The absolute configuration of 1-carboxyethyl substituents on common hexoses by circular dichroism.
Determination of the absolute configuration of the 1-carboxyethyl substituent on a monosaccharide by circular dichroism measurements was found to be a sensitive and simple method. It relies on comparison of the spectrum of a 1-carboxyethyl substituted sugar or sugar derivative with the spectra of (R)- and (S)-lactic acid in the region 200-260 nm in which the (R)- and (S)-configuration give negative and positive deltaepsilon, respectively. The oligo- or poly-saccharide containing a 1-carboxyethyl substituted sugar is hydrolyzed to monomers and the 1-carboxyethyl substituted sugar isolated by chromatography. The CD spectrum obtained for the 1-carboxyethyl substituted sugar in water solution at pH 2 is then compared with spectra of (R)- and (S)-lactic acid. The sign for the absorption and a maximum of comparable intensity and appearance around 210 nm, identify the stereochemistry.
Andersson
Lars
L
Department of Chemistry, Swedish University of Agricultural Sciences, PO Box 7015, SE-750 07 Uppsala, Sweden.
Kenne
Lennart
L
D002942:Circular Dichroism; D006601:Hexoses / Q000737:chemistry*; D007659:Ketones; D015394:Molecular Structure; D013237:Stereoisomerism
D006601:Hexoses; D007659:Ketones