The impact of cyclodextrins(CDs)on wine quality and stability remains largely unknown.This study systematically assessed the protective effect of the post-fermentation addition of CDs on color stability of red wine fr...The impact of cyclodextrins(CDs)on wine quality and stability remains largely unknown.This study systematically assessed the protective effect of the post-fermentation addition of CDs on color stability of red wine from the viewpoints of color characteristics,copigmentation and phenolic profiles.The grey relational analysis(GRA)and principal component analysis(PCA)methods were employed to dissect the key effective determinants related to color quality.The addition of CDs induced a significant hyperchromic effect of 8.19-25.40%,a significant bathochromic effect and an enhancement of the color intensity.Furthermore,the evolution of anthocyanin forms and the content of monomeric anthocyanins revealed that β-CD is a superior favorable cofactor during wine aging,but for long-term aging,2-HP-β-CD and 2-HP-γ-CD are more beneficial in promoting the formation of polymerized anthocyanins and color stability.This work provides an important reference for the use of CDs to enhance the color quality and stability of red wines.展开更多
In this study, the adsorption effect of β-cyclodextrin modified biochar (BC) on phenanthrene (PHE) in contaminated soil was investigated, aiming to provide an efficient and environmentally friendly remediation strate...In this study, the adsorption effect of β-cyclodextrin modified biochar (BC) on phenanthrene (PHE) in contaminated soil was investigated, aiming to provide an efficient and environmentally friendly remediation strategy for Polycyclic Aromatic Hydrocarbons (PAHs) contaminated soil. Through kinetic and isotherm analysis, β-CDBC-CA showed excellent phenanthrene adsorption performance, and the adsorption effect increased with the increase of time and was affected by temperature. The results show that β-CDBC-CA can not only effectively adsorb phenanthrene in soil, but also serve as a surfactant to help desorption phenanthrene adsorbed by soil organic matter and improve the efficiency of microbial degradation. The experimental data showed that the Elovich model could describe the adsorption behavior of β-CDBC-CA on phenanthrene well, while Langmuir and Freundlich models performed better in fitting parameters, revealing the adsorption mechanism of phenanthrene in contaminated soil by β-cyclodextrin-modified biochar. In addition, temperature has a significant effect on the adsorption capacity of β-CDBC-CA, and its application in soil remediation can be optimized by adjusting temperature. This study not only provides new materials and technical means for soil remediation but also provides important data support for an in-depth understanding of the environmental behavior of PAHs. By citing relevant research results, this study further improves the control and understanding of environmental risks of PAHs, which is of great significance for the protection of ecological environment and human health.展开更多
In this paper, biochar (BC) was used as raw material, activated by deionizing aqueous solution, NaCl solution, CA solution and HCl solution respectively. Epichlorohydrin (EPI) was used as crosslinking agent, and β-cy...In this paper, biochar (BC) was used as raw material, activated by deionizing aqueous solution, NaCl solution, CA solution and HCl solution respectively. Epichlorohydrin (EPI) was used as crosslinking agent, and β-cyclodextrin (β-CD) was used to modify biochar (BC). The prepared modified biochar materials were labeled with β-CDBC, β-CDBC-Na, β-CDBC-CA and β-CDBC-H, respectively. The infrared spectrum, X-ray diffractometer, scanning electron microscope and specific surface area of the four modified materials were tested. The results showed that the C-O stretching vibration peak at 1020 cm<sup>−</sup><sup>1</sup> of the modified materials was slightly offset compared with that of biochar. The characteristic absorption peaks of XRD pattern decrease obviously at 2θ = 26.7˚ and 29.5˚. It can be obviously observed on the electron microscope image that the surface is loaded or formed clathrates, and BET data and graphs also show that the specific surface area of the modified biochar is larger. Therefore, β-cyclodextrin successfully modified biochar and formed clathrates on the surface of biochar or was loaded in the pore structure of biochar, especially β-CDBC-CA achieved better modification effect. Because biochar and β-cyclodextrin raw materials are cheap, easy to prepare and green, and less prone to secondary pollution, it has a good advantage in environmental governance.展开更多
