Inclusion Complexes In Solution Research Articles

Studies on 6-chloro-5-(1-naphthyloxy)-2-(trifluoromethyl)-1H-benzimidazole/2-hydroxypropyl-β-cyclodextrin association: Characterization, molecular modeling studies, and in vivo anthelminthic activity

The purpose of this work is to study the molecular association that occurs between 2-hydroxypropyl-β-cyclodextrin (HPβCD) and 6-chloro-5-(1-naphthyloxy)-2-(trifluoromethyl)-1H-benzimidazole (RCB20), an antiparasitic compound recently found by our research group, with poor aqueous solubility. The complex stability constant and stoichiometric ratio determined by phase-solubility diagram and Job's plot provided evidence that HPβCD enhanced water solubility of RCB20 through inclusion complex formation. Two-dimensional ¹H NMR spectroscopy is used to study the molecular arrangement of inclusion complex in solution. These results are further supported using molecular modeling studies. In the solid state, the complexation is confirmed by differential scanning calorimetry, powder X-ray diffraction, and scanning electron microscopy. Finally, RCB20/HPβCD complex has better activity than RCB20 against the adult and muscle larvae phase of Trichinella spiralis.

Solubility, spectroscopic properties and photostability of Rhein/cyclodextrin inclusion complex

The host–guest interaction between Rhein (Rh) – an anthraquinonic drug characterized by low water solubility and recently considered for its potential antidiabetic and antitumoral activities other than for the well-established anti-inflammatory properties – with cyclodextrins (CDs) was investigated using phase-solubility diagrams. The typical A L phase-solubility profiles suggest the formation of the 1:1 inclusion complexes between Rh and the two CDs investigated, namely β-cyclodextrin and 2-hydroxypropyl-β-cyclodextrin and the resulting constant values of complex formation, K c, were estimated. Due to the higher K c value, complex of Rhein with 2-hydroxypropyl-β-cyclodextrin was chosen for further investigation. Characterization in solution of 2-hydroxypropyl-β-cyclodextrin/Rhein complex was achieved both by fluorescence and visible spectroscopic techniques. These results confirm the formation of inclusion complexes in solution and the 1:1 stoichiometry of the binary system. With respect to Rhein aqueous solution behavior, the inclusion complex appears to be able: (i) to enhance Rhein solubility; (ii) to control its neutral/anionic equilibrium; (iii) to affect both its electronic absorption and fluorescence spectra. Finally, the photostability of Rhein in the presence of cyclodextrins was evaluated.

Novel inclusion complex of ibuprofen tromethamine with cyclodextrins: Physico-chemical characterization

Guest–host interactions of ibuprofen tromethamine salt (Ibu.T) with native and modified cyclodextrins (CyDs) have been investigated using several techniques, namely phase solubility diagrams (PSDs), proton nuclear magnetic resonance ( 1H NMR), differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FT-IR), X-ray powder diffractometry (XRPD), scanning-electron microscopy (SEM) and molecular mechanics (MM). From the analysis of PSD data (A L-type) it is concluded that the anionic tromethamine salt of ibuprofen (p K a = 4.55) forms 1:1 soluble complexes with all CyDs investigated in buffered water at pH 7.0, while the neutral form of Ibu forms an insoluble complex with β-CyD (B S-type) in buffered water at pH 2.0. Ibu.T has a lower tendency to complex with β-CyD ( K 11 = 58 M −1 at pH 7.0) compared with the neutral Ibu ( K 11 = 4200 M −1) in water. Complex formation of Ibu.T with β-CyD (Δ G° = −20.4 kJ/mol) is enthalpy driven (Δ H° = −22.9 kJ/mol) and is accompanied by a small unfavorable entropy (Δ S° = −8.4 J/mol K) change. 1H NMR studies and MM computations revealed that, on complexation, the hydrophobic central benzene ring of Ibu.T and part of the isobutyl group reside within the β-CyD cavity leaving the peripheral groups (carboxylate, tromethamine and methyl groups) located near the hydroxyl group networks at either rim of β-CyD. PSD, 1H NMR, DSC, FT-IR, XRPD, SEM and MM studies confirmed the formation of Ibu.T/β-CyD inclusion complex in solution and the solid state.

