Seven new 4-hydroxyben l-substituted amino acid derivatives (1-7), together with 11 known compounds, were isolated from an aqueous extract of the rhizomes of Go,arodia data Blume. Their structures were determined by s...Seven new 4-hydroxyben l-substituted amino acid derivatives (1-7), together with 11 known compounds, were isolated from an aqueous extract of the rhizomes of Go,arodia data Blume. Their structures were determined by spectroscopic and chemical methods. Compounds 1-3 are pyroglutamate derivatives containing 4-hydroxybenzyl units at the N atom and 4-7 are the first examples of natural products with the 4-hydroxybenzyl unit linked vici a thioether bond to 2-hydroxy-3mercaptopropanoic acid (4-6) and 2-hydroxy-4-mercaptobutanoic acid (7), which would be biogenetically derived from cysteine and homocysteine, respectively. The structures of 1 and 2 were verified hi synthesis, while the absolute configurations of 4, 5 and 7 were assigned using Mosher 's method based on the MPA determination rule of A5Rs values. The known compound 4-(hydroxymethy0-5-nifrobenzene1,2-diol (8) exhibited activity against Fe2 r--cysteine induced rat liver microsomal lipid peroxidation with 1050 values of 9.99 x 10 6 mon. (C) 2015 Chinese Pharmaceutical Association and Institute of Materia Medica, Chinese Academy of Medical Sciences. Production and hosting by Elsevier B.'s/. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).展开更多
According to the chemical design, electrorheological properties of supramolecular complex from β-cyclodextrin polymer (β -CDP) were discussed. Six supramolecular complexes of β-cyclodextrin polymer with substituted...According to the chemical design, electrorheological properties of supramolecular complex from β-cyclodextrin polymer (β -CDP) were discussed. Six supramolecular complexes of β-cyclodextrin polymer with substituted salicylic acid and 3-hydroxy-2-naphthoic acid were synthesized by the solid-phase self-assembly method, and their component and structure were characterized by NMR, FT-IR, UV-vis and the fluorescence analysis. Then the electrorheological properties of their suspensions in silicone oil were investigated under DC electric fields. It was found that the yield stresses of these supramolecular complex ER fluids were 7.3–9.8 kPa at 4 kV/mm in DC electric field, which were enhanced by 34%–72% compared with that of pure β-CDP. Among them, that of β-CDP/3-hydroxy-2-naphthoic acid ER fluid was the highest. It was also found that the ER effect of supramolecular complexes can be controlled by changing different guests. When the substituted group is at phenyl ring, ER behavior can be slightly adjusted by the different substituted groups, their number as well as their position at phenyl ring. This can be proved by the measurement of dielectric properties.展开更多
Transition element substituted titanic acid nanotubes were fabricated by a hydrothermal method using transition elements (Cr, Mn, Fe, Co, Ni, Cu) doped anatase TiO2 nanopowders as precursors. The properties of product...Transition element substituted titanic acid nanotubes were fabricated by a hydrothermal method using transition elements (Cr, Mn, Fe, Co, Ni, Cu) doped anatase TiO2 nanopowders as precursors. The properties of products were characterized by SEM, TEM, XRD, EDX and Raman spectroscopy. The photodegradation performances of transition elements substituted titanic acid nanotubes for methylene blue were studied. The results show that the photocatalytic activities of Co, Fe and Cr substituted titanic acid nanotubes were increased to different extent, while the photocatalytic activities of Cu, Ni and Mn substituted titanic acid nanotubes were decreased evidently, indicating that these ions were poison to photocatalysts.展开更多
A series of novel pyrazole oxime derivatives containing oxazole ring were designed and synthesized. The title compounds were structurally confirmed by 1H NMR, 13C NMR spectra and elemental analyses. Preliminary bioass...A series of novel pyrazole oxime derivatives containing oxazole ring were designed and synthesized. The title compounds were structurally confirmed by 1H NMR, 13C NMR spectra and elemental analyses. Preliminary bioassay results showed that some of the title compounds displayed promising fungicidal activity besides insecticidal and acaricidal activity. Particularly, compound 8c exhibited potent fungicidal activity against cucumber Pseudoperonospora cubensis beyond good insecticidal activity against Aphis craccivora and Nilaparvata lugens.展开更多