2-acetoxy-benzencarboxylic acid is one of the most famous salicylate drugs today, a pharmaceutically active compound known as aspirin. It is poorly soluble in water which results in decreased bioavailability of the dr...2-acetoxy-benzencarboxylic acid is one of the most famous salicylate drugs today, a pharmaceutically active compound known as aspirin. It is poorly soluble in water which results in decreased bioavailability of the drug in the organism. The increase in water solubility of insoluble or poorly soluble drugs is therefore of great importance, which is the aim of this study. Inclusion of the drug in the molecule with a higher water solubility significantly increases its solubility and biological availability. Natural and hydrophilic derivatives of natural cyclodextrins are in the spotlight for their role as solubilizing excipients. Studies indicate that the use of β-cyclodextrin inclusion complexes with acetylsalicylic acid formed, increases the solubility of the drug in water. Many advantages of drug-complexation with cyclodextrins have been reported in scientific literature which includes increased solubility, enhanced bioavailability, improved stability, masking of bad test or odour, reduced side effect. Orally administered aspirin requires high and frequent dosing because it undergoes extensive pre systematic metabolism. Also chronic oral aspirin use is associated with serious gastrointestinal side-effects. Complexation with CD alleviates the side effects to some extent. The bioavailability and solubility of aspirin has to be increased to overcome the side-effects of aspirin related to stomach and gastro intestinal tract. The phase solubility study was performed according to the method of Higuchi and Connors by adding the 2-acetoxi-benzencarboxylic acid in excess to different concentrations of different beta cyclodextrins solutions. Phase solubility study records shown that the stability constant and complex stoichiometry of 2-acetoxi-benzencarboxylic acid-CD complexes gives linearly improve with the concentration of CD. Complexes were analyzed by UV-VIS spectroscopy and were characterized by infrared spectroscopy.展开更多
Six peralkylated β- cyclodec\xtrins used as capillary gas chromatographic stationary phases were prepared and characterized by differential by differential scannning calorimetry(DSC) and pyrolysis gas chromatograp...Six peralkylated β- cyclodec\xtrins used as capillary gas chromatographic stationary phases were prepared and characterized by differential by differential scannning calorimetry(DSC) and pyrolysis gas chromatography (PyGC). The DSC profiles illustrated that the peralkylated β-cyclodextrins synthesized possess the supercoooled state and the glass state below their melting point The PYGC results showed that the long-chain alkylated β-cyclodextrins are more thermostable than the short-chain. one All ofthese peralkylated β-cyclodextrins are suitable for use as capillary column gas chromatographic stationary phases,which can easily be coatal on the fused silica capilary columns and have nice chromatographic retention behaviour. For example, the capillary colunns coated with these materials can excellently separate three methylphenol isomers and six dimehylphenol isomers.展开更多
A new capillary gas chromatography stationary phase, monokis (2,6 di O benzyl 3 O propyl (3’)) hexakis(2,6 di O benzyl 3 O methyl) β CD bonded polysiloxane, was synthesized. It ex...A new capillary gas chromatography stationary phase, monokis (2,6 di O benzyl 3 O propyl (3’)) hexakis(2,6 di O benzyl 3 O methyl) β CD bonded polysiloxane, was synthesized. It exhibited separation abilities to disubstituted benzene isomers and some chiral solutes. It was also found that the polarity of CD derivatives can be lowered both by chemically bonding it to polysiloxane and by diluting it in polysiloxane. The separation abilities of the polysiloxane anchored CDs (SP CD) are higher than that of the unbonded CDs (S CD) and the diluted S CD at lower column temperature. Hydrosilylation reaction is one of the best methods to lower the operating temperature of CDs.展开更多
To investigate the non-covalent interaction between cyclodextrins （CD） and lithium ion, a stoichiometry of α-CD, β-CD, heptakis（2,6-di-O-methyl）-β-CD （DM-β-CD）, or heptakis（2,3,6-tri-O-methyl）-β-CD （TM-...To investigate the non-covalent interaction between cyclodextrins （CD） and lithium ion, a stoichiometry of α-CD, β-CD, heptakis（2,6-di-O-methyl）-β-CD （DM-β-CD）, or heptakis（2,3,6-tri-O-methyl）-β-CD （TM-β-CD） was mixed with lithium salt, respectively, and then incubated at room temperature for 10 min to reach the equilibrium. In posi- tive mode, the electrospray ionization mass spectrometry （ESI-MS） results demonstrated that lithium ion can conjugate to α-, β-, DM-β- or TM-β-CD and form 1：1 stoichiometric non-covalent complexes. The binding of the complexes was further confirmed by collision- induced dissociation. The dissociation constants Kdl of four complexes （Li＋α-CD, Li＋β- CD, Li＋DM-β-CD, and Li＋TM-β-CD） were determined by mass spectrometric titration. The results showed Kdl were 18.7, 26.7, 33.6, 30.5 μmol/L for the complexes of Li＋ with α-CD, β-CD, DM-β-CD, and TM-β-CD, respectively. Kdl for the Li＋ complexes of/3-CD is smaller than that of DM-β-CD due to its steric effect of the partial substituted -CH3. The Kdl for the Li＋ complexes of DM-β-CD is nearly in agreement with that of TM-β-CD, indicating Li＋ is more likely to locate in the small rim of DM-β-CD＇s hydrophobic cavity. The DFT results showed through electrostatic interaction, one Li＋ can strongly conjugate to four neighboring oxygen atoms. For the （α-CD＋Li）＋ complex, one Li＋ may also situate the small rim of α-CD＇s hydrophobic cavity to form a non-specific host-guest complex.展开更多
