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
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
In this study, the metal coordination ability of alpha-cyclodextrin (α-CD) was employed to complex gold and thus isolate and extract it from different matrices of acid-digests of electronic waste and soil. The crude ...In this study, the metal coordination ability of alpha-cyclodextrin (α-CD) was employed to complex gold and thus isolate and extract it from different matrices of acid-digests of electronic waste and soil. The crude α-CD used was extracted from cassava and yam starch of the non-edible plant species using E. coli α-cyclodextrin glucanotransferase (α-CGTase), with yields ≥ 62%. The reaction was monitored progressively by ultraviolet-visible spectroscopy and checked with infrared spectroscopy (IR) for the presence of α-CD. The crude α-CD extract without need for purification was refluxed with gold containing-electronic waste and soil predigested in a mixture of NaBr/HNO<sub>3</sub> for 4 - 7 days. Recoveries of up to 22.9% and 70.8% gold were achieved from electronic waste and soil, respectively using 0.1 M α-CD. This approach is cheap, effective, and environmentally benign.展开更多
Supercritical CO_(2)(SC-CO_(2))extraction offers a sustainable method for obtaining solvent-free oils rich in bioactive molecules,valuable for nutraceutical and functional food products.However,the limited stability o...Supercritical CO_(2)(SC-CO_(2))extraction offers a sustainable method for obtaining solvent-free oils rich in bioactive molecules,valuable for nutraceutical and functional food products.However,the limited stability of certain extract components can hinder their application.This study exploresα,β,andγcyclodextrins(CDs)as emulsifiers to enhance SC-CO_(2)-extracted tomato oil(TO)stability.TO/CD emulsions with high oil volume fractions(φ)of 60%,65%,70%,and 75%were prepared using the three types of CDs.Onlyα-CDs formed gel-like,stable emulsions up toφ=70%.Confocal microscopy revealed that increasingφled to morphological changes,including reduced droplet size,decreased roundness,and larger coalescence zones,affecting stability and functionality.Emulsions atφ60%showed optimal performance with reduced phase separation,high viscosity,smaller droplet size,and lower coalescence.The stability of carotenoids and tocopherols was evaluated under heat(50℃)and UV-C exposure to simulate accelerated aging and sterilization.Emulsions improved carotenoid stability at elevated temperatures compared to bulk TO.Tocopherols were highly stable in bulk TO and moderately stable in TO/α-CD emulsions.Under UV-C exposure,TO/α-CD emulsions enhanced carotenoid and tocopherol stability for up to 9 h,compared to pure TO.Further analysis withα-CDs and synthetic glyceryl trioctanoate(GTO)atφ=60%,65%,and 70%replicated the concentrations of lycopene andα-tocopherol in TO.These results suggest that TO/α-CD emulsions can serve as stable,high-quality ingredients for nutraceutical and functional food applications.展开更多
α-Cyclodextrin(α-CD)is characterized by its inherent hydrophobic cavity and favorable water solubility,serving as an effective means to enhance the solubility and stability of lipophilic substances.However,the encap...α-Cyclodextrin(α-CD)is characterized by its inherent hydrophobic cavity and favorable water solubility,serving as an effective means to enhance the solubility and stability of lipophilic substances.However,the encapsulation efficiency ofα-CD inclusion complexes remains relatively low.Therefore,in this study,the regulatory mechanisms of self-assembled nanostructures ofα-CD were explored.The structural differences ofα-CD self-assembled via hydrogen bonds under various pH conditions were investigated.Taking Vitamin D_(3)(VD_(3))as an example,the impact of these structures on encapsulation efficiency was verified,and theα-CD-VD_(3)inclusion complex(IC)was characterized.At pH 9,α-CD exhibited the smallest average particle size(134.36±1.17 nm)and the highest zeta potential(-43.20±1.94 mV),indicating excellent thermal stability.Fourier-transform infrared spectroscopy and proton nuclear magnetic resonance analyses revealed minimal hydrogen bonding betweenα-CD molecules at this pH,resulting in a maximum encapsulation efficiency of 89.27%forα-CD-VD_(3).The continuous variation method confirmed the formation of theα-CD-VD_(3)IC,with a binding constant of 265.32 M-1 and a Gibbs free energy of-3.30 kcal/mol.Theα-CD-VD_(3)aqueous solution demonstrated good stability under varying pH and salt ion conditions.In vitro release studies showed that theα-CD-VD_(3)IC was stable in simulated gastric fluid and efficiently released VD_(3)in simulated intestinal fluid.A stable aqueous delivery system based on the selfassembled structure ofα-CD has been successfully developed in this study,which holds broad application prospects in various fields,including pharmaceutical and food sciences.展开更多
