24 M. WINITZ 
66 J]. P. GREENSTEIN AND M. WINI1z, in Chemistry of the Amino Acids, J. Wiley and Sons, New 
York, I9g61, p. 105. 
67 M.C. Orry, J. P. GREENSTEIN, M. WINITZ AND S. M. BirnBaum, J. Am. Chem. Soc., 77 (1955) 
3112. 
68 J. W. PATTERSON AND W. R. BRoDE, Arch. Biochem., 2 (1943) 247. 
69 J. P. GREENSTEIN AND M. WrnitTz, in Chemistry of the Amino Acids, J. Wiley and Sons, New 
York, 1961, p. 205. 
70 N. Izumrya, R. WADE, M. Winitz, M. C. OTEY, S. M. BIRNBAUM, R. J. KOEGEL AND J. P. GREEN- 
STEIN, J]. dm. Chem. Soc., 79 (1957) 652. 
71 J. P. GREENSTEIN AND M. WinitTz, in Chemistry of the Amino Acids, J. Wiley and Sons, New 
York, 1961, p. 83. 
M. Win1tz, S. M. BIRNBAUM AND J. P. GREENSTEIN, J. Am. Chem. Soc., 77 (1955) 716. 
3'L. BENOITON AND L. P. BOUTHILLIER, Can. J. Chem., 33 (1955) 1473- 
74 —. ADAMS AND A. GOLDSTONE, J. Biol. Chem., 235 (1960) 3504. 
7° M. Winitz, J. POLLARD AND F. C. STEWARD, unpublished results. 
76 F.C. STEWARD AND J. POLLARD, private communication. 
2 
DISCUSSION 
Chairman: EUGENE ROBERTS 
ROcKLAND: Are there any significant differences in the infrared spectra of the isomeric forms of 
y-hydroxyglutamic acid? 
Winitz: There are quite significant differences. The infrared spectrum of the B-form of the 
amino acid is very sharp and shows quite definite peaks. The A-form of the amino acids shows a 
spectrum of indefinite character in which the peaks are not sharp but, rather, merge into each 
other. Of course, the p- and L-forms of the amino acid show the identical infrared pattern. 
PoLiarD: In Dr. Win1tz’s criteria for purity of amino acids, he indicated that one must obtaina 
homogeneous peak on ion exchange chromatography or a single spot on a paper chromatogram. 
We have noticed in the past that hydroxyamino acids, particular y-hydroxyamino acids, e.g., 
y-hydroxyvaline, will give two peaks during ion exchange chromatography using the method of 
PARTRIDGE AND BRIMLEy. Acid catalysis during the operation synthesizes some of the lactone 
which then runs as a basic rather than a neutral amino acid. The same is true for paper chromatog- 
raphy at certain pH’s; where the lactone has formed, this will appear as a separate spot on the 
chromatogram even though the crystalline starting material was perfectly pure. 
Winitz: Lactone formation is a rather common phenomenon among the y- and 6-hydroxyamino 
acids. Perhaps what should be done in an instance such as this is to make the observation, just as 
you have done, and then run a comparison with a highly pure synthetic preparation to ascertain 
whether or not it gives the same phenomenon. In this manner, you can unequivocally establish 
the purity of the natural material. 
PoLiaRD: Actually, the phenomenon of lactone formation has its uses, since the formation of 
these lactones is frequently employed in proposing a tentative structural assignment, prior to 
eventual synthesis and resolution of the appropriate stereoisomer. 
E. Roserts: I would like to compliment Dr. W1n1Tz on having done well an absolutely necessary 
job. One thing that many of us who were brought up in the old school have noticed is that the 
chemistry is getting more careless in many laboratories. While work has been accelerated greatly 
by paper-chromatographic methods, the precision of chemical characterization occasionally has 
become comparably more vague. This kind of discussion at the outset of a conference at which 
the occurrence of new substances may be discussed and spots on chromatograms given names is 
very appropriate. 
