Journal article

Reactions of simple and peptidic alpha-carboxylate radical anions with dioxygen in the gas phase

T Ly, BB Kirk, PI Hettiarachchi, BLJ Poad, AJ Trevitt, G Da Silva, SJ Blanksby

Physical Chemistry Chemical Physics | Published : 2011

Abstract

α-Carboxylate radical anions are potential reactive intermediates in the free radical oxidation of biological molecules (e.g., fatty acids, peptides and proteins). We have synthesised well-defined α-carboxylate radical anions in the gas phase by UV laser photolysis of halogenated precursors in an ion-trap mass spectrometer. Reactions of isolated acetate (CH 2CO 2 -) and 1-carboxylatobutyl (CH 3CH 2CH 2CHCO 2 -) radical anions with dioxygen yield carbonate (CO 3 -) radical anions and this chemistry is shown to be a hallmark of oxidation in simple and alkyl-substituted cross-conjugated species. Previous solution phase studies have shown that C α-radicals in peptides, formed from free radical d..

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University of Melbourne Researchers

Grants

Awarded by Australian Research Council


Funding Acknowledgements

S.J.B., B.L.J.P., T. L., G.d.S and A.J.T acknowledge funding through the Australian Research Council (DP0986738, DP110103889 and DP1094135) and B. B. K. is supported by an Australian Postgraduate Award. S.J.B. and A.J.T. acknowledge the generous provision of computing resources from the NCI National Facility (Canberra) through the Merit Allocation Scheme and G.d.S. is thankful to the Victorian Partnership for Advanced Computing (VPAC) for providing computational resources. B. B. K. and S.J.B. thank Dr Shuji Kato (University of Colorado, Boulder) for helpful discussions and providing a SigmaPlot routine for calculation of collision rates.