Crystalline inclusion complexes as media of molecular recognitions and selective reactions

2001 ◽  
Vol 73 (7) ◽  
pp. 1137-1145 ◽  
Author(s):  
Fumio Toda
Keyword(s):  
Inclusion Complexes ◽  
Chemical Reaction ◽  
Active Compound ◽  
Inclusion Complexation ◽  
Photochemical Reactions ◽  
Optically Active ◽  
Crystalline Inclusion ◽  
Guest Molecules ◽  
Water Suspension ◽  
Enantioselective Reactions

Hexaol host compounds which include guest molecules maximum in 1:6 ratio were prepared. Aromatic hexaol host, hexahydroxytriphenylene, was found to form chiral inclusion crystal by complexation with achiral guest molecules. Some interesting and important optical resolutions of rac-guests by inclusion complexation with a chiral host were described. When chemical reaction and the inclusion complexation procedures in a water suspension medium are combined, new economical and ecological method of the preparation of optically active compound can be established. When photochemical reactions are carried out in an inclusion crystal with a chiral host, enantioselective reactions occur, and optically active product can be obtained. Several successful reactions are described.

scholarly journals Inclusion complexes of 2-methoxyestradiol with dimethylated and permethylated β-cyclodextrins: models for cyclodextrin–steroid interaction

2015 ◽  
Vol 11 ◽  
pp. 2616-2630 ◽  
Author(s):  
Mino R Caira ◽  
Susan A Bourne ◽  
Halima Samsodien ◽  
Vincent J Smith
Keyword(s):  
Inclusion Complexes ◽  
Anticancer Agent ◽  
Inclusion Complexation ◽  
Aqueous Solubility ◽  
X Ray Diffraction ◽  
Guest Molecules ◽  
X Ray ◽  
Rapid Dissolution ◽  
First Time ◽  
Secondary Side

The interaction between the potent anticancer agent 2-methoxyestradiol (2ME) and a series of cyclodextrins (CDs) was investigated in the solid state using thermal analysis and X-ray diffraction, while the possibility of enhancing its poor aqueous solubility with CDs was probed by means of equilibrium solubility and dissolution rate measurements. Single crystal X-ray diffraction studies of the inclusion complexes between 2ME and the derivatised cyclodextrins heptakis(2,6-di-O-methyl)-β-CD (DIMEB) and heptakis(2,3,6-tri-O-methyl)-β-CD (TRIMEB) revealed for the first time the nature of the encapsulation of a bioactive steroid by representative CD host molecules. Inclusion complexation invariably involves insertion of the D-ring of 2ME from the secondary side of each CD molecule, with the 17-OH group generally hydrogen bonding to a host glycosidic oxygen atom within the CD cavity, while the A-ring and part of the B-ring of 2ME protrude from the secondary side. In the case of the TRIMEB·2ME complex, there is evidence that complexation proceeds with mutual conformational adaptation of host and guest molecules. The aqueous solubility of 2ME was significantly enhanced by CDs, with DIMEB, TRIMEB, randomly methylated β-CD and hydroxypropyl-β-CD being the most effective hosts. The 2:1 host–guest β-CD inclusion complex, prepared by two methods, yielded very rapid dissolution in water at 37 °C relative to untreated 2ME, attaining complete dissolution within 15 minutes (co-precipitated complex) and 45 minutes (complex from kneading).

