Kinetics of oxidation of some α-amino acids L(−) arginine, L(−) histidine, L(+) ornithine, L(−) tryptophan, L(−) threonine by sodium N-chloro-4 methyl benzene sulphonamide (chloramine-T) in alkaline medium
✍ Scribed by K. C. Gupta; Kumkum Gupta
- Publisher
- John Wiley and Sons
- Year
- 1985
- Tongue
- English
- Weight
- 610 KB
- Volume
- 17
- Category
- Article
- ISSN
- 0538-8066
No coin nor oath required. For personal study only.
✦ Synopsis
Kinetic studies of oxidation of L ( -) arginine, L ( + ) ornithine, L ( -) histidine, L(-) tryptophan, L(-) threonine have been carried out in alkaline medium. The reaction showed an inverse fractional order in OHand first-order dependence on both amino acid and chloroamine-T concentration. The effect of varying ionic strength (KC1) on the rate of oxidation is negligible. A general mechanism for the oxidation has been suggested by considering interaction between anionic species of amino acid and p-toluene-sulphochloramide. The effect of solvent and temperature have been also discussed. The fractional order obtained in OHis due to the fact that a fraction of overall reaction proceeds via an alternative OHindependent path. The combined rate law in accordance to observed kinetics is derived as
The rate constants predicted by the derived rate law as the concentration of OHions change, are in excellent agreement with the observed rate constants, thus further justifying these rate laws and hence the proposed mechanistic schemes.