Mesoporous silica materials containing microporous cavities provided by covalently bound ¦Â-cyclodextrin (CD ICS) were synthesized by co-condensation of a ¦Â-CD functionalized triethoxy silane (CD ICL) with tetraethyl orthosilicate (TEOS) by using neutral amine surfactants as structure directing agents (SDA). CD ICL was prepared by reacting ¦Â-CD with 3-isocyanatopropyltriethoxysilane. IR spectroscopy of CD ICL showed complete disappearance of isocyanato group at 2270 cm-1. 1H NMR results indicate an average of four isocyanate linkers covalently attached to random hydroxyl substituents of each molecule of ¦Â-CD. <p> Nine different CD ICS materials were synthesized using dodecylamine, tetradecylamine or hexadecylamine with ¦Â-CD (2, 4, and 6 mol %) with respect to TEOS. The incorporation of ¦Â-CD within the mesoporous framework was supported by IR, Raman, MALDI TOF MS, solid state 13C NMR CP-MAS and TGA results. Small angle X-ray diffraction results showed a peak at 2¦È ¡Ö 2.20, supporting the presence of an ordered silica mesostructure framework. For materials with same CD loading, the surface area and pore volume doubled as the surfactant from dodecylamine to hexadecylamine. However, as the CD loading increased from 2% to 6%, the surface area decreases by a factor of ~ 1.5. <p>MALDI TOF mass spectrometry showed two peaks at m/z 1157 a.m.u. and 1173 a.m.u. for [¦Â-CD + Na]+ and [¦Â-CD + K]+ respectively due to desorption of ¦Â-CD from the walls of the silica matrix. The 13C NMR CP MAS results showed 13C signals in the region ¦Ä=60-110 ppm due to the nuclei of ¦Â-CD. CD ICS materials were found to be effective as a sorbent in both gas and aqueous phases, respectively. The sorption capacity (mmol/g) of p-nitrophenol increased from 61% to 84% with an increase of CD loading from 2% to 6% and as the alkyl chain length of the SDA increases from dodecylamine to hexadecylamine. The adsorption isotherm of CH3Cl in the gas phase and that of p-nitrophenol in the aqueous phase at ambient temperature adopts a multilayer model of adsorption.

Mesoporous silica materials containing microporous cavities provided by covalently bound ¦Â-cyclodextrin (CD ICS) were synthesized by co-condensation of a ¦Â-CD functionalized triethoxy silane (CD ICL) with tetraethyl orthosilicate (TEOS) by using neutral amine surfactants as structure directing agents (SDA). CD ICL was prepared by reacting ¦Â-CD with 3-isocyanatopropyltriethoxysilane. IR spectroscopy of CD ICL showed complete disappearance of isocyanato group at 2270 cm-1. 1H NMR results indicate an average of four isocyanate linkers covalently attached to random hydroxyl substituents of each molecule of ¦Â-CD. <p> Nine different CD ICS materials were synthesized using dodecylamine, tetradecylamine or hexadecylamine with ¦Â-CD (2, 4, and 6 mol %) with respect to TEOS. The incorporation of ¦Â-CD within the mesoporous framework was supported by IR, Raman, MALDI TOF MS, solid state 13C NMR CP-MAS and TGA results. Small angle X-ray diffraction results showed a peak at 2¦È ¡Ö 2.20, supporting the presence of an ordered silica mesostructure framework. For materials with same CD loading, the surface area and pore volume doubled as the surfactant from dodecylamine to hexadecylamine. However, as the CD loading increased from 2% to 6%, the surface area decreases by a factor of ~ 1.5. <p>MALDI TOF mass spectrometry showed two peaks at m/z 1157 a.m.u. and 1173 a.m.u. for [¦Â-CD + Na]+ and [¦Â-CD + K]+ respectively due to desorption of ¦Â-CD from the walls of the silica matrix. The 13C NMR CP MAS results showed 13C signals in the region ¦Ä=60-110 ppm due to the nuclei of ¦Â-CD. CD ICS materials were found to be effective as a sorbent in both gas and aqueous phases, respectively. The sorption capacity (mmol/g) of p-nitrophenol increased from 61% to 84% with an increase of CD loading from 2% to 6% and as the alkyl chain length of the SDA increases from dodecylamine to hexadecylamine. The adsorption isotherm of CH3Cl in the gas phase and that of p-nitrophenol in the aqueous phase at ambient temperature adopts a multilayer model of adsorption.

