ISSN:
0006-3525
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Poly-L-prolines I and II were differentiated by the characteristic bands in the far infrared region. Form I showed two broad bands at about 280 and 160 cm-1 and form II two bands at, 400 and 670 cm.-1. Furthermore, three broad bands at about 250, 200, and 100 cm.-1 were observed in the spectrum for form II. Infrared absorption bands of the pentamer, hexamer, and octamer of tert-amyloxycarbonyl-L-proline were almost similar to those of poly-L-proline II in the 1800-75 cm.-1 region. In the far-infrared region, especially, the absorption bands of these three oligopeptides were in good agreement with that of poly-L-proline II. Accordingly we concluded that the molecules of pentamer, hexamer, and octamer had a helical structure of a left-handed threefold screw axis. The tetrapeptide of tert-amyloxycarbonyl-L-proline might also have a left-handed helix, probably one turn, since the tetramer clearly showed an absorption band at about 400 cm.--1 characteristic of poly-L-proline II.
Additional Material:
15 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/bip.1968.360060306
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