Kinetics and mechanism of oxidation of glutathione (reduced) (y-L-glutamyi-L-cysteinylglycine) by pyridinium chlorochromate in acid medium

P.G.Department of Chemistry, Utkal University, Vani Vihar, Bhubaneswar-751 004, Orissa, India Department of Chemistry, Christ College, Cuttack-753 008, Orissa, India E-mail : christdillipbaral@gmail.com Manuscript received online 13 April 2012, revised 04 August 2012, accepted 22 August 2012 The electron transfer reaction between glutathione (reduced) (GSH) and pyridinium chlorochromate (PCC) has been studied spectrophotometrically over the range 3.00 ≤ 103[GSH] ≤ 6.00 mol dm-3, 0.01 ≤ [H+] ≤ 0.03 mol dm-3 and 293 ≤ T ≤ 313 K. The rate of reaction is found to increase with the increase in [GSH)T and [H+)T· The reaction is found to exhibit first order dependence in [GSH)T, [H+)T and [PCC)T. The ∆H+ (kJ mol-1) and ∆S+ (JK-1 mol-1) for the electron transfer reaction are found to be 5.90 and -177.00. The product of the reaction was found to be GSSG [((2S)-2-amino-5-[ [ (2R) -3-[ (2R)-2-[ [ ( 4S) -4-am ino-5-hydroxy-5-oxo pentanoyl) amino ]-3-(carboxymethyI amino) -3- oxopropyl]disulfanyl-1-( carboxymethylamino )-1-oxopropan-2-yl)amino )-5-oxopentanoic acid]