Cyclodextrin Inclusion Compounds in Research and Industry

Abstract

a-, p-, and y-Cyclodextrins are cyclic oligosaccharides consisting of six, seven, or eight glucose units, which can be obtained on a large scale from starch. They form inclusion compounds with smaller molecules which fit into their 5-8 A cavity. These (crystalline) complexes are of interest for scientific research as, contrary to the classical clathrates, they exist in aqueous solution and can be used to study the hydrophobic interactions which are so important in biological systems. Cyclodextrins also serve as models both for polymeric starch and, in the form of their polyiodide complexes, for "blue iodine-starch". As cyclodextrins catalyze several chemical reactions they and their functionalized derivatives provide useful enzyme models. Cyclodextrins can be used to advantage in the production of pharmaceuticals, pesticides, foodstuffs, and toilet articles-the (micro-encapsulated) active and aromatic substances enclosed within them are protected from the effects of light and atmosphere and can be easily handled and stored in powder form. Substances which are not very soluble in water become more soluble in the presence of cyclodextrins-creams and emulsions can be stabilized, and the growth and yield of grain harvests can be increased. Cyclodextrins can be chemically modified for many different purposes; polymerized cyclodextrin or cyclodextrin bound to a polymer carrier have already been employed in gel inclusion and affinity chromatography.

Investigation of Cyclodextrin Inclusion Compounds Using FT-IR, SEM and X-Ray Diffraction

“…It is well known, CDs forming inclusion complex with various guests molecule with suitable polarity and dimension because of their special molecular structured internal hydrophobic cavity and external hydrophilic surface. In pharmaceutical more interest in CDs extends to enhance the solubility, chemical stability and bioavailability of poorly soluble drugs [1]. Tramadol drug is a typical opioid which is a centrally acting analgesic used for treating severe pain.…”

A synthetic icosahedral DNA-based host–cargo complex for functional in vivo imaging

“…In host-guest complexes, two independent entities are supramolecularly associated resulting typically in the entrapment of one of these (guest or cargo) inside the available volume of the other (host) 2 . Host-guest complexes based on synthetic molecular hosts, such as cyclodextrins 3 , calixarenes 4 , cucurbiturils 5 , porphyrins 6 , crown ethers 7 , zeolites 8 and cryptands 9 , form structurally well-defined, synthetic scaffolds. A general strategy to achieve encapsulation within synthetic hosts involves the controlled polymerization of host units resulting in a well-defined cavity within which the guest (cargo) is accommodated and stabilized by molecular recognition 2 .…”

On the specificity of cyclodextrin complexes detected by electrospray mass spectrometry

“…As a general rule, the complex is strong when there is size complementarity between the guest and the cavity of the CD [8,9]. ␣-cyclodextrin (␣-CD) has six glucopyranose units, ␤-cyclodextrin (␤-CD) has seven glucopyranose units, and ␥-cyclodextrin (␥-CD) has eight glucopyranose units [8,10]. Molecules containing aliphatic chains fit better into the small cavity of ␣-CD, while molecules containing phenyl groups fit better into the larger cavity of ␤-CD.…”