A series of chromone derivatives containing substituted pyrazole were designed and synthesized.Preliminary bioassays showed that most of the synthesized compounds exhibited good nematicidal activity in vivo against Me...A series of chromone derivatives containing substituted pyrazole were designed and synthesized.Preliminary bioassays showed that most of the synthesized compounds exhibited good nematicidal activity in vivo against Meloidogyne incognita at 10 mg/L. Among the tested compounds, A10 and A11 exhibited 100% inhibition rates. In addition, the molecular docking results indicated that both compound A10 and A11 interacts with amino acid residue Tyr121, Trp279, Tyr70, Trp84 and Phe330 of ACh E via hydrogen bond and p–p stacking. This investigation suggested that the chromone containing substituted pyrazole scaffold could be further optimized to explore novel, high-bioactivity nematicidal leads.展开更多
An additive-free and environmentally friendly strategy has been realized for the construction of S-substituted isothioureas through visible-light-induced multicomponent reaction starting fromα-diazoesters,aryl isothi...An additive-free and environmentally friendly strategy has been realized for the construction of S-substituted isothioureas through visible-light-induced multicomponent reaction starting fromα-diazoesters,aryl isothiocyanates,amines and cyclic ethers.This methodology features simple operation,mild reaction conditions,favorable functional group tolerance,easily available starting materials and high efficiency.展开更多
A molecular structural characterization （MSC） method called molecular vertexes correlative index （MVCI） was used to describe the structures of 30 substituted aromatic compounds. Through multiple linear regression ...A molecular structural characterization （MSC） method called molecular vertexes correlative index （MVCI） was used to describe the structures of 30 substituted aromatic compounds. Through multiple linear regression （MLR） and stepwise multiple regression （SMR）, a quantitative structure-toxicity relationship （QSTR） model with 4 variables was obtained. The correlation coefficient （R） of the model was 0.9467. Through partial least-squares regression （PLS）, another QSTR model with 5 principal components was obtained. The correlation coefficient （R） of the model was 0.9518. Both models were evaluated by performing the cross-validation with the leave-one-out （LOO） procedure and the Cross-Validation （CV） correlation coefficients （Rcv） were 0.9208 and 0.9214, respectively. The results suggested good stability and predictability of the models, and the molecular vertexes correlative index could successfully describe the structures of the substituted aromatic compounds.展开更多
Toxicities （-1gEC50） of 16 phenolic compounds against Q67 were determined, and structural parameters as well as thermodynamic parameters of these compounds were obtained through fully optimized calculations by using...Toxicities （-1gEC50） of 16 phenolic compounds against Q67 were determined, and structural parameters as well as thermodynamic parameters of these compounds were obtained through fully optimized calculations by using B3LYP method of density functional theory （DFT） at the 6-311G^＊＊ level. Moreover, a 3-parameter （molecular average polarizability （α）, heat energy corrected value （Eth） and the most positive hydrogen atomic charge （qH^＋）） correlation model with R^2 = 0.981 and q^2 = 0.967 to predict -1gEC50 was obtained from experimental data based on the above-mentioned parameters as theoretical descriptors. Therein a was the most significant on -1gEC50. Variance Inflation Factors （VIF）, t-value and cross-validation were applied to verify the model, confirming that the resultant model has fairly better stability and predictive ability to predict -1gEC50 of similar compounds.展开更多
