α-Cyclodextrin (''alpha''-cyclodextrin), sometimes abbreviated as α-CD, is a hexa

saccharide In organic chemistry, a carbohydrate () is a biomolecule consisting of carbon (C), hydrogen (H) and oxygen (O) atoms, usually with a hydrogen–oxygen atom ratio of 2:1 (as in water) and thus with the empirical formula (where ''m'' may or m ...

derived from

glucose Glucose is a simple sugar with the molecular formula . Glucose is overall the most abundant monosaccharide, a subcategory of carbohydrates. Glucose is mainly made by plants and most algae during photosynthesis from water and carbon dioxide, usi ...

. It is related to the β- (beta) and γ- (gamma)

cyclodextrin Cyclodextrins are a family of cyclic oligosaccharides, consisting of a macrocyclic ring of glucose subunits joined by α-1,4 glycosidic bonds. Cyclodextrins are produced from starch by enzymatic conversion. They are used in food, pharmaceutica ...

s, which contain seven and eight glucose units, respectively. All cyclodextrins are white, water-soluble solids with minimal toxicity. Cyclodextrins tend to bind other molecules in their quasi-cylindrical interiors. This inclusion (and release) behavior leads to applications in medicine. The compound is of wide interest because it exhibits host–guest properties, forming

inclusion compound In host–guest chemistry, an inclusion compound (also known as an inclusion complex) is a chemical complex in which one chemical compound (the "host") has a cavity into which a "guest" compound can be accommodated. The interaction between the h ...

Structure

In α-cyclodextrin, the six glucose subunits are linked end to end via α-1, 4 linkages. The result has the shape of a tapered cylinder, with six primary alcohols on one face and twelve secondary alcohol groups on the other. The exterior surface of cyclodextrins is somewhat hydrophilic whereas the interior core is hydrophobic. Alpha-CD

Applications

α-Cyclodextrin is marketed for a range of medical, healthcare, and food and beverage applications. For drug delivery, this cyclodextrin confers aqueous solubility to hydrophobic drugs and stability to labile drugs.

Synthesis

Cyclodextrins are natural starch-conversion products. For industrial use, they are manufactured by enzymatic degradation from vegetable raw materials, such as corn or potatoes. First, the starch is liquified either by heat treatment or using α-amylase. Then cyclodextrin glycosyltransferase (CGTase) is added for enzymatic conversion. CGTases produce diverse cyclodextrins. The selectivity of the synthesis can be improved by the addition of specific guests.

References

{{DEFAULTSORT:Cyclodextrin, alpha- Oligosaccharides Macrocycles

Structure

Applications

Synthesis

See also

References