In our previous study,a novel organic selenium compound Eb was synthesized and found to have significant antitumor activity with much less toxicity compared with the leading compound Ebselen.Unfortunately,Eb was pract...In our previous study,a novel organic selenium compound Eb was synthesized and found to have significant antitumor activity with much less toxicity compared with the leading compound Ebselen.Unfortunately,Eb was practically insoluble in water （2.57 μg/mL） and had very low oral bioavailability,thus its clinical application was greatly limited.In the present study,the inclusion complex of Eb with 2-hydroxypropyl-β-cyclodextrin （HP-βCD） was prepared and pharmacokinetics of Eb and the inclusion complex were investigated.The water solubility of Eb was dramatically enhanced by inclusion with HP-βCD,which reached 8.4 mg/mL.The pharmacokinetic study showed that the elimination half-life （t 1/2β） of Eb was between 22 h and 30 h and the distribution half-life （t 1/2α） of Eb was 1 h.The results indicated that Eb was rapidly distributed to tissues but slowly eliminated in rats.The absolute bioavailability of Eb/HP-βCD inclusion complex solution through the oral route was 28.3%,and it was 1552% that of Eb in its pure form.In summary,the absorption of Eb in the Eb/HP-βCD inclusion complex was better and faster than that of Eb in its pure form.展开更多
The inclusion-complex of CD-MCP （β-cyclodextrin （β-CD） including 1-methylcyclopropene （1-MCP）） was prepared and characterized. Basing on programmed-heating procedure and weight-temperature analysis, as well as...The inclusion-complex of CD-MCP （β-cyclodextrin （β-CD） including 1-methylcyclopropene （1-MCP）） was prepared and characterized. Basing on programmed-heating procedure and weight-temperature analysis, as well as the application of Satava-Sestak＇s, Ozawa＇s and Kissinger＇s methods, the mechanism and kinetics of thermal dissociation of this inclusion complex were studied. An additional mass loss is found at 170-180℃. The mechanism of thermal dissociation of CD-MCP is dominated by a one-dimensional random nucleation and subsequent growth process （A2/3）. The activation energy Es and the pre-exponential factor AS for the process are 102.14 kJ/mol and 3.63×10^10s^-1, respectively. This ES value shows that there is no strong chemical intere, ctions between β-CD and 1-MC;P,展开更多
The inclusion complexes of poorly water-soluble cephalosporin, cefuroxime axetil(CFA), were prepared with β-cyclodextrin(βCD) with or without addition of L-arginine(ARG) to improve its physicochemical properties. We...The inclusion complexes of poorly water-soluble cephalosporin, cefuroxime axetil(CFA), were prepared with β-cyclodextrin(βCD) with or without addition of L-arginine(ARG) to improve its physicochemical properties. We also investigated the effect of ARG on complexation efficiency(CE) of βCD towards CFA in an aqueous medium through phase solubility behaviour according to Higuchi and Connors. Although phase solubility studies showed AL(linear) type of solubility curve in presence and absence of ARG, the CE and association constant(Ks) of βCD towards CFA were significantly promoted in presence of ARG,justifying its use as a ternary component. The solid systems of CFA with βCD were obtained by spray drying technique with or without incorporation of ARG and characterized by differential scanning calorimetry(DSC), X-ray powder diffractometry(XRPD), scanning electron microscopy(SEM), and saturation solubility and dissolution studies. The molecular modeling studies provided a better insight into geometry and inclusion mode of CFA inside βCD cavity. The solubility and dissolution rate of CFA were significantly improved upon complexation with βCD as compared to CFA alone. However, ternary system incorporated with ARG performed better than binary system in physicochemical evaluation. In conclusion, ARG could be exploited as a ternary component to improve the physicochemical properties of CFA via βCD complexation.展开更多