Nanoparticles of hydroxyapatite（HAP）, strontium half substituted hydroxyapatite （SrCaHAP） and strontium totally substituted hydroxyapatite （SrHAP） were prepared by sol-gel-supercritical fluid drying （SCFD） met...Nanoparticles of hydroxyapatite（HAP）, strontium half substituted hydroxyapatite （SrCaHAP） and strontium totally substituted hydroxyapatite （SrHAP） were prepared by sol-gel-supercritical fluid drying （SCFD） method. The nanoparticles were characterized by element content analysis, FT-IR, XRD and TEM, and the effects of strontium substitution on crystal structure, crystallinity, particle shape and antibacterial properties of the nanoparticles on Escherichia coli, Staphylococcus aureus, Lactobacillus were researched. Results show that strontium can half and totally substitute for calcium and enter the structure of apatite according to the initial atomic ratios of Sr/[Sr＋Ca] as 0.5, 1. The substitution decreases the IR wavenumbers of SrCaHAP and SrHAP, and changes the morphology of the nanoparticles from short rod shaped HAP to needle shaped SrCaHAP, and back to short rod shaped SrHAP. The crystallinity of HAP is higher than that of SrCaHAP, but is lower than that of SrHAP. Moreover, the antibacterial property of SrCaHAP and SrHAP are improved after the calcium is half and totally substituted by strontium.展开更多
Rotationally inelastic He-H_(2),D_(2),T_(2) collision was studied quantum-mechanically.Converged cross sections were calculated by using the close coupling method for relative kinetic energies of 0.01 to 0.54 eV.Born-...Rotationally inelastic He-H_(2),D_(2),T_(2) collision was studied quantum-mechanically.Converged cross sections were calculated by using the close coupling method for relative kinetic energies of 0.01 to 0.54 eV.Born-Oppenheimer approximation was employed to determine the potential surface of He-D_(2),He-T_(2),and He-H_(2).Careful comparison between the cross sections of the isotopically substituted systems was carried out,and the regular changes of the total cross sections of the isotopically substituted He-H_(2) colliding systems were obtained.展开更多
Comprehensive Summary,A transition-metal-free one-pot direct synthesis of tetrathiophosphates(R^(1)S)_(2)P(S)SR^(2) from white phosphorus(P_(4)),through intermediate sodium alkyltetrathiophosphates(R^(1)S)_(2)P(S)SNa,...Comprehensive Summary,A transition-metal-free one-pot direct synthesis of tetrathiophosphates(R^(1)S)_(2)P(S)SR^(2) from white phosphorus(P_(4)),through intermediate sodium alkyltetrathiophosphates(R^(1)S)_(2)P(S)SNa,is presented.In the presence of NaSH,various disulfides such as diaryl disulfidbges and dialkyl disulfides are easily coupled with P_(4) to give sodium alkyltetrathiophosphates(R^(1)S)_(2)P(S)SNa in almost quantitative yield,which react with alkyl halides in one pot to generate(R^(1)S)_(2)P(S)SR2.Furthermore,S-(2-cyanoethyl)-substituted tetrathiophosphates(R^(1)S)_(2)P(S)SCH_(2)CH_(2)CN are successfully designed as a kind of tetrathiophosphorylation reagent to react with diaryl iodonium salts involving deprotection-dealkylation process.展开更多
In secondary lymphoid organs,mature B cells express membrane immunoglobulin(Ig)of M and D isotypes(IgM and IgD,respectively)of the same specificity through alternative splicing of a pre-mRNA encompassing the VDJ varia...In secondary lymphoid organs,mature B cells express membrane immunoglobulin(Ig)of M and D isotypes(IgM and IgD,respectively)of the same specificity through alternative splicing of a pre-mRNA encompassing the VDJ variable region and Cμand Cδheavy chain constant exons.1 After encountering antigen,B cells undergo class switch recombination(CSR)by which the Cμgene is substituted with Cγ,Cεor Cα,thereby generating IgG,IgE and IgA antibodies of the same antigenic specificity but with new effector functions.CSR requires the DNA-editing enzyme activation-induced deaminase(AID).展开更多
All stereoisomers of asperphenamate 1a and patriscabratine 2a were achieved with a high yield,and total synthesis of 2a is firstly described here.The absolute configuration of patriscabratine was determined as(S,S).Th...All stereoisomers of asperphenamate 1a and patriscabratine 2a were achieved with a high yield,and total synthesis of 2a is firstly described here.The absolute configuration of patriscabratine was determined as(S,S).The compounds 1a-d and 2a-d have been tested by MTT assay in T47D,MDA-MB231,HL60,Hela and SGC-7901 cell lines in vitro.Among them,the(R,S) stereoisomer shows the strongest anticancer effects,while the(S,R) shows the weakest one.展开更多
