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2018 Volume 81 Issue 3
2018, 81(3): 195-202
Abstract:
Poly(N-isopropylacrylamide) (PNIPAM) is one of the thermally responsive polymers, at the lower critical solution temperature (LCST), it undergoes a conformational transition. Its application in many areas, such as the drug delivery, gene transfer, biochemical analysis and so on can be widened by modification. In this article, the research progress in preparation and application of PNIPAM were reviewed, and the prospects of this field were also put forward.
Poly(N-isopropylacrylamide) (PNIPAM) is one of the thermally responsive polymers, at the lower critical solution temperature (LCST), it undergoes a conformational transition. Its application in many areas, such as the drug delivery, gene transfer, biochemical analysis and so on can be widened by modification. In this article, the research progress in preparation and application of PNIPAM were reviewed, and the prospects of this field were also put forward.
2018, 81(3): 203-208
Abstract:
To date, there have been two ways to synthesize homocamptothecin including semi-synthesis and total synthesis. The former is simple and concise, yet with few substituent groups. It only produces the racemic homocamptothecin. On the contrary, the latter can introduce various substituent groups on ring A and B. This protocol can bring the asymmetric synthesis into practice, though the route seems a little lengthy. All the study advance of homocamptothecin at home and abroad was reviewed. Each group's synthetic protocol was introduced in depth along with their research results. The outlook of homocamptothecin in the field of medicine was foreshown, with the indication of the future research direction.
To date, there have been two ways to synthesize homocamptothecin including semi-synthesis and total synthesis. The former is simple and concise, yet with few substituent groups. It only produces the racemic homocamptothecin. On the contrary, the latter can introduce various substituent groups on ring A and B. This protocol can bring the asymmetric synthesis into practice, though the route seems a little lengthy. All the study advance of homocamptothecin at home and abroad was reviewed. Each group's synthetic protocol was introduced in depth along with their research results. The outlook of homocamptothecin in the field of medicine was foreshown, with the indication of the future research direction.
2018, 81(3): 209-216
Abstract:
α-Aminonitriles are significantly important intermediates for the syntheses of numerous amino acids. At present, α-aminonitriles have been widely used in chemistry, biology, medicine and other fields. As one of the most important methods for synthesizing α-aminonitriles, the Strecker reaction has been attracting the great attention of the researchers. However, the traditional Strecker reaction takes highly toxic HCN as cyanide source, it is dangerous and requires harsh operating conditions, which severely limits the development of this reaction. Therefore, to find a non-toxic and eco-friendly cyanide is the key to solve this problem. In this paper, the new cyanide species reported in the past decade are divided into TMSCN (trimethylsilyl cyanide), metal cyanides and organic cyanides. Then, the progress of these three cyanide compounds in the synthesis of α-aminonitrile by Strecker reaction is reviewed. Particularly, the catalyst development and catalytic mechanism of Strecker reaction with TMSCN as cyanide source are expounded. The application of some commonly used metal cyanides and organic cyanides in the Strecker reaction is also introduced. Moreover, the research trends of Strecker reaction are prospected.
α-Aminonitriles are significantly important intermediates for the syntheses of numerous amino acids. At present, α-aminonitriles have been widely used in chemistry, biology, medicine and other fields. As one of the most important methods for synthesizing α-aminonitriles, the Strecker reaction has been attracting the great attention of the researchers. However, the traditional Strecker reaction takes highly toxic HCN as cyanide source, it is dangerous and requires harsh operating conditions, which severely limits the development of this reaction. Therefore, to find a non-toxic and eco-friendly cyanide is the key to solve this problem. In this paper, the new cyanide species reported in the past decade are divided into TMSCN (trimethylsilyl cyanide), metal cyanides and organic cyanides. Then, the progress of these three cyanide compounds in the synthesis of α-aminonitrile by Strecker reaction is reviewed. Particularly, the catalyst development and catalytic mechanism of Strecker reaction with TMSCN as cyanide source are expounded. The application of some commonly used metal cyanides and organic cyanides in the Strecker reaction is also introduced. Moreover, the research trends of Strecker reaction are prospected.