The inclusion complex of β-cyclodextrin （β-CD） with 4-chlorobenzoic acid was synthesized and its crystal structure was determined by single crystal X-ray diffraction under cryogenic condition. The complex contains...The inclusion complex of β-cyclodextrin （β-CD） with 4-chlorobenzoic acid was synthesized and its crystal structure was determined by single crystal X-ray diffraction under cryogenic condition. The complex contains two β-CDs, two 4-chlorobenzoic acids and twenty-nine water molecules in the asymmetric unit, and can be formulated as 2（C42H70O35）·2（CTH5O2Cl）·29（H2O）. In the crystal lattice, two β-CDs form a face-to-face dimer jointed together through hydrogen bonding between the secondary hydroxyl groups of β--CDs. Two 4-chlorobenzoic acid molecules which contact by C-Cl…π interactions are included in the β-CD dimer cavity. The β-CD dimers are arranged in brickwork-like pattern along the crystallographic a-axis. The effect of vip molecule length on the inclusion geometry was discussed by comparative study of some fl-CD complexes containing similar vips.展开更多
Inclusion compound of retinoic acid with (-cyclodextrin was prepared by coprecipitating method, the structure of resulting product was studied by elemental analysis, differential scanning caloriemetry(DSC) analysis, F...Inclusion compound of retinoic acid with (-cyclodextrin was prepared by coprecipitating method, the structure of resulting product was studied by elemental analysis, differential scanning caloriemetry(DSC) analysis, FT-IR spectroscopy and X-ray diffractometry, and the formed supramolecule self-assembles in aqueous solution according to molar ratio 2:1 of host-vip.展开更多
A series of monomethoxy poly（ethylene glycol） （mPEG） grafted copolyglutamates （PmPEGs） were synthesized through ring-opening polymerization （ROP） followed by click chemistry. Supramolecular hydrogels based on ...A series of monomethoxy poly（ethylene glycol） （mPEG） grafted copolyglutamates （PmPEGs） were synthesized through ring-opening polymerization （ROP） followed by click chemistry. Supramolecular hydrogels based on polymer inclusion complexes （ICs） between PmPEG and α-cyclodextriri （α-CD） were prepared in aqueous solution. The rheological measurements indicated their gelation properties were affected by several factors including the mPEG length, graft density and the sample concentration. These hydrogels displayed thermo-sensitive gel-sol transition under appropriate conditions due to the reversible mPEG and α-CD inclusion complexation. These hydrogels also showed pH-sensitive behavior due to the deprotonate of carboxylic acid side groups. The ICs formation of a channel-type crystalline structure induced gelation mechanism was verified by various techniques. In vitro cytotoxicity assays demonstrated that the supramolecular hydrogels are nontoxic and cytocompatible.展开更多
An inclusion complex of b-cyclodextrin with andrographolide (Andro) was prepared by using a convenient method of microwave irradiation. The structure of the inclusion complex was determined by the 1H NMR, 2D NMR spect...An inclusion complex of b-cyclodextrin with andrographolide (Andro) was prepared by using a convenient method of microwave irradiation. The structure of the inclusion complex was determined by the 1H NMR, 2D NMR spectroscopy as well as the elemental analysis.展开更多
Inclusion complex of Orange II withβ-Cyclodextrin(β-CD)and the anti-photolysis effect under UV-light were investigated.The molar ratio of inclusion complex ofβ-Cyclodextrin and OrangeⅡis 1∶1.The formation constan...Inclusion complex of Orange II withβ-Cyclodextrin(β-CD)and the anti-photolysis effect under UV-light were investigated.The molar ratio of inclusion complex ofβ-Cyclodextrin and OrangeⅡis 1∶1.The formation constant K=1.236×10^(3)L/mol was determined by the UV and Fluorescence spectra respectively,which was quite in accordance with the calculation with a modified Benesi-Hildbrand equation.The inclusion complex was characterized by the IR spectra and the molar ratio of inclusion complex is 1∶1 too.The formation constant K=1.266×10^(3)L/mol was determined by 1 H NMR analysis and was nearly the same by UV and fluorescence spectra.The photocatalytic decolorization rate of OrangeⅡsolutions containingβ-CD and TiO_(2)was smaller by 51.9%than that of the OrangeⅡsolutions only containing TiO_(2),while in the case of direct photolysis of OrangeⅡsolutions,β-CD can lower the photolysis rate by 48.1%under UV-light.This result indicatesβ-CD can inhibit the photolysis and photocatalytic decolorization of OrangeⅡunder UV-light.Theβ-CD inclusion complex was found to be persistent to UV-light photolysis.展开更多