Modification of photochemical reactivity through the use of clathrates: the Norrish type I and type II reactions in Dianin's compound

1985 ◽  
Vol 63 (10) ◽  
pp. 2719-2725 ◽  
Author(s):  
P. C. Goswami ◽  
Paul de Mayo ◽  
N. Ramnath ◽  
G. Bernard ◽  
N. Omkaram ◽  
...  
Keyword(s):  
Inclusion Complexes ◽  
Hydrogen Abstraction ◽  
Photochemical Reactions ◽  
Type I ◽  
Type Ii ◽  
Guest Molecules ◽  
Photochemical Reactivity ◽  
Norrish Type ◽  
Restricted Environment ◽  
Dianin's Compound

Dianin's compound (4-p-hydroxyphenyl-2,2,4-trimethylchroman) serves as host in a series of well-defined clathrate inclusion complexes with eleven linear, as well as branched chain, phenyl alkyl ketone guest molecules, chosen for their ability to undergo the Norrish type I and type II photochemical reactions in solution. The photochemical reactivity of the guest ketones within the clathrate cavity was determined by irradiation of the inclusion complexes in the solid state. The results were compared to the photoreactivity of the ketones in polar as well as nonpolar liquid media. In general, the inclusion complex medium brings about an enhancement of type I over type II reactivity and causes an increase in type II fragmentation compared to type II cyclization. This change in reactivity is interpreted as resulting from the relatively restricted environment of the clathrate cavity coupled with the greater motion required for the type II process (γ-hydrogen abstraction) compared to the type I reaction (α-cleavage), as well as from the greater steric requirements for type II cyclization (cyclobutanol formation) as compared to type II cleavage (1,4-hydroxybiradical scission).

scholarly journals Inclusion Complexation of Benzanilide and Fast Violet B with β-cyclodextrin-A Theoretical Approach

2020 ◽  
pp. 23-28
Author(s):  
A. Antony Muthu Prabhu
Keyword(s):  
Gas Phase ◽  
Aromatic Ring ◽  
Inclusion Complexes ◽  
Theoretical Investigation ◽  
Theoretical Approach ◽  
Inclusion Complexation ◽  
The Other ◽  
Guest Molecules ◽  
Och3 Group ◽  
Structural Assignment

The theoretical investigation of inclusion complexation of amide-imidol tautomer of two guest molecules benzanilide (BA) and fast violet B (FVB) with β-cyclodextrin (β-CD) using DFT B3LYP 3-21G  method in the gas phase. Benzanilide has no substitution in the basic skeleton and the other selected compound substituted with three groups such as –NH2, -CH3 and –OCH3 group in the same aromatic ring. The tautomer  of two selected compounds was formed the stable inclusion complexes with the β-CD supramolecule. The theoretically calculated complexation energy was observed the negative value for all the inclusion complexes. This method was applicable to determine the structural assignment of the inclusion complexes between BA, FVB and β-CD.

Synthesis of Amylosic Supramolecular Materials by Glucan Phosphorylase-Catalyzed Enzymatic Polymerization According to the Vine-Twining Approach

Synlett ◽  
2020 ◽  
Vol 31 (07) ◽  
pp. 648-656 ◽  
Author(s):  
Jun-ichi Kadokawa
Keyword(s):  
Inclusion Complexes ◽  
Inclusion Complexation ◽  
Soft Materials ◽  
Enzymatic Polymerization ◽  
Hierarchical Architecture ◽  
Supramolecular Network ◽  
Guest Molecules ◽  
Supramolecular Materials ◽  
Glucan Phosphorylase ◽  
Supramolecular Networks

This article overviews the synthesis of amylosic supramolecular materials through inclusion complexation in glucan phosphorylase (GP)-catalyzed enzymatic polymerization. Amylose is a polysaccharide that is known to form inclusion complexes with a number of hydrophobic small guest molecules. A pure amylose can be synthesized by the enzymatic polymerization of α-d-glucose 1-phosphate monomer with a maltooligosaccharide primer catalyzed by GP. The author has reported that the propagating amylosic chain in the enzymatic polymerization twines around hydrophobic polymers present in aqueous reaction media to form supramolecular inclusion complexes. As it is similar to the way that vines of a plant grow around a rod, this polymerization is termed ‘vine-twining polymerization’. Amylosic supramolecular network materials have been obtained through the vine-twining polymerization by using copolymers, where hydrophobic guest polymers are covalently grafted on hydrophilic main-chain polymers. The enzymatically produced amylosic chains form complexes with the guest polymers among graft copolymers, which act as cross-linking points to form supramolecular networks, resulting in the formation of soft materials, such as gels and films. Vine-twining polymerization using appropriately designed guest polymers has also been performed, which leads to supramolecular products that exhibit new functionality.1 Introduction2 Vine-Twining Polymerization to Form Supramolecular Inclusion Complexes3 Selective Complexation of Amylose toward Guest Polymers in Vine-Twining Polymerization4 Hierarchical Architecture of Amylosic Supramolecular Network Materials by Vine-Twining Polymerization Approach5 Hierarchical Fabrication of Amylosic Supramolecular Materials by Vine-Twining Polymerization Using Designed Guest Polymers6 Conclusions

