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2016 Volume 79 Issue 4
2016, 79(4): 292-298
Abstract:
In recent years, single-molecule force spectroscopy has been developed rapidly and applied in various fields. The investigation of biological structure, mechanical property, and molecular dynamics by single-molecule force spectroscopy can reveal the mechanism of intermolecular interaction at the single-molecule level. It will greatly help us understand the molecular recognition, biochemical process and the relationship between molecular structure and functions. This paper introduces three kinds of the most common single-molecule force spectroscopy: atomic force microscopy (AFM), optical tweezers (OT), and magnetic tweezers (MT) at first. Then the basic principle, development, and applications of other three kinds of massively parallel force spectroscopy: acoustic force spectroscopy (AFS), centrifugal force microscope (CFM), and force-induced remnant magnetization spectroscopy (FIRMS) are introduced briefly.
In recent years, single-molecule force spectroscopy has been developed rapidly and applied in various fields. The investigation of biological structure, mechanical property, and molecular dynamics by single-molecule force spectroscopy can reveal the mechanism of intermolecular interaction at the single-molecule level. It will greatly help us understand the molecular recognition, biochemical process and the relationship between molecular structure and functions. This paper introduces three kinds of the most common single-molecule force spectroscopy: atomic force microscopy (AFM), optical tweezers (OT), and magnetic tweezers (MT) at first. Then the basic principle, development, and applications of other three kinds of massively parallel force spectroscopy: acoustic force spectroscopy (AFS), centrifugal force microscope (CFM), and force-induced remnant magnetization spectroscopy (FIRMS) are introduced briefly.
2016, 79(4): 299-303
Abstract:
As an important fluorine-containing monomer for preparing the polymer having special features, perfluoroalkyl vinyl ether (PAVE) has received considerable attention because of its corresponding polymers with special features properties. According to the characteristics of PAVE,the preparation methods are reviewed, including the pyrolysis and reduction method. Moreover, the advantages and disadvantages of each method were discussed for exploring a better synthetic method.
As an important fluorine-containing monomer for preparing the polymer having special features, perfluoroalkyl vinyl ether (PAVE) has received considerable attention because of its corresponding polymers with special features properties. According to the characteristics of PAVE,the preparation methods are reviewed, including the pyrolysis and reduction method. Moreover, the advantages and disadvantages of each method were discussed for exploring a better synthetic method.
2016, 79(4): 304-313
Abstract:
2,6-Naphthalenedicarboxylic acid is a linear and rigid ligand with multiple coordinating atoms. Up to now, more than 100 kinds of 2,6-naphthalenedicarboxylic acid-based coordination polymers were reported. These coordination polymers show the abundant topological structures and potential application values. Here the structural characteristics and coordination modes of 2,6-naphthalenedicarboxylic acid ligand and the research advances of 2,6-naphthalenedicarboxylic acid-based coordination polymers according to various species of metal ions were summarized briefly. The application properties of 2,6-naphthalenedicarboxylic acid-based coordination polymers in the gas adsorption and separation, photoluminescence, magnetism and heterogeneous catalysis aspects were focused on, and the research prospects of these coordination polymers were presented.
2,6-Naphthalenedicarboxylic acid is a linear and rigid ligand with multiple coordinating atoms. Up to now, more than 100 kinds of 2,6-naphthalenedicarboxylic acid-based coordination polymers were reported. These coordination polymers show the abundant topological structures and potential application values. Here the structural characteristics and coordination modes of 2,6-naphthalenedicarboxylic acid ligand and the research advances of 2,6-naphthalenedicarboxylic acid-based coordination polymers according to various species of metal ions were summarized briefly. The application properties of 2,6-naphthalenedicarboxylic acid-based coordination polymers in the gas adsorption and separation, photoluminescence, magnetism and heterogeneous catalysis aspects were focused on, and the research prospects of these coordination polymers were presented.
2016, 79(4): 314-320
Abstract:
Porphyrins widely exist in nature and have a wide range of applications in the fields of the molecular self-assembly, biomimicry, electrochemistry, analytical chemistry, catalysis chemistry, and so on. Porphyrins with a variety of meso-substituents show different chemical properties, which have attracted wide attention. In this paper, the structural characteristics, physical and chemical properties of porphyrins were simply introduced firstly. Secondly, the tetraphenyl porphyrin which had relatively simple structures was chosen as example, its reaction mechanism was discussed. Thirdly, three kinds of synthetic methods for asymmetric meso-substituted porphyrins, i.e. mixed condensation synthesis, total synthesis and synthesis of preformed functionalization were described detailedly. Finally, the research progress of porphyrins in recent years was summarized and their development and application in the future were prospected.
