Natural chirality of methylene sites applied to the recognition of origin and to the study of biochemical mechanisms

Naturel abundance deuterium NMR has been applied to the quantitative determination of natural methylene chirality in amino acids of different configurations and in ethanols of different origins. An enantiomeric enrichment is detected for aspartic acid of the L series obtained from fermentation and the technique therefore provides an absolute method for identifying the natural origin of a given substance. In ethanols of different origins the pro‐R and pro‐S positions appear as naturally equally populated at the present level of precision of the experiments. These results provide a new source of information about reaction mechanisms in the natural conditions.