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Updated: Aug 1, 2026

Metabolomic Analysis of Rat Brain by High Resolution Nuclear Magnetic Resonance Spectroscopy of Tissue Extracts
Published on: September 21, 2014
N-acetyl-L-aspartate and acetate 1H NMR signal overlapping under mild acidic pH conditions
M Martin1, J Labouesse, P Canioni
1Institut de Biochimie Cellulaire du C.N.R.S., Université de Bordeaux II, France.
Abstract:
The pH dependence of methyl proton chemical shifts of acetate, acetoacetate, N-acetyl-L-aspartate (NAA), and N-acetyl-L-aspartyl-L-glutamate (NAAG) were studied from pH 3 to pH 9. Only slight shifts of acetoacetate, NAA, and NAAG methyl signals were observed, whereas the acetate signal was largely shifted as a result of the titration of its acidic function. At pH 4.7, acetate and NAA methyl signals overlapped, whereas at more acidic pH, the acetate signal appeared downfield when compared to that of NAA. Results are discussed in terms of spectra misinterpretation risks linked to uncontrolled sample pH, on the one hand, and in terms of pH control and contamination by exogenous acetate during perchloric acid cell extract preparation, on the other.
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