2018, 81(3): 217-222
Abstract:
Fenton technology is an effective method for the treatment of non-biodegradable organic pollutants. It can be carried out under mild conditions, but with the disadvantage of narrow pH range. In this paper, different methods of improving the catalyst and oxidant to expand the pH range were discussed, and the reaction mechanism of broadening the pH range was summarized. The catalyst modification includes the use of supported catalysts, iron and iron mineral catalysts, modified catalysts, non-ferrous metal active sites, etc. These catalysts can broaden the Fenton reaction pH range for their high catalytic activity over the wide pH range. Improvements to oxidants include the use of H2O2-containing solid oxidants such as percarbonates and persulfates, etc., using their own properties to achieve the purpose of broadening the pH range. Through the simultaneous improvement of the catalyst and the oxidant, the pH range of the Fenton reaction can be effectively broadened, and the formation of iron sludge can be avoided at the same time.
Fenton technology is an effective method for the treatment of non-biodegradable organic pollutants. It can be carried out under mild conditions, but with the disadvantage of narrow pH range. In this paper, different methods of improving the catalyst and oxidant to expand the pH range were discussed, and the reaction mechanism of broadening the pH range was summarized. The catalyst modification includes the use of supported catalysts, iron and iron mineral catalysts, modified catalysts, non-ferrous metal active sites, etc. These catalysts can broaden the Fenton reaction pH range for their high catalytic activity over the wide pH range. Improvements to oxidants include the use of H2O2-containing solid oxidants such as percarbonates and persulfates, etc., using their own properties to achieve the purpose of broadening the pH range. Through the simultaneous improvement of the catalyst and the oxidant, the pH range of the Fenton reaction can be effectively broadened, and the formation of iron sludge can be avoided at the same time.
2018, 81(3): 223-230
Abstract:
The methyl parathion molecularly imprinted electrochemical sensor was constructed based on WMCNTs and AuNPs, with tetramethylthiophenol (p-ATP) as functional monomer and methyl parathion (MP) as template molecule by electrochemical polymerization method. The electrochemical performance, selectivity, reproducibility and stability of the sensor were studied by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and differential pulse method (DPV). The prepared sensor was used to measure MP in the Yellow River sample with satisfactory results. This method has the advantages of easy preparation, good selectivity, high sensitivity and good reproducibility. It provides a very effective method for analysis of methyl parathion (MP).
The methyl parathion molecularly imprinted electrochemical sensor was constructed based on WMCNTs and AuNPs, with tetramethylthiophenol (p-ATP) as functional monomer and methyl parathion (MP) as template molecule by electrochemical polymerization method. The electrochemical performance, selectivity, reproducibility and stability of the sensor were studied by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and differential pulse method (DPV). The prepared sensor was used to measure MP in the Yellow River sample with satisfactory results. This method has the advantages of easy preparation, good selectivity, high sensitivity and good reproducibility. It provides a very effective method for analysis of methyl parathion (MP).
2018, 81(3): 231-235
Abstract:
The SiO2 and amorphous SiO2-Al2O3 (ASA) was prepared by stepwise precipitation method, and the Ni2P/ASA catalyst was fabricated by saturated volume impregnation and programmed-temperature reduction. Characterizations of the supports and catalysts were performed using XRD, FT-IR, N2 adsorption-desorption, H2-TPR and TEM, and then the effects of SiO2/Al2O3 mass ratio and specific surface area obtained with ASA on the Ni2P formation were mainly investigated. Results showed that with the increasing of Al2O3 content in ASA support the more content of P was required for the formation of Ni2P phase. Phosphorus firstly formed AlPO4 phase with alumina, hindered the formation of phosphorus-rich atmosphere, however phosphorus-rich atmosphere was pre-requisited to the formation of Ni2P phase, hence more P must be added to the carrier with more aluminum content to produce pure Ni2P phase. TEM results indicated that the formation of AlPO4 phase, in turn, promoted the reduction of Ni2P particle size and facilitated the dispersion of the catalyst. The specific surface area of the support has little influence on the formation of Ni2P phase