Supramolecular chemistry covers intermolecular interactions where non-covalent bonds are involved, and many of them are based on host-guest interactions. Cyclodextrins (CDs) are cyclic oligosaccharides consisting of 6-, 7- or 8-glucose units, which are called alpha-, beta- or gamma-CDs, respectively. They have hydrophobic interior and hydrophilic exterior, and are widely being used as hosts for various organic molecules. The formation of CD inclusion complexes with a variety of dyes has continuously drawn our interests, since CDs are readily available and have ability to include dye molecules altering their properties. The present thesis covers the study of inclusion complexes of CDs and chromophore dyes, largely in two ways; rotaxane and pseudorotaxane. The stable rotaxane structure is achieved with the synthesis of dye rotaxane. The introduction of CD ring around azo chromophore provides a simple way to improve the solubility and stability of azo dye. We have shown that by incorporating proper compounds as a coupler, azo dye rotaxanes can be used as pH indicators and metal ion sensors. We have described the synthesis of novel acetylene dye rotaxane using the Pd-catalyzed reaction of Heck-Cassar-Sonogashira-Hagihara type. Its fluorescence properties in the solid state as well as in solutions are examined and compared with those of free dye. Free dye, which has tetra-carboxylic groups, is found to be highly sensitive to various metal ions, exhibiting high Stern-Volmer constants, K(SV). On the contrary, acetylene dye rotaxane exhibits much less quenching against various quenchers. The appearance of fluorescent anisotropic structure has been observed by the formation of inclusion complex between acetylene dye and gamma-CD. Its structural nature is studied by various techniques, including fluorescence, fluorescence anisotropy, wide angle X-ray scattering (WAXD) and differential scanning calorimetry (DSC) measurements. Methyl orange, an acid azo dye, forms a dimeric inclusion complex with gamma-CD, resulting in the formation stable anisotropic aggregates. Several other azo dyes are found to form anisotropic supramolecule in the presence of gamma-CD, and their structural characteristic has been discussed in terms of the number and position of solubilizing groups.

Single-isomer sulfated cyclodextrins (SISCDs) have proven to be reliable, effective, robust means for separation of enantiomers by capillary electrophoresis (CE). SISCD derivatives used as chiral resolving agents in CE can carry the sulfo groups either at the C2, C3 or C6 positions of the glucopyranose subunits which provides varied intermolecular interactions to bring about favorable enantioselectivities. The first single-isomer, sulfated β-CD that carries the sulfo group at the C2 position, the sodium salt of heptakis(2-O-sulfo-3-O-methyl-6-Oacetyl) cyclomaltoheptaose (HAMS) has been synthesized. The purity of each synthetic intermediate and of the final product was determined by HILIC and reversed phase HPLC. The structural identity of each intermediate and the final product was verified by 1D, and 2D NMR, and MALDI-TOF mass spectrometry. HAMS has been used as chiral resolving agent for the CE separation of a set of nonionic, weak base and strong acid enantiomers in pH 2.5 background electrolytes. Rapid separations with satisfactory peak resolution values were obtained for the enantiomers of most of the nonionic and weak base analytes. Typically, low concentrations of HAMS were required to effect good enantiomer resolution. The trends in the effective mobilities and separation selectivities as a function of HAMS concentrations followed the predictions of the ionic strength-corrected charged resolving agent migration model (CHARM model). HAMS showed poor complexation with the anionic strong electrolyte enantiomers for which no peak resolution was observed. The separation patterns observed with HAMS as chiral resolving agent were compared with those of other β-cyclodextrin analogues, including heptakis(2-O-methyl- 3-O-acetyl-6-O-sulfo)-b-cyclodextrin (HMAS), heptakis(2-O-methyl-3,6-di-O-sulfo)-b- cyclodextrin (HMdiSu), heptakis(2,3-di-O-acetyl-6-O-sulfo)-b-cyclodextrin (HDAS) and heptakis(2,3-di-O-methyl-6-O-sulfo)-b-cyclodextrin (HDMS).

No description available.

