期刊文献+
共找到119篇文章
< 1 2 6 >
每页显示 20 50 100
18β-glycyrrhetinic acid inhibits proliferation of gastric cancer cells through regulating the miR-345-5p/TGM2 signaling pathway 被引量:3
1
作者 Xia Li Xiao-Ling Ma +8 位作者 Yi Nan Yu-Hua Du Yi Yang Dou-Dou Lu Jun-Fei Zhang Yan Chen Lei Zhang Yang Niu Ling Yuan 《World Journal of Gastroenterology》 SCIE CAS 2023年第23期3622-3644,共23页
BACKGROUND Gastric cancer(GC)is a common gastrointestinal malignancy worldwide.Based on cancer-related mortality,the current prevention and treatment strategies for GC still show poor clinical results.Therefore,it is ... BACKGROUND Gastric cancer(GC)is a common gastrointestinal malignancy worldwide.Based on cancer-related mortality,the current prevention and treatment strategies for GC still show poor clinical results.Therefore,it is important to find effective drug treatment targets.AIM To explore the molecular mechanism of 18β-glycyrrhetinic acid(18β-GRA)regulating the miR-345-5p/TGM2 signaling pathway to inhibit the proliferation of GC cells.METHODS CCK-8 assay was used to determine the effect of 18β-GRA on the survival rate of GES-1 cells and AGS and HGC-27 cells.Cell cycle and apoptosis were detected by flow cytometry,cell migration was detected by a wound healing assay,the effect of 18β-GRA on subcutaneous tumor growth in BALB/c nude mice was investigated,and the cell autophagy level was determined by MDC staining.TMT proteomic analysis was used to detect the differentially expressed autophagy-related proteins in GC cells after 18β-GRA intervention,and then the protein-protein interaction was predicted using STRING(https://string-db.org/).MicroRNAs(miRNAs)transcriptome analysis was used to detect the miRNA differential expression profile,and use miRBase(https://www.mirbase/)and TargetScan(https://www.targetscan.org/)to predict the miRNA and complementary binding sites.Quantitative real-time polymerase chain reaction was used to detect the expression level of miRNA in 18β-GRA treated cells,and western blot was used to detect the expression of autophagy related proteins.Finally,the effect of miR-345-5p on GC cells was verified by mir-345-5p overexpression.RESULTS 18β-GRA could inhibit GC cells viability,promote cell apoptosis,block cell cycle,reduce cell wound healing ability,and inhibit the GC cells growth in vivo.MDC staining results showed that 18β-GRA could promote autophagy in GC cells.By TMT proteomic analysis and miRNAs transcriptome analysis,it was concluded that 18β-GRA could down-regulate TGM2 expression and up-regulate miR-345-5p expression in GC cells.Subsequently,we verified that TGM2 is the target of miR-345-5p,and that overexpression of miR-345-5p significantly inhibited the protein expression level of TGM2.Western blot showed that the expression of autophagy-related proteins of TGM2 and p62 was significantly reduced,and LC3II,ULK1 and AMPK expression was significantly increased in GC cells treated with 18β-GRA.Overexpression of miR-345-5p not only inhibited the expression of TGM2,but also inhibited the proliferation of GC cells by promoting cell apoptosis and arresting cell cycle.CONCLUSION 18β-GRA inhibits the proliferation of GC cells and promotes autophagy by regulating the miR-345-5p/TGM2 signaling pathway. 展开更多
关键词 18β-glycyrrhetinic acid Gastric cancer MiR-345-5p TGM2 PROLIFERATION AUTOPHAGY
下载PDF
2-氯酮与Meldrum’s acid的反应研究 被引量:2
2
作者 丛志奇 尹炳柱 +2 位作者 金龙一 陈铁 李国雷 《化学试剂》 CAS CSCD 北大核心 2003年第6期321-322,366,共3页
探讨了2-氯(?)酮与Meldrum’s acid在不同条件下的反应结果,合成了化合物2-氧代-3-羧基-1-氧杂薁。并用1HN- MR,13CNMR和IR表征了其结构。
关键词 2-氯Zhuo酮 Meldrum′s acid 亲核试剂 2-氧代-3-羧基-1-氧杂薁 药物中间体
下载PDF