Porphyrins widely exist in nature and have a wide range of applications in the fields of the molecular self-assembly, biomimicry, electrochemistry, analytical chemistry, catalysis chemistry, and so on. Porphyrins with a variety of meso-substituents show different chemical properties, which have attracted wide attention. In this paper, the structural characteristics, physical and chemical properties of porphyrins were simply introduced firstly. Secondly, the tetraphenyl porphyrin which had relatively simple structures was chosen as example, its reaction mechanism was discussed. Thirdly, three kinds of synthetic methods for asymmetric meso-substituted porphyrins, i.e. mixed condensation synthesis, total synthesis and synthesis of preformed functionalization were described detailedly. Finally, the research progress of porphyrins in recent years was summarized and their development and application in the future were prospected.
2016, 79(4): 321-326
Abstract:
Ni-P micro-arrays material was fabricated by electroless plating method with etched porous aluminum template. The microstructure and elemental composition of the material were analyzed by SEM, EDS and XRD. Electrochemical measurements were performed to study the effect of plating temperature and time on the hydrogen evolution over-potential of Ni-P micro-arrays electrodes. The results showed that Ni-P micro-arrays electrode fabricated at 70℃ exhibits the highest electrocatalytic activity for hydrogen evolution reaction, and the over-potential was reduced by 100mV compared with the smooth Ni-P electrodes at 15 mA/cm2. Its exchange current density reached to 13.53×10-6A/cm2 which is about 10 times of the smooth group. Ni-P micro-arrays electrode has already formed the array structures completely after fabricated at 70℃ for 4h, it exhibits a low over-potential but no longer benefited from increasing time further. To characterize the catalytic performance of obtained coatings intuitively, photocatalytic water splitting experiments were performed in a two-compartment photoelectrochemical cell. As the cathode, Ni-P micro-arrays electrode shows a high hydrogen production rate which is about 200% faster than that of the smooth group.
Ni-P micro-arrays material was fabricated by electroless plating method with etched porous aluminum template. The microstructure and elemental composition of the material were analyzed by SEM, EDS and XRD. Electrochemical measurements were performed to study the effect of plating temperature and time on the hydrogen evolution over-potential of Ni-P micro-arrays electrodes. The results showed that Ni-P micro-arrays electrode fabricated at 70℃ exhibits the highest electrocatalytic activity for hydrogen evolution reaction, and the over-potential was reduced by 100mV compared with the smooth Ni-P electrodes at 15 mA/cm2. Its exchange current density reached to 13.53×10-6A/cm2 which is about 10 times of the smooth group. Ni-P micro-arrays electrode has already formed the array structures completely after fabricated at 70℃ for 4h, it exhibits a low over-potential but no longer benefited from increasing time further. To characterize the catalytic performance of obtained coatings intuitively, photocatalytic water splitting experiments were performed in a two-compartment photoelectrochemical cell. As the cathode, Ni-P micro-arrays electrode shows a high hydrogen production rate which is about 200% faster than that of the smooth group.
2016, 79(4): 327-331,348
Abstract:
A novel photocatalyst consisting of oxygen-deficient SnO2 nanoparticles which can effectively degrade methyl orange (MO) under visible light was synthesized by a simple hydrothermal method and characterized by XRD, TEM, HRTEM and UV-Vis diffuse reflectance spectra. The results showed that the band gap of as-prepared catalyst can be lowered to 2.90eV, and thus the visible light absorption of the catalyst can be enhanced. The photocatalytic activity of the as-prepared catalyst was evaluated by degradation of methyl orange (MO) under irradiation of visible light. The degradation rate of MO (10 mg/L) by oxygen-deficient SnO2 nanoparticles (1g/L) can reach above 99% in 40 min under visible light illumination. Because of simple synthesis, high catalytic performance, low costs and mild reaction environment, the synthesized catalyst provides a new approach to solve the problem of organic dyes pollution in environment.