Fluvoxamine(FXM)is a well-known selective serotonin reuptake inhibitor(SSRI)for treating depression and has recently been repurposed for efficacious treatment of coronavirus disease 2019.Although cyclodextrin(CD)encap...Fluvoxamine(FXM)is a well-known selective serotonin reuptake inhibitor(SSRI)for treating depression and has recently been repurposed for efficacious treatment of coronavirus disease 2019.Although cyclodextrin(CD)encapsulation effectively improves the physicochemical properties of structurally diverse SSRIs,the molecular understanding of their associations is deficient.This comprehensive study used single-crystal X-ray diffraction integrated with density functional theory(DFT)calculation to provide deep insights into the conformationally flexible FXM and its inclusion complexation withβ-CD.Xray analysis revealed the first crystallographic evidence of the uncomplexed 3FXM-H^(+)·3maleate-(1).Three FXM-H^(+)ions are counter-balanced by three planar maleate-ions to form a thin layer stabilized by infinite fused H-bond rings R_(4)^(4)(12)and R_(6)^(4)(16)and the interplay ofπ…π,CF…πand F…F interactions.For 2β-CD·2FXM-H^(+)·maleate^(2-)·23·2H_(2)O(2),the tail-to-tailβ-CD dimer encapsulates two FXM-H^(+)4-(trifluoromethyl)phenyl moieties,which are charge-balanced by the rare non-planar maleate2and stabilized by N…OH…O H-bonds and F…F interactions.This is a hostevip recognition pattern uniquely observed for allβ-CD complexes with halogen(X)-bearing SSRIs,indicating the essence of X…X interactions and the shielding of X-containing moieties in the wall of theβ-CD dimer.DFT calculations unveiled that the monomeric and dimericβ-CD-FXM complexes and FXM isomers are energetically stable,which alleviates the numbness and bitterness of the orally administered drug as previously patented.Additionally,an insightful conformational analysis of FXM emphasizes the importance of drug structural adaptation in pharmacological functions.展开更多
Nineβ‐cyclodextrin derivatives containing an amino group were synthesized via nucleophilic sub‐stitution from mono（6‐O‐p‐tolylsulfonyl）‐β‐cyclodextrin and used in asymmetric biomimetic Mi‐chael addition re...Nineβ‐cyclodextrin derivatives containing an amino group were synthesized via nucleophilic sub‐stitution from mono（6‐O‐p‐tolylsulfonyl）‐β‐cyclodextrin and used in asymmetric biomimetic Mi‐chael addition reactions in water at room temperature. The mechanism responsible for the moder‐ate activity and enantioselectivity of the β‐cyclodextrin derivatives was explored using nuclear magnetic resonance spectroscopy, namely 2D 1H rotating‐frame overhauser effect spectroscopy （ROESY）, ultraviolet absorption spectroscopy, and quantum chemical calculations, which provide a useful technique for investigating the formation of inclusion complexes. The effects of the pH of the reaction medium, theβ‐cyclodextrin derivative dosage, the structure of the modifying amino group, and various substrates on the yield and enantioselectivity were investigated. The results indicated that these factors had an important effect on the enantiomeric excess （ee） in the reaction system. Experiments using a competitor for inclusion complex formation showed that a hydrophobic cavity is necessary for enantioselective Michael addition. A comparison of the reactions using 4‐nitro‐β‐nitrostyrene and 2‐nitro‐β‐nitrostyrene showed that steric hindrance improved the enan‐tioselectivity. This was verified by the optimized geometries obtained from quantum chemical cal‐culations. An ee of 71%was obtained in the asymmetric Michael addition of cyclohexanone and 2‐nitro‐β‐nitrostyrene, using （S）‐2‐aminomethylpyrrolidine‐modified β‐CD as the catalyst, in an aqueous buffer solution, i.e., CH3COONa‐HCl （pH 7.5）.展开更多
The effect of various concentrations of 2-hydroxypropyl-β-cyclodextrin （HP-β-CD） on the solubility of dihydroartemisinin （DHA） in aqueous solution at different pHs was investigated. The influence of different co...The effect of various concentrations of 2-hydroxypropyl-β-cyclodextrin （HP-β-CD） on the solubility of dihydroartemisinin （DHA） in aqueous solution at different pHs was investigated. The influence of different concentrations of 2-hydroxypropyl-β- eyclodextrin on the stability of dihydroartemisinin at 50, 60, 70 and 80 ℃ was also studied. Inclusion complex of dihydroartemisinin with 2-hydroxypropyl-β-cyclodextrin was prepared and characterized by X-ray diffraction and differential scanning calorimetry. The 2-hydroxypropyl-β-cyclodextrin effectively inhibited the hydrolysis of dihydroartemisinin and greatly increased its solubility. Furthermore, we showed that the higher concentrations of 2-hydroxypropyl-β-cyclodextrin, the better stability and solubility of dihydroartemisinin. When the temperature was increased, the stability of dihydroartemisinin decreased. Our results indicated that 2-hydroxypropyl-β-cyclodextrin can be used as a stabilizer and solubilizer of dihydroartemisinin.展开更多
Cetyltrimethylammonium bromide （CTAB）/potassium bromide （KBr） micellar system has been used as a viscosity probe to study the inclusion complexation between β-cyclodextrin （β-CD） and CTAB. Viscosity measuremen...Cetyltrimethylammonium bromide （CTAB）/potassium bromide （KBr） micellar system has been used as a viscosity probe to study the inclusion complexation between β-cyclodextrin （β-CD） and CTAB. Viscosity measurements show that the inclusion complexation between β-CD and CTAB may cause the breakdown of CTAB/KBr wormlike micelles, resulting in the decrease of the solution viscosity. The viscosity minimum at Cβ-CD/CCTAB=2 indicate the molecular ratio of host molecule to vip molecule is 2：1 in the β-CD/CTAB inclusion complex.展开更多
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
