A new method for distinguishing α-amino acids from their β- and γ -isomers

✍ Scribed by Charles H. Stammer; Ronald G. Webb

• Publisher: Elsevier Science
• Year: 1966
• Tongue: French
• Weight: 221 KB
• Volume: 7
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(00)70110-9

✦ Synopsis

In the past, color tests (1) and various paper chrornatogmphy systems (2) using cupric ion have been used to distinguish between a-amino acids and various other amines and amino acids. These methods are qualitatively useful, but to our knowledge no simple procedure (3) is presently available to determine unequivocally that a given amino group is a-to a corboxyl function. During our recent work with three+ hydroxy-Dl-aspartic acid (threo-HAA) ond its derivatives, we observed that the protons of the a-carbomethoxyl group were shifted upfield some 42 c.p.s. when the amino function was tritylated, whereas the f%carbomethoxyl protons were essentially unaffected. On the basis of this observation, we have prepared (4) the methyl esters