Homolytic cleavage of the O-glycoside bond in carbohydrates: a steady-state radiolysis study.
نویسندگان
چکیده
The formation of products resulting from the O-glycoside bond cleavage following radiolysis of aqueous solutions of methyl-alpha-D-glucopyranoside (I), 3-O-methyl-alpha-D-glucopyranose (II), maltose, lactose, gentiobiose and cellobiose were studied. Radiation-induced destruction yields were also determined for dextran, laminarin and trimethylcelulose upon irradiation of their aqueous solutions. Oxygen, quinones and compounds capable of forming quinoid structures were found to inhibit radiation-induced homolytic destruction processes taking place in glycosides, di- and polysaccharides. The data obtained in this study enabled the authors to demonstrate an important role played by the fragmentation reaction of C-2 radicals which were generated from the starting substances in the formation of final radiolysis products.
منابع مشابه
A Facile and Environmental Friendly Method for C=N Bond Cleavage of Imines Using p-Toluenesulfonic Acid in Solid State
A simple, efficient and clean procedure has been developed for the cleavage of imines C=N bond. Deprotection of imines to their parent carbonyl and amine compounds was achieved using p-toluenesulfonic acid in the solid state condition at 25-45 ˚C. The salient features of this methodology are shorter reaction times, cheap processing, high yields of product and easy availability of the catalyst. ...
متن کاملTheoretical Study on Glycosyl Group Effect on Antioxidant Ability of Chrysin Bioflavonoid
Antioxidants are compounds which can prevent biological and chemical substances from oxidative damage by reactive oxygen species. Flavonoids are the most important class of polyphenolic compounds that because of their antioxidant characters possess biological activities and pharmacological effects. Chrysin-6-C-fucopyranoside and chrysin-3-malonyl-6-C-fucopyranoside are mono C-glycosyl derivativ...
متن کاملLaser-Induced Hydrogen Radical Removal in UV MALDI-MS Allows for the Differentiation of Flavonoid Monoglycoside Isomers
Negative-ion matrix-assisted laser desorption/ionization (MALDI) time-of-flight mass spectra and tandem mass spectra of flavonoid mono-O-glycosides showed the irregular signals that were 1 and/or 2 Da smaller than the parent deprotonated molecules ([M - H](-)) and the sugar-unit lost fragment ions ([M - Sugar - H](-)). The 1 and/or 2 Da mass shifts are generated with the removing of a neutral h...
متن کاملPhotochemical cleavage reactions of 8-quinolinyl sulfonates in aqueous solution.
Photochemical cleavage reactions of 8-quinolinyl benzenesulfonate derivatives and related sulfonates in aqueous solutions are reported. The 8-quinolinyl benzenesulfonates undergo photolysis upon photoirradiation at 300-330 nm to give the corresponding 8-quinolinols and benzenesulfonic acids with the production of only negligible amounts of byproducts. The effects of substituent groups of the 8-...
متن کاملInfluence of solvent composition on the kinetics of cyclooctene epoxidation by hydrogen peroxide catalyzed by iron(III) [tetrakis(pentafluorophenyl)] porphyrin chloride [(F20TPP)FeCl].
The epoxidation of cyclooctene catalyzed by iron(III) [tetrakis(pentafluorophenyl)] porphyrin chloride [(F20TPP)FeCl] was investigated in alcohol/acetonitrile solutions in order to determine the effects of the alcohol composition on the reaction kinetics. It was observed that alcohol composition affects both the observed rate of hydrogen peroxide consumption (the limiting reagent) and the selec...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- Journal of radiation research
دوره 46 3 شماره
صفحات -
تاریخ انتشار 2005