A novel photocatalyst consisting of oxygen-deficient SnO2 nanoparticles which can effectively degrade methyl orange (MO) under visible light was synthesized by a simple hydrothermal method and characterized by XRD, TEM, HRTEM and UV-Vis diffuse reflectance spectra. The results showed that the band gap of as-prepared catalyst can be lowered to 2.90eV, and thus the visible light absorption of the catalyst can be enhanced. The photocatalytic activity of the as-prepared catalyst was evaluated by degradation of methyl orange (MO) under irradiation of visible light. The degradation rate of MO (10 mg/L) by oxygen-deficient SnO2 nanoparticles (1g/L) can reach above 99% in 40 min under visible light illumination. Because of simple synthesis, high catalytic performance, low costs and mild reaction environment, the synthesized catalyst provides a new approach to solve the problem of organic dyes pollution in environment.
2016, 79(4): 332-337
Abstract:
The common corrosion behavior of 316L stainless steel is pitting corrosion. In this work, the electrochemical cycle polarization test, microbiological analysis, surface morphology and energy spectrum analysis were used to investigate the influence of magnetic field on the corrosion of 316L stainless steel in soil simulated solution containing SRB. The results showed that apply of magnetic field can inhibit the growth of SRB. There were local accumulation on surface film of 316L stainless steel without magnetic field, and the surface film uniformly arranges on the surface of substrate when applying magnetic field and the local accumulation areas decrease significantly. The pitting corrosion behaviors of 316L stainless steel in soil solution were both film rupture with or without magnetic fields and the pitting potential without applying magnetic field is lower than that of with magnetic field. Under the same immersion time, the area of lap ring with applying magnetic field is smaller than that of without applying magnetic field. The presence of magnetic field can effectively inhibit the formation and development of the pitting corrosion of 316L stainless steel and reduce the ability of induce pitting.
The common corrosion behavior of 316L stainless steel is pitting corrosion. In this work, the electrochemical cycle polarization test, microbiological analysis, surface morphology and energy spectrum analysis were used to investigate the influence of magnetic field on the corrosion of 316L stainless steel in soil simulated solution containing SRB. The results showed that apply of magnetic field can inhibit the growth of SRB. There were local accumulation on surface film of 316L stainless steel without magnetic field, and the surface film uniformly arranges on the surface of substrate when applying magnetic field and the local accumulation areas decrease significantly. The pitting corrosion behaviors of 316L stainless steel in soil solution were both film rupture with or without magnetic fields and the pitting potential without applying magnetic field is lower than that of with magnetic field. Under the same immersion time, the area of lap ring with applying magnetic field is smaller than that of without applying magnetic field. The presence of magnetic field can effectively inhibit the formation and development of the pitting corrosion of 316L stainless steel and reduce the ability of induce pitting.
2016, 79(4): 338-343
Abstract:
The dissociation constants (pKa) of two insensitive explosives 3,4-dinitropyrazole (DNP) and 3-nitro-1,2,4-triazol-5-one (NTO) were determined by five methods including titration, half neutralization, pH, electrical conductivity and UV-spectrophotometry. The results obtained from various methods were compared and discussed. The results showed that the methods of titration, half neutralization and UV-spectrophotometry are more suitable to determine the pKa of DNP, the relative error RE<5%; and methods of titration and pH are more suitable to determine the pKa of NTO, the relative error RE<4%. pKa of DNP is larger than that of NTO, which means acidity of DNP is weaker, so DNP have small causticity to the equipments and could preferably be used as melt-cast explosive carrier. Based on the advantages and disadvantages of the five methods, the appropriate methods for determining pKa of different chemical substances were summarized.
The dissociation constants (pKa) of two insensitive explosives 3,4-dinitropyrazole (DNP) and 3-nitro-1,2,4-triazol-5-one (NTO) were determined by five methods including titration, half neutralization, pH, electrical conductivity and UV-spectrophotometry. The results obtained from various methods were compared and discussed. The results showed that the methods of titration, half neutralization and UV-spectrophotometry are more suitable to determine the pKa of DNP, the relative error RE<5%; and methods of titration and pH are more suitable to determine the pKa of NTO, the relative error RE<4%. pKa of DNP is larger than that of NTO, which means acidity of DNP is weaker, so DNP have small causticity to the equipments and could preferably be used as melt-cast explosive carrier. Based on the advantages and disadvantages of the five methods, the appropriate methods for determining pKa of different chemical substances were summarized.