Supramolecular systems, which are formed by the noncovalent intermolecular interactions between molecules, are highly dynamic. The high reversibility of supramolecular systems leads to some functional features that cannot be achieved by the single chemical component. The kinetic information for the supramolecular systems can not be inferred from thermodynamic studies or structural studies. Furthermore, the information provided by the dynamic study can be employed to infer or explain the results from the thermodynamic study and the structural study. The first objective of this work was to study the dynamics and the binding mechanism of cucurbit[7]uril with a charged guest molecule (2-naphthyl-1-ethylammonium cation, NpAmH+). In general, the binding affinity of cucurbit[7]uril to the positively charged guests are very high compared with other host systems such as cyclodextrins and bile salt aggregates. In this work, the complexation of cucurbit[7]uril and NpAmH+ was studied from a kinetic point of view. Results showed that the high binding affinity of cucurbit[7]uril to NpAmH+ was due to the high association rate constant and the low dissociation rate constant for the complexation of cucurbit[7]uril and NpAmH+. Moreover, the competition between co-cations and NpAmH+ for the binding sites of cucurbituril molecules retarded the complexation process for cucurbit[7]uril binding to NpAmH+ and decreased the overall equilibrium constant for the formation of cucurbit[7]uril-NpAmH+ complex. The second objective of this work was to study the chiral recognition observed for the formation of 2:2 complexes between β-cyclodextrin and 2-naphthyl-1-ethanol (NpOH). The binding of β-cyclodextrin and NpOH leads to the formation of two 1:1 complexes and three 2:2 complexes. The binding dynamics of NpOH with β-cyclodextrin in the 1:1 complex is fast and occurs within microseconds. A much slower dynamics was observed for the formation of the 2:2 complex. Results showed that more 2:2 complex were formed for (R)-NpOH than for (S)-NpOH, which is due to the difference of the dissociation rate constant of the 2:2 complex for both NpOH enantiomers. The dissociation rate constant of the 2:2 complex for (R)-NpOH is 46.8% lower than that for (S)-NpOH while the association rate constant of the 2:2 complex are similar for both NpOH enantiomers. The third objective of this work was to study the dynamics and the binding mechanism of octa acid with pyrene. As known from the work of other researchers, the accessibility of small molecules (e.g. I- or O2) to pyrene bound to octa acid is largely limited by the octa acid capsule. In this study, a two-step successive process was observed for the complexation of octa acid and pyrene. The first step, which was related to the formation of octa acid-pyrene 1:1 complex, was sufficiently fast to be viewed as a pre-equilibrium process. The second step, which was related to the formation of octa acid-pyrene 2:1 complex, was slow on the millisecond – second time scale. The high binding affinity of octa acid to pyrene was observed, which is due to the low dissociation rate constant for the octa acid-pyrene 2:1 complex. / Graduate

Darbo tikslas – sumodeliuoti skystą oftalmologinę hidrofilinę sistemą su numatytais fizikocheminiais rodikliais ir įvertinti modelinės medžiagos – natrio diklofenako atpalaidavimą biofarmaciniu metodu in vitro. / Objective of work: to design liquid hydrophilic ophthalmic system with provided physicochemical characteristics and determine the release of the model material - sodium diclofenac in vitro.

