L-アスコルビン酸の安定性に関する研究(II)

その他

The present investigation was undertaken to see the the effects of the amino acids on the oxidation of ASA under the various pH conditions and to see the synergism of the amino acids. The following results were obtained.
At the acid pH, aspartic acid, glutamic acid, methionine and tryptophan showed the restraining-action for the oxidation of ASA. It was found, in contrast with this, that glycine, leucine, arginine, lysine and tyrosine showed the accelerating-action. And these tendencies were clearly recognized rather in the higher pH level than in lower one.
The aspects of the amino acids in the case of the neutral pH were essentially identical to that found at the acid pH.
In the case of the alkaline pH, a large portion of the amino acids showed the accelerating-action and the higher the pH, the more effective the action, except some kinds of the amino acids (i. e., asprtic acid, glutamic acid, proline, hydroxyproline and tryptophan). And the accelerating-action was significantly recognized in the case of glycine, valine, leucine, arginine and tyrosine. There was not any amino acid which raised the remaining ratio of ASA.
The acceleration effects of such amino acids as leucine or arginine or lysine or tyrosine were generally lowered by adding of the other ones having the restraining-action for the oxidation of ASA, except some examples. And it was found that the amino acids, such as aspartic acid or glutamic acid or methionine or tryptophan which restrained the oxidation of ASA, have raised the ASA remaining ratios of the other ones as a general rule, except a few kinds of cases. But these tendencies were not recognized in the case of alkaline condition, but in the case of acidic or neutral one.