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Far ultraviolet optical activity of saccharide derivatives. I. Xylan and cellulose acetates
Author(s) -
Mukherjee S.,
Marchessault R. H.,
Sarko A.
Publication year - 1972
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.1972.360110122
Subject(s) - chemistry , xylan , optical rotatory dispersion , degree of polymerization , substituent , cellulose , circular dichroism , polymerization , cotton effect , residue (chemistry) , polysaccharide , cellulose acetate , organic chemistry , polymer chemistry , stereochemistry , polymer
Optial rotatory dispersion (ORD) and Circular dichroism (CD) spectra of several β‐1,4 xylan and cellulose acetates and some of their oligomers were investigated. The CD spectra proved considerably superior in terms of information content and interpretability. Comparison of the xylan and cellulose acetate series which also included partially substited cellulose acetates showed that the sign of the CD of the C(6) acetyl was negative. Likewise, the combined contribution of C(1) and C(4) to their equatorially substituted acetyls was positive (with C(1) definitely Positive) and the combined contribution of C(2) eq and C(3) eq negative. The solution conformations of both polysaccharide acetates appeared to be random. The CD of White birch xylan acetate which is substituted on the average at every tenth residue with a 4‐ O ‐methyl glucuronic acid substituent, was sensitive to it. The xylan oligomer series also illustrated that CD may be used to determine the degree of polymerization of these oligomers up to about 20.