A series of five linked β-cyclodextrin (βCD) dimers N,N-bis(6 [superscript]A-deoxy-6[superscript]A-β-cyclodextrinyl)-succinamide, 66βCD₂su, N-((2[superscript]A S,3 [superscript]A S)-3 [superscript]A-deoxy-3 [superscript]A-β-cyclodextrinyl)-N’-(6 [superscript]A-deoxy-6 [superscript]A -β-cyclodextrinyl)-urea, 36βCD₂su, N,N-bis((2 [superscript]A S,3 [superscript]A S)-3 [superscript]A -deoxy-3 [superscript]A-β-cyclodextrinyl)-succinamide, 33βCD₂su, N,N-bis(6[superscript]A-deoxy-6[superscript]A-β-cyclodextrinyl)-urea, 66βCD₂ur, and N-((2 [superscript]A S,3 [superscript]A S)-3 [superscript]A-deoxy-3 [superscript]A-β-cyclodextrinyl)-N’-(6 [superscript]A -deoxy-6 [superscript]A -β-cyclodextrinyl)urea, 36βCD₂ur, has been prepared. The complexation of 6-(4’-(toluidinyl)naphthalene-2-sulphonate, TNS⁻, by βCD and the five linked βCD dimers was characterized by UV, fluorescence and 2D ¹H ROESY NMR spectroscopy. In aqueous phosphate buffer at pH 7.0, I = 0.10 mol dm⁻³ and 298.2 K, TNS⁻ forms host-guest complexes with βCD of stoichiometry βCD.TNS⁻ (K₁ = 3020 and 3320 dm³ mol⁻¹) and βCD₂.TNS⁻ (K₂ = 57 and 11 dm³ mol⁻¹) where the first and second values were determined in UV and fluorescence studies, respectively. For 66βCD₂su, 36βCD₂su, 33βCD₂su, 66βCD₂ur and 36βCD₂ur, the analogous K₁ = 16100, 10900, 10700, 55100 and 18300 dm³ mol⁻¹ and K₁ = 12500, 8700, 9600, 38000 and 9800 dm³ mol⁻¹(fluorimetric studies), respectively. ¹H 2D ROESY NMR studies provided evidence for variation of the mode of complexation of the TNS⁻ guest as the βCD host is changed. The factors affecting complexation are discussed. UV and ¹H NMR studies showed that 6-(4’-(t-butyl)-phenyl)naphthalene-2-sulphonate, BNS⁻, and its dimer, (BNS⁻)₂, form host-guest complexes with βCD of the stoichiometry βCD.BNS⁻ (K₁ = 5.54 × 10⁴ dm³ mol⁻¹ ) and βCD.BNS₂ ²⁻(K₂ = 3.07 × 10² dm³ mol⁻¹ ) where the complexation constant K₁ = [βCD.BNS⁻]/([βCD][BNS⁻] and K₂ = [βCD.(BNS⁻)₂]/([βCD.BNS⁻][BNS⁻]) in aqueous phosphate buffer at pH 7.0, I = 0.10 mol dm⁻³ and 298.2 K. For 66βCD₂su, 36βCD₂su, 33βCD₂su, 66βCD₂ur and 36βCD₂ur the analogous K₁ = 125, 74, 10.2, 364 and 16.1 (× 10⁴ dm³ mol⁻¹ ) and K₂ = 25.7, 2.30, 2.57, 17.6 and 17.2 (× 10² dm³ mol⁻¹ ), respectively. For the dimerisation of BNS⁻ K[subscript]d = 2.63 × 10² dm³ mol⁻¹ . Fluorimetric studies showed that the complexation stability for βCD.BNS⁻, forms βCD. BNS⁻, 66βCD₂su.BNS⁻, 36βCD₂su.BNS⁻, 33βCD₂su. BNS⁻, 66βCD₂ur.BNS⁻ and 36βCD₂ur. BNS⁻ characterized by K₁ = 4.67, 330, 101, 11.0, 435 and 29.6 (× 10⁴ dm³ mol⁻¹ ), respectively. The factors affecting the variations in these data are discussed. The enantioselectivity of substituted βCDs 6 [superscript]A -[bis (carboxylatomethyl)amino]-6 [superscript]A -deoxy-β-cyclodextrin (6βCDidaH₂) and (2 [superscript]A S,3 [superscript]A S)-3 [superscript]A -[bis(carboxylatomethyl)amino]-3[superscript]A -deoxy-β-cyclodextrin (3βCDidaH₂) and 6 [superscript]A -[tris(carboxylatomethyl)(2- aminoethyl)amino]-6 [superscript]A -deoxy-β-cyclodextrin (6βCDedtaH₃) and their Eu³ ⁺ complexes in forming host-guest complexes with six enantiomeric guests in D₂O was studied by 1D and 2D ¹H NMR (600 MHz) spectroscopy. The guests are D/L-tryptophanate (Trp⁻), 4-hydroxyl-D/L-phenylglycinate (4HOPhg⁻), D/L-histidinate (His⁻), D/L-pheniramine (Phm), D/L-phenylglycinate (Phg⁻) and (D/L)-β-phenylserinate (βPhs⁻). Enantioselective host-guest complexation was observed between the [Eu(6βCDida)]⁺ , [Eu(3βCDida)]⁺ and [Eu(6βCDedta)] complexes and Trp⁻, [Eu(6βCDida)]⁺ and [Eu(3βCDida)]⁺ and 4HOPhg⁻, and βCD, 6βCDida²⁻, 3βCDida²⁻, 6βCDedta³⁻ and