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N ‐bromosuccinimide oxidation of dipeptides and their amino acids: Synthesis, kinetics and mechanistic studies
Author(s) -
Gowda N. S. Linge,
Kumara M. N.,
Gowda D. Channe,
Rangappa K. S.
Publication year - 2006
Publication title -
international journal of chemical kinetics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.341
H-Index - 68
eISSN - 1097-4601
pISSN - 0538-8066
DOI - 10.1002/kin.20161
Subject(s) - chemistry , perchlorate , n bromosuccinimide , succinimide , kinetics , ionic strength , perchloric acid , medicinal chemistry , dipeptide , reaction rate constant , glycine , chloride , proline , amino acid , inorganic chemistry , ion , organic chemistry , aqueous solution , halogenation , biochemistry , physics , quantum mechanics
Dipeptides (DP), namely valyl–glycine (Val–Gly), alanyl–proline (Ala–Pro), and valyl–proline (Val–Pro) were synthesized by classical solution phase methods and characterized. The kinetics of oxidation of amino acids (AA) and DP by N ‐bromosuccinimide (NBS) was studied in the presence of perchlorate ions in acidic medium at 28°C. The reaction was followed spectrophotometrically at λ max = 240 nm. The reactions follow identical kinetics, being first order each in [NBS], [AA], and [DP]. No effect on [H + ], reduction product [succinimide], and ionic strength was observed. Effects of varying dielectric constant of the medium and addition of anions such as chloride and perchlorate were studied. Activation parameters have been computed. The oxidation products of the reaction were isolated and characterized. The proposed mechanism is consistent with the experimental results. An apparent correlation was noted between the rate of oxidation of AA and DP. © 2006 Wiley Periodicals, Inc. Int J Chem Kinet 38: 376–385, 2006