The solid Supramolecular complexes of β-cyclodextrin （β-CD） with ethylenediamine 1, diethylenetriamine 2 and triethylamine 3 were obtained and characterized using elemental analysis, powder X-ray diffraction, infr...The solid Supramolecular complexes of β-cyclodextrin （β-CD） with ethylenediamine 1, diethylenetriamine 2 and triethylamine 3 were obtained and characterized using elemental analysis, powder X-ray diffraction, infrared spectroscopy, thermogravimetric analysis, and ^1H nuclear magnetic resonance spectroscopy. Based on the results of elemental analysis and ^1H NMR, the vip-host stoichiometries of the three solid complexes were determined to be 5：2 for 1-β-CD, hl for 2-β-CD, and 1：3 for 3-β-CD. The yields were relative to the molar volume ratio of vip to β-CD cavity, and increased in the order： 1-β-CD〈2-3-CD〈3-β-CD. X-ray diffraction patterns of the inclusion complexes gave very good exhibitions not only in location of diffraction peaks but also in shape and diffraction intensity of the peaks due to the intermolecular complexations between β-CD and the vips. The formation of host-vip inclusion complexes exhibited obviously enhanced phase change temperatures of the complexed vips such as 1 and 3. The H-5 protons located at the narrower rim inside the CD cavity experienced a higher shift upon inclusion while all other protons experienced lower shifts.展开更多
The inclusion complex of β-cyclodextrin (β-CD) and sulfurized isobutylene (T321) was prepared with a co-precipitation method. The tribological properties of the complex with different concentrations were investigate...The inclusion complex of β-cyclodextrin (β-CD) and sulfurized isobutylene (T321) was prepared with a co-precipitation method. The tribological properties of the complex with different concentrations were investigated by a four-ball tester in the solution of polyethylene glycol-600 (PEG-600). The experimental results suggest that the complex exhibits better anti-friction and anti-wear properties than β-CD under different load conditions. The tribo-system shows the least friction coefficient when the concentration of the complex is 0.8%. During the friction process, the complex was decomposed into various molecular fragments and the T321 molecules were released onto the friction interface to provide effective lubrication. The XPS analytical results on the worn surfaces reveal that sulfide film formed by the released T321 plays a major role, and the iron alkoxide and carbon deposition films formed by the β-CD fragments have better anti-friction effect on the sulfide film surface. The interactions of different films result in the formation of a mixed boundary lubrication film.展开更多
A novel brideed bis（β-cvclodextrin）, 4, 4＇-diaminodiphenyl ether-bfiged-bis （6-aimino-6-deoxv-β-cyclodextrin） 3, has been synthesized and its inclusion complexation behavior with three linear＇vip dyes （AR, ...A novel brideed bis（β-cvclodextrin）, 4, 4＇-diaminodiphenyl ether-bfiged-bis （6-aimino-6-deoxv-β-cyclodextrin） 3, has been synthesized and its inclusion complexation behavior with three linear＇vip dyes （AR, NR and MB ） has been investigated by. means of fluorescence spectrometry. The-result obtained demonstrated that the novel bridged bis（β-cyclodextnn） showed much higher affinities towards vip dyes than native β-cyclodextrin.展开更多
Bakuchiol isolated from Psoralea corylifolia is a naturally occurring prenylated phenolic monoterpene with a variety of bioactivities.The aim of this study was to improve the water solubility and thermal stability of ...Bakuchiol isolated from Psoralea corylifolia is a naturally occurring prenylated phenolic monoterpene with a variety of bioactivities.The aim of this study was to improve the water solubility and thermal stability of bakuchiol through complexing it with hydroxypropyl-β-cyclodextrin(HP-β-CD).The bakuchiol/HP-β-CD inclusion complex's behavior and characterization were investigated by ultraviolet-visible(UV-vis)spectroscopy,Fourier transform infrared spectroscopy(FT-IR),thermogravimetric analysis(TGA),X-ray diffraction(XRD),1H nuclear magnetic resonance(NMR),and two-dimensional(2D)NMR.The obtained results indicated the formation of 1∶1 inclusion complex for bakuchiol with HP-β-CD.Water solubility of bakuchiol was significantly improved by complexation with HP-β-CD as demonstrated by phase solubility studies.The encapsulation of bakuchiol was confirmed by UV-vis,FT-IR,and XRD.The thermal stability was effectively enhanced by TGA and derivative thermogravimetry(DTG)analysis.In vitro antioxidant activity showed that bakuchiol/HP-β-CD inclusion complex had a little higher antioxidant ability than free bakuchiol.Moreover,we got the possible inclusion mode for the bakuchiol/HP-β-CD inclusion complex through NMR analysis.These results suggest that the inclusion complex can be a potentially useful approach in the design of novel formulations of bakuchiol for medical applications.展开更多
