Oxidation Behavior of L-Threonine by N-Bromophthalimide in Micellar System of Ctab

Abstract

The effect of cationic surfactant Cetyltrimethylammonium bromide (CTAB) molecules on the oxidation of L-threonine by N-bromophthalimide (NBP) has been studied at 308 K. The reaction exhibits first order dependence on NBP and fractional positive order on L-threonine and negative fractional order dependence on HClO 4. The effects of KCl, KBr, phthalimide, mercuric acetate and dielectric constant of the medium have also been studied and summarized. CTAB strongly catalyzes the reaction and after achieving a maximum the rate remains almost constant at higher concentrations of CTAB. This micellar effect has been analyzed, plotted and results are treated quantitatively in terms of Berezin model. The various activation parameters in presence and absence of CTAB have been also evaluated. A suitable mechanism along with rate law consistent with the experimental findings has been worked out. Based on the model association rate constants have been computed.

Water content and micelle size change during oxidation of sunflower and canola oils

“…Micellization is initiated as amphiphilic molecules and hydroperoxides begin to aggregate to form submicellar or pre‐micellar structures . As the concentration of water and different hydroperoxides increase, the micelles grow in size and become well defined . With increased concentration of water and surface active compounds, large micelles start to have a lower stability because of micellar collisions and coalescence .…”

Kinetics and Mechanism of Oxidation of L-Threonine by Periodate in Alkaline Medium

“…A precise understanding of the mechanism of such biological redox reactions is important as it helps in the synthesis of specific reaction products. Very few reports are available on the oxidation of L-threonine using peroxydisulphate [1], manganese(VII) [3], N-bromo p-toulenesulphonamide [3], peroxodiphosphate [4], manganese(III) [5,6], bis-(hydrogen periodato)argentite [7], N-bromonicotinamide(NBN) [8], N-chloro p-toulenesulfonamide [9], Chloramine-T [10,11], N-bromophthalimide [12] the product of oxidation is aldehyde and in the oxidation of threonine by hexacyanoferrate(III) [13] the oxidation product is α -ketohydroxybutyric acid. Periodate is a stable two electron oxidant with redox potential of 0.70V [14] in alkaline medium and is a more suitable reagent for the study of oxidation reactions of both organic and inorganic substrates [15][16][17][18][19].…”