the Eu³⁺complexes of the three substituted βCDs and Phm. The His⁻, Phg⁻ and βPhs⁻ enantiomers showed no evidence for selective host-guest complexation. The preparation of 3βCDidaH₂ and 6βCDedtaH₃ and the determination of their pK[subscript]a s are also reported. In collaboration with the research group of Prof. Matthew A. Tarr, (University of New Orleans, USA), the 6βCDida²⁻ and the 6βCDedta³⁻ has been utilized to improve Fenton oxidation of aromatic pollutants. To further support to this work, the binary complexation of Fe² ⁺ by 6βCDida²⁻ has been studied by potentiometric titrations. A series of six modified poly(acrylic acid)s 3% substituted with either βCD or the adamantyl moiety with different length of substituent chain was synthesised. To advance the understanding and control of aqueous supramolecular assembly, the host-guest interactions between the βCD substituted poly(acrylic acid)s and adamantane-1-carboxylic; adamantyl substituted poly(acrylic acid)s with βCD and linked βCD dimers; and between both βCD and adamantyl substituted poly(acrylic acid)s have been studied. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1311237 / Thesis (Ph.D.) -- University of Adelaide, School of Chemistry and Physics, 2008

A series of five linked β-cyclodextrin (βCD) dimers N,N-bis(6 [superscript]A-deoxy-6[superscript]A-β-cyclodextrinyl)-succinamide, 66βCD₂su, N-((2[superscript]A S,3 [superscript]A S)-3 [superscript]A-deoxy-3 [superscript]A-β-cyclodextrinyl)-N’-(6 [superscript]A-deoxy-6 [superscript]A -β-cyclodextrinyl)-urea, 36βCD₂su, N,N-bis((2 [superscript]A S,3 [superscript]A S)-3 [superscript]A -deoxy-3 [superscript]A-β-cyclodextrinyl)-succinamide, 33βCD₂su, N,N-bis(6[superscript]A-deoxy-6[superscript]A-β-cyclodextrinyl)-urea, 66βCD₂ur, and N-((2 [superscript]A S,3 [superscript]A S)-3 [superscript]A-deoxy-3 [superscript]A-β-cyclodextrinyl)-N’-(6 [superscript]A -deoxy-6 [superscript]A -β-cyclodextrinyl)urea, 36βCD₂ur, has been prepared. The complexation of 6-(4’-(toluidinyl)naphthalene-2-sulphonate, TNS⁻, by βCD and the five linked βCD dimers was characterized by UV, fluorescence and 2D ¹H ROESY NMR spectroscopy. In aqueous phosphate buffer at pH 7.0, I = 0.10 mol dm⁻³ and 298.2 K, TNS⁻ forms host-guest complexes with βCD of stoichiometry βCD.TNS⁻ (K₁ = 3020 and 3320 dm³ mol⁻¹) and βCD₂.TNS⁻ (K₂ = 57 and 11 dm³ mol⁻¹) where the first and second values were determined in UV and fluorescence studies, respectively. For 66βCD₂su, 36βCD₂su, 33βCD₂su, 66βCD₂ur and 36βCD₂ur, the analogous K₁ = 16100, 10900, 10700, 55100 and 18300 dm³ mol⁻¹ and K₁ = 12500, 8700, 9600, 38000 and 9800 dm³ mol⁻¹(fluorimetric studies), respectively. ¹H 2D ROESY NMR studies provided evidence for variation of the mode of complexation of the TNS⁻ guest as the βCD host is changed. The factors affecting complexation are discussed. UV and ¹H NMR studies showed that 6-(4’-(t-butyl)-phenyl)naphthalene-2-sulphonate, BNS⁻, and its dimer, (BNS⁻)₂, form host-guest complexes with βCD of the stoichiometry βCD.BNS⁻ (K₁ = 5.54 × 10⁴ dm³ mol⁻¹ ) and βCD.BNS₂ ²⁻(K₂ = 3.07 × 10² dm³ mol⁻¹ ) where the complexation constant K₁ = [βCD.BNS⁻]/([βCD][BNS⁻] and K₂ = [βCD.