Oxidation of L-proline

The alkaline Fe(CN)6 oxidations, described hereafter, were found to be first order in Fe(CN)g ion. The oxidation of DL-methionine (Meth) was fractional order both in Meth and OH ions. The mechanism assumed the formation of an adduct, of Fe(CN)6 and Meth, which decomposed to a radical in the rate-determining step. Further oxidation of the radical in the fast step resulted in the product methionine sulfoxide. The same reaction catalysed by Ru(III) was first order in Ru(III), had a fractional order in OH , and slowed with increasing methionine concentrations. The proposed mechanism suggested the formation of a complex between [Ru(H20)50H] +, the reactive Ru(III) species, and Meth. The product was methionine sulfone nitrile. The outer-sphere Ru(III)-catalysed oxidation of L-proline to glutamic acid was first order in Ru(III), fractional order in OH , and of zero order in proline.The oxidation of serine and threonine was first order in amino acid and zero order in OH . The reactivities of serine and threonine... 

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