Lanoconazole and Its Related Optically Active Compound NND-502: Novel Antifungal Imidazoles with a Ketene Dithioacetal Structure

2003 ◽  
Vol 2 (2) ◽  
pp. 147-160 ◽  
Author(s):  
Yoshimi Niwano ◽  
Tetsuto Ohmi ◽  
Akira Seo ◽  
Hiroki Kodama ◽  
Hiroyasu Koga ◽  
...  
Keyword(s):  
Active Compound ◽  
Optically Active ◽  
Ketene Dithioacetal

scholarly journals The guest polymer effect on the dissolution of drug–polymer crystalline inclusion complexes

RSC Advances ◽  
2021 ◽  
Vol 11 (22) ◽  
pp. 13091-13096
Author(s):  
Lu Chen ◽  
Yanbin Huang
Keyword(s):  
Inclusion Complex ◽  
Inclusion Complexes ◽  
Significant Influence ◽  
Crystalline Inclusion ◽  
Complex Crystals

Guest polymers have significant influence on the dissolution of drug–polymer inclusion complex crystals.

scholarly journals ß-Cyclodextrin Inclusion Complexes with Catechol-Containing Antioxidants Protocatechuic Aldehyde and Protocatechuic Acid—An Atomistic Perspective on Structural and Thermodynamic Stabilities

Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3574
Author(s):  
Thammarat Aree
Keyword(s):  
Inclusion Complexes ◽  
Protocatechuic Acid ◽  
Inclusion Complexation ◽  
Geometry Optimization ◽  
Therapeutic Effects ◽  
Full Geometry Optimization ◽  
Oh Groups ◽  
X Ray ◽  
Protocatechuic Aldehyde ◽  
Crystal Contacts

Protocatechuic aldehyde (PCAL) and protocatechuic acid (PCAC) are catechol derivatives and have broad therapeutic effects associated with their antiradical activity. Their pharmacological and physicochemical properties have been improved via the cyclodextrin (CD) encapsulation. Because the characteristics of b-CD inclusion complexes with PCAL (1) and PCAC (2) are still equivocal, we get to the bottom of the inclusion complexation by an integrated study of single-crystal X-ray diffraction and DFT full-geometry optimization. X-ray analysis unveiled that PCAL and PCAC are nearly totally shielded in the b-CD wall. Their aromatic rings are vertically aligned in the b-CD cavity such that the functional groups on the opposite side of the ring (3,4-di(OH) and 1-CHO/1-COOH groups) are placed nearby the O6–H and O2–H/O3–H rims, respectively. The preferred inclusion modes in 1 and 2 help to establish crystal contacts of OH×××O H-bonds with the adjacent b-CD OH groups and water molecules. By contrast, the DFT-optimized structures of both complexes in the gas phase are thermodynamically stable via the four newly formed host–guest OH⋯O H-bonds. The intermolecular OH×××O H-bonds between PCAL/PCAC 3,4-di(OH) and b-CD O6–H groups, and the shielding of OH groups in the b-CD wall help to stabilize these antioxidants in the b-CD cavity, as observed in our earlier studies. Moreover, PCAL and PCAC in distinct lattice environments are compared for insights into their structural flexibility.

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