Mn(III) oxidation of peptide polymers of elastin sequences: synthesis, kinetics and mechanistic study

Abiraj, K. and Ramesha Baba, A. and Srinivasa, G. R. and Channe Gowda, D. (2006) Mn(III) oxidation of peptide polymers of elastin sequences: synthesis, kinetics and mechanistic study. Journal of Physical Organic Chemistry, 19 (1). pp. 68-74. ISSN 1099-1395

Text (Full Text) Mn(III) oxidation of peptide polymer.pdf - Published Version Restricted to Registered users only Download (116kB) | Request a copy

Abstract

Abstract Protein based-polymers comprised of Ala-, Val- and Ile-containing tetrapeptide repeating sequences of elastin were synthesized based on the increasing order of hydrophobicity and subjected to metal-catalyzed oxidation to identify the amino acid residues, which are sensitive to oxidation. These polytetrapeptides (PTP) were oxidized using Mn(OAc)3 at 25°C and the kinetics of the reaction were monitored spectrophotometrically at λmax = 400 nm. A first-order rate dependence on the substrate concentration PTP and Mn(III) and an inverse order dependence on H+ has been observed. Further, the rate is independent of Mn(OAc)2. The effect of the dielectric constant on the rate was studied by varying the percentage of AcOH. Activation parameters were evaluated using Arrhenius and Eyring plots. The oxidation products were isolated and characterized. Based on the results obtained, a plausible mechanism involving Mn(OAc)4− is proposed. It is noteworthy that the rate of oxidation of poly(GGIP) was higher than those of poly(GGVP) and poly(GGAP). This may be due to their increased hydrophobicity. The overall order of rate of oxidation of PTP is poly(GGIP) > poly(GGVP) > poly(GGAP). Copyright © 2005 John Wiley \& Sons, Ltd.

Item Type:	Article
Subjects:	C Chemical Science > Chemistry
Divisions:	Department of > Chemistry
Depositing User:	LA manjunath user
Date Deposited:	30 Aug 2019 10:54
Last Modified:	23 Jun 2022 10:52
URI:	http://eprints.uni-mysore.ac.in/id/eprint/7396

Actions (login required)

View Item