Trimethylamine-d₉N-oxide is intended for use as an internal standard for the quantification of trimethylamine N-oxide by GC- or LC-MS. Trimethylamine N-oxide (TMAO) is a metabolite of choline, phosphatidylcholine, and L-carnitine .¹It is formed by gut microbiota-mediated metabolism of choline, phosphatidylcholine, and L-carnitine to TMA followed by oxidation of TMA by flavin-containing monooxygenase 3 (FMO3) in the liver.^1,2,3Dietary administration of TMAO (0.12% w/w) increases renal tubulointerstitial fibrosis, collagen deposition, and Smad3 phosphorylation in mice and increases aortic lesion area in atherosclerosis-proneApoE^-/-mice.^1,4Plasma levels of TMAO are elevated in patients with chronic kidney disease and decreased in patients with active, compared with inactive, ulcerative colitis.^1,2Elevated plasma levels of TMAO are associated with increased risk of cardiovascular disease.⁴

1.Tang, W.H.W., Wang, Z., Kennedy, D.J., et al.Gut microbiota-dependent trimethylamine N-oxide (TMAO) pathway contributes to both development of renal insufficiency and mortality risk in chronic kidney diseaseCirc. Res.116(3)448-455(2015) 2.Wilson, A., Teft, W.A., Morse, B.L., et al.Trimethylamine-N-oxide: A novel biomarker for the identification of inflammatory bowel diseaseDig. Dis. Sci.60(12)3620-3630(2015) 3.Zhang, L.S., and Davies, S.S.Microbial metabolism of dietary components to bioactive metabolites: Opportunities for new therapeutic interventionsGenome Med.8(1)46(2016) 4.Wang, Z., Klipfell, E., Bennett, B.J., et al.Gut flora metabolism of phosphatidylcholine promotes cardiovascular diseaseNature472(7341)57-63(2011)