A new modified blend ultrafiltration(UF)membrane with good hydrophilicity,high porosity and excellent anti-fouling performance was developed by using carboxylic multi-walled carbon nanotube(CMWCNT)as casting solution ...A new modified blend ultrafiltration(UF)membrane with good hydrophilicity,high porosity and excellent anti-fouling performance was developed by using carboxylic multi-walled carbon nanotube(CMWCNT)as casting solution additive.Furthermore,a composite nanofiltration(NF)membrane with large water flux and good retention rate was fabricated by using the PVDF/CMWCNT blend UF membrane as the substrate,and polyvinyl alcohol(PVA),β-cyclodextrin(β-CD)and polyethylenimine(PEI)as the coating solution.The results show that with the appropriate addition of CMWCNT in the casting solution,the surface roughness,porosity and recovery rate of the PVDF/CMWCNT blend UF membrane is obviously increased.The water flux of blend UF membrane is significantly improved when the CMWCNT content increases from 0 wt%to 0.2 wt%.The water flux of blend UF membrane with 0.2 wt%CMWCNT is 162.7 L/(m^(2)·h),which is 44.3%higher than that of the pure PVDF membrane.Whenβ-CD content is 0.8 wt%,the retention rate of Congo red by PVDF/CMWCNT/β-CD composite NF membrane reaches 98.7%,which is 28.3%higher than that of single PVA/PEI modified membrane.This research will provide a new idea and simple method for developing novel high-performance composite NF membranes.展开更多
Xiao et al reported on the natural product sinomenine(SIN),which is a traditional Chinese medicine for treating osteoporosis via its modulation of autophagy;however,SIN was dissolved in dimethyl sulfoxide prior to adm...Xiao et al reported on the natural product sinomenine(SIN),which is a traditional Chinese medicine for treating osteoporosis via its modulation of autophagy;however,SIN was dissolved in dimethyl sulfoxide prior to administration,which is not conducive to the development of clinical injectables.By comparing solubilization techniques,including amorphisation,emulsification,micellisation,nanocrystallisation and host-vip inclusion,we found that the solubilization of SIN by host-vip inclusion can enhance solubility and improve stability and has an increased release rate and enhanced bioavailability.Therefore,we conclude that host-vip inclusion holds promise for SIN solubilization.To solubilise SIN,we selectedβ-cyclodextrin as the host agent considering its excellent biocompatibility,efficient encapsulation ability,mature preparation process and adequate drug stability.If the prerequisites of SIN-β-cyclodextrin complexes in terms of safety,efficacy,stability and the relevant laws and regulations are met,its clinical application for the treatment of osteoporosis may be achieved.展开更多
Purely organic room-temperature phosphorescence(RTP)is current hotspot in the research fields of chemistry,biology,materials etc.Herein,we report that photo-thermal double response reversible ultralong RTP flexible el...Purely organic room-temperature phosphorescence(RTP)is current hotspot in the research fields of chemistry,biology,materials etc.Herein,we report that photo-thermal double response reversible ultralong RTP flexible elastic material with multicolor delayed fluorescence,which is constructed by 4-biphenylboronic acid(BOH),polyethylene glycol,2,2-bis(hydroxymethyl)propionic acid,isophorone diamine and isophorone diisocyanate copolymer.Importantly,the supramolecular phosphorescent elastomer not only exhibits extending RTP emission with a lifetime up to 1.21 s,but also gives a visible afterglow of 20 s via encapsulation of BOH unities by the deep cavities of hydroxypropyl-β-cyclodextrin(β-CD-HP)and in situ polymerization.Especially,after doping organic dyes(Fluorescein isothiocyanate,Sulforhodamine 101,Rhodamine B),supramolecular phosphorescent elastomer achieves multicolor delayed fluorescence realized by RTP energy transfer from phosphorescent donor to dye acceptors,which possesses reversible photo-thermal responsiveness and maintains high efficiency in delayed emission even after dozens of cycles.Present research provides a new approach for constructing multicolor delayed fluorescent supramolecular elastomers.展开更多