The inclusion complex of β-cyclodextrin with m-nitrophenoxyacetic acid was studied by single crystal X-ray diffraction,2D NMR spectroscopy and semi-empirical methods AMI.The crystallographic study shows that two β-c...The inclusion complex of β-cyclodextrin with m-nitrophenoxyacetic acid was studied by single crystal X-ray diffraction,2D NMR spectroscopy and semi-empirical methods AMI.The crystallographic study shows that two β-cyclodextrins are held together by hydrogen bonds to form head-to-head dimers.The disordered vip molecule adjusts itself to attain the most stable accommodation into the cavity in which the nitro group is located at the dimer interface while the carboxyl group is buried in the primary hydroxyl groups of β-cyclodextrin.The vip inside the cavity is disordered over two sites and exhibits mobility.Moreover,2D NMR spectroscopy and theoretical study show the same inclusion behavior.In comparison to the inclusion complex of β-cyclodextrin with p-nitrophenoxyacetic acid,the host-vip stoichiometries are different,i.e.,2：1 for m-nitrophenoxyacetic acid and 1：1 for p-nitrophenoxyacetic acid,while the inclusion orientation and the packing pattern of the host are similar in both complexes.展开更多
A supramolecular inclusion complex between β-cyclodextrin（β-CD） and α-naphthylacetic acid was prepared, and its crystal structure was investigated by single-crystal X-ray crystallography. The complex contains two...A supramolecular inclusion complex between β-cyclodextrin（β-CD） and α-naphthylacetic acid was prepared, and its crystal structure was investigated by single-crystal X-ray crystallography. The complex contains two β-CD molecules, one α-naphthylacetic acid, two ethanols and twenty-eight water molecules in the asymmetric unit, which could be formulated as [（C42H70O35）2·（C12H10O2）·（C2H5OH）2·28H2O]. Two β-CD molecules constitute a dimer by face-to-face contact of their secondary hydroxyl sides. At the interface of the dimer, one α-naphthylacetic acid molecule is sandwiched between two β-CD molecules. Each β-CD unit of the dimer includes one ethanol molecule in its cavity. The β-CD dimers are linked together via hydrogen bonding to form layers that are stacked in a brickwork-like pattern. The comparative study of some sandwich complexes elucidates that the interface of the β-CD dimer has a stronger inclusion capacity than the cavity of β-CD for some suitable planar vip molecules. The novel inclusion structure results from the competitive inclusion of α-naphthylacetic acid and ethanol.展开更多
The non-covalent complexes between lappaconitine （LA） and β-cyclodextrin （β-CD） have been detected and characterized by electrospray ionization combined with ion trap tandem mass spectrometry （ESI-MSn）. The ex...The non-covalent complexes between lappaconitine （LA） and β-cyclodextrin （β-CD） have been detected and characterized by electrospray ionization combined with ion trap tandem mass spectrometry （ESI-MSn）. The experimental results showed that only 1：1 non-covalent complex can be formed in different starting molar ratios of LA to β-CD. Furthermore, the diagnostic fragmentation of the β-CD-LA complex, with a significant contribution of covalent fragmentation of LA leaving the N-acetyl anthranoyl （AN） moiety inserted to β-CD, provided the convincing evidence for the formation of non-covalent complex between LA and β-CD and the cite of LA molecule included to cavity of β-CD assigned to AN residue.展开更多
Inclusion complexes(ICs) composed ofα-cyclodextrins(α-CD) and biodegradable comblike copolymers with poly(α,β-malic acid)(PMA) backbones and methylated poly(ethylene glycol)(mPEG) side chains were prepared by the ...Inclusion complexes(ICs) composed ofα-cyclodextrins(α-CD) and biodegradable comblike copolymers with poly(α,β-malic acid)(PMA) backbones and methylated poly(ethylene glycol)(mPEG) side chains were prepared by the host-vip reaction.Two series of ICs with mPEG750 and mPEG2000 were prepared.The stoichiometry(EG/CD) of all the ICs in mPEG2000 series was 3.1,no matter what the graft degree was.While in mPEG750 series,the stoichiometry(EG/CD) was very different:it increased with the amount of mPEG decreasing.Th...展开更多
The inclusion complex of podophyllotoxin (P) with β-cyclodextrin (β-CD) has been studied by X-ray diffractometry and 1HNMR、13CNMR spectroscopy. The complex structure is deduced.