Crystal Structure and Magnetic Property of 2-(Imidazo[1,2-α]pyri-din-2-yl)- 2-oxoacetic Acid and Its Perchlorate
3
作者 沈忱 张一曼 雍国平 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2015年第2期240-244,I0002,共6页
We herein report two crystals based on 2-(imidazo[1,2-a]pyridin-2-yl)-2-oxoacetic acid rad- ical and its perchlorate, and investigate the relationship between magnetic properties and crystal stacking structures or s... We herein report two crystals based on 2-(imidazo[1,2-a]pyridin-2-yl)-2-oxoacetic acid rad- ical and its perchlorate, and investigate the relationship between magnetic properties and crystal stacking structures or supramolecular interactions. 2-(imidazo[1,2-a]pyridin-2-yl)- 2-oxoaeetic acid radical in two crystals mainly exist as diamagnetic dimer formed via short atomic contacts or supramolecular interactions (hydrogen bonds, anion-Tr or lone- pair-~r interactions), leading to low magnetic susceptibilities. 2-(imidazo[1,2-a]pyridin-2-yl)- 2-oxoaeetic acid radical crystal exhibits quasi-one-dimensional columnar stacking chain and weak antiferromagnetism. However, its perchlorate crystal possesses one-dimensional double- stranded chain structure assembled through double hydrogen bonds and anion-To interactions, and reveals weak ferromagnetism. 展开更多
关键词 2-(Imidazo[1 2-α]pyridin-2-yl)-2-oxoacetic acid radical Crystallographic struc-ture Magnetic properties Organic compound
下载PDF
An efficient route towards R-2-phenoxypropionic acid synthesis for biotransformative production of R-2-(4-hydroxyphenoxy)propionic acid 被引量:3
4
作者 Haiyan Zhou Yizuo Li +4 位作者 Rui Jiang Xianlin Wang Yuanshan Wang Yaping Xue Yuguo Zheng 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2021年第4期315-323,共9页
R2(4hydroxyphenoxy)propionic acid(RHPPA)is a key intermediate for the synthesis of classic herbicides with high selectivity against grassy weed.The main route for RHPPA biosynthesis is to hydroxylate the substrate R2p... R2(4hydroxyphenoxy)propionic acid(RHPPA)is a key intermediate for the synthesis of classic herbicides with high selectivity against grassy weed.The main route for RHPPA biosynthesis is to hydroxylate the substrate R2phenoxypropionic acid(RPPA)at C4 position with microbes.In order to provide sufficient RPPA for the industrial production of RHPPA,an effective RPPA synthesis method was established and optimized in this work.The synthesis process mainly consisted of two steps:(1)synthesis of S2chloropropionic acid from Lalanine via diazotization and chlorination reactions;and(2)synthesis of RPPA from S2chloropropionic acid and phenol via etherification reaction.The optimal reaction conditions were as follows:HCl:NaNO_(2):KI:LAla=2.0:1.2:0.7:1.0(in molar),125℃reflux for 1.5 h,with KI as catalyst,and KI:S2chloropropionic acid:phenol=0.075:1.2:1.0(in molar).Under these conditions,an improved molar conversion rate(74.9%,calculated in phenol)was achieved.After extraction using anionic exchange resin Amberlite IRA400(CI),RPPA product with a purity of 95.08%was obtained.The purified RPPA was identified and evaluated in the application of the biotransformative production of RHPPA.The results indicated that the synthesized RPPA supported the RHPPA biosynthesis with a comparable yield as that of the standard RPPA.The RPPA synthesis method provided herein exhibited the advantages of low price and easy availability of raw materials,less toxicity of reagents,simple manipulations,and low equipment/instrument requirements. 展开更多
关键词 R-2-phenoxypropionic acid R-2-(4-hydroxyphenoxy)propionic acid BIOSYNTHESIS S-2-chloropropionic acid
下载PDF
