Thiol-catalysed hydrolysis of benzylpenicillin

Show simple item record Llinás, Antonio Donoso Pardo, Josefa Laurentina Vilanova Canet, Bartolomé Frau Munar, Juan Muñoz Izquierdo, Francisco Page, Michael I. 2018-11-20T08:26:47Z
dc.description.abstract [eng] Thiolysis of benzylpenicillin has been investigated by HPLC and 1H-NMR techniques. Thiols catalyse the hydrolysis of benzylpenicillin through the formation of a thioester intermediate. The catalytically reactive form of the thiol has been demonstrated to be the thiolate anion. Variation of reactivity with changing basicity of the thiolate anion generates a Brønsted βnuc value of 0.96, indicating that the breakdown of the tetrahedral intermediate is the rate-limiting step, as occurs in aminolysis and alcoholysis. Solvent kinetic isotope effects of 2.2<br>2.4 indicate that the solvent, water, probably acts as a general acid catalyst in the breakdown of the tetrahedral intermediate. PM3 theoretical calculations support the proposal that breakdown of the tetrahedral intermediate is rate-limiting. The experimental activation energies for the thiolysis of benzylpenicillin vary from 6.9 to 10.4 kcal/mol.
dc.format application/pdf
dc.relation.isformatof Versió postprint del document publicat a:
dc.relation.ispartof Journal of the Chemical Society-Perkin Transactions 2, 2000, p. 1521-1525
dc.rights (c) Llinás, Antonio et al., 2000
dc.subject.classification 54 - Química
dc.subject.other 54 - Chemistry. Crystallography. Mineralogy
dc.title Thiol-catalysed hydrolysis of benzylpenicillin
dc.type info:eu-repo/semantics/article
dc.type info:eu-repo/semantics/acceptedVersion 2018-11-20T08:26:47Z info:eu-repo/date/embargoEnd/2075-01-01
dc.embargo 2075-01-01
dc.rights.accessRights info:eu-repo/semantics/embargoedAccess

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