This study reveals that the noncovalent complexation betweenβ-CD and Cu（HMTA）^（2＋） makes a positive contribution to the coordination interaction between Cu^（2＋） and HMTA in a tricomponent system.Besides,mono-...This study reveals that the noncovalent complexation betweenβ-CD and Cu（HMTA）^（2＋） makes a positive contribution to the coordination interaction between Cu^（2＋） and HMTA in a tricomponent system.Besides,mono- and binuclear complexes：[β-CDCu]~＋ and[Cu·β-CDCu]~＋ were observed under the condition of ESI-MS.展开更多
The inclusion behavior of 4, 4＇ -Thiodiphenol （TDP）, a typical bisphenol and endocrine disruptor, reacts with β-cyclodextrin （β-CD） in aqueous solutions has been investigated by means of UV absorption spectrum ...The inclusion behavior of 4, 4＇ -Thiodiphenol （TDP）, a typical bisphenol and endocrine disruptor, reacts with β-cyclodextrin （β-CD） in aqueous solutions has been investigated by means of UV absorption spectrum and quantum-chemical calculation with Gaussian 98 software. The results show that the inclusion behavior of TDP is quite different in acidic solutions （pH 5.9） from that in alkaline solutions （pH 10.0）. This behavior difference is attributed to the different formula structures in aqueous solutions at acidic and alkaline pH values that are demonstrated by quantum- chemical modeling and calculation. TDP forms a 1 ： 1 fl-CD inclusion complex in aqueous solutions. The equiiibrium constant K was calculated to be 553.49 L/mol at pH 5.9 and 1 318.20 L/mol at pH 10.0 respectively for the inclusion complex reaction by using the modified Benesi-Heldbrand equation. After inclusion TDP＇s structure is changed especially at the inclusion part with the bond order becoming larger, which results in inhibitive photodegradation during direct photooxidation and H2O2 assisted photooxidation.展开更多
基金Natural Science Foundation of Beijing (Grant No. 7021001)the Foundation for the Special Program of the Following Novel Candidate Drug by Beijing S&T Committee (Grant No. H20220060190)National Natural Science Foundation (Grant No.30472036)
文摘In our previous study,a novel organic selenium compound Eb was synthesized and found to have significant antitumor activity with much less toxicity compared with the leading compound Ebselen.Unfortunately,Eb was practically insoluble in water （2.57 μg/mL） and had very low oral bioavailability,thus its clinical application was greatly limited.In the present study,the inclusion complex of Eb with 2-hydroxypropyl-β-cyclodextrin （HP-βCD） was prepared and pharmacokinetics of Eb and the inclusion complex were investigated.The water solubility of Eb was dramatically enhanced by inclusion with HP-βCD,which reached 8.4 mg/mL.The pharmacokinetic study showed that the elimination half-life （t 1/2β） of Eb was between 22 h and 30 h and the distribution half-life （t 1/2α） of Eb was 1 h.The results indicated that Eb was rapidly distributed to tissues but slowly eliminated in rats.The absolute bioavailability of Eb/HP-βCD inclusion complex solution through the oral route was 28.3%,and it was 1552% that of Eb in its pure form.In summary,the absorption of Eb in the Eb/HP-βCD inclusion complex was better and faster than that of Eb in its pure form.
文摘The inclusion-complex of CD-MCP （β-cyclodextrin （β-CD） including 1-methylcyclopropene （1-MCP）） was prepared and characterized. Basing on programmed-heating procedure and weight-temperature analysis, as well as the application of Satava-Sestak＇s, Ozawa＇s and Kissinger＇s methods, the mechanism and kinetics of thermal dissociation of this inclusion complex were studied. An additional mass loss is found at 170-180℃. The mechanism of thermal dissociation of CD-MCP is dominated by a one-dimensional random nucleation and subsequent growth process （A2/3）. The activation energy Es and the pre-exponential factor AS for the process are 102.14 kJ/mol and 3.63×10^10s^-1, respectively. This ES value shows that there is no strong chemical intere, ctions between β-CD and 1-MC;P,
文摘The inclusion complexes of poorly water-soluble cephalosporin, cefuroxime axetil(CFA), were prepared with β-cyclodextrin(βCD) with or without addition of L-arginine(ARG) to improve its physicochemical properties. We also investigated the effect of ARG on complexation efficiency(CE) of βCD towards CFA in an aqueous medium through phase solubility behaviour according to Higuchi and Connors. Although phase solubility studies showed AL(linear) type of solubility curve in presence and absence of ARG, the CE and association constant(Ks) of βCD towards CFA were significantly promoted in presence of ARG,justifying its use as a ternary component. The solid systems of CFA with βCD were obtained by spray drying technique with or without incorporation of ARG and characterized by differential scanning calorimetry(DSC), X-ray powder diffractometry(XRPD), scanning electron microscopy(SEM), and saturation solubility and dissolution studies. The molecular modeling studies provided a better insight into geometry and inclusion mode of CFA inside βCD cavity. The solubility and dissolution rate of CFA were significantly improved upon complexation with βCD as compared to CFA alone. However, ternary system incorporated with ARG performed better than binary system in physicochemical evaluation. In conclusion, ARG could be exploited as a ternary component to improve the physicochemical properties of CFA via βCD complexation.