A novel cyclodextrin-containing polymer was prepared by graftingβ-cyclodextrin onto the backbone of poly(D,L-lactic acid)(PLA).First,mono(6-(2-aminoethyl)amino-6-deoxy)-β-cyclodextrin(β-CD-6-en)was prepared by sulf...A novel cyclodextrin-containing polymer was prepared by graftingβ-cyclodextrin onto the backbone of poly(D,L-lactic acid)(PLA).First,mono(6-(2-aminoethyl)amino-6-deoxy)-β-cyclodextrin(β-CD-6-en)was prepared by sulfonylation and amination ofβ-cyclodextrin and modified poly(D,L-lactic acid)(MPLA)was prepared by free radical polymerization of maleic anhydride and PLA.Then,grafting ofβ-cyclodextrin derivative to MPLA backbone was carried out by N-acylation reaction of MPLA andβ-CD-6-en in dimethyl formamide.The...展开更多
A new and simple procedure for the spectrophotometric determination of the tricyclic antidepressant drug amitriptyline is proposed. The method is based on enhancement of sensitivity of the [AMIYTP]+ β-cyclodextrin an...A new and simple procedure for the spectrophotometric determination of the tricyclic antidepressant drug amitriptyline is proposed. The method is based on enhancement of sensitivity of the [AMIYTP]+ β-cyclodextrin and PEG molecules involved in formation of molecules inclusion complex, in presence of polyethylene glycol (PEG) medium. The mole ratio of [AMIYTP]+ β-cyclodextrin and PEG molecules in inclusion complex were determined by the curve fitting method. The value of molar absorptivity of {[AMIYTP: (β CD)] PEG} complex in term of the drug lies in rage of (2.20 - 2.23) × 104 L·mole–1·cm–1 at absorption maximum 242 nm. The slope, intercept and correlation co-efficient were found to be 14.21, 0.0046, and 0.998, respectively. The effect of analytical variables on the determination of the drug and composition of the ion associated complex are discussed in the paper. This method is applicable in the determina-tion of amitriptyline in the pharmaceutical preparations.展开更多
Aim To study the chromatographis beheviors of three new cinnamyl cyclodextrin derivative stationary phases. Mehtods Three new cinnamyl β-cyclodextrins, heptakis-(2, 6-di-O-cinnamyl-3-O-methyl)-β-CD, heptakis-(2, 6-...Aim To study the chromatographis beheviors of three new cinnamyl cyclodextrin derivative stationary phases. Mehtods Three new cinnamyl β-cyclodextrins, heptakis-(2, 6-di-O-cinnamyl-3-O-methyl)-β-CD, heptakis-(2, 6-di-O-cinnamyl-3-O-acetyl-)-β-CD and heptakis-2, 6-di-O-cirinamyl-3-O-trifluoroacetyl)-β-CD were synthesized and coatal on fused-silica capillary columns . Results The new stationary phases have better thermal stability, good column efficiency and excellent mpaxation power for some sutstituted benzene positional isomers. It was found that the introduction of cinnamyl groups has a significant effect on these stationary phases. Conclusion There new subetituted β-CD compounds are very suitable to be ed as gas chromatographic stationary phases.展开更多
The effect of β-cyclodextrins(β-CDs) on the enzymatical hydrolysis of chiral dichlorprop methyl ester (DCPPM) was studied. Four kinds of β-cyclodextrins(β-cyclodextrin, Partly methylated-CD(PM-β-CD), hydroxyprop...The effect of β-cyclodextrins(β-CDs) on the enzymatical hydrolysis of chiral dichlorprop methyl ester (DCPPM) was studied. Four kinds of β-cyclodextrins(β-cyclodextrin, Partly methylated-CD(PM-β-CD), hydroxypropyl-cyclodextrin(HP-β-CD) and carboxymethyl-cyclodextrin(CM-β-CD)) were used. Compared with 100% DCPPM in the absence of β-cyclodextrins, the activity of lipase decreased with the increase of β-cyclodextrin and PM-β-cyclodextrin. However, CM-β-cyclodextrin stimulated the lipase activity. The inhibition effect of β-cyclodextrin and PM-β-cyclodextrin on the hydrolysis of DCPPM is affected by many factors other than degree of the methylation blocking the active site of lipase. UV-Vis and Fourier transform infrared(FTIR) spectroscopy studies of the complexation of aqueous DCPPM with β-CDs provide fresh insight into the molecular structure of the complex and explain the effects of β-CDs on enzymatical hydrolysis of chiral DCPPM. Data showed that inclusion complexes had formed by complexation of the CM-β-CD with DCPPM and the solubility of DCPPM was increased in water, which leaded to the increased lipase activity.展开更多