A series of new pyrazole oximes bearing substituted thiazole ring were designed and prepared. The structures of the title compounds were identified by spectral analyses, The results of primary bioassay indicated that ...A series of new pyrazole oximes bearing substituted thiazole ring were designed and prepared. The structures of the title compounds were identified by spectral analyses, The results of primary bioassay indicated that some targeted compounds exhibited promising insecticidal activity besides acaricidal activity, particularly; compounds 8c and 8d were more potent against Tetranychus cinnabarinus and Plutella xylostella than other analogues.展开更多
The n-octanol/water partition coefficients （lgKow） of 18 substituted anilines were determined at 25 ℃ by shake-flask method. The geometrical optimization of substituted anilines has been performed at B3LYP/6-311G^...The n-octanol/water partition coefficients （lgKow） of 18 substituted anilines were determined at 25 ℃ by shake-flask method. The geometrical optimization of substituted anilines has been performed at B3LYP/6-311G^＊＊ level with Gaussian98 program, and the molecular surface areas of substituted anilines were calculated using ChemOffice 2004 program. The calculated structural parameters of substituted anilines were used as theoretical descriptors and the two-parameter （molecular surface area （MA） and the energy of the highest occupied molecular orbital （EaoMo）） quantitative structure-property relationship （QSPR） model of lgKow for substituted aniline with molecular structural parameters was developed by multi-linear regression method. The regression coefficient square （r^2） is 0.990 and the standard deviation SE 0.109. The model was validated by variance inflation factors （VIF） and t-test, and the results show that there exists small self-correlation between variables of the model with perfect stability. The model gives results in good qualitative agreement with experimental data. At last, the model was applied to predict lgKow values of five substituted anilines whose lgKow values have not been determined experimentally.展开更多
An rapid and efficient synthesis of 2, 4, 6-triarylpyridines is reported using substituted benzaldehydes, substituted acetophenones and ammonia as starting materials under microwave irradiation in the presence of PEG-...An rapid and efficient synthesis of 2, 4, 6-triarylpyridines is reported using substituted benzaldehydes, substituted acetophenones and ammonia as starting materials under microwave irradiation in the presence of PEG-400.展开更多
The thermal Claisen rearrangement of O-allyl substituted isotetronic acids 1 was successfully carried out within a glass microreactor operated with temperature at 150℃and a flow rate of 1 mL/h.The strategy provides a...The thermal Claisen rearrangement of O-allyl substituted isotetronic acids 1 was successfully carried out within a glass microreactor operated with temperature at 150℃and a flow rate of 1 mL/h.The strategy provides an efficient alternative way toβ-allyl substituted isotetronic acid derivatives 2 in high yields with much accelerated reaction speed.展开更多
Catechol (1) and 2-ethoxy-2-ethyl-3-hydroxy-4(1H)-pyridinone (4) derivatives can be oxidized to give ortho-quinone of 1,2-benzoquinone (2) and 2-ethoxy-2-ethyl-1,2(2H)-pyridine 3,4-dione (5) that subsequently dew Mich...Catechol (1) and 2-ethoxy-2-ethyl-3-hydroxy-4(1H)-pyridinone (4) derivatives can be oxidized to give ortho-quinone of 1,2-benzoquinone (2) and 2-ethoxy-2-ethyl-1,2(2H)-pyridine 3,4-dione (5) that subsequently dew Michael addition with nucleophiles. This reaction served a convenient route to synthesize 4,5-disubstituted 1,2-benzoquinones (3a-c) and 6-substituted-3-hydroxy-4(1H)-pyridinones (6a-f).展开更多
Heterocyclic ketene aminals 1 react with aryl azides 2 to give the titled compounds 3,and in some cases also with the formation of fused heterocycles 4.