Prednisone/Cyclodextrin Inclusion Complexation: Phase Solubility, Thermodynamic, Physicochemical and Computational Analysis

Guest–host interaction of prednisone (PN) with cyclodextrins (CDs) have been investigated using phase solubility diagrams (PSD), differential scanning calorimetry (DSC), X-ray powder diffractometry (XRPD), scanning electron microscopy (SEM) and molecular mechanical modeling (MM). Estimates of the complex formation constant (K 11) show that the tendency of PN to complex with CDs follows the order: β-CD>γ-CD>HP-β-CD>α-CD. At the same pH of 7.0, β-CD forms soluble 1:1 and insoluble 1:2 PN/CD complexes (BS-type PSDs). The thermodynamic functions for 1:1 PN/β-CD estimated at pH = 7.0 (ΔG 11 o =−20.8 kJ⋅mol−1) show that complexation is driven by enthalpy (−30.7 kJ⋅mol−1) but retarded by entropy (ΔS 11 o =−33.1 J⋅mol−1⋅K−1) changes. The MM modeling study indicates the formation of different isomeric 1:1 complexes with CDs. PSD, DSC, XRPD, SEM and MM studies established the formation of inclusion complexes in solution and the solid state.

Solubilization and Stabilization of Sodium Dicloxacillin by Cyclodextrin Inclusion

The aim of this work is to analyze the effect of cyclodextrin (CD) complexation on the solubilization and stabilization of sodium dicloxacillin in acid aqueous solutions. The effect of four cyclodextrins alpha-, beta-, gamma- and hydroxypropyl-beta-CD was studied. Phase solubility diagrams obtained are AL or BS type, depending on the cyclodextrin used and on the pH of the solution. The highest stability constants of the inclusion complexes are obtained with gamma-CD at pH 1 and 2 and HPbeta-CD at pH 3. The structure of the inclusion complex in solution is characterized by nuclear magnetic resonance (1H-NMR). This study suggests that the 7-oxo-4-thia-1-azabicyclo group is located in the CD cavity. Nevertheless, molecular modelling calculations predict two different orientations of dicloxacillin in the gamma-CD cavity in vacuum and in aqueous solution. In vacuum, the results predict the inclusion of the dichlorophenyl ring of dicloxacillin instead of 7-oxo-4-thia-1-azabicyclo group into the gamma-CD cavity. However, the results are different in aqueous solution and this conformation is confirmed by the NMR study. The effect of gamma-CD and HPbeta-CD in the stability of the drug in solution was studied. The degradation of sodium dicloxacillin in solution follows a pseudo-first-order kinetics and the cyclodextrin do not change this fact. Both cyclodextrins increase the stability of the drug but the efficacy is higher with gamma-CD.

Astemizole/Cyclodextrin Inclusion Complexes: Phase Solubility, Physicochemical Characterization and Molecular Modeling Studies

Guest–host interaction of astemizole (Astm) with cyclodextrins (CDs) has been investigated using phase solubility diagrams (PSD), differential scanning calorimetry (DSC), X-ray powder diffractometry (XRPD), proton nuclear magnetic resonance (1H-NMR) and molecular mechanical modeling (MM+). Estimates of the complex formation constant, K11, show that the tendency of Astm to complex with CDs follows the order: β-CD>HP-β-CD>γ-CD, α-CD. 1:1 Astm/β-CD complex formation at pH=5.0 was largely driven by the hydrophobic effect (desolvation), which was quantitatively estimated at −16.5 kJ⋅mol−1, whereas specific interactions contribute only −5.3 kJ⋅mol−1 to 1:1 complex stability (ΔG11o=−22.7 kJ⋅mol−1). The percentage contributions of the hydrophobic effect and specific interactions were therefore 73 and 27%, respectively. Both enthalpic and entropic factors contribute equally well (−11 kJ⋅mol−1 each) to 1:1 Astm/β-CD complex stability. 1H-NMR and MM+ molecular modeling studies indicate the formation of different isomeric 1:1 and 1:2 complexes. The dominant driving force for complexation is evidently van der Waals with very little electrostatic contribution. PSD, 1H-NMR, DSC, XRPD and MM+ studies proved the formation of inclusion complexes in solution and the solid state.

