Inclusion complex Dotaz Zobrazit nápovědu
Cucurbit[6]uril (CB6) and bispyridinium ethylene form a stable inclusion complex. A rotaxane derived from this complex was prepared in which a CB6 wheel shuttles along an axle in an NMR time-resolved regime.
- MeSH
- ethyleny chemie MeSH
- imidazoly chemie MeSH
- magnetická rezonanční spektroskopie MeSH
- molekulární struktura MeSH
- přemostěné cyklické sloučeniny chemie MeSH
- pyridinové sloučeniny chemie MeSH
- rotaxany chemická syntéza chemie MeSH
- teplota MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- cucurbit(6)uril MeSH Prohlížeč
- ethyleny MeSH
- imidazoly MeSH
- přemostěné cyklické sloučeniny MeSH
- pyridinové sloučeniny MeSH
- rotaxany MeSH
CONTEXT: Chlordecone (CLD) and β-hexachlorocyclohexane (β-HCH) are chlorinated pesticides that coexist as persistent organic pollutants in the groundwater of several countries in the Caribbean, being an environmental issue. This work evaluates theoretically the competitive formation of host-guest complexes pesticides@cyclodextrines (CDs) as an alternative for water purification and selective separation of pesticides. METHODS: Quantum mechanical calculations based on density functional theory (DFT) and classical molecular dynamics (MD) simulations were used to achieve information on geometries, energies, structure, and dynamics of guest-host complexes in the gas phase, implicit solvent medium, and in aqueous solutions. RESULTS: DFT studies showed that interactions of both pesticides with CDs are mediated by steric factors and guided by maximization of the hydrophobic interactions either with the other pesticide or with the CD cavity's inner atoms. MD results corroborate the formation of stable complexes of both pesticides with the studied CDs. α-CD exhibited a preference for the smaller β-HCH molecule over the CLD that could not perturb the formed complex. CONCLUSIONS: The simulation of competitive formation with γ-CD illustrated that this molecule could accommodate both pesticides inside its cavity. These results suggest that CDs with smaller cavity sizes such as α-CD could be used for selective separation of β-HCH from CLD in water bodies, while γ-CD could be used for methods that aim to remove both pesticides at the same time.
- Klíčová slova
- Cyclodextrins, DFT, Molecular dynamics, Molecular inclusion complexes, Pesticides,
- Publikační typ
- časopisecké články MeSH
This present study investigated the effect of Captisol, a chemically modified cyclodextrin, on the in vitro dissolution of glimepiride. We prepared glimepiride-Captisol complexes of different mass ratios (1:1, 1:2, and 1:3 w/w) by a physical mixing or freeze-drying technique, and found that complexation with Captisol enhanced the water solubility of glimepiride. Molecular docking and dynamic simulation predicted complex formation; at the same time, Fourier transform infrared spectroscopy, differential scanning calorimetry, powder X-ray diffractometry, and scanning electron microscope indicated molecular interactions that support complexation. We also found that an inclusion complex was better than a physical mixture in enhancing the complexation of glimepiride with Captisol and enhancing water solubility. Phase solubility study of the glimepiride-Captisol complex showed an AL-type profile, implying the formation of a 1:1 inclusion complex. The study also revealed that pH influenced the stability of the complex because the stability constant of the glimepiride-Captisol complex was higher in distilled water of pH ∼6.0 than in phosphate buffer of pH 7.2.
- Publikační typ
- časopisecké články MeSH
Per(2,3,6-tri-O-benzyl)-γ-cyclodextrin was debenzylated by DIBAL-H to produce a mixture of C6(I),C6(IV) and C6(I),C6(V) isomeric diols, which were separated and isolated. The C2-symmetrical C6(I),C6(V) diol was transformed into dithiol and dimerized to produce a γ-cyclodextrin duplex structure. A crystal structure revealed tubular cavity whose peripheries are slightly elliptically distorted. The solvent accessible volume of the cavity of the γ-CD duplex is about 740 Å(3). Due to this large inner space the duplex forms very stable inclusion complexes with steroids; bile acids examined in this study show binding affinities to the γ-cyclodextrin duplex in the range of 5.3 × 10(7) M(-1)-1.9 × 10(8) M(-1).
