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2019 Volume 82 Issue 10
2019, 82(10): 867-877
Abstract:
Aerogels have excellent properties such as low density, low thermal conductivity, high specific surface area and high porosity, which have a good application prospect in the fields of heat insulation, sensing, catalysis, adsorption and energy storage. However, the porous network structure of aerogels also causes low strength and poor toughness, which seriously restricts their practical application. Organic-inorganic composite process is an effective method to enhance the mechanical properties of aerogels. It has been found in recent years that the preparation of aerogels by organic-inorganic composite method can also impart other novel properties to aerogels such as flame retardancy. In this paper the new research progress in organic-inorganic composite aerogels was summerized, and its principle, synthetic methods and related properties were analyzed. Finally, the advantages, problems and the future development direction of organic-inorganic composite aerogels were discussed.
Aerogels have excellent properties such as low density, low thermal conductivity, high specific surface area and high porosity, which have a good application prospect in the fields of heat insulation, sensing, catalysis, adsorption and energy storage. However, the porous network structure of aerogels also causes low strength and poor toughness, which seriously restricts their practical application. Organic-inorganic composite process is an effective method to enhance the mechanical properties of aerogels. It has been found in recent years that the preparation of aerogels by organic-inorganic composite method can also impart other novel properties to aerogels such as flame retardancy. In this paper the new research progress in organic-inorganic composite aerogels was summerized, and its principle, synthetic methods and related properties were analyzed. Finally, the advantages, problems and the future development direction of organic-inorganic composite aerogels were discussed.
2019, 82(10): 878-885
Abstract:
Efficient enrichment and separation of pollutants are the key technologies for sample pretreatment, but usually the bottle-neck steps due to the complex of environmental samples and extremely low concentrations of pollutants. In this review, we introduce the recent and important progress regarding the developed materials for the enrichment and separation of representative aqueous contaminants:HCH and mercury. In addition, the existing problems of these environmental nanomaterials for enriching and separating pollutants are proposed. The future challenges of environmental nanomaterials are discussed as well.
Efficient enrichment and separation of pollutants are the key technologies for sample pretreatment, but usually the bottle-neck steps due to the complex of environmental samples and extremely low concentrations of pollutants. In this review, we introduce the recent and important progress regarding the developed materials for the enrichment and separation of representative aqueous contaminants:HCH and mercury. In addition, the existing problems of these environmental nanomaterials for enriching and separating pollutants are proposed. The future challenges of environmental nanomaterials are discussed as well.
2019, 82(10): 886-892
Abstract:
Molecular imaging has been experiencing an unprecedented expansion in recent years in biomedical fields and plays an important role in diagnosis and treatment. It is also an interdisciplinary discipline involving chemistry, medicine, biology, computer science, radiology, and materials science. With the development of molecular imaging, the key factor for molecular imaging is to synthesize smart and efficient imaging probes as well as the need for advanced imaging equipment. Excellent progress has been achieved in molecular imaging probes, and it has been widely applied in research and clinic. In this paper, the progress in main five types of molecular imaging probes, including ultrasound imaging probe, X-ray computed tomography (CT) imaging probe, optical imaging probe, nuclear magnetic resonance imaging (MRI) probe, positron emission tomography (PET) imaging probe were reviewed. The application of the molecular imaging probe was introduced. Finally, the development of molecular imaging in the future was prospected.
Molecular imaging has been experiencing an unprecedented expansion in recent years in biomedical fields and plays an important role in diagnosis and treatment. It is also an interdisciplinary discipline involving chemistry, medicine, biology, computer science, radiology, and materials science. With the development of molecular imaging, the key factor for molecular imaging is to synthesize smart and efficient imaging probes as well as the need for advanced imaging equipment. Excellent progress has been achieved in molecular imaging probes, and it has been widely applied in research and clinic. In this paper, the progress in main five types of molecular imaging probes, including ultrasound imaging probe, X-ray computed tomography (CT) imaging probe, optical imaging probe, nuclear magnetic resonance imaging (MRI) probe, positron emission tomography (PET) imaging probe were reviewed. The application of the molecular imaging probe was introduced. Finally, the development of molecular imaging in the future was prospected.