In this study polyrotaxane （PR）-based triblock copolymers were first synthesized via the atom transfer radical polymerization （ATRP） of N-isopropylacrylamide initiated with the self-assembly of a distal 2-bromoiso...In this study polyrotaxane （PR）-based triblock copolymers were first synthesized via the atom transfer radical polymerization （ATRP） of N-isopropylacrylamide initiated with the self-assembly of a distal 2-bromoisobutyryl end-capped Pluronie 17R4 with a varying amount of a-cyclodextrins （a-CDs） in the presence of CuCI/PMDETA at 25 ℃ in aqueous solution. The a-CDs entrapped on the copolymer chain were then linked with hexamethylene diisocyanate to give rise to novel slightly cross-linked polyrotaxanes （SCPRs） in DMF at 45 ℃. The structures of the PR-based triblock copolymers and SCPRs were characterized by 1H NMR, 13C CP/MAS, GPC and TGA analy- ses. The number-average molecular weight of the resulting SCPRs was nearly three and five times of their precursor after linking with a low polydispersity index range of 1.08--1.28. The thermo-responsive transition of both PR-based supramolecular polymers in aqueous solution was demonstrated by turbidity measurements and the self-aggregated morphologies were also evidenced by TEM observations.展开更多
Ofloxacin is an antibiotic with a wide range of activity against bacterial infections, but due to the high potential for toxicity when exposed to light, resolving this problem and further stabilizing the drug are amon...Ofloxacin is an antibiotic with a wide range of activity against bacterial infections, but due to the high potential for toxicity when exposed to light, resolving this problem and further stabilizing the drug are among the posed challenges. Inclusion complex formation between α-cyclodextrin (α-CD), ofloxacin (OFL) and polyethylene glycol (PEG) was prepared via two methods to produce nanocontainers with desirable stability. The effect of PEG as compatible solubilizing agent and mixing condition (in ultrasonic bath) were investigated in formation of an inclusion complex between α-CD/OFL. Obtained complexes were examined by FTIR, H-NMR, SEM, EDX and UV which indicated the formation of an inclusion complex between α-CD/OFL, in turn, is a mixture of the cage and channel structures. Differences between 1H-NMR, FTIR and XRD spectra of OFL, CDs and inclusion complex indicated the formation of α-CD/OFL and supramolecular containers in solid phase. These inclusion complexes loaded in PVA-based nanofibers for smart nanofibers with controlled release manner and higher stability of OFL. Obtained nanofiber showed that nanofibers containing CDs/OFL under sonic energy containing higher degree of OFL.展开更多
Neodymium selenide nanoparticles were synthesized and surface-modified usingβ-cyclodextrin-citrate to control agglomeration and achieve the desired particle size.The nanoparticles were characterized by various techni...Neodymium selenide nanoparticles were synthesized and surface-modified usingβ-cyclodextrin-citrate to control agglomeration and achieve the desired particle size.The nanoparticles were characterized by various techniques,including X-ray diffraction,transmission electron microscopy(TEM),and X-ray photoelectron spectroscopy(XPS).XRD results reveal high crystallinity,with characteristic peaks corresponding to Nd_(2)Se_(3),while TEM analysis shows rod-shaped nanoparticles with an average size of~55 nm.The presence of neodymium and selenium in the+3 oxidation state was confirmed by XPS.Thermogravimetric analysis indicates that theβ-cyclodextrin-citrate coating accounts for approximately30%of the nanoparticle mass and remains stable up to 800℃.The optical properties of the nanoparticles were studied using UV-Vis-NIR spectroscopy,revealing broad absorption in the UV and NIR regions.Magnetic characterization shows soft ferromagnetic behavior,with a saturation magnetization value of0.20 emu/g.The nanoparticles were used for controlled release of 5-fluorouracil,exhibiting a pHsensitive release profile.Studies on MCF-7 cells demonstrate that 5-fluorouracil-loade d nanoparticles enhance cytotoxicity,reactive oxygen species generation,and apoptosis compared to bare nanoparticles.The IC_(50) value of(13.78±1.24)μg/mL indicates a significantly high cytotoxic activity of the drug-loaded nanoparticles against breast cancer cell lines.These findings suggest that the nanoparticles are a promising drug delivery system for enhanced cancer treatment,combining the controlled drug release with targeted cellular effects.展开更多
A small shielding effect on the hydrogen atoms of chiral carbons of β-cyclodextrin （β-CD） was detected by 1H nuclear magnetic resonance, but a large environmental change of the chiral carbon atoms at high concentr...A small shielding effect on the hydrogen atoms of chiral carbons of β-cyclodextrin （β-CD） was detected by 1H nuclear magnetic resonance, but a large environmental change of the chiral carbon atoms at high concentration ratios of lithium carbonate （Li2CO3） to β-CD was observed by polarimetry in aqueous solution. These findings urged us to investigate whether different formation conditions of the molecule-ion system between Li2CO3 and β-CD in solid state were involved in different spectral performances. To answer the question, we prepared three adducts of Li2CO3 to β-CD, i.e., samples 1, 2, and 3, by magnetic stirring, solvothermal and grinding conditions, respectively. Powder X-ray diffraction and Fourier transformation infrared spectroscopy provided the information of formation of the three molecule-ion adducts. Besides, scanning electron microscope images provided different surface information of the three adducts. Further, significant spectral differences in thermal behavior of these adducts were found by thermogravimetry and derivative thermogravimetry.展开更多