基金the financial support from the Natural Science Foundation of Hainan Province(no.808145)Doctoral Foundation of Hainan Normal University(no.103303)
文摘The inclusion complex of β-cyclodextrin （β-CD） with 4-chlorobenzoic acid was synthesized and its crystal structure was determined by single crystal X-ray diffraction under cryogenic condition. The complex contains two β-CDs, two 4-chlorobenzoic acids and twenty-nine water molecules in the asymmetric unit, and can be formulated as 2（C42H70O35）·2（CTH5O2Cl）·29（H2O）. In the crystal lattice, two β-CDs form a face-to-face dimer jointed together through hydrogen bonding between the secondary hydroxyl groups of β--CDs. Two 4-chlorobenzoic acid molecules which contact by C-Cl…π interactions are included in the β-CD dimer cavity. The β-CD dimers are arranged in brickwork-like pattern along the crystallographic a-axis. The effect of vip molecule length on the inclusion geometry was discussed by comparative study of some fl-CD complexes containing similar vips.
文摘Inclusion compound of retinoic acid with (-cyclodextrin was prepared by coprecipitating method, the structure of resulting product was studied by elemental analysis, differential scanning caloriemetry(DSC) analysis, FT-IR spectroscopy and X-ray diffractometry, and the formed supramolecule self-assembles in aqueous solution according to molar ratio 2:1 of host-vip.
基金financially supported by the National Natural Science Fund for Distinguished Young Scholars(No.51225306)the National Natural Science Foundation of China(No.21434008)
文摘A series of monomethoxy poly（ethylene glycol） （mPEG） grafted copolyglutamates （PmPEGs） were synthesized through ring-opening polymerization （ROP） followed by click chemistry. Supramolecular hydrogels based on polymer inclusion complexes （ICs） between PmPEG and α-cyclodextriri （α-CD） were prepared in aqueous solution. The rheological measurements indicated their gelation properties were affected by several factors including the mPEG length, graft density and the sample concentration. These hydrogels displayed thermo-sensitive gel-sol transition under appropriate conditions due to the reversible mPEG and α-CD inclusion complexation. These hydrogels also showed pH-sensitive behavior due to the deprotonate of carboxylic acid side groups. The ICs formation of a channel-type crystalline structure induced gelation mechanism was verified by various techniques. In vitro cytotoxicity assays demonstrated that the supramolecular hydrogels are nontoxic and cytocompatible.
文摘An inclusion complex of b-cyclodextrin with andrographolide (Andro) was prepared by using a convenient method of microwave irradiation. The structure of the inclusion complex was determined by the 1H NMR, 2D NMR spectroscopy as well as the elemental analysis.
基金Supported by the National Natural Science Foundation of China(20177017)
文摘Inclusion complex of Orange II withβ-Cyclodextrin(β-CD)and the anti-photolysis effect under UV-light were investigated.The molar ratio of inclusion complex ofβ-Cyclodextrin and OrangeⅡis 1∶1.The formation constant K=1.236×10^(3)L/mol was determined by the UV and Fluorescence spectra respectively,which was quite in accordance with the calculation with a modified Benesi-Hildbrand equation.The inclusion complex was characterized by the IR spectra and the molar ratio of inclusion complex is 1∶1 too.The formation constant K=1.266×10^(3)L/mol was determined by 1 H NMR analysis and was nearly the same by UV and fluorescence spectra.The photocatalytic decolorization rate of OrangeⅡsolutions containingβ-CD and TiO_(2)was smaller by 51.9%than that of the OrangeⅡsolutions only containing TiO_(2),while in the case of direct photolysis of OrangeⅡsolutions,β-CD can lower the photolysis rate by 48.1%under UV-light.This result indicatesβ-CD can inhibit the photolysis and photocatalytic decolorization of OrangeⅡunder UV-light.Theβ-CD inclusion complex was found to be persistent to UV-light photolysis.
文摘The solid Supramolecular complexes of β-cyclodextrin （β-CD） with ethylenediamine 1, diethylenetriamine 2 and triethylamine 3 were obtained and characterized using elemental analysis, powder X-ray diffraction, infrared spectroscopy, thermogravimetric analysis, and ^1H nuclear magnetic resonance spectroscopy. Based on the results of elemental analysis and ^1H NMR, the vip-host stoichiometries of the three solid complexes were determined to be 5：2 for 1-β-CD, hl for 2-β-CD, and 1：3 for 3-β-CD. The yields were relative to the molar volume ratio of vip to β-CD cavity, and increased in the order： 1-β-CD〈2-3-CD〈3-β-CD. X-ray diffraction patterns of the inclusion complexes gave very good exhibitions not only in location of diffraction peaks but also in shape and diffraction intensity of the peaks due to the intermolecular complexations between β-CD and the vips. The formation of host-vip inclusion complexes exhibited obviously enhanced phase change temperatures of the complexed vips such as 1 and 3. The H-5 protons located at the narrower rim inside the CD cavity experienced a higher shift upon inclusion while all other protons experienced lower shifts.
