TABLE 2.
Actual and predicted 13C NMR signals for proposed metabolitesa
| Predicted results (ppm) | NMR results (ppm) | Functional group |
|---|---|---|
| Hexylsuccinic acid | ||
| 14.0 | 14.34 | Methyl (if addition to fumarate occurred at C-5 rather than at C-2) |
| 17.0 | 16.41 | Methyl closest to succinic acid |
| 32.7 | 30.98 | Methylene in succinic acid |
| 44.0 | 45.70, 46.25 | Methine in succinic acid |
| 4-Methyloctanoic acid | ||
| 14.0 | 14.34 | Methyl (if addition to fumarate occurred at C-5 rather than at C-2) |
| 19.7 | 17.12 | Methyl closest to succinic acid |
| 32.0 | 30.38 | Methylene “alpha” to carboxylic |
| 33.2 | 33.58 | Methylene “beta” to carboxylic |
a
For hexane the 14.34 ppm signal is also from unreacted 13C-labeled hexane. This signal also appears for metabolites in which the fumarate is added to the unlabeled end of hexane.