This paper presented an interesting nanoparticle-based drug delivery system with morphology transition behavior depending on the content of exposed PEG chain on the particle surface, which is adjustable by addition of...This paper presented an interesting nanoparticle-based drug delivery system with morphology transition behavior depending on the content of exposed PEG chain on the particle surface, which is adjustable by addition of different amount of cyclodextrin(α-CD). The effect of α-CD inclusion to the self-assembly behavior of methoxy polyethylene glycol(mPEG) grafted chitosan(CS) was studied. The results showed that the mPEG grafted chitosan(mPEG-g-CS) forms self-assembled nanoparticles with either micelle or hollow sphere morphology depending on the ratio of α-CD to mPEG, as characterized by atomic force microscopy(AFM), transmission electron microscopy(TEM), and X-ray diffraction(XRD). Their sizes and zeta potential increased from 257.6 nmto 768.2 nm and from +4.5 mV to +11.6 mV, respectively, with the increasing amount of α-CD. The correlation between zeta potential and particle size of α-CD/mPEG-g-CS nanoparticles indicated varied PEG density on surface of nanoparticles. Based on the above experimental observations, a likely mechanism for the morphological transition of the rod-coil graft copolymer mPEG-g-CS was proposed.展开更多
Polycyclic aromatic hydrocarbons（PAHs）/heavy metals/fluorine（F） mixed-contaminated sites caused by abandoned metallurgic plants are receiving wide attention. To address the associated environmental problems,this s...Polycyclic aromatic hydrocarbons（PAHs）/heavy metals/fluorine（F） mixed-contaminated sites caused by abandoned metallurgic plants are receiving wide attention. To address the associated environmental problems,this study was initiated to investigate the feasibility of using carboxymethyl-β-cyclodextrin（CMCD） and carboxymethyl chitosan（CMC） solution to enhance ex situ soil washing for extracting mixed contaminants. Further,Tenax extraction method was combined with a first-three-compartment model to evaluate the environmental risk of residual PAHs in washed soil. In addition,the redistribution of heavy metals/F after decontamination was also estimated using a sequential extraction procedure. Three successive washing cycles using50 g/L CMCD and 5 g/L CMC solution were effective to remove 94.3% of total PAHs,93.2% of Pb,85.8% of Cd,93.4% of Cr,83.2% of Ni and 97.3% of F simultaneously. After the 3rd washing,the residual PAHs mainly existed as very slowly desorbing fractions,which were in the form of well-aged,well-sequestered compounds; while the remaining Pb,Cd,Cr,Ni and F mainly existed as Fe–Mn oxide and residual fractions,which were always present in stable mineral forms or bound to non-labile soil fractions. Therefore,this combined cleanup strategy proved to be effective and environmentally friendly.展开更多
A facile, efficient and substrate-selective oxidation of aldehydes to carboxylic acids with NaClO catalyzed by β-cyclodextrin in water has been developed. A series of aldehydes which could form inclusion complex with...A facile, efficient and substrate-selective oxidation of aldehydes to carboxylic acids with NaClO catalyzed by β-cyclodextrin in water has been developed. A series of aldehydes which could form inclusion complex with β-cyclodextrin （β-CD） were oxidized selectively with excellent yields.展开更多
The goal of this study was to improve the solubility and oral bioavailability of tamibarotene by complexing it with hydroxypropyl-β-cyclodextrin(HP-β-CD).The inclusion complex of tamibarotene with hydroxypropyl-β-c...The goal of this study was to improve the solubility and oral bioavailability of tamibarotene by complexing it with hydroxypropyl-β-cyclodextrin(HP-β-CD).The inclusion complex of tamibarotene with hydroxypropyl-β-cyclodextrin(Am80-HP-β-CD)was prepared through a freeze-drying method at the mole ratio of 1:1(Am80:HP-β-CD).Fourier transform infrared spectroscopy(FT-IR)and differential scanning calorimetry(DSC)indicated the formation of Am80-HP-β-CD.In vitro dissolution studies showed that the solubility and dissolution percentage of Am80-HP-β-CD was improved substantially compared to Am80.An improved dissolution with approximately 97%drug release in 3 min was observed,in comparison with Am80 with approximately 60% release in 45 min.In vivo studies indicated that the AUC0-∞ has increased 2.79 times and the Cmax 4.37 times after the formation of inclusion complex.The decrease of tmaxindicated the Am80-HP-β-CD inclusion complex can be absorbed into blood faster.In short,the solubility and bio-availability of Am80 has notably increased with the complexation of HP-β-CD.Therefore,using the inclusion technique is a promising method to improve the solubility of insoluble drugs.展开更多
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.