Trimethoprim(TMP),as a broad-spectrum bacteriostatic antibiotic,is widely used in clinical anti-infection therapy and livestock breeding.However,its low water solubility leads to insufficient bioavailability,which has...Trimethoprim(TMP),as a broad-spectrum bacteriostatic antibiotic,is widely used in clinical anti-infection therapy and livestock breeding.However,its low water solubility leads to insufficient bioavailability,which has become a key problem restricting its development.Cyclodextrins and their derivatives,with their unique cyclic structures,can form inclusion complexes with TMP to improve its properties.This article reviews the pharmacological characteristics of TMP,the types and properties of common cyclodextrins,focusing on introducing various preparation methods of trimethoprim cyclodextrin inclusion complexes and multiple characterization methods for identifying the inclusion complexes,aiming to provide a reference for further research and development of trimethoprim cyclodextrin inclusion complexes.展开更多
Nanoscale drug delivery systems(nano-DDSs)have attracted intense interest in tumor chemotherapy in the last decades,to improve antitumor efficacy and minimize toxic and side effects.As a versatile supramolecular build...Nanoscale drug delivery systems(nano-DDSs)have attracted intense interest in tumor chemotherapy in the last decades,to improve antitumor efficacy and minimize toxic and side effects.As a versatile supramolecular building block,cyclodextrins(CDs)have been widely used in the fabrication of the smart nano-DDSs.Besides their multifunctionality,which makes them versatile core in the star(co)polymers for micellar nanomedicines,specific host-vip inclusion complexation via their hydrophobic cavities endows them diversified functions:(i)design of amphiphilic copolymers for micellar nanomedicines,(ii)supramolecular hydrogels and poly(pseudo)rotaxane nano-hydrogels as drug carriers,and(iii)recipient for direct and indirect drug-loading.In the present work,the recent progress of CDs in nano-DDSs for tumor chemotherapy was reviewed,classified by the crucial roles of CD units.Based on the structureperformance relationship,the future perspective was also proposed.展开更多
Microporous organic networks(MONs)are attractive adsorbents for use in sample pretreatment owning to their unique structure and properties.However,methods for constructing functional MONs are still limited because the...Microporous organic networks(MONs)are attractive adsorbents for use in sample pretreatment owning to their unique structure and properties.However,methods for constructing functional MONs are still limited because the lack of monomers via direct synthesis and their complex procedures via postmodification.To address this issue,a facile one-pot in situ doping strategy was proposed herein for synthesis a novel phenylboronic acid-functionalized magnetic cyclodextrin-based microporous organic network([PBA]_(3/4)-MCD-MON-0.04).[PBA]_(3/4)MCD-MON-0.04 was used for the selective and efficient extraction of sulfonylurea herbicides(SUHs)from complex food and environmental water samples via the synergistic hydrogen bonding,host-vip,hydrophobic andπ-πinteractions and the specific B-N coordination.[PBA]_(3/4)-MCD-MON-0.04 had a large surface area,high saturation magnetism,good reusability,and remarkable stability.A rapid,sensitive,and selective method was proposed for monitoring SUHs from diverse matrices.This study provides a new strategy for synthesizing novel and multifunctional magnetic CD-MONs-based adsorbents and reveals the considerable potential of CD-MONs in sample pretreatment.展开更多
Parkinson's disease(PD)is a debilitating and progressive neurodegenerative disorder with complex pathology and multiple membrane barriers that hinder drug delivery,resulting in the absence of ideal therapeutic dru...Parkinson's disease(PD)is a debilitating and progressive neurodegenerative disorder with complex pathology and multiple membrane barriers that hinder drug delivery,resulting in the absence of ideal therapeutic drugs with minimal side effects[1].Recently,natural medicine has garnered significant attention due to its remarkable efficacy and limited side effects.Icariin,a naturally occurring flavonoid,exhibits excellent potential as a therapeutic agent for neurodegenerative disease[2].However,its clinical application is limited by poor water solubility,low bioavailability,and high clearance