- MeSH
- dimerizace MeSH
- disulfidy chemie MeSH
- farmaceutická chemie metody MeSH
- gama-cyklodextriny chemická syntéza chemie MeSH
- imatinib mesylát chemie MeSH
- kalorimetrie MeSH
- kinetika MeSH
- koncentrace vodíkových iontů MeSH
- krystalografie rentgenová MeSH
- kyselina lithocholová chemie MeSH
- kyslík chemie MeSH
- magnetická rezonanční spektroskopie MeSH
- molekulární konformace MeSH
- rozpouštědla chemie MeSH
- steroidy chemie MeSH
- sulfhydrylové sloučeniny chemie MeSH
- termodynamika MeSH
- vazba proteinů MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- disulfidy MeSH
- gama-cyklodextriny MeSH
- gamma-cyclodextrin MeSH Prohlížeč
- imatinib mesylát MeSH
- kyselina lithocholová MeSH
- kyslík MeSH
- rozpouštědla MeSH
- steroidy MeSH
- sulfhydrylové sloučeniny MeSH
Due to the increase in fungal resistance to existing drugs, a need exists to search for new antifungals. This study aimed to evaluate the antifungal activity of α, β, and δ-damascone and inclusion complexes with β-cyclodextrin against different Candida spp. The inclusion complex of β-damascone was prepared by the co-evaporation method using three molar proportions (1:1; 2:1; 3:1 (βDA-βCD)) and analyzed using Fourier transform infrared spectroscopy (FTIR). Standard Candida albicans (CA INCQS 40,006), Candida krusei (CK INCQS 40,095), and Candida tropicalis (CT INCQS 40,042) strains were used to evaluate antifungal activity. The substances were tested individually or in association with fluconazole (FCZ). The IC50 and cell viability curve constructions were performed using the microdilution method. The minimum fungicidal concentration (MFC) was determined by the subculture method in a solid medium. The α, β, and δ-DA isolated or in combination with fluconazole (FCZ) showed significant antifungal activity. β-damascone showed effective complexation in the three molar proportions assayed; however, none of the inclusion complexes was demonstrated clinically significant effects against the fungal tested. Then, all compounds have shown promising antifungal activities; however, in vivo assays are necessary to have therapeutical application in the future.
- MeSH
- antifungální látky * chemie farmakologie MeSH
- beta-cyklodextriny * farmakologie MeSH
- Candida MeSH
- flukonazol farmakologie MeSH
- mikrobiální testy citlivosti MeSH
- norisoprenoidy farmakologie MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- antifungální látky * MeSH
- beta-cyklodextriny * MeSH
- flukonazol MeSH
- norisoprenoidy MeSH
The interaction of α-cyclodextrin (α-CD) with ten ionic surfactants (S) in water was systematically examined using isothermal titration calorimetry. The S comprised cationic and anionic head groups while the hydrocarbon alkyl chain length varied from eight to fourteen carbon atoms. The heat data were measured at five temperatures ranging from 283.15K to 318.15K and were treated simultaneously allowing the estimation of a thermodynamically consistent temperature dependence of the equilibrium constant, as well as the enthalpy and heat capacity for the sequential formation of the [α-CD·S] and the [α-CD2·S] inclusion complexes. All attempts to fit the data assuming that only [α-CD·S] complexes are present failed. It was found that the thermodynamic footprint of the [α-CD·S] complexes does not depend importantly on the head group, while the formation and stabilization of the [α-CD2·S] complexes is strongly influenced by the chemical nature of the polar head group. Several contributions to the thermodynamic parameters are discussed in detail. Among the studied surfactants, the decyl- and octylsulfates were identified as those with a predominant content of [α-CD2·S] complexes and hence they are promising candidates to form viscoelastic films at the liquid/air interface, as it was found previously for the dodecylsulfate surfactant.