Using N-bromosuccinimide and pyridine as the oxidation system to dehydrogenate aryl substituted semicarbazide to form azo compounds is described for the first time in this paper. Nine azo compounds have been prepared ...Using N-bromosuccinimide and pyridine as the oxidation system to dehydrogenate aryl substituted semicarbazide to form azo compounds is described for the first time in this paper. Nine azo compounds have been prepared in excellent yield under mild condition. This method only. needs simple instrument and short reaction time.展开更多
基金the National Natural Science Foundation of China (NNSFC Nos. 30825044 and 20932007)+1 种基金the Program for Changjiang Scholars and Innovative Research Team in University (PCSIRT, No. IRT1007)the National Science and Technology Project of China (Nos. 2012ZX09301002-002 and 2011ZX09307002-01) is acknowledged
文摘Seven new 4-hydroxyben l-substituted amino acid derivatives (1-7), together with 11 known compounds, were isolated from an aqueous extract of the rhizomes of Go,arodia data Blume. Their structures were determined by spectroscopic and chemical methods. Compounds 1-3 are pyroglutamate derivatives containing 4-hydroxybenzyl units at the N atom and 4-7 are the first examples of natural products with the 4-hydroxybenzyl unit linked vici a thioether bond to 2-hydroxy-3mercaptopropanoic acid (4-6) and 2-hydroxy-4-mercaptobutanoic acid (7), which would be biogenetically derived from cysteine and homocysteine, respectively. The structures of 1 and 2 were verified hi synthesis, while the absolute configurations of 4, 5 and 7 were assigned using Mosher 's method based on the MPA determination rule of A5Rs values. The known compound 4-(hydroxymethy0-5-nifrobenzene1,2-diol (8) exhibited activity against Fe2 r--cysteine induced rat liver microsomal lipid peroxidation with 1050 values of 9.99 x 10 6 mon. (C) 2015 Chinese Pharmaceutical Association and Institute of Materia Medica, Chinese Academy of Medical Sciences. Production and hosting by Elsevier B.'s/. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
基金This work was supported by the National Namral Science Foundation of China(Grant No.59832090)the National Natural Science Foundation of China for Distinguished Young Scholar(Grant No.50025207)the'863'Foundation(Grant No.2001AA327130).
文摘According to the chemical design, electrorheological properties of supramolecular complex from β-cyclodextrin polymer (β -CDP) were discussed. Six supramolecular complexes of β-cyclodextrin polymer with substituted salicylic acid and 3-hydroxy-2-naphthoic acid were synthesized by the solid-phase self-assembly method, and their component and structure were characterized by NMR, FT-IR, UV-vis and the fluorescence analysis. Then the electrorheological properties of their suspensions in silicone oil were investigated under DC electric fields. It was found that the yield stresses of these supramolecular complex ER fluids were 7.3–9.8 kPa at 4 kV/mm in DC electric field, which were enhanced by 34%–72% compared with that of pure β-CDP. Among them, that of β-CDP/3-hydroxy-2-naphthoic acid ER fluid was the highest. It was also found that the ER effect of supramolecular complexes can be controlled by changing different guests. When the substituted group is at phenyl ring, ER behavior can be slightly adjusted by the different substituted groups, their number as well as their position at phenyl ring. This can be proved by the measurement of dielectric properties.
文摘Transition element substituted titanic acid nanotubes were fabricated by a hydrothermal method using transition elements (Cr, Mn, Fe, Co, Ni, Cu) doped anatase TiO2 nanopowders as precursors. The properties of products were characterized by SEM, TEM, XRD, EDX and Raman spectroscopy. The photodegradation performances of transition elements substituted titanic acid nanotubes for methylene blue were studied. The results show that the photocatalytic activities of Co, Fe and Cr substituted titanic acid nanotubes were increased to different extent, while the photocatalytic activities of Cu, Ni and Mn substituted titanic acid nanotubes were decreased evidently, indicating that these ions were poison to photocatalysts.