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In this study, the metal coordination ability of alpha-cyclodextrin (α-CD) was employed to complex gold and thus isolate and extract it from different matrices of acid-digests of electronic waste and soil. The crude α-CD used was extracted from cassava and yam starch of the non-edible plant species using E. coli α-cyclodextrin glucanotransferase (α-CGTase), with yields ≥ 62%. The reaction was monitored progressively by ultraviolet-visible spectroscopy and checked with infrared spectroscopy (IR) for the presence of α-CD. The crude α-CD extract without need for purification was refluxed with gold containing-electronic waste and soil predigested in a mixture of NaBr/HNO<sub>3</sub> for 4 - 7 days. Recoveries of up to 22.9% and 70.8% gold were achieved from electronic waste and soil, respectively using 0.1 M α-CD. This approach is cheap, effective, and environmentally benign.
基金supported by NUTRAGE,CNR project FOE-2021 DBA.AD005.225in part by“ON Foods-Research and Inno-vation Network on Food and Nutrition Sustainability,Safety,and Security-Working ON Foods”(CUP B83C22004790001ONFOODS).
文摘Supercritical CO_(2)(SC-CO_(2))extraction offers a sustainable method for obtaining solvent-free oils rich in bioactive molecules,valuable for nutraceutical and functional food products.However,the limited stability of certain extract components can hinder their application.This study exploresα,β,andγcyclodextrins(CDs)as emulsifiers to enhance SC-CO_(2)-extracted tomato oil(TO)stability.TO/CD emulsions with high oil volume fractions(φ)of 60%,65%,70%,and 75%were prepared using the three types of CDs.Onlyα-CDs formed gel-like,stable emulsions up toφ=70%.Confocal microscopy revealed that increasingφled to morphological changes,including reduced droplet size,decreased roundness,and larger coalescence zones,affecting stability and functionality.Emulsions atφ60%showed optimal performance with reduced phase separation,high viscosity,smaller droplet size,and lower coalescence.The stability of carotenoids and tocopherols was evaluated under heat(50℃)and UV-C exposure to simulate accelerated aging and sterilization.Emulsions improved carotenoid stability at elevated temperatures compared to bulk TO.Tocopherols were highly stable in bulk TO and moderately stable in TO/α-CD emulsions.Under UV-C exposure,TO/α-CD emulsions enhanced carotenoid and tocopherol stability for up to 9 h,compared to pure TO.Further analysis withα-CDs and synthetic glyceryl trioctanoate(GTO)atφ=60%,65%,and 70%replicated the concentrations of lycopene andα-tocopherol in TO.These results suggest that TO/α-CD emulsions can serve as stable,high-quality ingredients for nutraceutical and functional food applications.
文摘α-Cyclodextrin(α-CD)is characterized by its inherent hydrophobic cavity and favorable water solubility,serving as an effective means to enhance the solubility and stability of lipophilic substances.However,the encapsulation efficiency ofα-CD inclusion complexes remains relatively low.Therefore,in this study,the regulatory mechanisms of self-assembled nanostructures ofα-CD were explored.The structural differences ofα-CD self-assembled via hydrogen bonds under various pH conditions were investigated.Taking Vitamin D_(3)(VD_(3))as an example,the impact of these structures on encapsulation efficiency was verified,and theα-CD-VD_(3)inclusion complex(IC)was characterized.At pH 9,α-CD exhibited the smallest average particle size(134.36±1.17 nm)and the highest zeta potential(-43.20±1.94 mV),indicating excellent thermal stability.Fourier-transform infrared spectroscopy and proton nuclear magnetic resonance analyses revealed minimal hydrogen bonding betweenα-CD molecules at this pH,resulting in a maximum encapsulation efficiency of 89.27%forα-CD-VD_(3).The continuous variation method confirmed the formation of theα-CD-VD_(3)IC,with a binding constant of 265.32 M-1 and a Gibbs free energy of-3.30 kcal/mol.Theα-CD-VD_(3)aqueous solution demonstrated good stability under varying pH and salt ion conditions.In vitro release studies showed that theα-CD-VD_(3)IC was stable in simulated gastric fluid and efficiently released VD_(3)in simulated intestinal fluid.A stable aqueous delivery system based on the selfassembled structure ofα-CD has been successfully developed in this study,which holds broad application prospects in various fields,including pharmaceutical and food sciences.
