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Conformations and optical rotatory properties of poly‐ O ‐acetylthreonine and poly‐ O ‐acetylallothreonine
Author(s) -
Kubota Shigeo,
Sugai Shintaro,
Noguchi Junzo
Publication year - 1968
Publication title -
biopolymers
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.556
H-Index - 125
eISSN - 1097-0282
pISSN - 0006-3525
DOI - 10.1002/bip.1968.360060907
Subject(s) - chemistry , optical rotatory dispersion , pyridine , dichloromethane , solvent , cotton effect , optically active , dispersion (optics) , crystallography , stereochemistry , circular dichroism , organic chemistry , optics , physics
Optically active poly‐ O ‐acetylthreonine and poly‐ O ‐acetyl‐allothreonine exist in the β form in pyridine, in 2‐chloruethanol–dichloromethane mixed solvent., and in the solid state. The optical rotatory dispersion of the β form of poly‐ O ‐acetyl‐ L ‐threonine in a 2‐ehloroethanol–dichlomethane mixture showed a Cotton effect in the 230 mμ region. The ORD data in the visible spectral region fit, the Moffitt. equation. The absolute values of b 0 , as measured in pyridine for polypeptides with a molecular weight above 17000, varied in the range 100–200°, the sign depending on the absolute configuration of the side chain.