immunochemistry 7 157-166 Schneider CH, de Week AL, Stauble E (1971 a) Carboxymethyl cellulose additives in penicillins and the elicitation of anaphylactic. Experientia 27 167-168 Schneider CH, Michl J, de Week AL (1971 b) Zur Antigenitat von Hapten-Polysaccharid-Konjugaten. Eur J Immunol 1 98-106... 

X 10" for benzylpenicillin. The ratio of the third-order rate constant, k K, for the copper(II) ion plus hydroxide ion catalysed hydrolysis of cephaloridine to the second-order rate constant for hydroxide-ion catalysed hydrolysis of the same substrate is 1.6 x 10 M. The corresponding ratio for benzylpenicillin is 1.2 x 10 °M. The transition state for cephaloridine hydrolysis is therefore stabilised by copper(II) ions ca 100-fold less than that for penicillin hydrolysis, but both transition states are greatly stabilised by the metal ion. Again, ad hoc explanations for this difference may be found in the lower basicity of the ring nitrogen in the tetrahedral intermediate formed from cephaloridine and/or a less favourable geometry. 

The compound 3, 6-bis(dimethylaminomethyl) catechol is a powerful catalyst of penicillin hydrolysis. Many of the characteristics of its cata.-lytic activity resemble those observed with a number of hydrolytic enzymes (pH optimum, presence of an intermediate, structural specificity necessary for optimum activity, basicity of the amine, susceptibility of the p-lactam to nucleophilic attack and role of the penicillin side chain in the interaction with the catalyst). The results obtained explain satisfactorily the high resistance level of cephalosporins to penicillinase Sb ... 

If the penicillin hydrolysis is ignored for the moment, the maximum achievable penicillin... 

The rate of penicillin hydrolysis is assumed to be first order in the penicillin concentration ... 

Fig. 10.6. The pH dependence of in benzyl penicillin hydrolysis 1) by native PAase and (2) by IPEC(PMANa/PAase Q-P4VP),

---