2016, 79(4): 344-348
Abstract:
The tertiary structure of human serum albumin (HSA) and the structure-reversibility at different pH values had been studied by DSC, DLS and CD. The results indicated that HSA proves to be the most stable structure at pH 7.0,and the melting temperature (Tm) is 68.17±0.06℃. The tertiary structure of HSA is changed at different pH values and the Tm of HSA is very close to the Tm at pH 7.0 when pH is adjusted back to 7.0 from different pH values. The size of HSA is larger at other different pH values than that at pH 7.0 and it gets smaller when pH is adjusted back to 7.0. The influence of pH on the secondary structure of HSA is detected by CD. Although HSA can be refolded when adjusted back to 7.0 from different pH values, it can't return back to the structure of HSA at pH 7.0.
The tertiary structure of human serum albumin (HSA) and the structure-reversibility at different pH values had been studied by DSC, DLS and CD. The results indicated that HSA proves to be the most stable structure at pH 7.0,and the melting temperature (Tm) is 68.17±0.06℃. The tertiary structure of HSA is changed at different pH values and the Tm of HSA is very close to the Tm at pH 7.0 when pH is adjusted back to 7.0 from different pH values. The size of HSA is larger at other different pH values than that at pH 7.0 and it gets smaller when pH is adjusted back to 7.0. The influence of pH on the secondary structure of HSA is detected by CD. Although HSA can be refolded when adjusted back to 7.0 from different pH values, it can't return back to the structure of HSA at pH 7.0.
2016, 79(4): 349-354
Abstract:
The molecularly imprinted polymer (MIP) with high selectivity to quercetin had been synthesized using quercetin as the template molecule and the modified attapulgite as carrier by surface molecular imprinting technology.The optimum of functional monomer, structure of MIP, binding properties and recognition ability of MIP for quercetin were discussed and characterized by spectroscopy and static method respectively. The results demonstrated that as-synthesized MIP possesses specific recognition selectivity and excellent binding affinity for quercetin, and it improves the binding rate of traditional MIPs. The MIP as solid phase extraction (SPE) materials coupled with HPLC was used for separation and enrichment of quercetin in cabbage. The recoveries of the method developed in this work were in the range from 84.0% to 90.6%, and the RSD was less than 5.6%.
The molecularly imprinted polymer (MIP) with high selectivity to quercetin had been synthesized using quercetin as the template molecule and the modified attapulgite as carrier by surface molecular imprinting technology.The optimum of functional monomer, structure of MIP, binding properties and recognition ability of MIP for quercetin were discussed and characterized by spectroscopy and static method respectively. The results demonstrated that as-synthesized MIP possesses specific recognition selectivity and excellent binding affinity for quercetin, and it improves the binding rate of traditional MIPs. The MIP as solid phase extraction (SPE) materials coupled with HPLC was used for separation and enrichment of quercetin in cabbage. The recoveries of the method developed in this work were in the range from 84.0% to 90.6%, and the RSD was less than 5.6%.
2016, 79(4): 355-359
Abstract:
In this study, imidazolium based acidic ionic liquids and CrCl3·6H2O were used to catalyze the hydrolysis of cellulose in ionic liquid 1-allyl-3-methylimidazolium chloride ([Amim]Cl) via microwave-assisted irradiation to prepare 5-hydroxymethyl furfural (5-HMF). The effects of the type and amount of catalysts, reaction temperature and time, amount of water on the degradation of cellulose were studied in details. The results indicated that [C2mim]HSO4 and CrCl3·6H2O are efficient catalysts for preparing 5-HMF. The cellulose can be completely converted with the highest TRS yield of 87.22% and 5-HMF yield of 50% under the condition of nMCC:nCr=10:1, the mass of [C2mim]HSO4=0.02g, and reaction temperature 160℃ under microwave-assisted heating for 30 min.
In this study, imidazolium based acidic ionic liquids and CrCl3·6H2O were used to catalyze the hydrolysis of cellulose in ionic liquid 1-allyl-3-methylimidazolium chloride ([Amim]Cl) via microwave-assisted irradiation to prepare 5-hydroxymethyl furfural (5-HMF). The effects of the type and amount of catalysts, reaction temperature and time, amount of water on the degradation of cellulose were studied in details. The results indicated that [C2mim]HSO4 and CrCl3·6H2O are efficient catalysts for preparing 5-HMF. The cellulose can be completely converted with the highest TRS yield of 87.22% and 5-HMF yield of 50% under the condition of nMCC:nCr=10:1, the mass of [C2mim]HSO4=0.02g, and reaction temperature 160℃ under microwave-assisted heating for 30 min.