Preparation and stability of the inclusion complex of astaxanthin with hydroxypropyl-β-cyclodextrin

The inclusion complex of astaxanthin (ASX) with hydroxypropyl-β-cyclodextrin (HP-β-CD) was prepared. Infrared spectroscopy (IR) proved the formation of the inclusion complex. The water solubility of the inclusion complex was >1.0mg/ml, which is much better than that of ASX. The solid state thermal behaviour of the inclusion complex was investigated by thermogravimetric/differential thermal analysis (TG/DTA). The starting decomposition temperature of ASX was enhanced to about 290°C. The stability of the inclusion complex in solution was also tested. Forming of the inclusion complex greatly enhanced the stability of ASX against light and oxygen. Furthermore, the release of ASX from the inclusion complex was controlled.

Photoresponsive Viscosity and Host−Guest Association in Aqueous Mixtures of Poly-Cyclodextrin with Azobenzene-Modified Poly(acrylic)acid

In aqueous solutions, beta-cyclodextrin (CD) and cyclodextrin-containing polymers (PolCD) associate with azobenzene-modified polyacrylate (AMP). Inclusion complexes in solution of CD (or PolCD) and AMP, and the viscosity of these mixtures, have been studied as a function of the composition of AMP and concentrations of samples. AMPs are random copolymers containing a low fraction of a light-responsive hydrophobic moieties (<10 mol % of 6-[4-alkylamido]phenylazobenzene acrylamide), and a charged hydrophilic unit, sodium acrylate. PolCDs are beta-cyclodextrin randomly conjugated with epichlorohydrin and fractionated to yield copolymers of average number of CD per chain equal to 50. In dilute solutions, the composition of complexes has been investigated by capillary electrophoresis and UV-vis spectrometry. Association between PolCD and AMP appears more complex than the conventional Benesi-Hildebrand scheme. We identified a tight (quantitative) binding regime followed by a gradual increase of the density of AMP-bound PolCD upon increasing the concentration of PolCD. At higher concentrations, the formation of large clusters has been characterized by the increase of viscosity by several decades. Light-triggered trans-conformation of the azobenzene moieties of AMPs leads to a marked photoswitch of viscosity. Reversible viscosity swings by up to 6-fold were achieved by alternative exposure to UV and visible lights. In contrast, the composition of PolCD/AMP complexes in dilute regime does not respond to light, though subtle modifications of the structures of complexes are reflected by variation of electrophoretic mobilities and UV spectra. The properties of interpolymer clusters and photoviscosity are accordingly the result of modification of the dynamics of association. In practice, the low concentration of photochrome makes it possible to obtain rapid responses in samples having a thickness of the order of cm. The data reported provide guidelines for the formulations of CD/polymer systems, specifically, viscosity enhancers, which should show promising developments in pharmaceuticals or cosmetics.

Complexation of Fluvastatin Sodium with β-Cyclodextrin: NMR Spectroscopic Study in Solution

1H NMR spectroscopic study of fluvastatin sodium (FLU), β-Cyclodextrin (β-CD) and their mixtures confirmed the formation of FLU/β-CD inclusion complex in solution. The stoichiometry of the complex was determined to be 1:1 and the overall binding constant (Ks) was calculated to be 340 M−1. Two dimensional COSY, ROESY and DEPTO experiments were performed for the unambiguous assignment of aromatic proton resonances and it was found that two isomeric forms of FLU are present in solution. It was confirmed with the help of ROESY spectral data that only F-substituted aromatic ring penetrates the β-CD cavity and there is chiral differentiation by the β-CD as one of the isomer binds more strongly, which is indicated by the intensity of correlation peaks. The mode of penetration of the guest into the β-CD cavity was also established and structure of the complex has been proposed.

Effect of the Simultaneous Addition of β-Cyclodextrin and the Herbicide Norflurazon on Its Adsorption and Movement in Soils

The effects of beta-cyclodextrin (BCD) on the sorption-desorption and transport processes of the herbicide norflurazon (NFL) in soils of different characteristics when both are applied simultaneously have been investigated. Adsorption-desorption studies of NFL on six soils of very different characteristics in the presence of BCD have been performed using a batch equilibration method and correlated to its mobility in homogeneous hand-packed soil columns. NFL determinations were undertaken by HPLC equipped with a diode array detector at a wavelength of 220 nm. BCD was also analyzed by HPLC with fluorimetric detection using a postcolumn reaction. The interaction of NFL with BCD yielded the formation of an inclusion complex in solution. When this complex is applied to soils, a large decrease in NFL adsorption capacity and an increase in its desorption were observed, due to the higher tendency of NFL-BCD complexes to remain in solution. The results obtained in adsorption and soil column experiments indicated that the influence of BCD on NFL mobility and availability depends on the different affinities of BCD to be sorbed on soils of different characteristics and on the concentration of BCD used. The lower the concentration of BCD added, the more tenaciously it adheres to the soil, and most of the BCD molecules would be adsorbed, providing a coating to soil particles that acts as a bridge between NFL and the soil surface, acting as an adsorbent and retarding the mobility of the herbicide. At higher concentrations of BCD, or in soils where its adsorption is very low, most of the BCD molecules are in the aqueous phase and NFL molecules tend to be complexed with BCD in solution, acting then as a solubilizing agent.

