Inhibition effect of {surfactant–substrate} aggregation on the rate of oxidation of reducing sugars by alkaline hexacyanoferrate(III)

Abstract

The effect of cationic (cetyltrimethylammonium bromide, CTAB), anionic (sodium lauryl sulfate, NaLS), and nonionic (Brij-35) surfactants on the rate of oxidation of some reducing sugars (xylose, glucose, and fructose) by alkaline hexacyanoferrate(III) has been studied in the temperature range from 35 to 50 • C. The rate of oxidation is strongly inhibited in the presence of surfactant. The inhibition effect of surfactant on the rate of reaction has been observed below critical micelle concentration (CMC) of CTAB. In case of NaLS and Brij-35, the inhibition effect was above CMC, at which the surfactant abruptly associates to form micelle. The kinetic data have been accounted for by the combination of surfactant molecule(s) with a substrate molecule in case of CTAB and distribution of substrate into micellar and aqueous pseudophase in case of NaLS and Brij-35. The binding parameters (binding constants, partition coefficients, and free-energy transfer from water to micelle) in case of NaLS and Brij-35 have been evaluated with the help of Menger and Portnoy model reported for micellar inhibition.

Facile destruction of formulated chlorpyrifos through green oxidation catalysis

“…Ion pairing has been implicated as the source of increased resistance to oxidation in other reactions. 57 TAML activators are functional analogues of catalase-peroxidase enzymes where the catalase activity becomes increasingly dominant as the peroxidase substrate become increasingly oxidatively resistant. 58 Catalyst deactivation also competes with the peroxidase-like activity.…”

Inhibition Effect of Surfactants in Alkaline Kmno4 Oxidation of Disaccharides: A Kinetic Study

“…The synthetic and mechanistic aspects of permanganate have recently been discussed by Mishra et al 1 . Due to biological importance of carbohydrates to living organism the kinetics of oxidation of sugars have also been a subject of extensive research [2][3][4][5][6][7][8][9][10] .Micelles have become a subject of great interest [11][12][13][14][15][16][17] to the organic chemists because of their unusual catalysis of organic reactions and to biochemists because of their similarity to biological membrane and globular proteins. The reaction in micellar media may follow two patterns, one in which the surfactants provides a medium for reaction but does not participate in it.…”

Antagonism in (conventional anionic–gemini anionic) mixed micelle catalyzed oxidation of D‐fructose by alkaline chloramine‐T: A kinetic study

“…The enediol anion of the reducing sugar serves as the reacting species [11,19,20] of reducing sugars.…”

“…The formation of (surfactant-reducing sugar) aggregates in the case of a normal anionic surfactant, namely, sodium lauryl sulfate (NaLS) and anionic gemini surfactant, namely, sodium salt of bis(1-dodecenyl succinamic acid) (NaBDS), and their resistance to react with oxidant hexacyanoferrate(III) has recently been observed [11,12]. However, both the surfactants, that is, NaLS and NaBDS, showed an accelerating effect on the rate of oxidation of D-fructose by alkaline chloramine-T, that is, sodium salt of N -chloro-toluenep-sulfonamide (CAT), which serves as an effective oxidant in acidic, basic, or neutral medium [13,14].…”