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1.
Ana Figueiras Laura Ribeiro M. Teresa Vieira Francisco Veiga 《Journal of inclusion phenomena and macrocyclic chemistry》2007,57(1-4):173-177
In this work, we illustrate the usefulness of cyclodextrins, namely, methyl-β-cyclodextrin (MβCD), an amorphous, methylated
derivative of the natural β-cyclodextrin (βCD), as a tool to form an inclusion complex with omeprazole (OME), a poorly water
soluble drug. Solid binary systems between OME and MβCD were prepared experimentally in a stoichiometry 1:1 by different techniques
(physical mixing, kneading, spray-drying and freeze-drying). Afterward these products were characterized by Fourier transformation-infrared
spectroscopy (FTIR); X-ray diffractometry (XRD) and scanning electron microscopy (SEM). The results obtained suggest that
spray-drying and freeze-drying methods yield a higher degree of amorphous entities suggesting the formation of inclusion complexes
between OME and MβCD. 相似文献
2.
Carolina Jullian Muriel Alfaro Gerald Zapata-Torres Claudio Olea-Azar 《Journal of solution chemistry》2010,39(8):1168-1177
The formation of the complexes of galangin (GAL) with native β-cyclodextrin (βCD), and with its substituted counterparts such
as dimethyl-βCD (DMβCD) and hydroxypropyl-βCD (HPβCD), was studied by fluorescence spectra in aqueous medium. The binding
association constants (K
a) of the complexes were determined at different temperatures. The formation constants obtained have the following trend upon
complex formation at the three temperatures studied: HPβCD > DMβCD > βCD. The thermodynamic data for the inclusion of GAL
in DMβCD and HPβCD indicated that is mainly enthalpy driven whereas for βCD it is an entropy-driven process. 相似文献
3.
The interactions of carotenoids (bixin, β-carotene and lycopene) with CCl3OO. in aqueous and i-propylalcohol solution saturated with air have been studied by pulse radiolysis. For bixin and β-carotene
reaction products from forming process, absorbing in the region of 650 nm, is observed with concomitant carotenoid bleaching
(bixin at 500 nm, β-carotene at 450 nm). Their rate constants from forming process are 1.78 ×108 and 7.8 ×107 mol-1 · L · s-1 respectively. However, in the case of lycopene, no such a forming process of reaction as bixin and β-carotene can be observed
although there is the bleaching reaction (rate constant 4 ×107 mol-1 · L · s-1). The results suggest that the carotenoid radical cation and an additional radical are produced in the case of bixin and
β-carotene, whereas lycopene undergoes electron transfer with CCl3OO., forming cation radical. 相似文献
4.
Matioli Graciette Zanin Gisella M. De Moraes Flávio F. 《Applied biochemistry and biotechnology》2002,98(1-9):947-961
The influence of substrate or product level on the initial velocity of cyclodextrin (CD) production by cyclodextringlycosyltransferase
from a Brazilian isolate of Bacillus firmus was studied. Our results indicate that the product γ-CD is a stronger inhibitor to the reaction than β-CD. Small saccharides
could also inhibit CD production, although to a lesser extent than the products, and maltose was the strongest inhibitor among
small saccharides. Increasing substrate concentration resulted in greater reduction on enzyme activity for the formation of
β-CD than for γ-CD. We modeled the kinetics of CD production with a set of four reversible reactions including the cyclization/coupling
reaction that forms/opens CDs, and three disproportionation reactions. Our model on the initial velocity data explained well
the substrate inhibition phenomenon. Kinetic parameters were determined by fitting the initial velocity data into our model. 相似文献
5.