Aim To study the chromatographic behaviors of two dipentyl cyclodextrin derivative stationary phases. Methods Two new β-cyclodextrin derivatives, heptakis-[2, 6-di-O-pentyl-3-O-(4-nitrobenzyl)] -β-CD and heptakis-[...Aim To study the chromatographic behaviors of two dipentyl cyclodextrin derivative stationary phases. Methods Two new β-cyclodextrin derivatives, heptakis-[2, 6-di-O-pentyl-3-O-(4-nitrobenzyl)] -β-CD and heptakis-[2, 6-di-O-pentyl-3 -O-(5 -hexenyl)]-β-CD, were synthesized and coatal on fed-silica capillary columns. The chromatographic behaviors of the columns were characterized . Results It was found that the she, polarity, and aromatic property of the substituted group at the 3-position of heptakis-(2, 6 - di - O - pentyl) - β - cyclodextrins greatly influenced their chromatographic properties and separation ability. The introduction of aromatic group or a group containing a double-bond may bring π-π interactions between the host and guest molecules, and therefore increases the separation ability of the β-CDs for substituted benzene isomers. Conclusion The new substituted β-CD compounds are very suitable for being used as gas chromatogaphic stationary phases.展开更多
A sensitive optical waveguide（OWG） sensor which can be used to detect volatile organic compounds（VOCs） was presented.The sensing device（element） was fabricated by means of the immobilization of polyvinyl pyrroli...A sensitive optical waveguide（OWG） sensor which can be used to detect volatile organic compounds（VOCs） was presented.The sensing device（element） was fabricated by means of the immobilization of polyvinyl pyrrolidone（PVP）-cyclodextrin（CD） composite film over a single-mode potassium ion exchanged glass OWG via spin-coating method.The sensor shows higher response to styrene gas than to other VOCs and displays a linear response to styrene gas in a range of 1―1000 μL/L.展开更多
The objectives of the study were to investigate the effects of β-cyclodextrin(βCD) and hydroxypropyl-β-cyclodextrin(HPβCD) on the solubility and dissolution rate of norfloxacin prepared using three different metho...The objectives of the study were to investigate the effects of β-cyclodextrin(βCD) and hydroxypropyl-β-cyclodextrin(HPβCD) on the solubility and dissolution rate of norfloxacin prepared using three different methods, at drug to cyclodextrin weight ratios of 1:1, 1:2, 1:4 and 1:8. All the methods increased the solubility and dissolution rate of norfloxacin via inclusion complexation with βCD and HPβCD. Norfloxacin was converted from crystalline to amorphous form through inclusion complexation. Solvent evaporation method was the most effective method in terms of norfloxacin solubilisation, while inclusion complex of HPβCD has higher solubility than βCD complex when prepared using the same procedure.展开更多
The conformation of mono-6-O-p-nitrobenzoyl-β-cyclodextrin was studied with B3LYP/6-311g**//PM3 calculations in vacuum and in water solution. It was concluded that the p-nitrobenzoyl group of the molecule should be ...The conformation of mono-6-O-p-nitrobenzoyl-β-cyclodextrin was studied with B3LYP/6-311g**//PM3 calculations in vacuum and in water solution. It was concluded that the p-nitrobenzoyl group of the molecule should be located above the primary hydroxyls of the cyclodextrin instead of being completely enclosed by the cavity. It was proposed that the behavior might be caused by the requirement of a cis ester bond in the self-included conformation of the molecule.展开更多
A novel β-cyclodextrin(β-CD)derivative bearing diethanolamine moiety was synthesized by a convenient method with 63% yield,and the new host compound was characterized by (13)~C-NMR,FT-IR spectra etc,
A novel chiral stationary phase （CSP） was prepared by immobilizing mono（6A-N-1-（2-hydroxyl）-phenylethylimino-6A- deoxy）-β-cyclodextrin onto the surface of silica gel via a longer spacer. This chiral stationary ...A novel chiral stationary phase （CSP） was prepared by immobilizing mono（6A-N-1-（2-hydroxyl）-phenylethylimino-6A- deoxy）-β-cyclodextrin onto the surface of silica gel via a longer spacer. This chiral stationary phase exhibited good enantioselectivity for a variety of chiral compounds under reversed-phase conditions.展开更多
Current formulation development strongly relies on trial-and-error experiments in the laboratory by pharmaceutical scientists,which is time-consuming,high cost and waste materials.This research aims to integrate vario...Current formulation development strongly relies on trial-and-error experiments in the laboratory by pharmaceutical scientists,which is time-consuming,high cost and waste materials.This research aims to integrate various computational tools,including machine learning,molecular dynamic simulation and physiologically based absorption modeling(PBAM),to enhance andrographolide(AG)/cyclodextrins(CDs)formulation design.The light GBM prediction model we built before was utilized to predict AG/CDs inclusion's binding free energy.AG/γ-CD inclusion complexes showed the strongest binding affinity,which was experimentally validated by the phase solubility study.The molecular dynamic simulation was used to investigate the inclusion mechanism between AG andγ-CD,which was experimentally characterized by DSC,FTIR and NMR techniques.PBAM was applied to simulate the in vivo behavior of the formulations,which were validated by cell and animal experiments.Cell experiments revealed that the presence of D-α-Tocopherol polyethylene glycol succinate(TPGS)significantly increased the intracellular uptake of AG in MDCKMDR1 cells and the absorptive transport of AG in MDCK-MDR1 monolayers.The relative bioavailability of the AG-CD-TPGS ternary system in rats was increased to 2.6-fold and 1.59-fold compared with crude AG and commercial dropping pills,respectively.In conclusion,this is the first time to integrate various computational tools to develop a new AG-CD-TPGS ternary formulation with significant improvement of aqueous solubility,dissolution rate and bioavailability.The integrated computational tool is a novel and robust methodology to facilitate pharmaceutical formulation design.展开更多