Extraction Equilibria of Trimellitic and [ 1,1′-Biphenyl]-2,2′-dicarboxylic Acid with 1-Octanol, 50%TBP, and 10%TRPO in Kerosene 被引量:2
5
作者 周智勇 秦炜 戴猷元 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2008年第6期867-870,共4页
To explore the feasibility of extracting aromatic acid products from oxidizing coal, two aromatic acids, trimellitic and [1,1′-biphenyl]-2,2′-dicarboxylic acid, were selected as the solutes, and the extraction equil... To explore the feasibility of extracting aromatic acid products from oxidizing coal, two aromatic acids, trimellitic and [1,1′-biphenyl]-2,2′-dicarboxylic acid, were selected as the solutes, and the extraction equilibrium of the acids were studied with 1-octanol, 50% tributyl phosphate (TBP) in kerosene, and 10% trialkylphosphine oxide (TRPO) in kerosene. The results showed that the degree of extraction of [1,1′-biphenyl]-2,2′-dicarboxylic acid was larger than that of trimellitic acid for all of the solvent, and the extraction capacity with TRPO is more effective than the one with TBP. The extraction behavior of aromatic polyacid is different from that of carboxylic acid, and the reactive extraction function of aromatic acids with TBP and TRPO is not as effective as that of carboxylic acid. 1-octanol could be used to remove [1,1′-biphenyl]-2,2′-dicarboxylic acid from the mixture of trimellitic acid and [1,1′-biphenyl]-2,2′-dicarboxylic acid. Because the weak hydrogen bond association exists between -OH in 1-octanol and -COOH in aromatic acid, the extractive selectivity of [ 1, 1′-biphenyl]-2,2′-dicarboxylic to trimellitic acid depends on the stoichiometric ratio. 展开更多
关键词 trimellitic acid [1 1′-biphenyl]-2 2-dicarboxylic acid extraction equilibrium 1-octanol TBP and TRPO
下载PDF
Synthesis, Crystal Structure and DNA-Binding Property of a Mn(Ⅱ) Complex Based on 5-(Tri-fluoromethyl)pyridine-2-carboxylic Acid 被引量:4
6
作者 WANG Jia-Kai LI Bing +2 位作者 WU Huan-Ping TIAN Xiao-Yan MA Xiao-Xia 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2019年第8期1349-1355,共7页
A new complex Mn(Htpc)2(H2O)2(1, Htpc = 5-(trifluoromethyl)pyridine-2-carboxylic acid) has been synthesized and characterized by elemental analysis, IR, TG and single-crystal X-ray diffraction. 1 belongs to triclinic ... A new complex Mn(Htpc)2(H2O)2(1, Htpc = 5-(trifluoromethyl)pyridine-2-carboxylic acid) has been synthesized and characterized by elemental analysis, IR, TG and single-crystal X-ray diffraction. 1 belongs to triclinic system, space group P■ with a = 5.0885(10), b = 6.5574(13), c = 14.016(3) ?, β = 90.67(3)o, V = 436.34(17) ?3, Z = 1, Dc = 1.793 g·cm-3, μ = 0.855 mm-1, Mr = 471.18, F(000) = 235, the final R = 0.0454 and wR = 0.1134 for 1998 observed reflections with I > 2σ(I). The Mn(Ⅱ) ion is coordinated by two N and two O atoms from two Htpc as well as two O atoms from two coordinated water molecules, forming a 0D motif with distorted octahedral coordinate geometry. The adjacent 0D units are linked into 1D chains through hydrogen bond O(1W)–H(1 WB)···O(2), and via the O(1 W)–H(1 WA)···O(1) hydrogen bond the neighboring 1D chains are connected into a 2D supramolecular layer. Moreover, the interactions between the ligand and its complex with CT-DNA were studied by EtBr fluorescence probe, which suggested that these compounds bind to CT-DNA through an intercalation mode. The binding constants were 0.41 and 0.64 for Htpc and complex 1, respectively. It indicates that the interaction between complex 1 and CT-DNA is stronger than Htpc. 展开更多
关键词 5-(trifluoromethyl)pyridine-2-carboxylic acid crystal structure DNA fluorescence SPECTRA
下载PDF
