Desaturation isotope effects

The isopropyl group of ezlopitant, which bears a 2-methoxy-5-isopropylbenzylamino group, is oxidized by both CYP3A4 and CYP2D6 to the tertiary alcohol and the desaturated 1-methylvinyl moiety . The alcohol was specifically shown not to be a precursor of the unsaturated product, and a small primary isotope effect was observed when deuterium was placed at the benzylic but not methyl carbons of the isopropyl group. Although not studied in detail, concurrent hydroxylation and... 

Emken, E.A., Adlof, R.O., Duval, S.M., and Nelson, G.J. 1999. Effect of dietary docosahexaenoic acid on desaturation and uptake in vivo of isotope-labeled oleic, linoleic, and linolenic acids by male subjects. Lipids 34, 785-791. 

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