基金supported by the Regional Collaborative Innovation Project in Xinjiang Autonomous Region of China(2022E02011)the National Key R&D Program of China(2019YFD1002500)the Key Project of Research and Development Plan in Ningxia Hui Autonomous Region of China(2018BBF02001)。
文摘The impact of cyclodextrins(CDs)on wine quality and stability remains largely unknown.This study systematically assessed the protective effect of the post-fermentation addition of CDs on color stability of red wine from the viewpoints of color characteristics,copigmentation and phenolic profiles.The grey relational analysis(GRA)and principal component analysis(PCA)methods were employed to dissect the key effective determinants related to color quality.The addition of CDs induced a significant hyperchromic effect of 8.19-25.40%,a significant bathochromic effect and an enhancement of the color intensity.Furthermore,the evolution of anthocyanin forms and the content of monomeric anthocyanins revealed that β-CD is a superior favorable cofactor during wine aging,but for long-term aging,2-HP-β-CD and 2-HP-γ-CD are more beneficial in promoting the formation of polymerized anthocyanins and color stability.This work provides an important reference for the use of CDs to enhance the color quality and stability of red wines.
文摘In this study, the adsorption effect of β-cyclodextrin modified biochar (BC) on phenanthrene (PHE) in contaminated soil was investigated, aiming to provide an efficient and environmentally friendly remediation strategy for Polycyclic Aromatic Hydrocarbons (PAHs) contaminated soil. Through kinetic and isotherm analysis, β-CDBC-CA showed excellent phenanthrene adsorption performance, and the adsorption effect increased with the increase of time and was affected by temperature. The results show that β-CDBC-CA can not only effectively adsorb phenanthrene in soil, but also serve as a surfactant to help desorption phenanthrene adsorbed by soil organic matter and improve the efficiency of microbial degradation. The experimental data showed that the Elovich model could describe the adsorption behavior of β-CDBC-CA on phenanthrene well, while Langmuir and Freundlich models performed better in fitting parameters, revealing the adsorption mechanism of phenanthrene in contaminated soil by β-cyclodextrin-modified biochar. In addition, temperature has a significant effect on the adsorption capacity of β-CDBC-CA, and its application in soil remediation can be optimized by adjusting temperature. This study not only provides new materials and technical means for soil remediation but also provides important data support for an in-depth understanding of the environmental behavior of PAHs. By citing relevant research results, this study further improves the control and understanding of environmental risks of PAHs, which is of great significance for the protection of ecological environment and human health.
文摘In this paper, biochar (BC) was used as raw material, activated by deionizing aqueous solution, NaCl solution, CA solution and HCl solution respectively. Epichlorohydrin (EPI) was used as crosslinking agent, and β-cyclodextrin (β-CD) was used to modify biochar (BC). The prepared modified biochar materials were labeled with β-CDBC, β-CDBC-Na, β-CDBC-CA and β-CDBC-H, respectively. The infrared spectrum, X-ray diffractometer, scanning electron microscope and specific surface area of the four modified materials were tested. The results showed that the C-O stretching vibration peak at 1020 cm<sup>−</sup><sup>1</sup> of the modified materials was slightly offset compared with that of biochar. The characteristic absorption peaks of XRD pattern decrease obviously at 2θ = 26.7˚ and 29.5˚. It can be obviously observed on the electron microscope image that the surface is loaded or formed clathrates, and BET data and graphs also show that the specific surface area of the modified biochar is larger. Therefore, β-cyclodextrin successfully modified biochar and formed clathrates on the surface of biochar or was loaded in the pore structure of biochar, especially β-CDBC-CA achieved better modification effect. Because biochar and β-cyclodextrin raw materials are cheap, easy to prepare and green, and less prone to secondary pollution, it has a good advantage in environmental governance.