基金funded by the National Natural Science Foundation of China (No.21202089)the Research Foundation of the Six People Peak of Jiangsu Province (Nos.2011-SWYY-009,2013-SWYY-013)the Technology Project Fund of Nantong City (Nos.AS2013004,CP12013002)
文摘A series of novel pyrazole oxime derivatives containing oxazole ring were designed and synthesized. The title compounds were structurally confirmed by 1H NMR, 13C NMR spectra and elemental analyses. Preliminary bioassay results showed that some of the title compounds displayed promising fungicidal activity besides insecticidal and acaricidal activity. Particularly, compound 8c exhibited potent fungicidal activity against cucumber Pseudoperonospora cubensis beyond good insecticidal activity against Aphis craccivora and Nilaparvata lugens.
基金financial supported by the National Natural Science Foundation of China (No. 21672061)National Key Research Program of China (No. 2017YFD0200505)Fundamental Research Funds for the Central Universities (No. 222201718004)
文摘A series of chromone derivatives containing substituted pyrazole were designed and synthesized.Preliminary bioassays showed that most of the synthesized compounds exhibited good nematicidal activity in vivo against Meloidogyne incognita at 10 mg/L. Among the tested compounds, A10 and A11 exhibited 100% inhibition rates. In addition, the molecular docking results indicated that both compound A10 and A11 interacts with amino acid residue Tyr121, Trp279, Tyr70, Trp84 and Phe330 of ACh E via hydrogen bond and p–p stacking. This investigation suggested that the chromone containing substituted pyrazole scaffold could be further optimized to explore novel, high-bioactivity nematicidal leads.
基金financially supported by Natural Science Foundation of Shandong Province(No.ZR2021MB065)the major innovation fund of Shandong Province(No.2021ZDSYS_(2)3)the National Natural Science Foundation of China(Nos.21976105,22101237).
文摘An additive-free and environmentally friendly strategy has been realized for the construction of S-substituted isothioureas through visible-light-induced multicomponent reaction starting fromα-diazoesters,aryl isothiocyanates,amines and cyclic ethers.This methodology features simple operation,mild reaction conditions,favorable functional group tolerance,easily available starting materials and high efficiency.
基金supported by the Foundation of Education Bureau,Sichuan Province(09ZB036)
文摘A molecular structural characterization （MSC） method called molecular vertexes correlative index （MVCI） was used to describe the structures of 30 substituted aromatic compounds. Through multiple linear regression （MLR） and stepwise multiple regression （SMR）, a quantitative structure-toxicity relationship （QSTR） model with 4 variables was obtained. The correlation coefficient （R） of the model was 0.9467. Through partial least-squares regression （PLS）, another QSTR model with 5 principal components was obtained. The correlation coefficient （R） of the model was 0.9518. Both models were evaluated by performing the cross-validation with the leave-one-out （LOO） procedure and the Cross-Validation （CV） correlation coefficients （Rcv） were 0.9208 and 0.9214, respectively. The results suggested good stability and predictability of the models, and the molecular vertexes correlative index could successfully describe the structures of the substituted aromatic compounds.
基金supported by the Natural Science Foundation of Zhejiang Province (No. 2008Y507280)
文摘Toxicities （-1gEC50） of 16 phenolic compounds against Q67 were determined, and structural parameters as well as thermodynamic parameters of these compounds were obtained through fully optimized calculations by using B3LYP method of density functional theory （DFT） at the 6-311G^＊＊ level. Moreover, a 3-parameter （molecular average polarizability （α）, heat energy corrected value （Eth） and the most positive hydrogen atomic charge （qH^＋）） correlation model with R^2 = 0.981 and q^2 = 0.967 to predict -1gEC50 was obtained from experimental data based on the above-mentioned parameters as theoretical descriptors. Therein a was the most significant on -1gEC50. Variance Inflation Factors （VIF）, t-value and cross-validation were applied to verify the model, confirming that the resultant model has fairly better stability and predictive ability to predict -1gEC50 of similar compounds.
