ISSN:
0006-3525
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
N-Carboxyanhydride of S-carbobenzoxymethyl-L-cysteine was polymerized by the addition of ethylamine as an initiator at anhydride-initiator ratios A/I = 3, 4, 6, 8, 12, and 16. Acetylation of the amino terminal was carried out with p-nitrophenylacetate. After debenzylation, low-molecular-weight samples of poly(S-carboxymethyl-L-cysteine) were obtained for A/I = 8, 12, and 16. These samples were fractionated by ion-exchange chromatography (DEAE-cellulose). About six fractions of narrow molecular-weight distributions were obtained. Their degrees of polymerization (DP) ranged from 8 to 16, as determined from proton nmr and also estimated based on their elution volumes on the ion-exchange chromatography at constant ionic strengths. This range of DP covered the range of interest concerning the formation of the β-structure in aqueous solutions; a fraction did not form the β-structure, whereas another fraction did. The results of the gel filtration (Biogel P-10) of the fractionated samples were consistent with the estimated DPs.
Additional Material:
10 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/bip.360221005
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