文摘2-acetoxy-benzencarboxylic acid is one of the most famous salicylate drugs today, a pharmaceutically active compound known as aspirin. It is poorly soluble in water which results in decreased bioavailability of the drug in the organism. The increase in water solubility of insoluble or poorly soluble drugs is therefore of great importance, which is the aim of this study. Inclusion of the drug in the molecule with a higher water solubility significantly increases its solubility and biological availability. Natural and hydrophilic derivatives of natural cyclodextrins are in the spotlight for their role as solubilizing excipients. Studies indicate that the use of β-cyclodextrin inclusion complexes with acetylsalicylic acid formed, increases the solubility of the drug in water. Many advantages of drug-complexation with cyclodextrins have been reported in scientific literature which includes increased solubility, enhanced bioavailability, improved stability, masking of bad test or odour, reduced side effect. Orally administered aspirin requires high and frequent dosing because it undergoes extensive pre systematic metabolism. Also chronic oral aspirin use is associated with serious gastrointestinal side-effects. Complexation with CD alleviates the side effects to some extent. The bioavailability and solubility of aspirin has to be increased to overcome the side-effects of aspirin related to stomach and gastro intestinal tract. The phase solubility study was performed according to the method of Higuchi and Connors by adding the 2-acetoxi-benzencarboxylic acid in excess to different concentrations of different beta cyclodextrins solutions. Phase solubility study records shown that the stability constant and complex stoichiometry of 2-acetoxi-benzencarboxylic acid-CD complexes gives linearly improve with the concentration of CD. Complexes were analyzed by UV-VIS spectroscopy and were characterized by infrared spectroscopy.
文摘Six peralkylated β- cyclodec\xtrins used as capillary gas chromatographic stationary phases were prepared and characterized by differential by differential scannning calorimetry(DSC) and pyrolysis gas chromatography (PyGC). The DSC profiles illustrated that the peralkylated β-cyclodextrins synthesized possess the supercoooled state and the glass state below their melting point The PYGC results showed that the long-chain alkylated β-cyclodextrins are more thermostable than the short-chain. one All ofthese peralkylated β-cyclodextrins are suitable for use as capillary column gas chromatographic stationary phases,which can easily be coatal on the fused silica capilary columns and have nice chromatographic retention behaviour. For example, the capillary colunns coated with these materials can excellently separate three methylphenol isomers and six dimehylphenol isomers.
文摘A new capillary gas chromatography stationary phase, monokis (2,6 di O benzyl 3 O propyl (3’)) hexakis(2,6 di O benzyl 3 O methyl) β CD bonded polysiloxane, was synthesized. It exhibited separation abilities to disubstituted benzene isomers and some chiral solutes. It was also found that the polarity of CD derivatives can be lowered both by chemically bonding it to polysiloxane and by diluting it in polysiloxane. The separation abilities of the polysiloxane anchored CDs (SP CD) are higher than that of the unbonded CDs (S CD) and the diluted S CD at lower column temperature. Hydrosilylation reaction is one of the best methods to lower the operating temperature of CDs.
文摘To investigate the non-covalent interaction between cyclodextrins （CD） and lithium ion, a stoichiometry of α-CD, β-CD, heptakis（2,6-di-O-methyl）-β-CD （DM-β-CD）, or heptakis（2,3,6-tri-O-methyl）-β-CD （TM-β-CD） was mixed with lithium salt, respectively, and then incubated at room temperature for 10 min to reach the equilibrium. In posi- tive mode, the electrospray ionization mass spectrometry （ESI-MS） results demonstrated that lithium ion can conjugate to α-, β-, DM-β- or TM-β-CD and form 1：1 stoichiometric non-covalent complexes. The binding of the complexes was further confirmed by collision- induced dissociation. The dissociation constants Kdl of four complexes （Li＋α-CD, Li＋β- CD, Li＋DM-β-CD, and Li＋TM-β-CD） were determined by mass spectrometric titration. The results showed Kdl were 18.7, 26.7, 33.6, 30.5 μmol/L for the complexes of Li＋ with α-CD, β-CD, DM-β-CD, and TM-β-CD, respectively. Kdl for the Li＋ complexes of/3-CD is smaller than that of DM-β-CD due to its steric effect of the partial substituted -CH3. The Kdl for the Li＋ complexes of DM-β-CD is nearly in agreement with that of TM-β-CD, indicating Li＋ is more likely to locate in the small rim of DM-β-CD＇s hydrophobic cavity. The DFT results showed through electrostatic interaction, one Li＋ can strongly conjugate to four neighboring oxygen atoms. For the （α-CD＋Li）＋ complex, one Li＋ may also situate the small rim of α-CD＇s hydrophobic cavity to form a non-specific host-guest complex.