文摘Nanoparticles of hydroxyapatite（HAP）, strontium half substituted hydroxyapatite （SrCaHAP） and strontium totally substituted hydroxyapatite （SrHAP） were prepared by sol-gel-supercritical fluid drying （SCFD） method. The nanoparticles were characterized by element content analysis, FT-IR, XRD and TEM, and the effects of strontium substitution on crystal structure, crystallinity, particle shape and antibacterial properties of the nanoparticles on Escherichia coli, Staphylococcus aureus, Lactobacillus were researched. Results show that strontium can half and totally substitute for calcium and enter the structure of apatite according to the initial atomic ratios of Sr/[Sr＋Ca] as 0.5, 1. The substitution decreases the IR wavenumbers of SrCaHAP and SrHAP, and changes the morphology of the nanoparticles from short rod shaped HAP to needle shaped SrCaHAP, and back to short rod shaped SrHAP. The crystallinity of HAP is higher than that of SrCaHAP, but is lower than that of SrHAP. Moreover, the antibacterial property of SrCaHAP and SrHAP are improved after the calcium is half and totally substituted by strontium.
文摘Rotationally inelastic He-H_(2),D_(2),T_(2) collision was studied quantum-mechanically.Converged cross sections were calculated by using the close coupling method for relative kinetic energies of 0.01 to 0.54 eV.Born-Oppenheimer approximation was employed to determine the potential surface of He-D_(2),He-T_(2),and He-H_(2).Careful comparison between the cross sections of the isotopically substituted systems was carried out,and the regular changes of the total cross sections of the isotopically substituted He-H_(2) colliding systems were obtained.
基金supported by the National Key Research and Development Program of China(2020YFA0608300)the NSFC(21772163,21778042 and 41876072)NFFTBS(J1310024)。
文摘Comprehensive Summary,A transition-metal-free one-pot direct synthesis of tetrathiophosphates(R^(1)S)_(2)P(S)SR^(2) from white phosphorus(P_(4)),through intermediate sodium alkyltetrathiophosphates(R^(1)S)_(2)P(S)SNa,is presented.In the presence of NaSH,various disulfides such as diaryl disulfidbges and dialkyl disulfides are easily coupled with P_(4) to give sodium alkyltetrathiophosphates(R^(1)S)_(2)P(S)SNa in almost quantitative yield,which react with alkyl halides in one pot to generate(R^(1)S)_(2)P(S)SR2.Furthermore,S-(2-cyanoethyl)-substituted tetrathiophosphates(R^(1)S)_(2)P(S)SCH_(2)CH_(2)CN are successfully designed as a kind of tetrathiophosphorylation reagent to react with diaryl iodonium salts involving deprotection-dealkylation process.
基金This work was financially supported through a grant from the ANR(project EpiSwitch-3'RR 2016).NG was supported through a grant from the Association de Specialisation et dOrientation Scientifique(Lebanon)and the municipality of Khiam(Lebanon).HI was supported through a grant from CORC(FA/NP 2015-109)and the University of Limoges.The authors thank the GenoLim platfom and the Cytometry platfom of the University of Limoges for sequencing and cell sorting FB was supported through a grant from the Fondation Partenariale de IUniversite de Limoges and ALURAD.
文摘In secondary lymphoid organs,mature B cells express membrane immunoglobulin(Ig)of M and D isotypes(IgM and IgD,respectively)of the same specificity through alternative splicing of a pre-mRNA encompassing the VDJ variable region and Cμand Cδheavy chain constant exons.1 After encountering antigen,B cells undergo class switch recombination(CSR)by which the Cμgene is substituted with Cγ,Cεor Cα,thereby generating IgG,IgE and IgA antibodies of the same antigenic specificity but with new effector functions.CSR requires the DNA-editing enzyme activation-induced deaminase(AID).