2019, 82(10): 893-898, 892
Abstract:
Quantum dots (QDs) are nano-luminescent particles with excellent luminescent properties, which have broad application prospects in solar energy utilization and fluorescence detection. Combining QDs with another fluorophore can be used as a ratiometric fluorescence probe to visually detect target substances and improve detection sensitivity. In this paper, the types, preparation methods and application of QDs ratiometric fluorescence probes were reviewed, and the shortcomings were analyzed, so as to provide reference for the development of ratiometric fluorescence probes with excellent performance.
Quantum dots (QDs) are nano-luminescent particles with excellent luminescent properties, which have broad application prospects in solar energy utilization and fluorescence detection. Combining QDs with another fluorophore can be used as a ratiometric fluorescence probe to visually detect target substances and improve detection sensitivity. In this paper, the types, preparation methods and application of QDs ratiometric fluorescence probes were reviewed, and the shortcomings were analyzed, so as to provide reference for the development of ratiometric fluorescence probes with excellent performance.
2019, 82(10): 899-908
Abstract:
Using pregnenlone as a raw material, ten titled compounds and related intermediates were designed and synthesized by esterification on 3-hydroxyl and structural modification on 20-carbonyl. Their structures were characterized by IR, NMR and HRMS. The antiproliferative activities of these compounds were evaluated against HeLa (human cervical cancer), A549 (Human lung cancer), TPC-1(Human thyroid cancer), CNE-2 (nasopharyngeal carcinoma) and human HEK-293T (Normal kidney epithelial) by MTT method in vitro. The results showed that intermediates 2d and 3d display distinct antiproliferative activity against A549 with IC50 of 7.9μmol/L and 10.3 μmol/L, which were not toxic to HEK-293T cells.
Using pregnenlone as a raw material, ten titled compounds and related intermediates were designed and synthesized by esterification on 3-hydroxyl and structural modification on 20-carbonyl. Their structures were characterized by IR, NMR and HRMS. The antiproliferative activities of these compounds were evaluated against HeLa (human cervical cancer), A549 (Human lung cancer), TPC-1(Human thyroid cancer), CNE-2 (nasopharyngeal carcinoma) and human HEK-293T (Normal kidney epithelial) by MTT method in vitro. The results showed that intermediates 2d and 3d display distinct antiproliferative activity against A549 with IC50 of 7.9μmol/L and 10.3 μmol/L, which were not toxic to HEK-293T cells.
2019, 82(10): 909-916
Abstract:
In order to find novel benzimidazole derivatives having potent bioactivities, a series of 2-thiol benzimidazole derivatives (4a~4q) were designed and synthesized using bromacetic acid as starting material. Their cell antiproliferative activities against human cervical cancer cell line (Hela), human breast cancer cells (MCF-7), human hepatoma cells (HepG2) and human non-small cell lung cancer cell lines cells (A549) were estimated in vitro via thiazolyl blue tetrazolium bromide (MTT) assay method. The results showed that most target compounds exhibit moderate antitumor activities, especially the compound 2-((1H-benzo[d]imidazol-2-yl)thio)-1-(4-benzhydrylpiperazin-1-yl)ethan-1-one (4l) has stronger inhibitory activity against HepG2 cell lines with the IC50 value of 12.62±0.78μmol/L, which is close to the control Gefitinib (11.72±0.38μmol/L). Moreover, the structure-activity relationship (SAR) of the derivatives was discussed by molecular studies.
In order to find novel benzimidazole derivatives having potent bioactivities, a series of 2-thiol benzimidazole derivatives (4a~4q) were designed and synthesized using bromacetic acid as starting material. Their cell antiproliferative activities against human cervical cancer cell line (Hela), human breast cancer cells (MCF-7), human hepatoma cells (HepG2) and human non-small cell lung cancer cell lines cells (A549) were estimated in vitro via thiazolyl blue tetrazolium bromide (MTT) assay method. The results showed that most target compounds exhibit moderate antitumor activities, especially the compound 2-((1H-benzo[d]imidazol-2-yl)thio)-1-(4-benzhydrylpiperazin-1-yl)ethan-1-one (4l) has stronger inhibitory activity against HepG2 cell lines with the IC50 value of 12.62±0.78μmol/L, which is close to the control Gefitinib (11.72±0.38μmol/L). Moreover, the structure-activity relationship (SAR) of the derivatives was discussed by molecular studies.