F. Taneri T. Güneri Z. Aigner O. Berkesi M. Kata 《Journal of Thermal Analysis and Calorimetry》2004,76(2):471-479
γ-Cyclodextrin and dimethyl-β-cyclodextrin were used as solubilizing agents for a very poorly water-soluble drug, an imidazole
derivative antifungal agent, clotrimazole; with the aim of improving the physicochemical properties of the drug. Solid products
were prepared by physical mixing, kneading, precipitation and spray-drying methods in 1:1 and 1:2 drug:cyclodextrin molar
ratios. Drug interactions were studied by thermoanalytical methods such as DSC, DTA, TG and DTG, X-ray diffractometry and
Fourier transformation-infrared spectroscopy. The results demonstrated the formation of inclusion complexes in some products.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
6.
I. Vélaz J. R. Isasi M. Sánchez M. Uzqueda G. Ponchel 《Journal of inclusion phenomena and macrocyclic chemistry》2007,57(1-4):65-68
Several β-cyclodextrin polymers (βCDP) have been obtained by cross-linking β-cyclodextrin (βCD) with the reagent epichlorohydrin
(EP). It is expected that these polymers are capable of retaining different organic molecules by adsorbing them on its network
and also by forming inclusion complexes with βCDs. In this work, two soluble polymers containing 39% and 48% βCD and other
insoluble ones with 65% and 74% βCD have been studied. The total amount of CD in the polymers could not be available for complexation.
This parameter has been calculated by means of the decrease of colour intensity of phenolphthalein solutions when different
amounts of βCDP were added. The insoluble polymer with 74% βCD appears to possess less CD available than that with 65% βCD,
probably due to the higher cross-linking degree of the former. On the other hand, a higher availability of CD is found for
the soluble polymer which contains 48% βCD. Moreover, the amount of glycerol monoether groups formed as a side effect during
the cross-linking process has been determined and related to the epichlorohydrin content, structure and swelling properties
of the polymers. It is concluded that, varying the synthesis conditions, it is possible to induce structural modifications
in the hydrogel networks which can improve their practical applications. 相似文献
7.
Angela Lopedota Adriana Trapani Annalisa Cutrignelli Valentino Laquintana Nunzio Denora Massimo Franco Giuseppe Trapani Gaetano Liso 《Journal of inclusion phenomena and macrocyclic chemistry》2007,57(1-4):425-432
The objective of this work was to develop a novel microparticulate system based on the mucoadhesive polymer Eudragit-RS 100
and cyclodextrins (CDs), potentially useful for the oral administration of Glutathione (γ–glutamylcysteinylglycine, GSH).
For this purpose, an oil-in-oil (O/O) emulsion-solvent evaporation method was used for the preparation of microparticles (MPs)
containing GSH alone or together with one of the following CDs: α-, β-, γ-, methyl-β-(Me-β-), hydroxypropyl-β-(HP-β-) or sulfobutylether-β-cyclodextrin
(SBE7m-β-CD). MPs were obtained by emulsifying a mixture of Eudragit RS 100, GSH, CD and magnesium stearate in acetone or acetonitrile
with a mixture of liquid paraffin and Span 80. Size, encapsulation efficiency, and drug release of the prepared MPs were evaluated.
The results clearly indicated that all the examined properties were dependent on the water-miscible solvents and CD used.
In particular, MPs prepared by using acetone or acetonitrile showed different size distributions with mean diameters in the
ranges 82–350 and 15–22 μm, respectively. Moreover, encapsulation efficiency values were found to be high in all cases (71–99%)
and was significantly affected by the CD type. The GSH release rates were evaluated employing dissolution media with different
pH values (1.2, 6.8 and 7.4) and the following rank order was obtained for MPs prepared using acetone: MPs incorporating Me-β-CD > MPs
without CD > MPs incorporating the remaining CDs. On the other hand, MPs prepared using acetonitrile gave the highest GSH
release rate. Finally, stability of GSH encapsulated in MPs containing HP-β-CD to enzymatic attack by pepsin A, α-chymotrypsin,
and γ-glutamyltranspeptidase was also investigated. 相似文献
8.
