Cyclodextrins

Many metabolically important compounds, such as, fat soluble vitamins and hormones have very low solubilities in aqueous solutions. Various approaches have been taken to utilize these compounds in tissue and cell culture applications. One such approach is to use a non-toxic solubilizer such as cyclodextrin.

Cyclodextrins are cyclic oligosaccharides consisting of 6, 7, or 8 glucopyranose units, usually referred to as α-, ß-, or γ-cyclodextrins, respectively. These naturally occurring compounds have relatively rigid doughnut-shaped structures, and have attracted interest as possible natural complexing agents. The unique structures of these compounds owe their stability to intramolecular hydrogen bonding between the C2- and C3-hydroxyl groups of neighboring glucopyranose units. The molecule takes on the shape of a torus with the C2- and C3-hydroxyls located around the larger opening and the more reactive C6-hydroxyl aligned around the smaller opening. The arrangement of C6-hydroxyls opposite the hydrogen bonded C2- and C3-hydroxyls forces the oxygen bonds into close proximity within the cavity, leading to an electron rich, hydrophobic interior. The size of this hydrophobic cavity is a function of the number of glucopyranose units forming the cyclodextrin.

Cavity size is the major determinant as to which cyclodextrin is used in complexation. "Fit" is critical to achieving good incorporation of cyclodextrins. Six glucopyranose unit compounds or α-cyclodextrins have small cavities which are not capable of accepting many molecules. Eight-glucopyranose unit compounds or γ-cyclodextrins have much larger cavities than many molecules to be incorporated and cyclodextrin hydrophobic charges can’t effectively interact to facilitate complexation. The cavity diameter of ß-cyclodextrins or ß-glucopyranose unit compounds is well-suited for use with molecules the size of hormones, vitamins and many compounds frequently used in tissue and cell culture applications. For this reason, ß-cyclodextrin is most commonly used as a complexing agent. Hydrophobic molecules are incorporated into the cavity of cyclodextrins by displacing water. This reaction is favored by the repulsion of the molecule by water. This effectively encapsulates the molecule of interest within the cyclodextrin, rendering the molecule water soluble. When the water soluble complex is diluted in a much larger volume of aqueous solvent, the process is reversed, thereby releasing the molecule of interest into the solution.

Product #

Description

Add to Cart

C4680 α-Cyclodextrin powder, BioReagent, suitable for cell culture, ≥98%
C4805 β-Cyclodextrin powder, BioReagent, suitable for cell culture, ≥97%
C4930 γ-Cyclodextrin powder, BioReagent, suitable for cell culture, ≥98%
C0926 (2-Hydroxypropyl)-β-cyclodextrin powder, BioReagent, suitable for cell culture
H107 (2-Hydroxypropyl)-β-cyclodextrin powder
H5784 (2-Hydroxypropyl)-β-cyclodextrin solution
H125 (2-Hydroxypropyl)-γ-cyclodextrin solid
C4555 Methyl-β-cyclodextrin powder, BioReagent, suitable for cell culture