2019, 82(10): 917-925
Abstract:
Colony stimulating factor 1 receptor (CSF-1R) is a member of the type Ⅲ receptor tyrosine kinase family, which plays a crucial role in the regulation of the monocyte/macrophage system. Abnormal expression of CSF-1R and its ligands is closely related to tumor progression. Therefore, CSF-1R signaling might be an effective target for anti-cancer therapy. In this study, the three-dimensional quantitative structure-activity relationship (3D-QSAR) models were generated for 54 dihydropyrimido[4, 5-d]pyrimidine CSF-1R inhibitors using comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) methods. The cross-validation coefficient (q2) of the CoMFA model and CoMSIA model were 0.725 and 0.636, and the fitting verification coefficients (r2) were 0.960 and 0.958. The results showed that both models have good predictive ability. The contour maps of the models could visually reflect the effect of different substituents on the activity, and the stereo field and the hydrophobic field contributed more to the activity. The molecular docking study showed that the amino acid residue Cys666 and Asp796 play a role in the ligand-receptor binding process, and the molecular docking binding mode is consistent with the results obtained by 3D-QSAR. The information could provide a theoretical basis for further optimization of this class CSF-1R inhibitors.
Colony stimulating factor 1 receptor (CSF-1R) is a member of the type Ⅲ receptor tyrosine kinase family, which plays a crucial role in the regulation of the monocyte/macrophage system. Abnormal expression of CSF-1R and its ligands is closely related to tumor progression. Therefore, CSF-1R signaling might be an effective target for anti-cancer therapy. In this study, the three-dimensional quantitative structure-activity relationship (3D-QSAR) models were generated for 54 dihydropyrimido[4, 5-d]pyrimidine CSF-1R inhibitors using comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) methods. The cross-validation coefficient (q2) of the CoMFA model and CoMSIA model were 0.725 and 0.636, and the fitting verification coefficients (r2) were 0.960 and 0.958. The results showed that both models have good predictive ability. The contour maps of the models could visually reflect the effect of different substituents on the activity, and the stereo field and the hydrophobic field contributed more to the activity. The molecular docking study showed that the amino acid residue Cys666 and Asp796 play a role in the ligand-receptor binding process, and the molecular docking binding mode is consistent with the results obtained by 3D-QSAR. The information could provide a theoretical basis for further optimization of this class CSF-1R inhibitors.
2019, 82(10): 926-936
Abstract:
With the wide application of organophosphorus compounds (OPs), they have been detected in an increasing number of environmental media. Most OPs are poisonous, but people often lack fast and effective prediction methods to evaluate the toxicity. In this paper, the toxicity of 36 OPs was predicted by using different QSAR models combined with molecular descriptors by computer with E-Dragon software. Using the backward method as the screening result, root mean square error (RMSE) as evaluation standard, we found that the 14 molecular descriptors have a great influence on the linear kernel function of support vector machine (SVM) model. In the cross-validation results of SVM models, the correlation coefficient between the calculated value and the actual value was 0.913, the root mean square error is 0.388. In the results of external test verification, the average relative error was 9.10%. In addition, we also used multiple linear regression (MLR), artificial neural network (ANN) and partial least squares regression (PLS) models to predict the toxicity of OPs. The cross-validation results showed that the correlation coefficients between the calculated values and the actual values of the three models are 0.878, 0.686 and 0.620, respectively. Therefore, the linear kernel SVM model is an effective method for the toxicity prediction of OPs.