Ana Figueiras Laura Ribeiro J. J. Torres-Labandeira Francisco J. B. Veiga 《Journal of inclusion phenomena and macrocyclic chemistry》2007,57(1-4):531-535
Interactions between a benzimidazolic derivative, omeprazole (OME), beta-cyclodextrin (βCD) and a chemically modified βCD,
methyl-beta-cyclodextrin (MβCD) were investigated in aqueous solution by UV-VIS spectroscopy and in solid state by differential
scanning calorimetry (DSC). Phase solubility studies were used to evaluate the complexation in aqueous solution. The two solubility
diagrams obtained were AL type, indicating the formation of a drug-cyclodextrin complex with 1:1 stoichiometry. The complex of OME with MβCD showed
a higher stability constant (K
S) than those with βCD. Some evidences of inclusion complexation in solid state were obtained from DSC. Only in thermal curves
of OME-βCD lyophilized product and in OME-MβCD spray-dried and lyophilized systems the melting point of the drug disappeared
completely suggesting the possible formation of an inclusion complex. 相似文献
9.
The enantioresolution of zolmitriptan was performed using cyclodextrin (CD)-modified capillary zone electrophoresis (CZE)
with hydroxypropyl-β-CD (HP-β-CD) as the chiral selector. The influence of experimental conditions on the enantioseparation
of zolmitriptan, such as pH, temperature, applied voltage, and concentrations of running electrolyte and CD, was systematically
investigated, obtaining a baseline separation of two enantiomers by the use of a 25 mM sodium dihydrogen phosphate (SDPH)
running electrolyte (pH 2.4) containing 30 mM HP-β-CD at 15 °C. Binding constants for each enantiomer–HP-β-CD pair at different
temperatures, as well as thermodynamic parameters for binding, were calculated. A nonlinear van’t Hoff plot was obtained,
indicating that the thermodynamic parameters of complexation were temperature-dependent for zolmitriptan enantiomers. The
significant contribution of the enthalpy difference to the Gibbs free energy change suggested a stereomeric barrier mechanism
for chiral recognition.
Figure Resolution of zolmitriptan enantiomers was achieved by using CD-modified CZE
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
10.
Taneri F. Güneri T. Aigner Z. Berkesi O. Kata M. 《Journal of Thermal Analysis and Calorimetry》2003,74(3):769-777
Inclusion complexation between cyclodextrin derivatives (hydroxypropyl-β-cyclodextrin and methyl-β-cyclodextrin) and a very
poorly water-soluble antifungal agent, ketoconazole, was studied. Solid products were prepared by physical mixing, kneading
and spray-drying methods in four molecular ratios: 2:1, 1:1, 1:2 and 1:3. The possibility of complex formation between the
drug and the cyclodextrins was studied by thermal analysis. Supplementary techniques, such as X-ray diffractometry and Fourier
transformation-infrared spectroscopy, were also applied to interpret the results of the thermal study of the products.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
11.
We developed a novel computerized approach based on lag-k autocorrelation coefficients (LCCs) and linear models (LMs) to estimate the concentration of lycopene in foods by the spectroscopy. The LCCs were calculated using the data obtained using whole visible scans from 400 to 600 nm (vide supra) of lycopene standards and food samples (ketchup, tomato juice and tomato sauce). The chaotic parameter (CP) was then transferred into a LM to estimate the concentration of lycopene compound. The integrated LCC/visible spectroscopy method developed can be considered as a satisfactory analytical technique able to estimate lycopene concentration in food samples in a fast accurate way, with a mean prediction error lower than 5.7% and a mean correlation coefficient higher than 0.957. 相似文献
12.