基金supported by the Ratchadapisek Sompoch Endowment Fund,Chulalongkorn University,Thailand(Grant No.:RCU_67_023_010).
文摘Fluvoxamine(FXM)is a well-known selective serotonin reuptake inhibitor(SSRI)for treating depression and has recently been repurposed for efficacious treatment of coronavirus disease 2019.Although cyclodextrin(CD)encapsulation effectively improves the physicochemical properties of structurally diverse SSRIs,the molecular understanding of their associations is deficient.This comprehensive study used single-crystal X-ray diffraction integrated with density functional theory(DFT)calculation to provide deep insights into the conformationally flexible FXM and its inclusion complexation withβ-CD.Xray analysis revealed the first crystallographic evidence of the uncomplexed 3FXM-H^(+)·3maleate-(1).Three FXM-H^(+)ions are counter-balanced by three planar maleate-ions to form a thin layer stabilized by infinite fused H-bond rings R_(4)^(4)(12)and R_(6)^(4)(16)and the interplay ofπ…π,CF…πand F…F interactions.For 2β-CD·2FXM-H^(+)·maleate^(2-)·23·2H_(2)O(2),the tail-to-tailβ-CD dimer encapsulates two FXM-H^(+)4-(trifluoromethyl)phenyl moieties,which are charge-balanced by the rare non-planar maleate2and stabilized by N…OH…O H-bonds and F…F interactions.This is a hostevip recognition pattern uniquely observed for allβ-CD complexes with halogen(X)-bearing SSRIs,indicating the essence of X…X interactions and the shielding of X-containing moieties in the wall of theβ-CD dimer.DFT calculations unveiled that the monomeric and dimericβ-CD-FXM complexes and FXM isomers are energetically stable,which alleviates the numbness and bitterness of the orally administered drug as previously patented.Additionally,an insightful conformational analysis of FXM emphasizes the importance of drug structural adaptation in pharmacological functions.
基金supported by the National Natural Science Foundation of China (21425627,21376279)~~
文摘Nineβ‐cyclodextrin derivatives containing an amino group were synthesized via nucleophilic sub‐stitution from mono（6‐O‐p‐tolylsulfonyl）‐β‐cyclodextrin and used in asymmetric biomimetic Mi‐chael addition reactions in water at room temperature. The mechanism responsible for the moder‐ate activity and enantioselectivity of the β‐cyclodextrin derivatives was explored using nuclear magnetic resonance spectroscopy, namely 2D 1H rotating‐frame overhauser effect spectroscopy （ROESY）, ultraviolet absorption spectroscopy, and quantum chemical calculations, which provide a useful technique for investigating the formation of inclusion complexes. The effects of the pH of the reaction medium, theβ‐cyclodextrin derivative dosage, the structure of the modifying amino group, and various substrates on the yield and enantioselectivity were investigated. The results indicated that these factors had an important effect on the enantiomeric excess （ee） in the reaction system. Experiments using a competitor for inclusion complex formation showed that a hydrophobic cavity is necessary for enantioselective Michael addition. A comparison of the reactions using 4‐nitro‐β‐nitrostyrene and 2‐nitro‐β‐nitrostyrene showed that steric hindrance improved the enan‐tioselectivity. This was verified by the optimized geometries obtained from quantum chemical cal‐culations. An ee of 71%was obtained in the asymmetric Michael addition of cyclohexanone and 2‐nitro‐β‐nitrostyrene, using （S）‐2‐aminomethylpyrrolidine‐modified β‐CD as the catalyst, in an aqueous buffer solution, i.e., CH3COONa‐HCl （pH 7.5）.
文摘The effect of various concentrations of 2-hydroxypropyl-β-cyclodextrin （HP-β-CD） on the solubility of dihydroartemisinin （DHA） in aqueous solution at different pHs was investigated. The influence of different concentrations of 2-hydroxypropyl-β- eyclodextrin on the stability of dihydroartemisinin at 50, 60, 70 and 80 ℃ was also studied. Inclusion complex of dihydroartemisinin with 2-hydroxypropyl-β-cyclodextrin was prepared and characterized by X-ray diffraction and differential scanning calorimetry. The 2-hydroxypropyl-β-cyclodextrin effectively inhibited the hydrolysis of dihydroartemisinin and greatly increased its solubility. Furthermore, we showed that the higher concentrations of 2-hydroxypropyl-β-cyclodextrin, the better stability and solubility of dihydroartemisinin. When the temperature was increased, the stability of dihydroartemisinin decreased. Our results indicated that 2-hydroxypropyl-β-cyclodextrin can be used as a stabilizer and solubilizer of dihydroartemisinin.
基金This work was supported by the Doctor Research Foundation of Anhui University of Architecture （No.20101201） and the Postdoctoral Science Foundation of Anhui University of Architecture （No.20110101）.