2016, 79(4): 360-365
Abstract:
Four new lapatinib derivatives were prepared using N'-(2-cyano-4-iodophenyl)-N,N-dimethyl-formamidine as the starting material by Dimroth rearrangement, Suzuki coupling, reductive amination in turn. The structures of the reaction intermediates and target compounds were characterized with the NMR, IR and HRMS. The antitumor activities of these compounds on SW480, A549 and A431 tumor cells were tested preliminarily by the MTT method in vitro experiment. The results indicated that they had significant inhibition on the growth of tumor cells, especially compound 5a showed good growth inhibitory activity on all the test cells (IC50:5.78~13.38μmol/L) which is similar as that of lapatinib (IC50:4.80~14.90μmol/L).
Four new lapatinib derivatives were prepared using N'-(2-cyano-4-iodophenyl)-N,N-dimethyl-formamidine as the starting material by Dimroth rearrangement, Suzuki coupling, reductive amination in turn. The structures of the reaction intermediates and target compounds were characterized with the NMR, IR and HRMS. The antitumor activities of these compounds on SW480, A549 and A431 tumor cells were tested preliminarily by the MTT method in vitro experiment. The results indicated that they had significant inhibition on the growth of tumor cells, especially compound 5a showed good growth inhibitory activity on all the test cells (IC50:5.78~13.38μmol/L) which is similar as that of lapatinib (IC50:4.80~14.90μmol/L).
2016, 79(4): 366-371
Abstract:
To detect malachite green (MG) in the aquatic product easily and sensitively, molecularly imprinted polymer (MIP) microspheres were prepared via in-situ polymerization method with MG as template, α-methacrylic acid (MAA) as functional monomer, ethylene glycol dimethacrylate (EGDMA) as cross-linker and acetonitrile/toluene (V/V=3:1) solution as solvent. Then the MG-MIP-96-well detecting plates detected by the method of chemilumineseent immunoassay (CLIA) were developed by coating the MIPs in the 96-well plates. The standard curve of as-developed method is y=-29197.49x+1945998.45, R2=0.9416, linearity range is 30~66.64 ng/mL, the LOD is 3.355ng/mL, the intra and inter-assay coefficient of variation are 7.38%~18.07% and 12.45%~17.52%, the intra and inter-assay recovery are 103.41%~144.45% and 100.07%~143.20%, and the crossover rates are 27.97% and 30.97% with specifically detecting the MG's analogue, pararosaniline (PA) and crystal violet (CV). The experiment results showed that the as-developed method has great potential in practical application.
To detect malachite green (MG) in the aquatic product easily and sensitively, molecularly imprinted polymer (MIP) microspheres were prepared via in-situ polymerization method with MG as template, α-methacrylic acid (MAA) as functional monomer, ethylene glycol dimethacrylate (EGDMA) as cross-linker and acetonitrile/toluene (V/V=3:1) solution as solvent. Then the MG-MIP-96-well detecting plates detected by the method of chemilumineseent immunoassay (CLIA) were developed by coating the MIPs in the 96-well plates. The standard curve of as-developed method is y=-29197.49x+1945998.45, R2=0.9416, linearity range is 30~66.64 ng/mL, the LOD is 3.355ng/mL, the intra and inter-assay coefficient of variation are 7.38%~18.07% and 12.45%~17.52%, the intra and inter-assay recovery are 103.41%~144.45% and 100.07%~143.20%, and the crossover rates are 27.97% and 30.97% with specifically detecting the MG's analogue, pararosaniline (PA) and crystal violet (CV). The experiment results showed that the as-developed method has great potential in practical application.
