**Author details**

H-NMR

H-

**2.6. Interaction and recognition of natural compounds**

peptides with CyDs is discussed.

Applications

486

groups in the peptide [77].

solution have been studied [80].

**3. Conclusion**

Finally the spectral change and interaction of some natural compounds such as alkaloids and

Complex formation of the glutathione and some of its derivatives with bridged β-CyD such

spectroscopy [76]. Polymerization of the amyloid beta-peptide (Abeta) has been identified as a major feature of the pathogenesis of Alzheimer's disease (AD). Inhibition of the formation of these toxic polymers of Abeta has emerged as an approach for developing therapeutics for AD. NMR and circular dichroism (CD) spectra were used to investigate the interaction between CyD and Abeta. CD spectral analyses show that β-CyD inhibits the aggregation of Abeta. Analysis of the one-dimensional proton NMR spectra of the mixture of Abeta with β-CyD clearly indicates that there are chemical shift changes in the aromatic ring and the methyl

A series of CyDs –cinchona alkaloid inclusion complexes were prepared from β-CyD and some of its derivaties and four cinchona alkaloids, and their inclusion complexation behavior was investigated by means of fluorescence, UV/Vis and 2D NMR spectroscopy. The results showed that the cinchona alkaloids can be efficiently encapsulated in the CyD cavity in an acidic environment and sufficiently released in a neutral environment, which makes these CyD derivatives the potential carriers for cinchona alkaloids [78,79]. Using colorimetry and 1

NMR and UV spectroscopy, together with solubility methods,the interaction of natural and hydroxylpropylated CyDs with xanthine, theophylline, theobromine, and caffeine in aqueous

Combination of the spectrophotometric methods and some separation methods such as capilla‐ ry electrophoresis (CE) and micellar electrokinetic chromatography (MEKC) in the presence of CyDs have been used successfully for the quantitative analysis of natural alkaloids [80,81].

CyDs are a versatile tool in the molecular recognition and sensing. Formation of inclusion complex cause to some spectral changes which have been used successfully for the study of host-guest interactions. Additionally the desired spectral changes as the results of complex formation have been used for promote analyte detection and continue to inspire creative applications. The most sensible spectral changes were reported for chemical and fluorescence indicators. These considerable changes have been used for the study and better detection of many absorbing and especially fluorescent species. Moreover many spectrochemically silent organic and some inorganic compounds cause color/fluorescence change in CyD and indicator solutions, because of their competition to form inclusion complex. These changes cause to recognition of the target competitive hosts. On this basis some "indicator modified cyclodex‐ trin" in which indicator is linked to cyclodextrin via a spacer, was synthesized that change color/fluorescence in response to the presence of molecules, ions and many biologically

as 2,2′-diseleno-bridged β-CyD were determined by UV-Vis. absorption and 1

An Integrated View of the Molecular Recognition and Toxinology - From Analytical Procedures to Biomedical

Lida Khalafi1 and Mohammad Rafiee2

1 Department of Chemistry, Shahr-e-Qods Branch, Islamic Azad University, Tehran, Iran

2 Department of Chemistry, Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan, Iran
