Deuterium NMR study of the origin of hydrogen in fatty acids produced in vivo by chicken

The origin of hydrogen in fatty acids produced in vivo by chicken was studied by using isotope tracing monitored by ²H NMR. Chickens were fed with deuterium‐labeled water, deuterium‐labeled glucose/fructose and trideuterated acetate. The site‐specific isotope distribution of the fatty acids produced in vivo by the chickens was analyzed after transformation into methyl esters. A connection was observed between the hydrogen atoms of the feeds and water and those of the different molecular positions of the fatty acids produced by chicken. Water hydrogen makes an important contribution to the formation of the lipids. The hydrogen of the enzyme‐bound acetyl or malonyl moiety in acyl‐CoA may be transferred from the C‐1, C‐2 or C‐6 of glucose or fructose and indirectly from water. The hydrogen introduced by the cofactor NADPH may be abstracted from C‐1 and C‐3 of glucose, through its regeneration in the pentose phosphate metabolism pathway, and contains hydrogen atoms of water. The exogenous acetate enters into the in vivo fatty acid biosynthesis pathway in an efficient way and can make an important contribution to the biosynthesis of the lipids.