Tiago Alves Castro Bruna Santos Leite Larissa Santos Assuno Tayane de Jesus Freitas Nelson Barros Colauto Giani Andrea Linde Deborah Murowaniecki Otero Bruna Aparecida Souza Machado Camila Duarte Ferreira Ribeiro 《Molecules (Basel, Switzerland)》2021,26(23)
Most dyes used in the food industry are synthetic and can be a health hazard. Red tomato may serve as a natural alternative dye to replace synthetic colorants. This study aimed to review the literature on the addition of red tomato products (powder tomato, paste, freeze-dried, tomato peel powder, tomato pomace) to reduce the usage of synthetic dyes in the food industry. Red tomato products have been used as coloring in pasta, bologna, sausages, cookies, crackers, macaroons, hamburgers, breads, muffins, cheeses, and nuggets. The trans-cis isomerization of lycopene by oxidative processes directly affects the color of the pigment. The lycopene contained in tomato has antioxidant activity and could reduce or eliminate other oxidants and/or synthetic preservatives in food. Moreover, tomatoes in foods have high sensory scores, nutritional appeal, and marketing potential. However, its use as a food colorant has been not extensively explored. Therefore, further studies are still required, especially on the stability of carotenoids in tomatoes used in processed foods. 相似文献
13.
Kim Lambertsen Larsen Stig Bruse Andersen Anne Louise Mørkbak Reinhard Wimmer 《Journal of inclusion phenomena and macrocyclic chemistry》2007,57(1-4):185-190
The inclusion complexes between fusidate, 3-keto fusidate, 11-keto fusidate and 11-deoxy fusidate and α-, β-, and γ-cyclodextrin
(CD) were studied using capillary electrophoresis. By monitoring the changes in mobility of the negatively charged compounds
in the presence of varying amount of CD the stability constants of the complexes formed could be obtained. In the case of
α- and β-CD the obtained results could be modelled to a simple model assuming 1:1 stoichiometry, revealing, not surprisingly,
that β-CD formed a stronger complex compared to α-CD. A model assuming 1:2 (fusidate:CD) stoichiometry could be fitted to
the data obtained with γ-CD. The results showed that the different fusidanes formed very strong 1:1 complexes with γ-CD as
well as a quite weak 1:2 complex. 3-keto-, 11-keto- and 11-deoxy-fusidate formed stronger complexes compared to fusidate,
probably due to an decrease in hydrophilicity caused by the reduced number of hydroxyl groups. The complex between γ-CD and
fusidate was studied by use of 2D-NMR spectroscopy. The results showed that most of the hydrogen atoms of fusidate show interactions
with the hydrogen atoms in the cavity of γ-CD. The interaction pattern suggests that fusidate may be fully embedded in the
cavity of γ-CD. No interactions between fusidate and the hydrogen atoms situated at the outside of the CD were found. 相似文献
14.
O. G. Ganina S. G. Zamotaeva M. A. Nosarev O. V. Kosenkova M. I. Naumov A. S. Shavyrin J.-P. Finet A. Yu. Fedorov 《Russian Chemical Bulletin》2005,54(7):1606-1611
2-(Azidomethyl)phenyllead triacetate was obtained by the reaction of 2-(azidomethyl)phenylboronic acid with lead tetraacetate.
A strategy for the synthesis of isoquinoline derivatives was proposed that involves a reaction of this organolead reagent
with enolizable substrates followed by annelation in the presence of triphenylphosphine. The use of 2-(azidomethyl)phenylboronic
acid allowed α-arylation products to be obtained from β-diketones and natural β-oxo lactones in good yields.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1560–1565, July, 2005. 相似文献
15.