New self-assembled dinuclear Pd(II) and Pt(II) metallomacrocycles of a 4,4′-bipyridin-1-ium ligand with an inner cavity

New dinuclear Pd(II) and Pt(II) metallocycles of 1-(pyridin-4-ylmethyl)-4,4′-bipyridin-1-ium ligand with an inner cavity were prepared and its inclusion complexes in solution studied. The cavity of macrocycle 6b presents a nearly optimal size to form supramolecular complexes through π-stacking interactions with electron-rich aromatic units. On the contrary, the distance between the two pseudoparallel bipyridinium units in 3b is too short to allow the insertion of aromatic guests.

Sildenafil/cyclodextrin complexation: Stability constants, thermodynamics, and guest–host interactions probed by 1H NMR and molecular modeling studies

Guest–host interactions of sildenafil (Sild) with cyclodextrins (CyDs) have been investigated using several techniques including phase solubility diagrams (PSD), differential scanning calorimetry (DSC), X-ray powder diffractometry (XRPD), proton nuclear magnetic resonance ( 1H NMR) and molecular mechanical modeling (MM +). Estimates of the complex formation constant ( K 11) show that the tendency of Sild to complex with CyDs follows the order: β-CyD > HP-β-CyD > γ-CyD, α-CyD, where K 11 values at pH 8.7 and 30 °C were 150, 68 and 46, 43 M −1, respectively. Ionization of Sild reduces its tendency to complex with β-CyD, where protonated (at pH 3.6) and anionic Sild (at pH 12.1) species have K 11 values of 17 and 42 M −1, respectively, compared with 150 M −1 for neutral Sild (at pH 8.7). The hydrophobic character of Sild was found to provide 39% of the driving force for complex stability, while other factors including specific interactions contribute −7.9 kJ/mol. Complex formation of Sild with β-CyD (Δ G° = −22.9 kJ/mol) is largely driven by enthalpy (Δ H° = −19.8 kJ/mol) and slight entropy (Δ S° = 10.3 J/mol K) changes. 1H NMR and MM + studies indicate formation of two isomeric 1:1 complexes: one involving complete inclusion of the phenyl-moiety into the β-CyD cavity while the other pertaining to partial inclusion of the pyrimidinone moiety. The dominant driving force for complexation is evidently van der Waals with very little electrostatic contribution. DSC, XRPD and 1H NMR studies proved the formation of inclusion complex in solution and the solid state.

Preparation and characterization of inclusion complex of norflurazon and beta-cyclodextrin to improve herbicide formulations.

The formulation of inclusion complexes of the herbicide norflurazon as guest and beta-cyclodextrin (beta-CD) as host has been studied as a first step in the use of cyclodextrins to obtain improved formulations of this herbicide. The interaction of norflurazon with beta-CD produced the formation of an inclusion complex in solution and in solid state. The inclusion of norflurazon in beta-CD in solution was studied by phase solubility, and an apparent stability constant of 360 M(-)(1), a 1:1 stoichiometric ratio for the complex, and up to 5-fold increase in norflurazon solubility were determined. Three processing methods (kneading, spray drying and vacuum evaporation) were used to prepare norflurazon-beta-CD solid inclusion complexes. X-ray diffraction, infrared spectroscopy, differential scanning calorimetry, and scanning electron microscopy techniques were used to study the solid complexes. From the different solid systems, an increase of norflurazon aqueous dissolution rate was obtained in comparison to the uncomplexed herbicide. This finding is a first step to obtain controlled release and/or protective formulations of norflurazon, which allow a more rational application of norflurazon, diminishing the use of organic solvents and increasing its efficacy.