rates.Here,an aqueous formulation of icariin/hydroxypropyl-β-cyclodextrin(HP-β-CD)supramolecular inclusion complex was obtained to optimize icariin properties.Furthermore,icariin cyclodextrin supramolecular inclusion complex based thermosensitive(icariin gels)was innovated.At lower temperatures,it remained in a liquid phase with high fluidity.Upon reaching the gelation temperature,it underwent a transition to a gel phase with significantly reduced fluidity,which may be suitable for the design of an intranasal delivery system for PD treatment.The innovative approach capitalizes on the exceptional characteristics of HP-β-CD,which was utilized to synergize with nasal delivery for targeted brain delivery and with icariin for PD treatment[3,4].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
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
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-vip complex.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
The contamination of soils by polycyclic aromatic hydrocarbons (PAHs) is a widespread environmental problem and the remediation of PAHs from these areas has been a major concern. The effectiveness of many in situ bi...The contamination of soils by polycyclic aromatic hydrocarbons (PAHs) is a widespread environmental problem and the remediation of PAHs from these areas has been a major concern. The effectiveness of many in situ bioremediation systems may be constrained by low contaminant bioavailability due to limited aqueous solubility or a large magnitude of sorption. The objective of this research was to evaluate the effect of methyl-β-cyclodextrin (MCD) on bioaugmentation by Paracoccus sp. strain HPD-2 of an aged PAH-contaminated soil. When 10% (W/W) MCD amendment was combined with bioaugmentation by the PAH-degrading bacterium Paracoccus sp. strain HPD-2, the percentage degradation of total PAHs was significantly enhanced up to 34.8%. Higher counts of culturable PAH- degrading bacteria and higher soil dehydrogenase and soil polyphenol oxidase activities were observed in 10% (W/W) MCD-assisted bioaugmentation soil. This MCD-assisted bioaugmentation strategy showed significant increases (p 〈 0.05) in the average well color development (AWCD) obtained by the BIOLOG Eco plate assay, Shannon-Weaver index (H) and Simpson index (λ) compared with the controls, implying that this strategy at least partially restored the microbiological functioning of the PAH-contaminated soil. The results suggest that MCD-aided bioaugmentation by Paracoccus sp. strain HPD-2 may be a promising practical bioremediation strategy for aged PAH-contaminated soils.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
基金Funded by the National Natural Science Foundation of China(No.52278453)Basic Scientific Research Project of Colleges and Universities of Liaoning Provincial Department of Education(Nos.LJ212410153013,LJKQZ2021060)。
文摘A new modified blend ultrafiltration(UF)membrane with good hydrophilicity,high porosity and excellent anti-fouling performance was developed by using carboxylic multi-walled carbon nanotube(CMWCNT)as casting solution additive.Furthermore,a composite nanofiltration(NF)membrane with large water flux and good retention rate was fabricated by using the PVDF/CMWCNT blend UF membrane as the substrate,and polyvinyl alcohol(PVA),β-cyclodextrin(β-CD)and polyethylenimine(PEI)as the coating solution.The results show that with the appropriate addition of CMWCNT in the casting solution,the surface roughness,porosity and recovery rate of the PVDF/CMWCNT blend UF membrane is obviously increased.The water flux of blend UF membrane is significantly improved when the CMWCNT content increases from 0 wt%to 0.2 wt%.The water flux of blend UF membrane with 0.2 wt%CMWCNT is 162.7 L/(m^(2)·h),which is 44.3%higher than that of the pure PVDF membrane.Whenβ-CD content is 0.8 wt%,the retention rate of Congo red by PVDF/CMWCNT/β-CD composite NF membrane reaches 98.7%,which is 28.3%higher than that of single PVA/PEI modified membrane.This research will provide a new idea and simple method for developing novel high-performance composite NF membranes.
基金Supported by Guangdong Basic and Applied Basic Research Foundation,No.2024A1515011236General Program of Administration of Traditional Chinese Medicine of Guangdong Province,No.20241071.