基金Funded by the Natural Science Foundation of China(No.50603032)Education Commission of Chongqing(No.KJ090617)the Science and Technology Plan Project of Jiulongpo District,Chongqing,China(No.2008Q95)
文摘A novel cyclodextrin-containing polymer was prepared by graftingβ-cyclodextrin onto the backbone of poly(D,L-lactic acid)(PLA).First,mono(6-(2-aminoethyl)amino-6-deoxy)-β-cyclodextrin(β-CD-6-en)was prepared by sulfonylation and amination ofβ-cyclodextrin and modified poly(D,L-lactic acid)(MPLA)was prepared by free radical polymerization of maleic anhydride and PLA.Then,grafting ofβ-cyclodextrin derivative to MPLA backbone was carried out by N-acylation reaction of MPLA andβ-CD-6-en in dimethyl formamide.The...
文摘A new and simple procedure for the spectrophotometric determination of the tricyclic antidepressant drug amitriptyline is proposed. The method is based on enhancement of sensitivity of the [AMIYTP]+ β-cyclodextrin and PEG molecules involved in formation of molecules inclusion complex, in presence of polyethylene glycol (PEG) medium. The mole ratio of [AMIYTP]+ β-cyclodextrin and PEG molecules in inclusion complex were determined by the curve fitting method. The value of molar absorptivity of {[AMIYTP: (β CD)] PEG} complex in term of the drug lies in rage of (2.20 - 2.23) × 104 L·mole–1·cm–1 at absorption maximum 242 nm. The slope, intercept and correlation co-efficient were found to be 14.21, 0.0046, and 0.998, respectively. The effect of analytical variables on the determination of the drug and composition of the ion associated complex are discussed in the paper. This method is applicable in the determina-tion of amitriptyline in the pharmaceutical preparations.
文摘Aim To study the chromatographis beheviors of three new cinnamyl cyclodextrin derivative stationary phases. Mehtods Three new cinnamyl β-cyclodextrins, heptakis-(2, 6-di-O-cinnamyl-3-O-methyl)-β-CD, heptakis-(2, 6-di-O-cinnamyl-3-O-acetyl-)-β-CD and heptakis-2, 6-di-O-cirinamyl-3-O-trifluoroacetyl)-β-CD were synthesized and coatal on fused-silica capillary columns . Results The new stationary phases have better thermal stability, good column efficiency and excellent mpaxation power for some sutstituted benzene positional isomers. It was found that the introduction of cinnamyl groups has a significant effect on these stationary phases. Conclusion There new subetituted β-CD compounds are very suitable to be ed as gas chromatographic stationary phases.
文摘The effect of β-cyclodextrins(β-CDs) on the enzymatical hydrolysis of chiral dichlorprop methyl ester (DCPPM) was studied. Four kinds of β-cyclodextrins(β-cyclodextrin, Partly methylated-CD(PM-β-CD), hydroxypropyl-cyclodextrin(HP-β-CD) and carboxymethyl-cyclodextrin(CM-β-CD)) were used. Compared with 100% DCPPM in the absence of β-cyclodextrins, the activity of lipase decreased with the increase of β-cyclodextrin and PM-β-cyclodextrin. However, CM-β-cyclodextrin stimulated the lipase activity. The inhibition effect of β-cyclodextrin and PM-β-cyclodextrin on the hydrolysis of DCPPM is affected by many factors other than degree of the methylation blocking the active site of lipase. UV-Vis and Fourier transform infrared(FTIR) spectroscopy studies of the complexation of aqueous DCPPM with β-CDs provide fresh insight into the molecular structure of the complex and explain the effects of β-CDs on enzymatical hydrolysis of chiral DCPPM. Data showed that inclusion complexes had formed by complexation of the CM-β-CD with DCPPM and the solubility of DCPPM was increased in water, which leaded to the increased lipase activity.
