HPLC and 1H-NMR study of chiral recognition in some thromboxane antagonists induced by β-cyclodextrin

Casy, A. F.; Cooper, Andrew; Jefferies, T.M.; Gaskell, R. M.; Greatbanks, D.; Pickford, R.

doi:10.1016/0731-7085(91)80002-q

Cited by 27 publications

(9 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This indicates that there may be factors other than complex stability that contribute to the discrimination process. 19 The intramolecular NOEs observed in (+)-ephedrine in complex with ␤-CD were the same as those found for the free molecule (data not shown). In contrast to that observation, there were two cross-peaks missing for the (−)- enantiomer (between the CH-CH 3 group and both H1 and the aromatic protons), reflecting the different interaction of the two ligands with the CD.…”

Section: Roesy Spectra Of Single Ephedrine Enantiomerssupporting

confidence: 73%

Chiral discrimination by NMR spectroscopy of ephedrine and N-methylephedrine induced by ?-cyclodextrin, heptakis(2,3-di-O-acetyl)?-cyclodextrin, and heptakis (6-O-acetyl)?-cyclodextrin

et al. 1997

View full text Add to dashboard Cite

Section: Roesy Spectra Of Single Ephedrine Enantiomerssupporting

confidence: 73%

Chiral discrimination by NMR spectroscopy of ephedrine and N-methylephedrine induced by ?-cyclodextrin, heptakis(2,3-di-O-acetyl)?-cyclodextrin, and heptakis (6-O-acetyl)?-cyclodextrin

et al. 1997

View full text Add to dashboard Cite

“…[21][22][23] In this study it has been assumed that p-CD and MPB form a 1:l complex. A similar mechanism of interaction between p-CD and MPB, because of the molecular dimensions of the latter, would lead to an engulfment of MPB almost entirely within the p-CD cavity.…”

Section: Results and Discussion The Structure Of P-cyclodextrin Complmentioning

confidence: 99%

“…A number of previous studies on p-CD complexation using NMR techniques have suggested that the insertion of a phenyl group from a drug structure into the macrocycle cavity leads to hydrophobic bonding interactions within the torus cavity. [21][22][23] In this study it has been assumed that p-CD and MPB form a 1:l complex. A similar mechanism of interaction between p-CD and MPB, because of the molecular dimensions of the latter, would lead to an engulfment of MPB almost entirely within the p-CD cavity.…”

Section: Results and Discussion The Structure Of P-cyclodextrin Complmentioning

confidence: 99%

Molecular modelling of the inclusion complexes between β‐cyclodextrin and (R)/(S)‐methylphenobarbitone and its application to HPLC

Durham

Liang

1994

Chirality

View full text Add to dashboard Cite

Molecular modelling of beta-cyclodextrin and optimisation of its potential energy suggests that a favoured conformation is that distorted from a symmetrical torus. The inclusion of water molecules into the torus cavity simulates the increased stability in an aqueous solvent. Complexes of beta-cyclodextrin with (R)- and (S)-enantiomers of methylphenobarbitone have been modelled and energetically optimised by the application of molecular mechanics. The simulations suggests that the guest molecules adopt an orientation in which the phenyl ring is projected into the torus cavity, with in each case the plane of the ring parallel to a longer axis of the distorted torus and slightly displaced from the axis through the torus cavity. It is suggested that the asymmetry in the macrocyclic ring contributes to chiral recognition as a result of additional discriminatory binding to the barbiturate ring residue of each enantiomer, which occupy different 3D geometries. The enantiomers form complexes of different minimum potential energies. The resulting difference in complex stability can be related to the behaviour of beta-cyclodextrin, as a mobile phase additive in reverse-phase HPLC to effect chiral separation of rac-methylphenobarbitone during chromatography.

show abstract

“…For instance, 1 H NMR experiments can provide information about the stoichiometry, stability, and the structure of CD complexes (Connors, 1996;Szejtli & Osa, 1996;Yamamoto & Inoue, 1989). In particular, Job's plot, which correlates the chemical shift and the host/guest ratio, has been widely used to determine complex stoichiometry (Greatbanks & Pickford, 1987;Casy et al, 1991). The possibility of detecting inclusion complexes by NMR spectroscopy is based on the expectation that if a guest molecule is incorporated into the CD cavity, the screening constants of the CD protons inside the cavity (H 3 and H 5 ) should be sensitive to the changed environment, but the outside protons (H 1 , H 2 , and H 4 ), should not ( Fig.…”

Section: Preparation and Nmr Evidence Of CD Complex Formation In Aquementioning

confidence: 99%

Water soluble biocompatible vesicles based on polysaccharides and oligosaccharides inclusion complexes for carotenoid delivery

Polyakov

Kispert

2015

Carbohydrate Polymers

View full text Add to dashboard Cite

Since carotenoids are highly hydrophobic, air- and light-sensitive hydrocarbon compounds, developing methods for increasing their bioavailability and stability towards irradiation and reactive oxygen species is an important goal. Application of inclusion complexes of "host-guest" type with polysaccharides and oligosaccharides such as arabinogalactan, cyclodextrins and glycyrrhizin minimizes the disadvantages of carotenoids when these compounds are used in food processing (colors and antioxidant capacity) as well as for production of therapeutic formulations. Cyclodextrin complexes which have been used demonstrated enhanced storage stability but suffered from poor solubility. Polysaccharide and oligosaccharide based inclusion complexes play an important role in pharmacology by providing increased solubility and stability of lipophilic drugs. In addition they are used as drug delivery systems to increase absorption rate and bioavailability of the drugs. In this review we summarize the existing data on preparation methods, analysis, and chemical reactivity of carotenoids in inclusion complexes with cyclodextrin, arabinogalactan and glycyrrhizin. It was demonstrated that incorporation of carotenoids into the "host" macromolecule results in significant changes in their physical and chemical properties. In particular, polysaccharide complexes show enhanced photostability of carotenoids in water solutions. A significant decrease in the reactivity towards metal ions and reactive oxygen species in solution was also detected.

show abstract

HPLC and 1H-NMR study of chiral recognition in some thromboxane antagonists induced by β-cyclodextrin

Cited by 27 publications

References 15 publications

Chiral discrimination by NMR spectroscopy of ephedrine and N-methylephedrine induced by ?-cyclodextrin, heptakis(2,3-di-O-acetyl)?-cyclodextrin, and heptakis (6-O-acetyl)?-cyclodextrin

Chiral discrimination by NMR spectroscopy of ephedrine and N-methylephedrine induced by ?-cyclodextrin, heptakis(2,3-di-O-acetyl)?-cyclodextrin, and heptakis (6-O-acetyl)?-cyclodextrin

Molecular modelling of the inclusion complexes between β‐cyclodextrin and (R)/(S)‐methylphenobarbitone and its application to HPLC

Water soluble biocompatible vesicles based on polysaccharides and oligosaccharides inclusion complexes for carotenoid delivery

Contact Info

Product

Resources

About