2016, 79(4): 372-376
Abstract:
The polyacrylamide (PAM) solution was treated by using Fe(II)(EDTA) chelate/UV catalytic ozonation process. The effect of hydraulic retention time (HRT), single O3 and the system of Fe(II)(EDTA) chelate/UV catalytic ozonation on viscosity and PAM removal rate of the solution were analyzed in detail. The change rule of B/C with the variation of HRT and the efficiency of the system on biodegradability of PAM solution were investigated. Moreover, the effect of surfactant and oxalic acid on the process to oxidize PAM solution was also discussed separately. The result showed that the method can well degrade the PAM solution. The viscosity of the PAM solution is decreased 57% in the first 15min, the PAM removal rate is up to 75% and the B/C ratio is improved from 0.121 to 0.423 by a large margin within 120min. The surfactant only has a small influence on the process to reduce the solution viscosity. In addition, because acidic condition caused by adding oxalic acid restrains the decomposition of O3 in aqueous solution, it is not conducive to the catalytic ozone oxidation degradation process, and the viscosity reduction efficiency and PAM removal rate of the solution in oxalic acid/Fe(II)(EDTA)/O3 system is lower than that in Fe(II)(EDTA)/O3 system.
The polyacrylamide (PAM) solution was treated by using Fe(II)(EDTA) chelate/UV catalytic ozonation process. The effect of hydraulic retention time (HRT), single O3 and the system of Fe(II)(EDTA) chelate/UV catalytic ozonation on viscosity and PAM removal rate of the solution were analyzed in detail. The change rule of B/C with the variation of HRT and the efficiency of the system on biodegradability of PAM solution were investigated. Moreover, the effect of surfactant and oxalic acid on the process to oxidize PAM solution was also discussed separately. The result showed that the method can well degrade the PAM solution. The viscosity of the PAM solution is decreased 57% in the first 15min, the PAM removal rate is up to 75% and the B/C ratio is improved from 0.121 to 0.423 by a large margin within 120min. The surfactant only has a small influence on the process to reduce the solution viscosity. In addition, because acidic condition caused by adding oxalic acid restrains the decomposition of O3 in aqueous solution, it is not conducive to the catalytic ozone oxidation degradation process, and the viscosity reduction efficiency and PAM removal rate of the solution in oxalic acid/Fe(II)(EDTA)/O3 system is lower than that in Fe(II)(EDTA)/O3 system.
2016, 79(4): 377-380
Abstract:
Microwave-assisted chemical reactions have attracted interest for decades, but hot spots and thermal runaway prevent the further development of microwave heating in chemical engineering. In order to solve these problems, it is needed to study the interaction between electromagnetic wave and chemical reactions. The polarization of the chemical reactions is the basis to investigate the interaction between electromagnetic wave and chemical reactions. The expression of polarization of the polar-molecule reactions is derived with modified Smoluchowski-Debye equation. The polarization of the chemical reactions is actually a response of a linear time varying system, which is a Markov process under certain conditions. The aim of this paper is to discuss the relation between the time domain and the frequency domain representation of the polarization of chemical reactions, along with the limitations of the representation in the frequency domain.
Microwave-assisted chemical reactions have attracted interest for decades, but hot spots and thermal runaway prevent the further development of microwave heating in chemical engineering. In order to solve these problems, it is needed to study the interaction between electromagnetic wave and chemical reactions. The polarization of the chemical reactions is the basis to investigate the interaction between electromagnetic wave and chemical reactions. The expression of polarization of the polar-molecule reactions is derived with modified Smoluchowski-Debye equation. The polarization of the chemical reactions is actually a response of a linear time varying system, which is a Markov process under certain conditions. The aim of this paper is to discuss the relation between the time domain and the frequency domain representation of the polarization of chemical reactions, along with the limitations of the representation in the frequency domain.
2016, 79(4): 381-383
Abstract:
Bergenin is attracting more and more attention due to its wide range of biological activities. In this work, eight aza-bergenin derivatives were synthesized by Mannich reaction and Mitsunobu reaction, and their structures were characterized by 1H NMR, 13C NMR and HRMS. Their antitumor activities were studied in vitro against human tumor cell line A549 by the MTT assay. The results revealed that compound 3c and 3d are the most potential compounds against A549 (IC50=3.74μmol/L and 5.05μmol/L, respectively), which showed better activity than bergenin and could be used as the lead compounds for further research.
Bergenin is attracting more and more attention due to its wide range of biological activities. In this work, eight aza-bergenin derivatives were synthesized by Mannich reaction and Mitsunobu reaction, and their structures were characterized by 1H NMR, 13C NMR and HRMS. Their antitumor activities were studied in vitro against human tumor cell line A549 by the MTT assay. The results revealed that compound 3c and 3d are the most potential compounds against A549 (IC50=3.74μmol/L and 5.05μmol/L, respectively), which showed better activity than bergenin and could be used as the lead compounds for further research.