Hydrothermal Syntheses and Crystal Structures of Six Complexes Constructed from 1,3,5-Benzenetricarboxylic Acid and 4'-(4-Pyridyl)-2,2':6',2''-terpyridine Mixed Ligands 被引量:4
7
作者 乔宇 王炫博 +4 位作者 周艳凤 刘力辉 车广波 刘春波 刘晓腾 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2017年第8期1381-1394,共14页
Six new transition metal complexes, [Zn(HBTC)(PYTPY)]n·n PYTPY(1), [Cu(HBTC)(PYTPY)]n·n PYTPY(2), [Co(HBTC)(PYTPY)]n·n DMF(3), [Mn(HBTC)(PYTPY)]n·n DMF(4), [Cd(HBTC)(PYTP... Six new transition metal complexes, [Zn(HBTC)(PYTPY)]n·n PYTPY(1), [Cu(HBTC)(PYTPY)]n·n PYTPY(2), [Co(HBTC)(PYTPY)]n·n DMF(3), [Mn(HBTC)(PYTPY)]n·n DMF(4), [Cd(HBTC)(PYTPY)(H2O)]n·2nH2O(5), and [Co(HBTC)(PYTPY)(H2O)2](6),(H3BTC = 1,3,5-benzenetricarboxylic acid, PYTPY = 4'-(4-pyridyl)-2,2':6',2''-terpyridine, DMF = N,N?-dimethylformamide), have been synthesized and characterized by elemental analysis, IR and X-ray single-crystal diffraction. Complexes 1~5 all feature one-dimensional chain structures, and complex 6 exhibits a zero-dimensional structure. Complexes 1~5 present three-dimensional(3D) supramolecular frameworks via π-π stacking interactions, whenas 6 has also a 3D supramolecular structure assembled by hydrogen bonding. Meanwhile, complexes 1 ~ 6 exhibit the thermal stabilities and photoluminescent properties. 展开更多
关键词 transition metal complex 1 3 5-benzenetricarboxylic acid 4'-(4-pyridyl)-2 2' 6' 2''-terpyridine crystal structure
下载PDF
A New Luminescent Cd(Ⅱ) Coordination Polymer Constructed with 2-(Carboxymethoxy) benzoic Acid 被引量:5
8
作者 王秀艳 李冠霆 +3 位作者 孙迪雅 张莹 刘东雪 徐占林 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2018年第12期1939-1944,1845,共7页
In this work, we synthesized a new Cd(Ⅱ) coordination polymer, [Cd(L)(cmb)H;O]· H;O(1), by using mixed 2-(carboxymethoxy)benzoic acid(H2 cmb) and typical chelating N-donor ligands 2-(2-fluoro-6-fluoro... In this work, we synthesized a new Cd(Ⅱ) coordination polymer, [Cd(L)(cmb)H;O]· H;O(1), by using mixed 2-(carboxymethoxy)benzoic acid(H2 cmb) and typical chelating N-donor ligands 2-(2-fluoro-6-fluorophenyl)-1 H-imidazo[4,5-f][1,10]phenanthroline ligand(L). 1 crystallizes in monoclinic, space group P21/c with a = 17.6150(8), b = 9.7811(4), c = 18.1603(8) ?, β = 118.9150(10)o, V = 2738.9(2) ?;, Z = 4, C28 H20 CdF2 N4 O7, Mr = 674.88, Dc = 1.637 g/cm3, F(000) = 1352, μ(Mo Ka) = 0.865 mm–1, R = 0.0643 and w R = 0.1976. In 1, the cmb2– anions link neighboring Cd(Ⅱ) atoms in a bis-chelating mode, yielding a one-dimensional chain structure along the b axis. The L ligands are attached on one side of the chain through chelating the Cd(Ⅱ) atoms, and are stacked with those of an adjacent chain through π-π interactions to generate a one-dimensional double-chain structure. Furthermore, the one-dimensional double-chains are stacked by C–H???π interactions between the carbon atom of L ligand and the benzene ring of cmb2–ligand to give a layer structure. Moreover, the solid state luminescent property of 1 was also investigated at room temperature. 展开更多
关键词 crystal structure coordination polymer 2-(carboxymethoxy)benzoic acid
下载PDF
Syntheses, Structures and Photoluminescence of the Cadmium(Ⅱ) and Copper(Ⅱ) Complexes Based on 4'-(4''-Pyridyl)-2,2':6',2''-terpyridine and 1,4-Benzenedicarboxylic Acid Ligands 被引量:3
9
作者 张兴晶 王璐瑶 +2 位作者 尉兵 张文通 车广波 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2015年第7期1069-1079,共11页