The SiO2 and amorphous SiO2-Al2O3 (ASA) was prepared by stepwise precipitation method, and the Ni2P/ASA catalyst was fabricated by saturated volume impregnation and programmed-temperature reduction. Characterizations of the supports and catalysts were performed using XRD, FT-IR, N2 adsorption-desorption, H2-TPR and TEM, and then the effects of SiO2/Al2O3 mass ratio and specific surface area obtained with ASA on the Ni2P formation were mainly investigated. Results showed that with the increasing of Al2O3 content in ASA support the more content of P was required for the formation of Ni2P phase. Phosphorus firstly formed AlPO4 phase with alumina, hindered the formation of phosphorus-rich atmosphere, however phosphorus-rich atmosphere was pre-requisited to the formation of Ni2P phase, hence more P must be added to the carrier with more aluminum content to produce pure Ni2P phase. TEM results indicated that the formation of AlPO4 phase, in turn, promoted the reduction of Ni2P particle size and facilitated the dispersion of the catalyst. The specific surface area of the support has little influence on the formation of Ni2P phase
2018, 81(3): 236-240
Abstract:
In this study, the photo degradation of the size-fractionated (0.45μm-100kDa, 100kDa-5kDa, < 5kDa) dissolved organic matter (DOM) at different light sources was investigated. Measurements of dissolved organic carbon (DOC) and UV254 absorbance showed that sunlight exposure led to the decrease of DOM in all the three fractions over a 6-days period of 6 h/d irradiation, and the presence of UVC light in natural sunlight can speedup DOM elimination. The parallel factor (PARAFAC) analysis of fluorescence excitation emission matrices (EEM) revealed the presence of three humic-like components (C1:UVA+UVC; C2:UVA+UVB; C3:UVC) in the DOM samples. In addition, the fluorescent components in large-size DOM fractions (>5kDa) were not sensitive to sunlight exposure, and some of which increased upon sunlight exposure. However, the C1 and C2 in the small-size DOM fractions (< 5kDa) were much more susceptible to sunlight exposure, both of which decreased significantly after the 6-days incubation. But, the C3 components in all DOM fractions were found to be photo-produced. Also, the presence of the UVC light in sunlight can somewhat speedup the elimination of C1 and C2 or decrease the generation of C3.
In this study, the photo degradation of the size-fractionated (0.45μm-100kDa, 100kDa-5kDa, < 5kDa) dissolved organic matter (DOM) at different light sources was investigated. Measurements of dissolved organic carbon (DOC) and UV254 absorbance showed that sunlight exposure led to the decrease of DOM in all the three fractions over a 6-days period of 6 h/d irradiation, and the presence of UVC light in natural sunlight can speedup DOM elimination. The parallel factor (PARAFAC) analysis of fluorescence excitation emission matrices (EEM) revealed the presence of three humic-like components (C1:UVA+UVC; C2:UVA+UVB; C3:UVC) in the DOM samples. In addition, the fluorescent components in large-size DOM fractions (>5kDa) were not sensitive to sunlight exposure, and some of which increased upon sunlight exposure. However, the C1 and C2 in the small-size DOM fractions (< 5kDa) were much more susceptible to sunlight exposure, both of which decreased significantly after the 6-days incubation. But, the C3 components in all DOM fractions were found to be photo-produced. Also, the presence of the UVC light in sunlight can somewhat speedup the elimination of C1 and C2 or decrease the generation of C3.
2018, 81(3): 241-247, 266
Abstract:
Dibutyl phthalate (DBP) is one of the most widely used phthalates, which is refractory organic pollutants and has strong endocrine disrupting effect. In the present study, the isolated DBP degrading bacteria, Enterobacter sp.S8 was applied to investigated the effects of the co-metabolism substrate type and reaction conditions on the co-metabolism degradation efficiency of DBP, while the reaction kinetics and the stability of the enzyme were studied. The results showed that the biodegradation efficiency of S8 to DBP was only 30.2% without co-metabolism substrate, while the highest DBP biodegradation efficiency was 75.6% with optimal conditions:the temperature of 30℃, the pH of 7, the methanol dosage of 20 mg/L and the DBP initial concentration of 300 mg/L. The initial concentration of DBP had the greatest effects on the co-metabolism biodegradation of DBP. The present study provides a basis for the treatment the DBP contaminated environments by co-metabolism.
