RAMAN AND INFRA - RED SPECTRA OF AMINO ACIDS.

Abstract

Raman spectra of 12 amino acids have bcen recorded using the 6328 Aradiation from a He-Ne laser as exciter. The substances studies are (1) L-arginine,(2) L-cystine,(3) L-glutamic acid,(4) L-glutanztc acid-HCI,(5) Monosodium glutamate,(6) L-glutanzine,(7) Hydroxy-L-proline, (8) L-isoleucine, (9) L-se' me, (10) L-threonine, (11) L-tyroiine and (12) L-valine. Eleven of them have been recorded for the first time. The infra-red spectra of these compounds and also of (13) L-leucine and (14) L-proline have also been recorded in the region 400-4000° cm -I . Some of the infra-red absorption spectra were recorded also at 100°K. The N-H stretching  modes are influenced by hydrogen bonding. Raman lines characteristic of NH 43- and COO - groups have been identified in 'many of the amino acids. It has been shown that the appearance of band at 2100 cm -1 which is assigned to a combination of the torsional oscillation and degenerate deformation of the NH1 groups can also beused a "finger print" for the identification of NH 1 groups in amino acids.