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Different strategies for selective monoacylation of hexoaldoses in acetone
Author(s) -
Arcos Jose A.,
Bernabé Manuel,
Otero Cristina
Publication year - 1998
Publication title -
journal of surfactants and detergents
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.349
H-Index - 48
eISSN - 1558-9293
pISSN - 1097-3958
DOI - 10.1007/s11743-998-0035-1
Subject(s) - chemistry , acetone , selectivity , mannose , solvent , solubility , organic chemistry , chromatography , sugar , extraction (chemistry) , candida antarctica , hildebrand solubility parameter , lipase , catalysis , enzyme
Experimental protocols for the selective production of 6‐ O ‐acylhexoaldose emulsifiers from precursor sugars (mannose, glucose, and galactose) and corresponding fatty acids are compared. The protocols employ an immobilized Candida antarctica lipase in a solvent (acetone) which is both easily eliminated and accepted by the European Economic Community for use as an extraction solvent in the manufacture of foods and/or food additives. This comparative study provides guidelines for selection of appropriate conditions for quantitative monoacylation of aldoses in acetone, on the basis of the solubilities of the precursor sugar and the monoester in acetone at different temperatures. Although relatively low temperatures (<40°C) favor precipitation of glucose monoesters, higher temperatures (e.g., 55°C) should be used to increase solubility of mannose and thus selectivity of the reaction leading to the mannose ester. Galactose is transformed with poor selectivity to the desired monoester by these procedures. Factors affecting the viability of these synthetic reactions in acetone are also discussed.