Østerlie M 《Journal of chromatographic science》2005,43(9):473-477
A reverse-phase high-performance liquid chromatography (HPLC) method for the determination of lycopene in an alkaline lipid phase is described, and pigment stability in stored tomato sausage is reported. To avoid and replace the use of nitrite, lycopene from tomato products is added to minced meat and a tomato sausage with natural color is produced. Tomato sausage with and without nitrite were smoked in a smoking compartment and stored (4 degrees C and 8 degrees C) for 25 and 17 days, respectively. Among other factors, the quality of the tomato sausage depends on stability of lycopene during process and storage. Lycopene, being lipophilic, is extracted together with the polar and neutral fat in food. Efforts to purify lycopene from the fatty content will result in loss of pigment. The triacylglycerides obstruct the detection of lycopene by spectrophotometry or by HPLC with diode-array detection. To solve this problem, the triacylglycerides are hydrolyzed to free fatty acids just before analyzing lycopene on a column tolerating alkaline samples. At the end of the storage, loss of pigment in the sausage without nitrite was 26% stored at 4 degrees C and 19% at 8 degrees C. Corresponding results for the sausage with nitrite added as well as tomato paste show the loss of pigment is 20% and 45%. For each type of fatty food extracted, it is important to minimize the use of alkaline solutions because the HPLC equipment may be susceptible to alkaline conditions. 相似文献
16.
BRUNELLA CAPPELLO CLELIA DI MAIO MARIA IERVOLINO AGNESE MIRO 《Journal of inclusion phenomena and macrocyclic chemistry》2006,54(3-4):289-294
Aim of the present work was to investigate the effect of hydroxypropyl-β-cyclodextrin (HP-β-CD) on the solubility, dissolution rate and stability of Valsartan (VAL), a drug used orally for the treatment of hypertension. Phase solubility studies demonstrated the ability of the HP-β-CD to complex VAL and to increase drug solubility. The dissolved amount of VAL increased linearly with the addition of HP-β-CD according to an AL type plot. The apparent stability constant of the complex, calculated supposing a 1:1 stoichiometry, was 296±7 M−1. VAL/HP-β-CD interactions were also studied by 13C-NMR spectroscopy. Equimolar VAL/HP-β-CD solid systems were prepared by physical-mixing and freeze-drying, and their properties in the solid state studied by DSC and FT-IR analysis. The results provided clear indications of the formation of a new solid phase corresponding to the inclusion complex in the freeze-dried sample. The dissolution profiles of the drug from each solid system were affected by its physico-chemical properties, the freeze-dried being the most rapidly dissolving form. The thermal stability of the complex was studied, also determining the number and identity of the decomposition products of the drug. The stability studies revealed that the VAL/HP-β-CD complex significantly decreases the rate of VAL degradation. These results suggest that CD technology would be a very useful method to overcome the solubility and the stability problems of VAL. 相似文献
17.
Khalid R. Temsamani Harry B. Mark Wlodzimierz Kutner Apryll M. Stalcup 《Journal of Solid State Electrochemistry》2002,6(6):391-395
A functionalized stable film of poly(pyrrole-sulfated β-cyclodextrin) has been obtained electrochemically in LiClO4 aqueous solution using a simple 1:1 mixture of pyrrole (Py) monomer and sulfated β-cyclodextrin (SβCD). Different cyclic
voltammetric behavior is obtained for polypyrrole (PPy) and poly(Py-βSCD) during electrosynthesis. Scanning electron microscopy
(SEM) and energy dispersive X-ray analysis (EDAX) measurements on the two films have confirmed the presence of CD in the films
and show that CD preferentially dopes the polymer even in the presence of a large excess of perchlorate supporting electrolyte.
The morphology of the new polymers shows a more organized system under SEM examination. Contrary to conventional PPy films,
this new polymer offers a wide potential range for electroanalytical exploration from selective electrodes to preconcentration/sampling
devices.
Electronic Publication 相似文献
18.
