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Substituent Distribution in Hydroxyethyl Starch
Author(s) -
Merkus H. G.,
Mourits J. W.,
De Galan L.,
De Jong W. A.
Publication year - 1977
Publication title -
starch ‐ stärke
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.62
H-Index - 82
eISSN - 1521-379X
pISSN - 0038-9056
DOI - 10.1002/star.19770291203
Subject(s) - substituent , hydrolysate , chemistry , hydroxyethyl starch , derivative (finance) , distribution (mathematics) , reaction rate constant , medicinal chemistry , carbon atom , starch , organic chemistry , hydrolysis , alkyl , kinetics , mathematics , mathematical analysis , biochemistry , physics , quantum mechanics , financial economics , economics
The substituent distribution of hydroxyethyl starch has been determined at various degrees of substitution (MS = 0.03–1.9) by capillary gas chromatography of the silylated hydrolysate. In the monosubstituted derivatives 70–80% of the hydroxyethyl groups is attached to the C2 atom. The ratio of C3 to C6 monohydroxyethylated products changes from 2 to 0.2 when increasing the MS from 0.03 to 1.9. At high MS (around 2) the disubstituted products consist for about 50% of 2‐hydroxyethoxyethyl derivative, which indicates a strong preference for the consecutive reaction of the newly formed hydroxyl group of 2 hydroxyethyl‐anhydroglucose. The distribution of mono‐ and polysubstituted products is in agreement with a model of consecutive reactions with average relative rate constants for mono‐, di‐ and higher substitution of 1.30, 1.05 and 0.85 respectively.