With the wide application of organophosphorus compounds (OPs), they have been detected in an increasing number of environmental media. Most OPs are poisonous, but people often lack fast and effective prediction methods to evaluate the toxicity. In this paper, the toxicity of 36 OPs was predicted by using different QSAR models combined with molecular descriptors by computer with E-Dragon software. Using the backward method as the screening result, root mean square error (RMSE) as evaluation standard, we found that the 14 molecular descriptors have a great influence on the linear kernel function of support vector machine (SVM) model. In the cross-validation results of SVM models, the correlation coefficient between the calculated value and the actual value was 0.913, the root mean square error is 0.388. In the results of external test verification, the average relative error was 9.10%. In addition, we also used multiple linear regression (MLR), artificial neural network (ANN) and partial least squares regression (PLS) models to predict the toxicity of OPs. The cross-validation results showed that the correlation coefficients between the calculated values and the actual values of the three models are 0.878, 0.686 and 0.620, respectively. Therefore, the linear kernel SVM model is an effective method for the toxicity prediction of OPs.
Catalysis Performance of Ni-Co/TiO2 for Production of Cyclopentanone and Cyclopentanol from Furfural
2019, 82(10): 937-941
Abstract:
TiO2 was used as a carrier to load the bimetallic active component Ni-Co, and the catalyst was prepared by a typical wetness impregnation method and was used in the reaction of furfural catalytic hydrogenation to cyclopentanone and cyclopentanol. The effects of Ni-Co loading, reaction time, reaction temperature and reaction pressure on the products were also discussed. The composition and reaction mechanism of the catalyst were discussed by means of XRD, BET, H2-TPR and SEM. In the catalytic hydrogenation of furfural with 10%Ni-10%Co-TiO2, under the optimized conditions, the formation rates of cyclopentanone and cyclopentanone reached 53.4% and 17.1% respectively.
TiO2 was used as a carrier to load the bimetallic active component Ni-Co, and the catalyst was prepared by a typical wetness impregnation method and was used in the reaction of furfural catalytic hydrogenation to cyclopentanone and cyclopentanol. The effects of Ni-Co loading, reaction time, reaction temperature and reaction pressure on the products were also discussed. The composition and reaction mechanism of the catalyst were discussed by means of XRD, BET, H2-TPR and SEM. In the catalytic hydrogenation of furfural with 10%Ni-10%Co-TiO2, under the optimized conditions, the formation rates of cyclopentanone and cyclopentanone reached 53.4% and 17.1% respectively.
2019, 82(10): 942-945
Abstract:
Dihydropyrazole is an important five-membered N-heterocyclic compound with a broad range of biological activities, which widely exist in various active natural products. In this study, eight new 3-aryl-5-(2-thienyl)-4, 5-dihydro-1H-pyrazole derivatives (4a~4h) have been prepared, and their structures were characterized by IR, 1H NMR and 13C NMR. The in vitro anti-inflammatory activities of title compounds have been tested by lipopolysaccharide (LPS)-stimulated RAW-264.7 macrophages. The biological results indicated that the sulfonamide derivatives 4a, 4e and 4h display potential anti-inflammatory activity. Especially compound 4a had the most inhibitory effect on NO generation (IC50=12.64μmol/L, which is comparable to the positive control drug dexamethasone), and could be used as a lead compound for further studies.
Dihydropyrazole is an important five-membered N-heterocyclic compound with a broad range of biological activities, which widely exist in various active natural products. In this study, eight new 3-aryl-5-(2-thienyl)-4, 5-dihydro-1H-pyrazole derivatives (4a~4h) have been prepared, and their structures were characterized by IR, 1H NMR and 13C NMR. The in vitro anti-inflammatory activities of title compounds have been tested by lipopolysaccharide (LPS)-stimulated RAW-264.7 macrophages. The biological results indicated that the sulfonamide derivatives 4a, 4e and 4h display potential anti-inflammatory activity. Especially compound 4a had the most inhibitory effect on NO generation (IC50=12.64μmol/L, which is comparable to the positive control drug dexamethasone), and could be used as a lead compound for further studies.