- Klíčová slova
- -Cyclodextrin, Complexation, Inclusion complex, Isothermal titration calorimetry, Surfactant, Thermodynamic,
- Publikační typ
- časopisecké články MeSH
A new unidirectional light-driven molecular motor suitable for host-guest surface inclusion complexes with tris(o-phenylene)cyclotriphosphazene (TPP) was synthesized. The motor molecules formed regular two-dimensional trigonal arrays covering the large facets of disc-shaped TPP nanocrystals. Photochemical and thermal isomerization studies demonstrated that the light-driven rotation of the anchored motors is similar to that observed in solution and is not compromised neither by either the surface confinement or the density of surface coverage (50 vs 100%).
We have prepared organic guest molecules in which two pyridinium rings are connected through an aromatic/aliphatic bridge bearing a carboxyl group. The supramolecular interactions between these guests and macrocyclic hosts cucurbit[7]uril (CB7) and cucurbit[8]uril (CB8) has been studied. We have demonstrated that the binding modes of the complexes depend on the type of central bridge present in the guest molecules and the size of the macrocycle. We have also showed that the binding mode between cucurbiturils and guests with aromatic bridges is pH independent. On the other hand, a guest containing an aliphatic bridge and CB7 formed a pseudorotaxane, which behaved as a pH-driven molecular switch.
- MeSH
- imidazoly chemie MeSH
- magnetická rezonanční spektroskopie MeSH
- makromolekulární látky chemická syntéza chemie MeSH
- molekulární modely MeSH
- molekulární struktura MeSH
- oxid uhličitý chemie MeSH
- přemostěné cyklické sloučeniny chemie MeSH
- rotaxany chemická syntéza chemie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- carboxyl radical MeSH Prohlížeč
- cucurbit(7)uril MeSH Prohlížeč
- cucurbit(8)uril MeSH Prohlížeč
- imidazoly MeSH
- makromolekulární látky MeSH
- oxid uhličitý MeSH
- přemostěné cyklické sloučeniny MeSH
- rotaxany MeSH
The rigid duplex cyclodextrin 6 composed of two alpha-cyclodextrin macrocycles connected with two disulfide bonds in "transannular" (C6(I), C6(IV)) positions was prepared from partially debenzylated alpha-cyclodextrin 1 in four steps in 73% overall yield. In the last key step involving oxidative coupling of the thiol 5, predominance of the target duplex 6 can be attained under conditions of thermodynamic control. The structure of duplex cyclodextrin was established by MS as well as 2-D NMR methods and confirmed by a single-crystal X-ray analysis. The ability of the duplex cyclodextrin 6 to bind alpha,omega-alkanediols (C9-C14) and 1-alkanols (C9 and C10) was studied by isothermal titration calorimetry in aqueous solutions. The stability constants of the complexes gradually increase with the alkyl chain length and reach an unprecedently high value of K = 8.6 x 10(9) M(-1) for 1,14-tetradecanediol. It was found that the doubly bridged dimer 6 exhibits higher binding affinity toward the series of alpha,omega-alkanediols than the singly bridged analogue 10 by about 2 orders of magnitude in K (M(-1)) or 3.1-3.3 kcal/mol in deltaG(o), the enhancement being due to enthalpic factors. Theoretical calculations using DFT-D methods suggest that the enthalpic contribution stems from dispersion interactions.
- MeSH
- alfa-cyklodextriny chemická syntéza chemie MeSH
- alkoholy chemie MeSH
- dimerizace MeSH
- disulfidy chemie MeSH
- krystalografie rentgenová MeSH
- molekulární konformace MeSH
- molekulární modely MeSH
- termodynamika MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- alfa-cyklodextriny MeSH
- alkoholy MeSH
- alpha-cyclodextrin MeSH Prohlížeč
- disulfidy MeSH
A supramolecular complex between benzoates and a bambusuril crystallizes out immediately after mixing in chloroform but only in the presence of residual water molecules. In this complex each of the two portals of the macrocycle is occupied by one benzoate. Carboxylate groups are connected through hydrogen bonding interactions with one molecule of water positioned between them in the center of the bambusuril cavity. Similar water assisted host-guest behavior was also observed when tosylates instead of benzoates were used.
- Publikační typ
- časopisecké články MeSH
