Aldoses families

Figure 16-19 shows the structures of all members of the D-aldose family. The circle (head) represents the aldehyde, and the lines to the left or right indicate the orientation of the -OH on each of the chiral carbon atoms. The bottom carbon atom is an achiral -CH2OH. (Note that the mirror image of each aldose in Figure 16-19 is the L-enantiomer.)... 

Fig. 1. The family of D-aldoses derive from D-glyceraldehyde by chain extension at the carbonyl carbon atom.

Figure 1.27 Common monosaccharides of the aldose and ketose families found in biological molecules.

Rhetsinine (2), isolated from the hot water extract of Evodia rutae-carpa (family Rutaceae), was found to inhibit aldose reductase with an IC50 value of 24.1 /rM furthermore, the isolate inhibited sorbitol accumulation by 79.3% at 100 This compound could find potential use in the treatment of diabetic complications. Tetramethylpyrazine (3), one of the active components in Qing Huo Yi Hao, displayed strong antioxidant and endothelial protective effects, which can be comparable as Qing Huo Yi Hao this result indicated that some therapeutic potential of Qing Huo Yi Hao for vascular complications of diabetes may be attributed to the presence of tetramethylpyrazine (3). ... 

The triterpenoid constituents, 3p,22(3-dihydroxyolean-12-en-29-oic acid (85), tingenone (86), tingenine B (87 22(3-hydroxytingenone), regeol A (88) and triptocalline A (89) isolated from Salacia chinensis L. (family Celastraceae), were examined on rat lens for aldose reductase inhibitory activity the test compounds 85-89 were evaluated to exhibit rat lens aldose reducatse inhibitory activity with IC50 values of 26,13, 7.0,30, and 14 /rM, respectively. ... 

A family of enzymes that catalyze the molybdenum- or tungsten-cofactor dependent conversion of aldehydes to carboxylates, often using ferredoxin. See also Aldose Reductase... 

Aldose sugars make up a large part of the carbohydrate family, but the ones that are really worth knowing are part of the D-family. The simplest of these D-sugars is the triose glyceraldehyde. From there you have 2 tetroses, 4 pentoses, and 8 hexoses. Each of these aldose sugars has an enantiomer. 

Aldose reductase (ALR2 EC 1.1.1.21) is an 36 kDa enzyme that catalyzes the reduction of a wide range of carbonyl-containing compounds to their corresponding alcohols. It is a member of an extensive aldo-keto oxidoreductase enzyme family, a collection of structurally similar proteins expressed in both animals and plants. Most members of the enzyme family possess similarities in molecular mass, pH optimum, coenzyme dependence, and demonstrate overlapping specificity for many substrates and inhibitors. 

The simple sugars, or monosaccharides, are poly-hydroxyaldehydes (aldoses) or polyhydroxyketones (ketoses).1-5 All have the composition (CH20)n, hence the family name carbohydrate. A typical sugar, and the one with the widest distribution in nature, is glucose. 

Dehydrogenases often act primarily to reduce a carbonyl compound rather than to dehydrogenate an alcohol. These enzymes may still be called dehydrogenases. For example, in the lactic acid fermentation lactate is formed by reduction of pyruvate but we still call the enzyme lactate dehydrogenase. In our bodies this enzyme functions in both directions. However, some enzymes that act mainly in the direction of reduction are called reductases. An example is aldose reductase, a member of a family of aldo-keto reductases71 73 which have (a / P)8-barrel structures.74 76... 

---