文摘All stereoisomers of asperphenamate 1a and patriscabratine 2a were achieved with a high yield,and total synthesis of 2a is firstly described here.The absolute configuration of patriscabratine was determined as(S,S).The compounds 1a-d and 2a-d have been tested by MTT assay in T47D,MDA-MB231,HL60,Hela and SGC-7901 cell lines in vitro.Among them,the(R,S) stereoisomer shows the strongest anticancer effects,while the(S,R) shows the weakest one.
基金financial supported by the National Natural Science Foundation of China(No.21202089)China Postdoctoral Science Foundation(No.2013M531145)the Research Foundation of the Six People Peak of Jiangsu Province(No.2013-SWYY-013)
文摘A series of new pyrazole oximes bearing substituted thiazole ring were designed and prepared. The structures of the title compounds were identified by spectral analyses, The results of primary bioassay indicated that some targeted compounds exhibited promising insecticidal activity besides acaricidal activity, particularly; compounds 8c and 8d were more potent against Tetranychus cinnabarinus and Plutella xylostella than other analogues.
基金This work was supported by the National Natural Science Foundation of China (No. 20737001)
文摘The n-octanol/water partition coefficients （lgKow） of 18 substituted anilines were determined at 25 ℃ by shake-flask method. The geometrical optimization of substituted anilines has been performed at B3LYP/6-311G^＊＊ level with Gaussian98 program, and the molecular surface areas of substituted anilines were calculated using ChemOffice 2004 program. The calculated structural parameters of substituted anilines were used as theoretical descriptors and the two-parameter （molecular surface area （MA） and the energy of the highest occupied molecular orbital （EaoMo）） quantitative structure-property relationship （QSPR） model of lgKow for substituted aniline with molecular structural parameters was developed by multi-linear regression method. The regression coefficient square （r^2） is 0.990 and the standard deviation SE 0.109. The model was validated by variance inflation factors （VIF） and t-test, and the results show that there exists small self-correlation between variables of the model with perfect stability. The model gives results in good qualitative agreement with experimental data. At last, the model was applied to predict lgKow values of five substituted anilines whose lgKow values have not been determined experimentally.
基金We thank the National Natural Science Foundation of China(NO.20272047)the Northwest Normal University Science and Technology Development Foundation of China for financial support.
文摘An rapid and efficient synthesis of 2, 4, 6-triarylpyridines is reported using substituted benzaldehydes, substituted acetophenones and ammonia as starting materials under microwave irradiation in the presence of PEG-400.
文摘The thermal Claisen rearrangement of O-allyl substituted isotetronic acids 1 was successfully carried out within a glass microreactor operated with temperature at 150℃and a flow rate of 1 mL/h.The strategy provides an efficient alternative way toβ-allyl substituted isotetronic acid derivatives 2 in high yields with much accelerated reaction speed.
基金Project supported by the National Natural Science Foundation of China (No. 29872061)Guangdong Science Foundation (No. 980320).
文摘Catechol (1) and 2-ethoxy-2-ethyl-3-hydroxy-4(1H)-pyridinone (4) derivatives can be oxidized to give ortho-quinone of 1,2-benzoquinone (2) and 2-ethoxy-2-ethyl-1,2(2H)-pyridine 3,4-dione (5) that subsequently dew Michael addition with nucleophiles. This reaction served a convenient route to synthesize 4,5-disubstituted 1,2-benzoquinones (3a-c) and 6-substituted-3-hydroxy-4(1H)-pyridinones (6a-f).
文摘Heterocyclic ketene aminals 1 react with aryl azides 2 to give the titled compounds 3,and in some cases also with the formation of fused heterocycles 4.
文摘Using N-bromosuccinimide and pyridine as the oxidation system to dehydrogenate aryl substituted semicarbazide to form azo compounds is described for the first time in this paper. Nine azo compounds have been prepared in excellent yield under mild condition. This method only. needs simple instrument and short reaction time.