基金Funded by the National Natural Science Foundation of China(No.51075366)
文摘The inclusion complex of β-cyclodextrin (β-CD) and sulfurized isobutylene (T321) was prepared with a co-precipitation method. The tribological properties of the complex with different concentrations were investigated by a four-ball tester in the solution of polyethylene glycol-600 (PEG-600). The experimental results suggest that the complex exhibits better anti-friction and anti-wear properties than β-CD under different load conditions. The tribo-system shows the least friction coefficient when the concentration of the complex is 0.8%. During the friction process, the complex was decomposed into various molecular fragments and the T321 molecules were released onto the friction interface to provide effective lubrication. The XPS analytical results on the worn surfaces reveal that sulfide film formed by the released T321 plays a major role, and the iron alkoxide and carbon deposition films formed by the β-CD fragments have better anti-friction effect on the sulfide film surface. The interactions of different films result in the formation of a mixed boundary lubrication film.
基金supported by the Yunnan Province Natural Science Foundation （Nos. 2003C009M and 2003B0014Q）
文摘A novel brideed bis（β-cvclodextrin）, 4, 4＇-diaminodiphenyl ether-bfiged-bis （6-aimino-6-deoxv-β-cyclodextrin） 3, has been synthesized and its inclusion complexation behavior with three linear＇vip dyes （AR, NR and MB ） has been investigated by. means of fluorescence spectrometry. The-result obtained demonstrated that the novel bridged bis（β-cyclodextnn） showed much higher affinities towards vip dyes than native β-cyclodextrin.
基金Fundamental Research Funds for the Central Universities(No.2232018D3-40)National Natural Science Foundation of China(No.81671508)。
文摘Bakuchiol isolated from Psoralea corylifolia is a naturally occurring prenylated phenolic monoterpene with a variety of bioactivities.The aim of this study was to improve the water solubility and thermal stability of bakuchiol through complexing it with hydroxypropyl-β-cyclodextrin(HP-β-CD).The bakuchiol/HP-β-CD inclusion complex's behavior and characterization were investigated by ultraviolet-visible(UV-vis)spectroscopy,Fourier transform infrared spectroscopy(FT-IR),thermogravimetric analysis(TGA),X-ray diffraction(XRD),1H nuclear magnetic resonance(NMR),and two-dimensional(2D)NMR.The obtained results indicated the formation of 1∶1 inclusion complex for bakuchiol with HP-β-CD.Water solubility of bakuchiol was significantly improved by complexation with HP-β-CD as demonstrated by phase solubility studies.The encapsulation of bakuchiol was confirmed by UV-vis,FT-IR,and XRD.The thermal stability was effectively enhanced by TGA and derivative thermogravimetry(DTG)analysis.In vitro antioxidant activity showed that bakuchiol/HP-β-CD inclusion complex had a little higher antioxidant ability than free bakuchiol.Moreover,we got the possible inclusion mode for the bakuchiol/HP-β-CD inclusion complex through NMR analysis.These results suggest that the inclusion complex can be a potentially useful approach in the design of novel formulations of bakuchiol for medical applications.
文摘The inclusion complex of β-cyclodextrin with m-nitrophenoxyacetic acid was studied by single crystal X-ray diffraction,2D NMR spectroscopy and semi-empirical methods AMI.The crystallographic study shows that two β-cyclodextrins are held together by hydrogen bonds to form head-to-head dimers.The disordered vip molecule adjusts itself to attain the most stable accommodation into the cavity in which the nitro group is located at the dimer interface while the carboxyl group is buried in the primary hydroxyl groups of β-cyclodextrin.The vip inside the cavity is disordered over two sites and exhibits mobility.Moreover,2D NMR spectroscopy and theoretical study show the same inclusion behavior.In comparison to the inclusion complex of β-cyclodextrin with p-nitrophenoxyacetic acid,the host-vip stoichiometries are different,i.e.,2：1 for m-nitrophenoxyacetic acid and 1：1 for p-nitrophenoxyacetic acid,while the inclusion orientation and the packing pattern of the host are similar in both complexes.