2019, 82(10): 946-949
Abstract:
Based on CoMFA method, 3D-QSAR between the molecular structures and their inhibitory activities (pMP) of 21 novel triazol-ethiadiazole derivatives against PTP1B were established. 17 compounds in the training set were served to build the predicting model, and the test set of five compounds were used to validate the model. The coefficients of the cross-validation (Rcv2) and non cross-validation (R2) for CoMFA model established in this study were 0.432 and 0.975, respectively. The results showed that the model has strong stability and good predictability. In this model, the contributions of the steric and electrostatic fields were 59.2% and 40.8%, respectively. It is shown that the main factors affecting the inhibitory activity (pMP) are steric hindrance and hydrophobicity of substituents, followed by hydrogen bonding and coordination of substituents. Base on the results and discussion, we also designed three novel molecules with satisfied predictions activity for the further experimental validation.
Based on CoMFA method, 3D-QSAR between the molecular structures and their inhibitory activities (pMP) of 21 novel triazol-ethiadiazole derivatives against PTP1B were established. 17 compounds in the training set were served to build the predicting model, and the test set of five compounds were used to validate the model. The coefficients of the cross-validation (Rcv2) and non cross-validation (R2) for CoMFA model established in this study were 0.432 and 0.975, respectively. The results showed that the model has strong stability and good predictability. In this model, the contributions of the steric and electrostatic fields were 59.2% and 40.8%, respectively. It is shown that the main factors affecting the inhibitory activity (pMP) are steric hindrance and hydrophobicity of substituents, followed by hydrogen bonding and coordination of substituents. Base on the results and discussion, we also designed three novel molecules with satisfied predictions activity for the further experimental validation.
2019, 82(10): 950-953
Abstract:
The determination of rate law from experimental data is one of the most important parts of chemical kinetics. The methods used in textbooks and literatures are linear fitting methods of reactant concentration or pressure, most of which are with heavy workload. Many reactions are studied by measuring the physical properties of the system instead of reactant concentration, but there is no universal method to determine rate law from physical properties. Here a universal method for determining rate law from curve fitting of physical properties or reactant concentration is presented, both the reaction order and rate constant are obtained at the same time. The good fitting results for reactions of all kinds of orders are obtained. This method is of great significance for chemical kinetics.
The determination of rate law from experimental data is one of the most important parts of chemical kinetics. The methods used in textbooks and literatures are linear fitting methods of reactant concentration or pressure, most of which are with heavy workload. Many reactions are studied by measuring the physical properties of the system instead of reactant concentration, but there is no universal method to determine rate law from physical properties. Here a universal method for determining rate law from curve fitting of physical properties or reactant concentration is presented, both the reaction order and rate constant are obtained at the same time. The good fitting results for reactions of all kinds of orders are obtained. This method is of great significance for chemical kinetics.
2019, 82(10): 954-959
Abstract:
The appearance of graphene in 2004 overturned the traditional theory and created a carbon paradigm from zero dimension to three dimensions. Through the research on the history of graphene discovery, it is known that in the 1840s, scientists conducted a lot of research on graphite oxide, which promoted the discovery of graphene. In the 1950s, theoretical physicists made theoretical assumptions about the existence of graphene. To the 1980s, scientists explored the allotropes of carbon and made unremitting efforts to prepare single-layer graphene. After many failures, the researchers finally succeeded in preparing graphene in 2004 and began to study its properties. The discovery of graphene has brought about a shift in scientific understanding and a breakthrough in technology.
The appearance of graphene in 2004 overturned the traditional theory and created a carbon paradigm from zero dimension to three dimensions. Through the research on the history of graphene discovery, it is known that in the 1840s, scientists conducted a lot of research on graphite oxide, which promoted the discovery of graphene. In the 1950s, theoretical physicists made theoretical assumptions about the existence of graphene. To the 1980s, scientists explored the allotropes of carbon and made unremitting efforts to prepare single-layer graphene. After many failures, the researchers finally succeeded in preparing graphene in 2004 and began to study its properties. The discovery of graphene has brought about a shift in scientific understanding and a breakthrough in technology.
