Representative urine ¹H NMR spectra from control and CR treated rats after 14 days of treatment: A, CR-treated group; B, control group.

<p>Assignments of endogenous metabolites were based on comparing chemical shifts and multiplicities of peaks to the literature as well as the Metabonomics Toolbox (<a href="http://www.hmdb.ca" target="_blank">http://www.hmdb.ca</a>). The spectra were taken for urine samples containing 0.2 M Na₂HPO₄/NaH₂PO₄, pH 7.4 and 0.05% TSP as a chemical shift reference.