基金Supported by the Natural Science Foundation of Hainan Province, China(No.808145)the Doctoral Foundation of Hainan Normal University, China(No.103303)the Key Discipline of Hainan Province Organic Chemistry, China(No.006).
文摘A supramolecular inclusion complex between β-cyclodextrin（β-CD） and α-naphthylacetic acid was prepared, and its crystal structure was investigated by single-crystal X-ray crystallography. The complex contains two β-CD molecules, one α-naphthylacetic acid, two ethanols and twenty-eight water molecules in the asymmetric unit, which could be formulated as [（C42H70O35）2·（C12H10O2）·（C2H5OH）2·28H2O]. Two β-CD molecules constitute a dimer by face-to-face contact of their secondary hydroxyl sides. At the interface of the dimer, one α-naphthylacetic acid molecule is sandwiched between two β-CD molecules. Each β-CD unit of the dimer includes one ethanol molecule in its cavity. The β-CD dimers are linked together via hydrogen bonding to form layers that are stacked in a brickwork-like pattern. The comparative study of some sandwich complexes elucidates that the interface of the β-CD dimer has a stronger inclusion capacity than the cavity of β-CD for some suitable planar vip molecules. The novel inclusion structure results from the competitive inclusion of α-naphthylacetic acid and ethanol.
基金supported by the National Natural Science Foundation of China(No.30472134,20173057)the State Great Basic Research Project of China(No.2003CCA03100)the Great Research Project of Chinese Academy of Sciences(No.KGCX2-SW-213-06).
文摘The non-covalent complexes between lappaconitine （LA） and β-cyclodextrin （β-CD） have been detected and characterized by electrospray ionization combined with ion trap tandem mass spectrometry （ESI-MSn）. The experimental results showed that only 1：1 non-covalent complex can be formed in different starting molar ratios of LA to β-CD. Furthermore, the diagnostic fragmentation of the β-CD-LA complex, with a significant contribution of covalent fragmentation of LA leaving the N-acetyl anthranoyl （AN） moiety inserted to β-CD, provided the convincing evidence for the formation of non-covalent complex between LA and β-CD and the cite of LA molecule included to cavity of β-CD assigned to AN residue.
基金supported by the National Basic Research Program of China(National 973 program,No2005CB623903)National Natural Science Foundation of China(No20604016)Sichuan Youth Science & Technology Foundation(No07ZQ026-013)
文摘Inclusion complexes(ICs) composed ofα-cyclodextrins(α-CD) and biodegradable comblike copolymers with poly(α,β-malic acid)(PMA) backbones and methylated poly(ethylene glycol)(mPEG) side chains were prepared by the host-vip reaction.Two series of ICs with mPEG750 and mPEG2000 were prepared.The stoichiometry(EG/CD) of all the ICs in mPEG2000 series was 3.1,no matter what the graft degree was.While in mPEG750 series,the stoichiometry(EG/CD) was very different:it increased with the amount of mPEG decreasing.Th...
文摘The inclusion complex of podophyllotoxin (P) with β-cyclodextrin (β-CD) has been studied by X-ray diffractometry and 1HNMR、13CNMR spectroscopy. The complex structure is deduced.
文摘This study reveals that the noncovalent complexation betweenβ-CD and Cu（HMTA）^（2＋） makes a positive contribution to the coordination interaction between Cu^（2＋） and HMTA in a tricomponent system.Besides,mono- and binuclear complexes：[β-CDCu]~＋ and[Cu·β-CDCu]~＋ were observed under the condition of ESI-MS.
基金Supported by the National Natural Science Foundation of China (20177017 and 20477031).
文摘The inclusion behavior of 4, 4＇ -Thiodiphenol （TDP）, a typical bisphenol and endocrine disruptor, reacts with β-cyclodextrin （β-CD） in aqueous solutions has been investigated by means of UV absorption spectrum and quantum-chemical calculation with Gaussian 98 software. The results show that the inclusion behavior of TDP is quite different in acidic solutions （pH 5.9） from that in alkaline solutions （pH 10.0）. This behavior difference is attributed to the different formula structures in aqueous solutions at acidic and alkaline pH values that are demonstrated by quantum- chemical modeling and calculation. TDP forms a 1 ： 1 fl-CD inclusion complex in aqueous solutions. The equiiibrium constant K was calculated to be 553.49 L/mol at pH 5.9 and 1 318.20 L/mol at pH 10.0 respectively for the inclusion complex reaction by using the modified Benesi-Heldbrand equation. After inclusion TDP＇s structure is changed especially at the inclusion part with the bond order becoming larger, which results in inhibitive photodegradation during direct photooxidation and H2O2 assisted photooxidation.