文摘Xiao et al reported on the natural product sinomenine(SIN),which is a traditional Chinese medicine for treating osteoporosis via its modulation of autophagy;however,SIN was dissolved in dimethyl sulfoxide prior to administration,which is not conducive to the development of clinical injectables.By comparing solubilization techniques,including amorphisation,emulsification,micellisation,nanocrystallisation and host-vip inclusion,we found that the solubilization of SIN by host-vip inclusion can enhance solubility and improve stability and has an increased release rate and enhanced bioavailability.Therefore,we conclude that host-vip inclusion holds promise for SIN solubilization.To solubilise SIN,we selectedβ-cyclodextrin as the host agent considering its excellent biocompatibility,efficient encapsulation ability,mature preparation process and adequate drug stability.If the prerequisites of SIN-β-cyclodextrin complexes in terms of safety,efficacy,stability and the relevant laws and regulations are met,its clinical application for the treatment of osteoporosis may be achieved.
基金financially supported by the National Natural Science Foundation of China(No.22131008)。
文摘Purely organic room-temperature phosphorescence(RTP)is current hotspot in the research fields of chemistry,biology,materials etc.Herein,we report that photo-thermal double response reversible ultralong RTP flexible elastic material with multicolor delayed fluorescence,which is constructed by 4-biphenylboronic acid(BOH),polyethylene glycol,2,2-bis(hydroxymethyl)propionic acid,isophorone diamine and isophorone diisocyanate copolymer.Importantly,the supramolecular phosphorescent elastomer not only exhibits extending RTP emission with a lifetime up to 1.21 s,but also gives a visible afterglow of 20 s via encapsulation of BOH unities by the deep cavities of hydroxypropyl-β-cyclodextrin(β-CD-HP)and in situ polymerization.Especially,after doping organic dyes(Fluorescein isothiocyanate,Sulforhodamine 101,Rhodamine B),supramolecular phosphorescent elastomer achieves multicolor delayed fluorescence realized by RTP energy transfer from phosphorescent donor to dye acceptors,which possesses reversible photo-thermal responsiveness and maintains high efficiency in delayed emission even after dozens of cycles.Present research provides a new approach for constructing multicolor delayed fluorescent supramolecular elastomers.
基金Academic Fund for Students of Foshan University in 2024(Project No.:xsjj202409zrb11)。
文摘Trimethoprim(TMP),as a broad-spectrum bacteriostatic antibiotic,is widely used in clinical anti-infection therapy and livestock breeding.However,its low water solubility leads to insufficient bioavailability,which has become a key problem restricting its development.Cyclodextrins and their derivatives,with their unique cyclic structures,can form inclusion complexes with TMP to improve its properties.This article reviews the pharmacological characteristics of TMP,the types and properties of common cyclodextrins,focusing on introducing various preparation methods of trimethoprim cyclodextrin inclusion complexes and multiple characterization methods for identifying the inclusion complexes,aiming to provide a reference for further research and development of trimethoprim cyclodextrin inclusion complexes.
文摘Nanoscale drug delivery systems(nano-DDSs)have attracted intense interest in tumor chemotherapy in the last decades,to improve antitumor efficacy and minimize toxic and side effects.As a versatile supramolecular building block,cyclodextrins(CDs)have been widely used in the fabrication of the smart nano-DDSs.Besides their multifunctionality,which makes them versatile core in the star(co)polymers for micellar nanomedicines,specific host-vip inclusion complexation via their hydrophobic cavities endows them diversified functions:(i)design of amphiphilic copolymers for micellar nanomedicines,(ii)supramolecular hydrogels and poly(pseudo)rotaxane nano-hydrogels as drug carriers,and(iii)recipient for direct and indirect drug-loading.In the present work,the recent progress of CDs in nano-DDSs for tumor chemotherapy was reviewed,classified by the crucial roles of CD units.Based on the structureperformance relationship,the future perspective was also proposed.