Inclusion Complexes Oriented in Thermotropic Liquid-Crystalline Solvents Studied with Carbon-13 NMR

The inclusion complex of cryptophane-A and chloroform dissolved in two nonchiral liquid-crystalline environments was investigated via 13C NMR. Stable solutions of oriented complexes were prepared using aromatic (ZLI 1132) and aliphatic (ZLI 1695) thermotropic nematic liquid crystals as solvents; ordering of the complexes was manifested by the 1H−13C dipolar splitting of the 13C resonance of labeled chloroform. In both solutions, the dipolar splitting for the bound ligands was substantially larger than that obtained for the free ligands, indicating a significant increase in ligand ordering upon complexation despite the absence of direct contact with the oriented solvent molecules. A similar enhancement in ordering was observed for complexed ligands compared to that for free ligands in both liquid-crystalline solvents. Also, the application of heteronuclear decoupling to the ZLI 1695 solution resulted in a reduced line width for the bound 13C chloroform resonance, suggesting that a significant component of the observed line broadening may originate from intermolecular couplings between host and guest molecules. These results demonstrate the potential for using restored dipolar couplings to investigate structural and dynamical aspects of inclusion complexes in solution.

Utility of nuclear magnetic resonance spectroscopy to characterize the structure of dexamethasone sodium phosphate inclusion complexes with cyclodextrins in solution and to analyze potential competitive effects

The interaction between dexamethasone sodium phosphate (DSP) and four cyclodextrin (CyD) derivatives [2,6‐di‐O‐β‐cyclodextrin (DIMEB), γ‐cyclodextrin (γ‐CyD), and hydroxypropyl‐β‐cyclodextrin with either 2.7 or 4.6 degrees of substitution (HPβCyD 2.7 and HPβCyD 4.6, respectively)] was investigated by proton nuclear magnetic resonance spectroscopy (1H NMR). The data suggested the formation of inclusion complexes in solution in which B and C rings of the molecule are located inside the cavity. Nevertheless, the structure, in terms of depth within CyD, depends on the derivative considered. Molecular mechanics calculations of DSP complexes with DIMEB and γ‐CyD support the NMR results. The potential displacement of DSP from the CyD cavity by usual ophthalmic drugs (e.g., polymyxin B, trimethoprim, and benzalkonium chloride) was determined by NMR. The technique has been found useful to analyze this problem in pharmaceutical preparations

On the specificity of cyclodextrin complexes detected by electrospray mass spectrometry

α-cyclodextrin complexes with linear α,ω-dicarboxylic acids were investigated by electrospray mass spectrometry. These hydrophobic complexes are known to have an equilibrium binding constant that increases with the diacid chain length. However, the electrospray mass spectrometry (ES-MS) spectra showed that the relative intensity of the complex did not vary significantly with chain length. This contradiction is caused by a contribution of nonspecific adducts to the signal of the complex in ES-MS. In order to estimate the contribution of nonspecific adducts to the total intensity of the complexes with α-cyclodextrin, the comparison was made between α-cyclodextrin and maltohexaose, the latter being incapable of making inclusion complexes in solution. The signal observed for complexes between diacids and maltohexaose can only result from nonspecific electrostatic aggregation, and is found to be more favorable with the shorter diacids. This is also supported by MS/MS experiments. A procedure is described which allows estimation of the contribution of the nonspecific complex in the spectra of the complexes with α-cyclodextrin by using the relative intensity of the complex with maltohexaose. The contribution of the specific complex to the total signal intensity is found to increase with the diacid chain length, which is in agreement with solution behavior.

Structure, dynamics, and stability of beta-cyclodextrin inclusion complexes of aspartame and neotame.

Studies of the high-intensity sweetener aspartame show that its stability is significantly enhanced in the presence of beta-cyclodextrin (beta-CyD). At a 5:1 beta-CyD/aspartame molar ratio, the stability of aspartame is 42% greater in 4 mM phosphate buffer (pH 3.1) compared to solutions prepared without beta-CyD. Solution-state (1)H NMR experiments demonstrate the formation of 1:1 beta-CyD/aspartame complexes, stabilized by the interaction of the phenyl-ring protons of aspartame with the H3 and H5 protons of beta-CyD. Inclusion complex formation clearly accounts for the observed stability enhancement of aspartame in solution. The formation of inclusion complexes in solution is also demonstrated for beta-CyD and neotame, a structural derivative of aspartame containing an N-substituted 3,3-dimethylbutyl group. These complexes are stabilized by the interaction of beta-CyD with both phenyl-ring and dimethylbutyl protons. Solid-state NMR experiments provide additional characterization, clearly demonstrating the formation of inclusion complexes in lyophilized solids prepared from solutions of beta-CyD and either aspartame or neotame.