文摘Aim To study the chromatographic behaviors of two dipentyl cyclodextrin derivative stationary phases. Methods Two new β-cyclodextrin derivatives, heptakis-[2, 6-di-O-pentyl-3-O-(4-nitrobenzyl)] -β-CD and heptakis-[2, 6-di-O-pentyl-3 -O-(5 -hexenyl)]-β-CD, were synthesized and coatal on fed-silica capillary columns. The chromatographic behaviors of the columns were characterized . Results It was found that the she, polarity, and aromatic property of the substituted group at the 3-position of heptakis-(2, 6 - di - O - pentyl) - β - cyclodextrins greatly influenced their chromatographic properties and separation ability. The introduction of aromatic group or a group containing a double-bond may bring π-π interactions between the host and guest molecules, and therefore increases the separation ability of the β-CDs for substituted benzene isomers. Conclusion The new substituted β-CD compounds are very suitable for being used as gas chromatogaphic stationary phases.
基金Supported by the National Natural Science Foundation of China(No.20965008)
文摘A sensitive optical waveguide（OWG） sensor which can be used to detect volatile organic compounds（VOCs） was presented.The sensing device（element） was fabricated by means of the immobilization of polyvinyl pyrrolidone（PVP）-cyclodextrin（CD） composite film over a single-mode potassium ion exchanged glass OWG via spin-coating method.The sensor shows higher response to styrene gas than to other VOCs and displays a linear response to styrene gas in a range of 1―1000 μL/L.
文摘The objectives of the study were to investigate the effects of β-cyclodextrin(βCD) and hydroxypropyl-β-cyclodextrin(HPβCD) on the solubility and dissolution rate of norfloxacin prepared using three different methods, at drug to cyclodextrin weight ratios of 1:1, 1:2, 1:4 and 1:8. All the methods increased the solubility and dissolution rate of norfloxacin via inclusion complexation with βCD and HPβCD. Norfloxacin was converted from crystalline to amorphous form through inclusion complexation. Solvent evaporation method was the most effective method in terms of norfloxacin solubilisation, while inclusion complex of HPβCD has higher solubility than βCD complex when prepared using the same procedure.
文摘The conformation of mono-6-O-p-nitrobenzoyl-β-cyclodextrin was studied with B3LYP/6-311g**//PM3 calculations in vacuum and in water solution. It was concluded that the p-nitrobenzoyl group of the molecule should be located above the primary hydroxyls of the cyclodextrin instead of being completely enclosed by the cavity. It was proposed that the behavior might be caused by the requirement of a cis ester bond in the self-included conformation of the molecule.
文摘A novel β-cyclodextrin(β-CD)derivative bearing diethanolamine moiety was synthesized by a convenient method with 63% yield,and the new host compound was characterized by (13)~C-NMR,FT-IR spectra etc,
基金Financial support from the National Natural Science Foundation of China (No.20572009)
文摘A novel chiral stationary phase （CSP） was prepared by immobilizing mono（6A-N-1-（2-hydroxyl）-phenylethylimino-6A- deoxy）-β-cyclodextrin onto the surface of silica gel via a longer spacer. This chiral stationary phase exhibited good enantioselectivity for a variety of chiral compounds under reversed-phase conditions.
基金financially supported by the FDCT Project 0029/2018/A1the University of Macao Research Grants(MYRG2019-00041-ICMS)performed in part at the High-Performance Computing Cluster(HPCC)which is supported by Information and Communication Technology Office(ICTO)of the University of Macao。
文摘Current formulation development strongly relies on trial-and-error experiments in the laboratory by pharmaceutical scientists,which is time-consuming,high cost and waste materials.This research aims to integrate various computational tools,including machine learning,molecular dynamic simulation and physiologically based absorption modeling(PBAM),to enhance andrographolide(AG)/cyclodextrins(CDs)formulation design.The light GBM prediction model we built before was utilized to predict AG/CDs inclusion's binding free energy.AG/γ-CD inclusion complexes showed the strongest binding affinity,which was experimentally validated by the phase solubility study.The molecular dynamic simulation was used to investigate the inclusion mechanism between AG andγ-CD,which was experimentally characterized by DSC,FTIR and NMR techniques.PBAM was applied to simulate the in vivo behavior of the formulations,which were validated by cell and animal experiments.Cell experiments revealed that the presence of D-α-Tocopherol polyethylene glycol succinate(TPGS)significantly increased the intracellular uptake of AG in MDCKMDR1 cells and the absorptive transport of AG in MDCK-MDR1 monolayers.The relative bioavailability of the AG-CD-TPGS ternary system in rats was increased to 2.6-fold and 1.59-fold compared with crude AG and commercial dropping pills,respectively.In conclusion,this is the first time to integrate various computational tools to develop a new AG-CD-TPGS ternary formulation with significant improvement of aqueous solubility,dissolution rate and bioavailability.The integrated computational tool is a novel and robust methodology to facilitate pharmaceutical formulation design.