(BNS⁻)₂]/([βCD.BNS⁻][BNS⁻]) in aqueous phosphate buffer at pH 7.0, I = 0.10 mol dm⁻³ and 298.2 K. For 66βCD₂su, 36βCD₂su, 33βCD₂su, 66βCD₂ur and 36βCD₂ur the analogous K₁ = 125, 74, 10.2, 364 and 16.1 (× 10⁴ dm³ mol⁻¹ ) and K₂ = 25.7, 2.30, 2.57, 17.6 and 17.2 (× 10² dm³ mol⁻¹ ), respectively. For the dimerisation of BNS⁻ K[subscript]d = 2.63 × 10² dm³ mol⁻¹ . Fluorimetric studies showed that the complexation stability for βCD.BNS⁻, forms βCD. BNS⁻, 66βCD₂su.BNS⁻, 36βCD₂su.BNS⁻, 33βCD₂su. BNS⁻, 66βCD₂ur.BNS⁻ and 36βCD₂ur. BNS⁻ characterized by K₁ = 4.67, 330, 101, 11.0, 435 and 29.6 (× 10⁴ dm³ mol⁻¹ ), respectively. The factors affecting the variations in these data are discussed. The enantioselectivity of substituted βCDs 6 [superscript]A -[bis (carboxylatomethyl)amino]-6 [superscript]A -deoxy-β-cyclodextrin (6βCDidaH₂) and (2 [superscript]A S,3 [superscript]A S)-3 [superscript]A -[bis(carboxylatomethyl)amino]-3[superscript]A -deoxy-β-cyclodextrin (3βCDidaH₂) and 6 [superscript]A -[tris(carboxylatomethyl)(2- aminoethyl)amino]-6 [superscript]A -deoxy-β-cyclodextrin (6βCDedtaH₃) and their Eu³ ⁺ complexes in forming host-guest complexes with six enantiomeric guests in D₂O was studied by 1D and 2D ¹H NMR (600 MHz) spectroscopy. The guests are D/L-tryptophanate (Trp⁻), 4-hydroxyl-D/L-phenylglycinate (4HOPhg⁻), D/L-histidinate (His⁻), D/L-pheniramine (Phm), D/L-phenylglycinate (Phg⁻) and (D/L)-β-phenylserinate (βPhs⁻). Enantioselective host-guest complexation was observed between the [Eu(6βCDida)]⁺ , [Eu(3βCDida)]⁺ and [Eu(6βCDedta)] complexes and Trp⁻, [Eu(6βCDida)]⁺ and [Eu(3βCDida)]⁺ and 4HOPhg⁻, and βCD, 6βCDida²⁻, 3βCDida²⁻, 6βCDedta³⁻ and the Eu³⁺complexes of the three substituted βCDs and Phm. The His⁻, Phg⁻ and βPhs⁻ enantiomers showed no evidence for selective host-guest complexation. The preparation of 3βCDidaH₂ and 6βCDedtaH₃ and the determination of their pK[subscript]a s are also reported. In collaboration with the research group of Prof. Matthew A. Tarr, (University of New Orleans, USA), the 6βCDida²⁻ and the 6βCDedta³⁻ has been utilized to improve Fenton oxidation of aromatic pollutants. To further support to this work, the binary complexation of Fe² ⁺ by 6βCDida²⁻ has been studied by potentiometric titrations. A series of six modified poly(acrylic acid)s 3% substituted with either βCD or the adamantyl moiety with different length of substituent chain was synthesised. To advance the understanding and control of aqueous supramolecular assembly, the host-guest interactions between the βCD substituted poly(acrylic acid)s and adamantane-1-carboxylic; adamantyl substituted poly(acrylic acid)s with βCD and linked βCD dimers; and between both βCD and adamantyl substituted poly(acrylic acid)s have been studied. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1311237 / Thesis (Ph.D.) -- University of Adelaide, School of Chemistry and Physics, 2008

A ciclodextrina glicosiltransferase (CGTase) é a única enzima capaz de catalisar a reação de ciclização a partir do amido e, assim, formar oligossacarídeos cíclicos conhecidos como ciclodextrinas (CDs). Através desta reação é produzida uma mistura de α-, β- e γ-CD que, respectivamente, contém 6, 7 e 8 resíduos de glicose. As CDs têm atraído enorme atenção devido ao seu grande potencial de aplicação em diversas áreas da indústria. Potencial este proporcionado por sua estrutura cônica, com interior hidrofóbico, capaz de encapsular sólidos, líquidos e gases, conferindo propriedades importantes e protegendo-os. Neste trabalho foi estudada a imobilização de uma CGTase em sílica mesoporosa de forma direcionada às cisteínas presentes em sua superfície, alterando a exposição do sítio ativo. A ligação via cisteínas nativas da proteína aumentou em quatro vezes a eficiência da imobilização, quando comparada a ligação via grupamento amino. Esta, no entanto, apresentou maior atividade enzimática em faixas mais amplas de temperatura e pH, além de maior estabilidade operacional, mantendo 100 % de sua atividade após 200 h de