M. I. El-Barghouthi N. A. Masoud J. K. Al-Kafawein A. A. Abdoh 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2006,80(7):1050-1055
The inclusion behavior of Itraconazole (Itra) with β-cyclodextrin (β-CD) and 2-hydroxypropyl-β-cyclodextrin (HP-β-CD) was
investigated by using phase solubility and molecular mechanics techniques. The effects of pH and temperature on complex stabilit
were also explored. The aqueous solubility of Itra was significantly enhanced as CD concentration increased. Itra tends to
form 1: 3 complexes with β-and HP-β-CD at pH ≥ 4 and 1: 2 at pH 2. Thermodynamic parameters for Itra/HP-β-CD show that the
1: 1 complex is driven by enthalpy but retarded by entropy changes. In contrast, the formation of 1: 2 and 1: 3 complexes
is largely favored by entropy due to higher desolvation induced by total enclosure of Itra with two (or three) favorably interacting
CD molecules. The inclusion mode of Itra/β-CD complexes was proved by molecular mechanics technique, which provided a powerful
means for understanding inclusion interactions and processes.
Published in Russian in Zhurnal Fizicheskoi Khimii, 2006, Vol. 80, No. 7, pp. 1200–1205.
The text was submitted by the authors in English. 相似文献
19.
Putcharin Chittiteeranon Suganya Soontaros Piamsook Pongsawasdi 《Journal of inclusion phenomena and macrocyclic chemistry》2007,57(1-4):69-73
AHTN (7-Acetyl-1,1,3,4,4,6-hexamethyl-1,2,3,4-tetrahydronaphthalene), commercially known as fixolide or tonalide, is a synthetic
fragrance widely used in replace of natural musk odor which is more expensive. It is a popular fragrance material added in
the manufacturing of personal care and household products, such as perfumes, soaps, shampoos, detergents, and fabric softeners.
AHTN is semivolatile and is degraded under light exposure and high temperature. This work focuses on the complexation of AHTN
with cyclodextrins in the effort to stabilize the fragrance material. AHTN was complexed with β-cyclodextrin, methyl (MβCD),
and hydroxypropyl (HPβCD) derivatives in the mole ratio 1:1, 1:2, and 1:3 guest:host, and the complexes formed by physical
mixing, co-precipitation, kneading, and freeze-drying were analyzed by DSC and FTIR. Percent AHTN included in the complex
was also determined by hexane extraction and GC analysis. It was found that no inclusion complex was formed in the physical
mixture. When co-precipitation method was performed, only βCD could form inclusion complex with AHTN, while the other two
derivatives could not. Using 1:2 AHTN:βCD, no free AHTN was left in the complex as evidenced by DSC and FTIR spectrum. In
kneading and freeze-drying methods, complexes could be formed with all CDs tested. However, co-precipitation method with 1:2
AHTN:βCD and kneading method with 1:2 AHTN:MβCD provided the highest complex yield with highest amount of AHTN included in
the complex. AHTN in the complex form was more stable against high temperature and UV exposure than its free form. 相似文献
20.
José Lamartine Soares-Sobrinho Monica Felts de La Roca Soares Pedro José Rolim-Neto Juan J. Torres-Labandeira 《Journal of Thermal Analysis and Calorimetry》2011,106(2):319-325
Although not being the ideal drug due to its low solubility and high toxicity, the benznidazole is the drug currently chosen
for Chagas disease treatment. The deep knowledge about the characteristics of the drug in addition to the knowledge of more
effective vectorization techniques of drugs in pharmaceutical forms allows a faster and cheaper development of a new therapeutic
alternative in comparison to the introduction of a new molecule in the treatment. The aim of this study is the characterization
of inclusion complexes Benznidazole and cyclodextrins in solid state. The interactions between Benznidazole (BNZ) and β-cyclodextrins
(β-CD) modified: randomly methylated β-CD (RMβCD) and sulfobutylether β-CD (SBβCD) were studied by differential scanning calorimetry
(DSC), fourier transform-infrared spectroscopy, RAMAN, and scanning electron microscopy. The preparation of solid-state binary
systems by different techniques, namely, kneading, evaporated, and freeze-drying. The results suggest the formation of inclusion
complexes of the drug with both CDs types in solid state by the techniques which were used, based on physicochemical data
of interaction compared to the drug or the CDs/drug physical mixture. Thus, the preparation technique played an important
role in the BNZ and modified CDs. 相似文献