β-Cyclodextrin sometimes abbreviated as β-CD, is a hepta

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 may ...

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, using ...

. The α- (alpha), 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, pharmaceutical, ...

s correspond to six, seven, and eight glucose units, respectively. β-Cyclodextrin is the most used natural cyclodextrin in marketed medicines. The reason for this lies in the ease of its production and subsequent low price (more than 10,000 tons produced annually with an average bulk price of approximately 5 USD per kg).

Structure

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

Physical properties

β-Cyclodextrin exists as a white (colorless) powder or crystals. The density of its saturated hydrate crystal (βCD·12H₂O) is 1.46 g/cm³. β-Cyclodextrin is moderately soluble in water and

glycerin Glycerol (), also called glycerine in British English and glycerin in American English, is a simple triol compound. It is a colorless, odorless, viscous liquid that is sweet-tasting and non-toxic. The glycerol backbone is found in lipids known ...

; well soluble in

dimethyl sulfoxide Dimethyl sulfoxide (DMSO) is an organosulfur compound with the formula ( CH3)2. This colorless liquid is the sulfoxide most widely used commercially. It is an important polar aprotic solvent that dissolves both polar and nonpolar compounds a ...

dimethylformamide Dimethylformamide is an organic compound with the formula ( CH3)2NC(O)H. Commonly abbreviated as DMF (although this initialism is sometimes used for dimethylfuran, or dimethyl fumarate), this colourless liquid is miscible with water and the majo ...

pyridine Pyridine is a basic heterocyclic organic compound with the chemical formula . It is structurally related to benzene, with one methine group replaced by a nitrogen atom. It is a highly flammable, weakly alkaline, water-miscible liquid with a d ...

, HFIP, and

ethylene glycol Ethylene glycol (IUPAC name: ethane-1,2-diol) is an organic compound (a vicinal diol) with the formula . It is mainly used for two purposes, as a raw material in the manufacture of polyester fibers and for antifreeze formulations. It is an odo ...

; and insoluble in

ethanol Ethanol (abbr. EtOH; also called ethyl alcohol, grain alcohol, drinking alcohol, or simply alcohol) is an organic compound. It is an Alcohol (chemistry), alcohol with the chemical formula . Its formula can be also written as or (an ethyl ...

and

acetone Acetone (2-propanone or dimethyl ketone), is an organic compound with the formula . It is the simplest and smallest ketone (). It is a colorless, highly volatile and flammable liquid with a characteristic pungent odour. Acetone is miscib ...

Applications

The cavity diameter of β-cyclodextrins is well-suited for use with molecules the size of various biomolecules. For this reason, β-cyclodextrin is most commonly used as a complexing agent. β-Cyclodextrin is widely used in medicine, pharmacy, food industry, textiles.

Derivatives

While as β-cyclodextrin has rather poor solubility, industry uses its derivatives with much better solubility. Most applied derivatives are: 2-hydroxypropyl-β-cyclodextrin (HPbCD), randomly methylated β-cyclodextrin (RAMEB), and β-cyclodextrin sulfobutyl ether sodium salt (SBEbCD). All these derivatives have solubility more than 500 mg/mL.

References

{{DEFAULTSORT:Cyclodextrin, beta- Oligosaccharides Starch Macrocycles Chelating agents E-number additives