文摘Cetyltrimethylammonium bromide （CTAB）/potassium bromide （KBr） micellar system has been used as a viscosity probe to study the inclusion complexation between β-cyclodextrin （β-CD） and CTAB. Viscosity measurements show that the inclusion complexation between β-CD and CTAB may cause the breakdown of CTAB/KBr wormlike micelles, resulting in the decrease of the solution viscosity. The viscosity minimum at Cβ-CD/CCTAB=2 indicate the molecular ratio of host molecule to vip molecule is 2：1 in the β-CD/CTAB inclusion complex.
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.
基金This work was supported by the Natural Science Foundation of China （No. 20974015） and the Doctoral Program Foundation of Ministry of Education of China （No. 20091101110029）. Wang Jin also thanks the sup- port from YUMIAO foundation of Beijing Institute of Technology.
文摘In this study polyrotaxane （PR）-based triblock copolymers were first synthesized via the atom transfer radical polymerization （ATRP） of N-isopropylacrylamide initiated with the self-assembly of a distal 2-bromoisobutyryl end-capped Pluronie 17R4 with a varying amount of a-cyclodextrins （a-CDs） in the presence of CuCI/PMDETA at 25 ℃ in aqueous solution. The a-CDs entrapped on the copolymer chain were then linked with hexamethylene diisocyanate to give rise to novel slightly cross-linked polyrotaxanes （SCPRs） in DMF at 45 ℃. The structures of the PR-based triblock copolymers and SCPRs were characterized by 1H NMR, 13C CP/MAS, GPC and TGA analy- ses. The number-average molecular weight of the resulting SCPRs was nearly three and five times of their precursor after linking with a low polydispersity index range of 1.08--1.28. The thermo-responsive transition of both PR-based supramolecular polymers in aqueous solution was demonstrated by turbidity measurements and the self-aggregated morphologies were also evidenced by TEM observations.
文摘Ofloxacin is an antibiotic with a wide range of activity against bacterial infections, but due to the high potential for toxicity when exposed to light, resolving this problem and further stabilizing the drug are among the posed challenges. Inclusion complex formation between α-cyclodextrin (α-CD), ofloxacin (OFL) and polyethylene glycol (PEG) was prepared via two methods to produce nanocontainers with desirable stability. The effect of PEG as compatible solubilizing agent and mixing condition (in ultrasonic bath) were investigated in formation of an inclusion complex between α-CD/OFL. Obtained complexes were examined by FTIR, H-NMR, SEM, EDX and UV which indicated the formation of an inclusion complex between α-CD/OFL, in turn, is a mixture of the cage and channel structures. Differences between 1H-NMR, FTIR and XRD spectra of OFL, CDs and inclusion complex indicated the formation of α-CD/OFL and supramolecular containers in solid phase. These inclusion complexes loaded in PVA-based nanofibers for smart nanofibers with controlled release manner and higher stability of OFL. Obtained nanofiber showed that nanofibers containing CDs/OFL under sonic energy containing higher degree of OFL.
文摘Neodymium selenide nanoparticles were synthesized and surface-modified usingβ-cyclodextrin-citrate to control agglomeration and achieve the desired particle size.The nanoparticles were characterized by various techniques,including X-ray diffraction,transmission electron microscopy(TEM),and X-ray photoelectron spectroscopy(XPS).XRD results reveal high crystallinity,with characteristic peaks corresponding to Nd_(2)Se_(3),while TEM analysis shows rod-shaped nanoparticles with an average size of~55 nm.The presence of neodymium and selenium in the+3 oxidation state was confirmed by XPS.Thermogravimetric analysis indicates that theβ-cyclodextrin-citrate coating accounts for approximately30%of the nanoparticle mass and remains stable up to 800℃.The optical properties of the nanoparticles were studied using UV-Vis-NIR spectroscopy,revealing broad absorption in the UV and NIR regions.Magnetic characterization shows soft ferromagnetic behavior,with a saturation magnetization value of0.20 emu/g.The nanoparticles were used for controlled release of 5-fluorouracil,exhibiting a pHsensitive release profile.Studies on MCF-7 cells demonstrate that 5-fluorouracil-loade d nanoparticles enhance cytotoxicity,reactive oxygen species generation,and apoptosis compared to bare nanoparticles.The IC_(50) value of(13.78±1.24)μg/mL indicates a significantly high cytotoxic activity of the drug-loaded nanoparticles against breast cancer cell lines.These findings suggest that the nanoparticles are a promising drug delivery system for enhanced cancer treatment,combining the controlled drug release with targeted cellular effects.
基金ACKNOWLEDGMENTS This work was supported by the Innovation Foundation of Graduate Students in University of Science and Technology of China （No.KD2008020）, and the Natural Science Foundation of Anhui Province （No.090416228）.
