Model catalysts which simulate penicillinase III. Structure-reactivity relationship in catalysis of penicillin hydrolysis by morpholinomethyl derivatives of catechol and pyrogallol

✍ Scribed by Renaat D. Kinget; Michael A. Schwartz

• Publisher: John Wiley and Sons
• Year: 1968
• Tongue: English
• Weight: 526 KB
• Volume: 57
• Category: Article
• ISSN: 0022-3549
• DOI: 10.1002/jps.2600571119

✦ Synopsis

Studies of catalysis of hydrolysis of benzylpenicillin by aminoalkylcatechols have been extended to a series of morpholinomethyl derivatives of catechol and pyrogallol. Catalytic rate constants for each of the active s ecies are related to their basicity and presence or absence of electrophilic groups a n l a positively charged amine in proper position to assist nucleophilic attack by a phenolate ion. Ionization constants for these compounds determined spectrally were the same as those determined potentiometrically indicating that the catalytic species are hybrids between charged amine and phenolate ion. The structures of these species are correlated with their efficiency as catalysts on the basis of a mechanism involving participation by up to four functional groups on the catalyst.