Dibutyl phthalate (DBP) is one of the most widely used phthalates, which is refractory organic pollutants and has strong endocrine disrupting effect. In the present study, the isolated DBP degrading bacteria, Enterobacter sp.S8 was applied to investigated the effects of the co-metabolism substrate type and reaction conditions on the co-metabolism degradation efficiency of DBP, while the reaction kinetics and the stability of the enzyme were studied. The results showed that the biodegradation efficiency of S8 to DBP was only 30.2% without co-metabolism substrate, while the highest DBP biodegradation efficiency was 75.6% with optimal conditions:the temperature of 30℃, the pH of 7, the methanol dosage of 20 mg/L and the DBP initial concentration of 300 mg/L. The initial concentration of DBP had the greatest effects on the co-metabolism biodegradation of DBP. The present study provides a basis for the treatment the DBP contaminated environments by co-metabolism.
2018, 81(3): 248-252
Abstract:
Starting from 2-thiohydantoin, substituted benzaldehydes, methyl iodide and pyridin-3-ylmethyl amine, a series of 5-substituted benzylidene-2-[(pyridine-3-yl)methylamino]-1H-imidazol-4(5H)-ones (3a~3i) were synthesized by Knoevenagel condensation, methylation and substitution reactions. The structures of the target compounds were characterized by IR, 1H NMR, 13C NMR and HRMS. The preliminary antifungal activity results indicated that all target compounds display moderate inhibitory activities against B. cinerea at the concerntration of 100μg/mL, with inhibition rates in the range of 69.5%~83.2%. Most of the target compounds exhibited notable activities against S. sclerotiorum at the same dosage, with inhibition rates in the range of 87.9%~100%, which were higher than that of the control fungicides, triazolone and chlorothalonil.
Starting from 2-thiohydantoin, substituted benzaldehydes, methyl iodide and pyridin-3-ylmethyl amine, a series of 5-substituted benzylidene-2-[(pyridine-3-yl)methylamino]-1H-imidazol-4(5H)-ones (3a~3i) were synthesized by Knoevenagel condensation, methylation and substitution reactions. The structures of the target compounds were characterized by IR, 1H NMR, 13C NMR and HRMS. The preliminary antifungal activity results indicated that all target compounds display moderate inhibitory activities against B. cinerea at the concerntration of 100μg/mL, with inhibition rates in the range of 69.5%~83.2%. Most of the target compounds exhibited notable activities against S. sclerotiorum at the same dosage, with inhibition rates in the range of 87.9%~100%, which were higher than that of the control fungicides, triazolone and chlorothalonil.
2018, 81(3): 253-257
Abstract:
Copper (Ⅱ) complexes are likely to become the next generation of anti-tumor drugs. Schiff base was synthesized from 2-amino-5-chlorophenol and 2-quinolinecarbaldehyde, which was used as ligand to further complex with Cu (Ⅱ) to form complex 1. In vitro anti-tumor tests of complex 1 and HSA-1 complex on different tumor cells were carried out. The results indicated that HSA can improve the anti-tumor activity of complex 1 and reduce the toxicity to normal cells. Mitochondrial membrane potential assays revealed that copper(Ⅱ) complex induced apoptosis might mediate via the mitochondrial pathway.
Copper (Ⅱ) complexes are likely to become the next generation of anti-tumor drugs. Schiff base was synthesized from 2-amino-5-chlorophenol and 2-quinolinecarbaldehyde, which was used as ligand to further complex with Cu (Ⅱ) to form complex 1. In vitro anti-tumor tests of complex 1 and HSA-1 complex on different tumor cells were carried out. The results indicated that HSA can improve the anti-tumor activity of complex 1 and reduce the toxicity to normal cells. Mitochondrial membrane potential assays revealed that copper(Ⅱ) complex induced apoptosis might mediate via the mitochondrial pathway.
2018, 81(3): 258-266
Abstract:
The interactions of glucose and inositol respectively with ascorbic acid (AA) were studied by electrochemistry, density functional theory methods and atoms in molecules analysis. The electrochemical results of the two mixed systems in aqueous solution and phosphate buffer saline (PBS) solution showed that the hydrogen atoms on the enediol of AA can form hydrogen bonds with the oxygen atoms on hydroxyl of glucose/inositol, making the electro-oxidation reaction of AA more difficult, which is further confirmed by quantum chemical calculation.
The interactions of glucose and inositol respectively with ascorbic acid (AA) were studied by electrochemistry, density functional theory methods and atoms in molecules analysis. The electrochemical results of the two mixed systems in aqueous solution and phosphate buffer saline (PBS) solution showed that the hydrogen atoms on the enediol of AA can form hydrogen bonds with the oxygen atoms on hydroxyl of glucose/inositol, making the electro-oxidation reaction of AA more difficult, which is further confirmed by quantum chemical calculation.