reação contínua a 60 °C e pH 4. Ainda que apresentando menor estabilidade da ligação, o derivado obtido por ligação dissulfeto manteve 40 % da atividade inicial durante 200 h e então, o suporte pôde ser recarregado e reutilizado por igual período. Os suportes desenvolvidos apresentaram estabilidade satisfatória, possibilitando o uso do derivado imobilizado em reator de leito fixo operado de forma contínua. Quando avaliado em relação a produção das três ciclodextrinas principais, o derivado cuja imobilização da enzima ocorreu via grupamento amino, evidenciou a possibilidade de modulação da produção apenas variando as condições de reação. α- e β-CD foram produzidas preferencialmente em pH 8,0 e 2 min (3,44 mg mL-1 e 3,51 mg mL-1, respectivamente), enquanto que pH mais ácido (4,0) e maior tempo de reação (141 min) favoreceram a formação de γ-CD (3,35 mg mL-1), com baixa formação α-CD (0,75 mg mL-1). Por fim, os resultados deste estudo evidenciam a importância da imobilização da CGTase para a estabilização de sua estrutura a fim de aplicá-la em sistemas contínuos de produção de CDs onde é possível modular o perfil dos produtos gerados em função das condições de reação, aumentando assim a produtividade do biocatalisador. / Cyclodextrin glycosyltransferase (CGTase) is the only enzyme capable of catalyzing the cyclization reaction from the starch and thus forming cyclic oligosaccharides known as cyclodextrins (CDs). Through this reaction, is produced a mixture of α-, β- and γ-CD containing, 6, 7 and 8 glucose residues respectively. Cyclodextrins (CD) have been attracting considerable attention because of its great potential for application in various areas of industry. This potential is provided by its conical structure with hydrophobic interior, capable of encapsulating solids, liquids and gases, changing important features and protecting them. In this work, the immobilization of CGTase in mesoporous silica was studied in a way directed to cysteines present on its surface, altering the exposure of the active site. The connection via native cysteine of the protein increased by four times the efficiency of immobilization compared to amino groups connection. The binding of amino groups, however, showed greater enzymatic activity in wider ranges of temperature and pH, and higher operational stability, while maintaining 100 % of its activity after 200 h of continuous reaction at 60 °C and pH 4. Although showing less stable connection, the derivative obtained by disulfide bond retained 40 % of the initial activity for 200 h and then, the support could be reloaded and reused for the same period. Developed supports showed satisfactory stability, enabling the use of the derivative assets in a packed bed reactor and operated continuously. It was demonstrated the possibility of modulating the CDs production just varying the reaction conditions, using the derivative of which the enzyme immobilization occurred via amino group, to evaluate the production of three main cyclodextrins. α- and β-CD were produced preferentially at pH 8.0 and 2 min (3.44 mg mL-1 and 3.51 mg mL-1, respectively), whereas the more acid pH (4.0) and longer reaction (141 min) favored the formation of γ-CD (3.35 mg mL-1 and 0.75 mg mL-1 of α-CD). Finally, the results of this study show the importance of the immobilization of CGTase to the stabilization of its structure in order to apply it in continuous CD production systems, where it is possible to modulate the profile of the products generated as a function of the reaction conditions, thus increasing the productivity of the biocatalyst.