Sugar alcohols sorbitol

The sugar alcohols sorbitol (hR, 15 — 20), mannitol (hRf 20—25) and xylitol hRf 30 — 35) appeared as light to dark brown chromatogram zones on a beige-colored background. The detection limits were 1 ng substance per chromatogram zone. 

Another complication of diabetes is blindness, which is due to blood vessel damage at the back of the eye (proliferative retinopathy), this accounts for about 12% of all blindness. In hyperglycemia, fructose is only slowly metabolized, and sorbitol accumulates in tissues. Because aldose reductase is found in kidneys, optic nerve, and peripheral neurons, retinopathy and painful neuropathies develop in poorly controlled or long-standing diabetes as a result of sugar alcohol (sorbitol) accumulation. Aldose reductase inhibitors, such as tokestat (5.129) or sorbinil (5.130), have been evaluated as agents to ameliorate these additional symptoms of diabetes. 

Mammalian sperm cells metabolize D-fructose preferentially as a source of energy. Fructose is formed in cells of the seminal vesicle from D-glucose via reduction to the sugar alcohol sorbitol using NADPH, followed by oxidation of sorbitol to fructose using NAD+. The fructose concentration... 

Omission of the grinding procedure significantly lowered the amount of Acp formed (compare No. 4 to No. 8). The same result was obtained when either the yeast protein was precipitated by addition of ammonium sulfate (compare No. 6 to No. 10) or when the sugar was replaced by the sugar alcohol sorbitol (No. 9). These results suggest that glycolytic enzymes liberated by the grinding process are involved in the formation of precursors for Acp. 

When the sugar alcohol sorbitol is heated with stearic acid in the presence of a catalyst, two reactions occur sorbitol cyclizes to form the hve-membered sorbitan ring and the remaining primary hydroxyl group is esterihed by the acid. The resulting sorbitan monostearate (Figure 17) is oil soluble, with a rather low HLB value, and... 

Fructose synthesis from glucose in the polyol pathway occurs in seminal vesicles and other tissues. Aldose reductase converts glucose to the sugar alcohol sorbitol (a polyol), which is then oxidized to fructose. In the lens of the eye, elevated levels of sorbitol in diabetes mellitus may contribute to cataract formation. 

Fructose can be synthesized from glucose in the polyol pathway. The polyol pathway is named for the first step of the pathway in which sugars are reduced to the sugar alcohol by the enzyme aldose reductase (Fig. 29.4) Glucose is reduced to the sugar alcohol sorbitol, and sorbitol is then oxidized to fructose. 

Avoid laxatives, such as sugar alcohols (sorbitol)... 

Sugar substitutes are those compounds that are used like sugars (sucrose, glucose) for sweetening, but are metabolized without the influence of insulin. Important sugar substitutes are the sugar alcohols, sorbitol, xylitol and mannitol and, to a certain extent, fructose (cf. 19.1.4.5-19.1.4.7). 

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