2018, 81(3): 267-273
Abstract:
The Euler multiphase flow model and the Finite-Rate/Eddy-Dissipation model were used to study the flow characteristics of solid-liquid two-phase flow and the gas-liquid-solid flow in the vertical pipeline. The results showed that the velocity distribution and the volume distribution of hydrate both exhibit a fluctuation-uniform-fluctuation law with the change of height effected by gas from decomposition of hydrate slurry. Besides, it was found that the gas producing from hydrate dissociation on the slurry transportation has a drag reduction effect, and it can be proposed that natural gas hydrate three-phase flow slurry flow rate should not be less than 3.0 m/s. Finally, the relationship between the loss of the hydraulic lift and the flow rate of the hydrate slurry was fitted through the analysis of the resistance characteristics of the pipeline, which will provide guidance on the economic upgrading of gas hydrate slurry pipelines.
The Euler multiphase flow model and the Finite-Rate/Eddy-Dissipation model were used to study the flow characteristics of solid-liquid two-phase flow and the gas-liquid-solid flow in the vertical pipeline. The results showed that the velocity distribution and the volume distribution of hydrate both exhibit a fluctuation-uniform-fluctuation law with the change of height effected by gas from decomposition of hydrate slurry. Besides, it was found that the gas producing from hydrate dissociation on the slurry transportation has a drag reduction effect, and it can be proposed that natural gas hydrate three-phase flow slurry flow rate should not be less than 3.0 m/s. Finally, the relationship between the loss of the hydraulic lift and the flow rate of the hydrate slurry was fitted through the analysis of the resistance characteristics of the pipeline, which will provide guidance on the economic upgrading of gas hydrate slurry pipelines.
2018, 81(3): 274-277
Abstract:
Gourd is a common vegetable, and most varieties are covered with a layer of powder similar to 'white frost' when ripe. The wettability, structural morphology and composition of the white frost on the surface of gourd were studied by use of scanning electron microscope, contact angle measuring instrument, Fourier infrared spectroscopy, X-ray diffractometer, etc. The white frost was found to be of superhydrophobicity, as exhibited by the contact angle of water droplets on the surface, up to 154.8±3.5° and the rolling angle, less than 5°. The results also showed that the white frost on the surface had a micro and nano hierarchical topological roughness structures, mainly composed of long-chain fatty acids and long-chain alkane esters. The synergistic effect of such a hierarchical structure and the chemical composition determines the superhydrophobicity of the surface. This work provides data accumulation for further understanding and design of such structural materials.
Gourd is a common vegetable, and most varieties are covered with a layer of powder similar to 'white frost' when ripe. The wettability, structural morphology and composition of the white frost on the surface of gourd were studied by use of scanning electron microscope, contact angle measuring instrument, Fourier infrared spectroscopy, X-ray diffractometer, etc. The white frost was found to be of superhydrophobicity, as exhibited by the contact angle of water droplets on the surface, up to 154.8±3.5° and the rolling angle, less than 5°. The results also showed that the white frost on the surface had a micro and nano hierarchical topological roughness structures, mainly composed of long-chain fatty acids and long-chain alkane esters. The synergistic effect of such a hierarchical structure and the chemical composition determines the superhydrophobicity of the surface. This work provides data accumulation for further understanding and design of such structural materials.
2018, 81(3): 278-287
Abstract:
The first-year undergraduates are always racked by the solubility rule of metal halides in water. In this paper, firstly, the chemical bonds were deduced from atomic structures and molecular structures. Then, the dissolve modes in water were derived from the chemical bonds. Thirdly, the correlation between the energy changes and the solubilities was analyzed based on thermodynamic data, and finally, the solubility rule of halides in water was revealed.
The first-year undergraduates are always racked by the solubility rule of metal halides in water. In this paper, firstly, the chemical bonds were deduced from atomic structures and molecular structures. Then, the dissolve modes in water were derived from the chemical bonds. Thirdly, the correlation between the energy changes and the solubilities was analyzed based on thermodynamic data, and finally, the solubility rule of halides in water was revealed.
