Maple syrup organic acids

Menkes, J. (1959) Maple syrup disease isolation and identification of organic acids in the urine. 

Dancis, J., Levitz, M., Westall, R. (1960) Maple syrup urine disease branched-chain keto-aciduria. Pediatrics 25, 72-79. Menkes, J.H. (1959) Maple syrup disease isolation and identification of organic acids in the urine. Pediatrics 23, 348-353. 

In inherited metabolic disorders, not only is total protein a major consideration, but also the balance of individual amino acids. Excessive or imbalanced plasma amino add concentrations negatively affect absorption, protein synthesis, and brain concentrations of indispensable amino acids. In PKU, high blood phenylalanine concentrations cause high phenylalanine concentrations on the brain [52, 53]. In organic acidemias and maple syrup urine disease, imbalances in several or more indispensable amino adds can significantly affect protein synthesis (Fig. 7.5) (Chap. 11). 

Figure 3 The total ion ourrent ohromatogram obtained for the organic acids isolated from the sodium borodeuteride-treated urine of a patient with maple syrup urine disease. The ratios of the H-labelled to unlabelled analogues for 2-hydroxyisovaleric acid, 2-hydroxyisooaproio acid and the two 2-hydroxy-3-methylvaleric acid diastereomers are respectively 0.24, 34.5, 30.0 and 3.70.

Fig. 10.3 Chromatogram of organic acids extracted from the urine of an untreated patient with branched-chain keto aciduria (maple syrup urine disease), extracted and separated as described in the legend to Fig. 10.2. The chromatogram illustrates the overlapping peaks in the regions occupied by 3-hydroxybutyric, 2-hydroxyisovaleric and 2-oxoisovaleric acids (peak 1) and 2-oxo-3-methyl-valeric, 2-hydroxyisocaprioic and 2-oxoisocaproic acids (peak 2) and phosphate (peak 3). Other peaks of interest are (4) citric, (5) 4-hydroxyphenyl-lactic, (6) 4-hydroxyphenylpyruvic, (7) n-tetracosane (standard) and (8) -hexacosane (standard). (Compare with Fig. 10.4.)...

Table 10.1. Organic acid concentrations in urine from patients with untreated classical branched-chain keto aciduria (maple syrup urine disease). 

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