文摘A small shielding effect on the hydrogen atoms of chiral carbons of β-cyclodextrin （β-CD） was detected by 1H nuclear magnetic resonance, but a large environmental change of the chiral carbon atoms at high concentration ratios of lithium carbonate （Li2CO3） to β-CD was observed by polarimetry in aqueous solution. These findings urged us to investigate whether different formation conditions of the molecule-ion system between Li2CO3 and β-CD in solid state were involved in different spectral performances. To answer the question, we prepared three adducts of Li2CO3 to β-CD, i.e., samples 1, 2, and 3, by magnetic stirring, solvothermal and grinding conditions, respectively. Powder X-ray diffraction and Fourier transformation infrared spectroscopy provided the information of formation of the three molecule-ion adducts. Besides, scanning electron microscope images provided different surface information of the three adducts. Further, significant spectral differences in thermal behavior of these adducts were found by thermogravimetry and derivative thermogravimetry.
基金supported by Science and Technology Commission of Shanghai Municipality (Nos. 17ZR1406600, 10DZ2220500, 11DZ2260600)National Natural Science Foundation of China (No.21577037)
文摘This paper presented an interesting nanoparticle-based drug delivery system with morphology transition behavior depending on the content of exposed PEG chain on the particle surface, which is adjustable by addition of different amount of cyclodextrin(α-CD). The effect of α-CD inclusion to the self-assembly behavior of methoxy polyethylene glycol(mPEG) grafted chitosan(CS) was studied. The results showed that the mPEG grafted chitosan(mPEG-g-CS) forms self-assembled nanoparticles with either micelle or hollow sphere morphology depending on the ratio of α-CD to mPEG, as characterized by atomic force microscopy(AFM), transmission electron microscopy(TEM), and X-ray diffraction(XRD). Their sizes and zeta potential increased from 257.6 nmto 768.2 nm and from +4.5 mV to +11.6 mV, respectively, with the increasing amount of α-CD. The correlation between zeta potential and particle size of α-CD/mPEG-g-CS nanoparticles indicated varied PEG density on surface of nanoparticles. Based on the above experimental observations, a likely mechanism for the morphological transition of the rod-coil graft copolymer mPEG-g-CS was proposed.
基金supported by the National Natural Science Foundation of China (Nos.41030531,41001335G,21377138 and 41271464b)
文摘Polycyclic aromatic hydrocarbons（PAHs）/heavy metals/fluorine（F） mixed-contaminated sites caused by abandoned metallurgic plants are receiving wide attention. To address the associated environmental problems,this study was initiated to investigate the feasibility of using carboxymethyl-β-cyclodextrin（CMCD） and carboxymethyl chitosan（CMC） solution to enhance ex situ soil washing for extracting mixed contaminants. Further,Tenax extraction method was combined with a first-three-compartment model to evaluate the environmental risk of residual PAHs in washed soil. In addition,the redistribution of heavy metals/F after decontamination was also estimated using a sequential extraction procedure. Three successive washing cycles using50 g/L CMCD and 5 g/L CMC solution were effective to remove 94.3% of total PAHs,93.2% of Pb,85.8% of Cd,93.4% of Cr,83.2% of Ni and 97.3% of F simultaneously. After the 3rd washing,the residual PAHs mainly existed as very slowly desorbing fractions,which were in the form of well-aged,well-sequestered compounds; while the remaining Pb,Cd,Cr,Ni and F mainly existed as Fe–Mn oxide and residual fractions,which were always present in stable mineral forms or bound to non-labile soil fractions. Therefore,this combined cleanup strategy proved to be effective and environmentally friendly.
基金the National Natural Science Foundation of China(No.20776053)the Program for New Century Excellent Talents in University(No.NCET-06-740)for providing financial support for this project.
文摘A facile, efficient and substrate-selective oxidation of aldehydes to carboxylic acids with NaClO catalyzed by β-cyclodextrin in water has been developed. A series of aldehydes which could form inclusion complex with β-cyclodextrin （β-CD） were oxidized selectively with excellent yields.
文摘The goal of this study was to improve the solubility and oral bioavailability of tamibarotene by complexing it with hydroxypropyl-β-cyclodextrin(HP-β-CD).The inclusion complex of tamibarotene with hydroxypropyl-β-cyclodextrin(Am80-HP-β-CD)was prepared through a freeze-drying method at the mole ratio of 1:1(Am80:HP-β-CD).Fourier transform infrared spectroscopy(FT-IR)and differential scanning calorimetry(DSC)indicated the formation of Am80-HP-β-CD.In vitro dissolution studies showed that the solubility and dissolution percentage of Am80-HP-β-CD was improved substantially compared to Am80.An improved dissolution with approximately 97%drug release in 3 min was observed,in comparison with Am80 with approximately 60% release in 45 min.In vivo studies indicated that the AUC0-∞ has increased 2.79 times and the Cmax 4.37 times after the formation of inclusion complex.The decrease of tmaxindicated the Am80-HP-β-CD inclusion complex can be absorbed into blood faster.In short,the solubility and bio-availability of Am80 has notably increased with the complexation of HP-β-CD.Therefore,using the inclusion technique is a promising method to improve the solubility of insoluble drugs.