基金supported by the National Natural Science Foundation of China(Nos.22174071 and 22206114)the Natural Science Foundation of Shandong Province(Nos.ZR2022YQ08 and ZR2022QB085)+2 种基金the Innovation Team of Shandong Higher School Youth Innovation Technology Program(No.2023KJ344)the Academic Promotion Program(No.2019LJ003)Joint Innovation Team for Clinical&Basic Research(No.202401)of Shandong First Medical University。
文摘Microporous organic networks(MONs)are attractive adsorbents for use in sample pretreatment owning to their unique structure and properties.However,methods for constructing functional MONs are still limited because the lack of monomers via direct synthesis and their complex procedures via postmodification.To address this issue,a facile one-pot in situ doping strategy was proposed herein for synthesis a novel phenylboronic acid-functionalized magnetic cyclodextrin-based microporous organic network([PBA]_(3/4)-MCD-MON-0.04).[PBA]_(3/4)MCD-MON-0.04 was used for the selective and efficient extraction of sulfonylurea herbicides(SUHs)from complex food and environmental water samples via the synergistic hydrogen bonding,host-vip,hydrophobic andπ-πinteractions and the specific B-N coordination.[PBA]_(3/4)-MCD-MON-0.04 had a large surface area,high saturation magnetism,good reusability,and remarkable stability.A rapid,sensitive,and selective method was proposed for monitoring SUHs from diverse matrices.This study provides a new strategy for synthesizing novel and multifunctional magnetic CD-MONs-based adsorbents and reveals the considerable potential of CD-MONs in sample pretreatment.
基金supported by the National Natural Science Foundation of China(Grant No.:82104399)the Science and Technology Project of Haihe Laboratory of Modern Chinese Medicine,China(Grant No.:22HHZYSS00001).
文摘Parkinson's disease(PD)is a debilitating and progressive neurodegenerative disorder with complex pathology and multiple membrane barriers that hinder drug delivery,resulting in the absence of ideal therapeutic drugs with minimal side effects[1].Recently,natural medicine has garnered significant attention due to its remarkable efficacy and limited side effects.Icariin,a naturally occurring flavonoid,exhibits excellent potential as a therapeutic agent for neurodegenerative disease[2].However,its clinical application is limited by poor water solubility,low bioavailability,and high clearance rates.Here,an aqueous formulation of icariin/hydroxypropyl-β-cyclodextrin(HP-β-CD)supramolecular inclusion complex was obtained to optimize icariin properties.Furthermore,icariin cyclodextrin supramolecular inclusion complex based thermosensitive(icariin gels)was innovated.At lower temperatures,it remained in a liquid phase with high fluidity.Upon reaching the gelation temperature,it underwent a transition to a gel phase with significantly reduced fluidity,which may be suitable for the design of an intranasal delivery system for PD treatment.The innovative approach capitalizes on the exceptional characteristics of HP-β-CD,which was utilized to synergize with nasal delivery for targeted brain delivery and with icariin for PD treatment[3,4].
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-vip complex.
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supported by the Natural Science Foundation of Jiangsu Province (No. BK2009016)the Chinese National Environmental Protection Special Funds for Scientific Research on Public Causes (No. 2010467016)the National High Technology Research and Development Program (863) of China (No. 2007AA061101)
文摘The contamination of soils by polycyclic aromatic hydrocarbons (PAHs) is a widespread environmental problem and the remediation of PAHs from these areas has been a major concern. The effectiveness of many in situ bioremediation systems may be constrained by low contaminant bioavailability due to limited aqueous solubility or a large magnitude of sorption. The objective of this research was to evaluate the effect of methyl-β-cyclodextrin (MCD) on bioaugmentation by Paracoccus sp. strain HPD-2 of an aged PAH-contaminated soil. When 10% (W/W) MCD amendment was combined with bioaugmentation by the PAH-degrading bacterium Paracoccus sp. strain HPD-2, the percentage degradation of total PAHs was significantly enhanced up to 34.8%. Higher counts of culturable PAH- degrading bacteria and higher soil dehydrogenase and soil polyphenol oxidase activities were observed in 10% (W/W) MCD-assisted bioaugmentation soil. This MCD-assisted bioaugmentation strategy showed significant increases (p 〈 0.05) in the average well color development (AWCD) obtained by the BIOLOG Eco plate assay, Shannon-Weaver index (H) and Simpson index (λ) compared with the controls, implying that this strategy at least partially restored the microbiological functioning of the PAH-contaminated soil. The results suggest that MCD-aided bioaugmentation by Paracoccus sp. strain HPD-2 may be a promising practical bioremediation strategy for aged PAH-contaminated soils.
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.