Aldoses

Comparison of an aldose (left, example D - glucose ) with a ketose (right, example D - fructose ). In all aldoses, carbon atom 1 is part of the carbonyl function of an aldehyde.

Aldoses (polyhydroxyaldehydes) are carbohydrates from the group of monosaccharides . They contain an aldehyde group that gives them their name and thus differ from the ketoses , which have a keto group (see illustration). An important representative of the aldoses is D - glucose . The prefix “Aldo-” indicates the affiliation to the aldoses: For example, one speaks of aldohexoses or aldopentoses .

The oxidation of the aldehyde group of the aldoses yields aldonic acids , their reduction alditols . The specific oxidation of the primary alcohol group provides uronic acids .

“Pedigree” of the D alcases. By adding (HC – OH) groups, the basic structure is lengthened so that further sugars can be derived (from trioses with three carbon atoms to hexoses with six carbon atoms). The direction of rotation of polarized light is indicated by (+) or (-).
( 1 ) D - (+) - glyceraldehyde ;
( 2a ) D - (-) - erythrosis ; ( 2b ) D - (-) - threose ;
( 3a ) D - (-) - ribose ; ( 3b ) D - (-) - arabinose ; ( 3c ) D - (+) - xylose ; ( 3d ) D - (-) - lyxose ;
( 4a ) D - (+) - allose ; ( 4b ) D - (+) - alto rose ; ( 4c ) D - (+) - glucose ; ( 4d ) D - (+) - mannose ; ( 4e ) D - (-) - gulose ; ( 4f ) D - (-) - idose ; ( 4g ) D - (+) - galactose ; ( 4h ) D - (+) - Talose

literature

• D. Voet, J. Voet: Biochemistry , 4th ed., Wiley, Weinheim 2011. ISBN 978-0-47057095-1 .
• Hans-Dieter Belitz , Werner Grosch, Peter Schieberle : Food chemistry . 4th edition, Springer, Berlin 2009. ISBN 978-3-540-69935-4 .

Individual evidence

1. ↑ Adalbert Wollrab: Organic chemistry: an introduction for teacher training and minor students . 4th edition. Springer Spectrum, Berlin [a. a.] 2014, ISBN 978-3-642-45143-0 , p. 788-789 .