sorbitol

Sorbitol
IUPAC name	(2S,3R,4R,5R)-Hexane-1,2,3,4,5,6-hexol
Other names	D-glucitol D-Sorbitol
Identifiers
CAS number	50-70-4 Y
PubChem	82170
MeSH	Sorbitol
SMILES	O[C@H]([C@H](O)CO)[C@H](O)[C@@H](O)CO
Properties
Molecular formula	C6H14O6
Molar mass	182.17 g mol−1
Density	1.489 g/cm³
Melting point	95 °C
Boiling point	296 °C
Y (what is this?)  (verify) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

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Sorbitol, also known as glucitol, is a sugar alcohol that the human body metabolises slowly. It is obtained by reduction of glucose changing the aldehyde group to an additional hydroxyl group.

Uses

Sweetener

Sorbitol is a sugar substitute often used in diet foods (including diet drinks and ice cream) and sugar-free chewing gum, mints and cough syrups. It may be listed under the inactive ingredients. It also occurs naturally in many stone fruits and berries from trees of the genus Sorbus.^[1] Sorbitol is referred to as a nutritive sweetener because it provides dietary energy: 2.6 kilocalories (11 kilojoules) per gram versus the average 4 kilocalories (17 kilojoules) for carbohydrates.

Laxative

Sorbitol can be used as a non-stimulant laxative as either an oral suspension or enema. It works by drawing water into the large intestine, thereby stimulating bowel movements.^[2] Sorbitol has been determined safe for use by the elderly although it is not recommended without consultation with a clinician.^[3]

Medicine

Sorbitol is used in bacterial culture media to distinguish Escherichia coli 0154:H7 from most other strains of E. coli^{[citation needed]}.

Sorbitol, combined with kayexalate, helps the body rid itself of excess potassium ions in a hyperkalaemic state.^[4] The kayexalate exchanges sodium ions for potassium ions in the bowel, while sorbitol helps to eliminate it.

Health care, food, and cosmetics

Sorbitol is often used in modern cosmetics as a humectant and thickener^{[citation needed]}. Sorbitol is often used in mouthwash and toothpaste. Some transparent gels can only be made with sorbitol as it has a refractive index sufficiently high for transparent formulations. Sorbitol is used as a cryoprotectant additive (mixed with sucrose and sodium polyphosphates) in the manufacture of surimi, a highly refined fish paste most commonly produced from Alaska (or walleye) pollock (Theragra chalcogramma).^{[citation needed]} It is also used as a humectant in some cigarettes.^[5]

Other uses

A mixture of sorbitol and potassium nitrate has found some success as an amateur solid rocket fuel.^[6]

Sorbitol is identified as a potential key chemical intermediate^[7] from biomass resources. Complete reduction of sorbitol opens the way to alkanes such as hexane which can be used as a biofuel. Sorbitol itself provides much of the hydrogen required for the transformation.

19 C₆O₆H₁₄ → 13 C₆H₁₄ + 36 CO₂ + 42 H₂O

The above chemical reaction is exothermic; 1.5 mole of sorbitol generates approximately 1 mole of hexane. When hydrogen is co-fed, no carbon dioxide is produced.

Medical importance

Even in the absence of dietary sorbitol, cells produce sorbitol naturally. Too much sorbitol production can cause damage.^[8] Diabetic retinopathy and neuropathy may be related to excess sorbitol in the cells of the eyes and nerves. The source of this sorbitol in diabetics is excess glucose, which goes through the sorbitol-aldose reductase pathway.^[9]

In some human enzymes deficiencies such as galactosemia, sorbitol excess arises and can cause damage to the body. In diabetes mellitus, enzyme deficiency in the lens of the eye may cause sorbitol accumulation and cataracts^{[citation needed]}.

Overdose effects

Ingesting large amounts of sorbitol can lead to abdominal pain, gas, and mild to severe diarrhea.^{[citation needed]} Sorbitol ingestion of 20 grams (0.7 oz) per day as sugar-free gum has led to severe diarrhea leading to unintended weight loss of 11 kilograms (24 lb) in a woman originally weighing 52 kilograms (110 lb); another patient required hospitalization after habitually consuming 30 grams (1 oz) per day.^[10] Sorbitol can also aggravate irritable bowel syndrome.^[11]

Compendial status

• Food Chemical Codex ^[12]
• European Pharmacopoeia ^[13] 6.1 ^[14]
• British Pharmacopoeia 2009 ^[15]
• Japanese Pharmacopoeia 15^{[citation needed]}

See also

• Mannitol
• Mouthwash
• Xylitol

External links

• NIH Diabetes dictionary — see entry on sorbitol

Notes & References