Molecular Modeling (MM2 and PM3) and Experimental (NMR and Thermal Analysis) Studies on the Inclusion Complex of Salbutamol and β-Cyclodextrin

The inclusion complex of salbutamol and beta-cyclodextrin (beta-CD) is studied by computational (MM2 and PM3) and experimental techniques. Molecular modeling calculations predict two different orientations of salbutamol in the beta-CD cavity in vacuo and in aqueous solution. In vacuo calculations show that the introduction of the aromatic ring of salbutamol is preferred to the introduction of the tert-butyl group into the beta-CD cavity. However, in aqueous solution both computational methods predict the introduction of the alkyl chain instead of the aromatic ring in the beta-CD cavity contrary to experimental results published previously. These quantitative predictions were experimentally confirmed here by studying the inclusion complex in solution by NMR. A 1:1 stoichiometry was found by (1)H NMR studies for this complex. A 2D ROESY (rotating-frame Overhauser enhancement spectroscopy) experiment shows that there are no cross-peaks between the aromatic protons of salbutamol and any of the protons of beta-CD. Cross-peaks for the protons of the tert-butyl group and protons inside the cavity of beta-CD demonstrate the full involvement of this group in the complexation process and confirm the orientation of the complex predicted by molecular modeling. The solid-state complex was prepared and its stoichiometry (beta-CD.C(13)H(21)NO(3).8H(2)O) and dissociation process studied by thermogravimetric analysis.

Gas-Phase Ion−Molecule Reactions between a Series of Protonated Diastereomeric Cavitands and Neutral Amines Studied by ESI-FTICRMS: Gas-Phase Inclusion Complex Formation

Ion−molecule reactions of protonated cavitands with neutral amines have been studied using electrospray ionization (ESI) Fourier transform ion cyclotron resonance (FTICR) mass spectrometry. The cavitands studied are built by bridging a resorcin[4]arene skeleton with four aryl phosphate units. Each of the PO bonds can be directed toward the inside or the outside of the cavity leading to six stable diastereoisomers. ESI proved to be an effective ionization method for the cavitands, although the range of ionic species observed strongly depended on the orientation of the PO groups in the isomers and the solvent composition used. Five protonated diastereoisomers were studied in ion−molecule reactions with various types of neutral amines, and the corresponding reaction efficiencies were calculated. The data were compared with that observed for the complexes generated in solution. Collision-induced dissociation (CID) was used to study the structure and relative stability of the complexes formed from different diastereomers both in solution and in the gas phase. The results clearly show that inclusion complexes are formed in the gas phase, but only for some isomers. Although all of the protonated diastereoisomers reacted with amines, the reaction rates were much lower for the diastereoisomers known to form inclusion complexes in solution. When a proton bound dimer was formed, which had the hydrogen bonding established outside the cavity, the reaction took place at the collision rate. Also, CID results confirmed the inclusion complex formation. The cavitand isomers, carrying two or more coordinating PO groups oriented toward the inside of the cavity, proved to be strong ligands for the charged species, including the proton, organic ammonium ions, and even alkali metal cations, with cesium showing the highest affinity.

Inclusion of Organic Pollutants in Cyclodextrins and Derivatives

Both (−)-geosmin and (+)-2-methyl-isoborneol are the main compounds responsible for the unpleas-and smells found in the vicinity of water-processing plant. Attempts to eliminate them using oxidation, filtration and/or biologic degradation processes are only partly efficient. The use of cage molecules could provide an alternative solution. In this respect, cyclodextrins and derivatives have demonstrated their role as candidates as hosts for these highly hydrophobic compounds. In this paper, we evidence the complexation of above mentionned pollutants by cyclodextrins using high-resolution proton Nuclear Magnetic Resonance spectroscopy. The latter method is also used to afford a three-dimensional structure of inclusion complexes in solution and to show that cyclodextrins can as well discriminate between the optical isomers of synthetic geosmin and methyl-isoborneol. Finally, a solution to the problem of waste waters is proposed.