Two new metal-organic complexes [Cd2(1,4-BDC)(4-pytyp)(H2O)4]·(1,4-BDC)(1) and [Cu2(1,4-BDC)(4-pytyp)2(H2O)2]·(1,4-BDC)·8H2O(2)(4-pytyp = 4'-(4''-pyridyl)-2,2':6',2''-terp... Two new metal-organic complexes [Cd2(1,4-BDC)(4-pytyp)(H2O)4]·(1,4-BDC)(1) and [Cu2(1,4-BDC)(4-pytyp)2(H2O)2]·(1,4-BDC)·8H2O(2)(4-pytyp = 4'-(4''-pyridyl)-2,2':6',2''-terpyridine, 1,4-H2 BDC = 1,4-benzenedicarboxylic acid) have been synthesized under hydrothermal conditions and characterized by elemental analysis, infrared analysis and X-ray single-crystal diffraction. The scrutiny of single-crystal structure reveals that complex 1 forms to a 3D supramolecular network linked by π-π stacking interactions and hydrogen bonds. X-ray diffraction analysis reveals that complex 2 exhibits a 3D supramolecular network linked through complicated hydrogen bonds. The thermogravimetric analysis and photoluminescent properties of 1 and 2 are discussed in detail. 展开更多
关键词 cadmium(Ⅱ) complex copper(Ⅱ) complex 4'-(4''-pyridyl)-2 2':6' 2''-terpyridine 1 4-benzenedicarboxylic acid crystal structure
下载PDF
A Green Synthesis of 2-Ethylanthraquinone by Dehydration of 2-(4'-ethylbenzoyl) benzoic Acid over Solid Acid Catalysts 被引量:1
10
作者 Ren Shu XU Xin Wen GUO Gui Ru WANG Zhu Xia ZHANG 《Chinese Chemical Letters》 SCIE CAS CSCD 2005年第12期1587-1589,共3页
The dehydration of 2-(4'-ethylbenzoyl) benzoic acid (BE acid) to 2-ethylanthraquinone (2-EAQ) was investigated over solid acid catalysts. The results showed that H-beta zeolite catalyst modified by dilute HNO3 ... The dehydration of 2-(4'-ethylbenzoyl) benzoic acid (BE acid) to 2-ethylanthraquinone (2-EAQ) was investigated over solid acid catalysts. The results showed that H-beta zeolite catalyst modified by dilute HNO3 solution exhibited an excellent performance. In our study, the conversion of BE acid can reach 96.7%, and the selectivity to 2-EAQ is up to 99.6%. 展开更多
关键词 2-ETHYLANTHRAQUINONE 2-(4'-ethylbenzoyl) benzoic acid H-BETA DEHYDRATION
下载PDF
Synthesis and Crystal Structure of One Mixed-ligand Coordination Polymer Based on the Novel Terphenyl-2,5,2',5'-tetracarboxylic Acid Ligand 被引量:2
11
作者 张修堂 张炉青 +3 位作者 张梁栋 范黎明 魏培海 张书香 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2012年第10期1518-1523,共6页
Solvothermal reaction of aromatic terphenyl-2,5,2',5'-tetracarboxylic acid (Hnqptc) ligand and the transitional metal cation of Mn11 in the presence of 3-(2-pyridyl)pyrazole (pp) affords one new coordination p... Solvothermal reaction of aromatic terphenyl-2,5,2',5'-tetracarboxylic acid (Hnqptc) ligand and the transitional metal cation of Mn11 in the presence of 3-(2-pyridyl)pyrazole (pp) affords one new coordination polymer, [Mn(qptc)0.5(pp)2]n·n(H2O) (1). The structure has been determined by single-crystal X-ray diffraction analyses and further characterized by elemental analyses, IR, TGA, and magnetism. The carboxyl groups of qptc4 exhibit a μ1-η1:η0 coordination mode, and the qptc4- acts as a H-shaped ligand linking the Mn11 centers together to form a 2D polymeric [Mn(qptc)0.5]n layer. The crystal of 1 crystallizes in orthorhombic, space group Pbca with a = 9.3119(12), b = 20.848(3), c = 26.134(3) A, V= 5073.4(11) A3, Z= 8, C27HIgMnN6O5,Mr=562.42, Dc = 1.473 g/cm3, F(000) = 2304 and μ(MoKa) = 0.571 mm-1. The final R = 0.0468 and wR = 0.1196 for 4429 observed reflections with I 〉 2σ(I) and R = 0.0797 and wR = 0.1383 for all data. 展开更多
关键词 terphenyl-2 5 2 5'-tetracarboxylic acid 3-2-pyridyl)pyrazole manganese(II)
下载PDF
Syntheses, Characterization and Antitumour Activities of Rare Earth Metal Complexes with 2-(((4,6-dimethyl)-2-Pyrimidinyl)thio)-Acetic Acid 被引量:1
12
作者 曲建强 王流芳 +3 位作者 刘瑛琦 宋玉民 王印月 贾晓飞 《Journal of Rare Earths》 SCIE EI CAS CSCD 2006年第1期15-19,共5页
Eight rare earth metal ( Ⅲ ) complexes with 2- ( ((4,6-dimethyl)-2-pyrimidinyl) thio)-acetic acid, LnL3· n H2O [HL = 2-(((4,6-dimethyl)-2-pyrimidinyl)thio)-acetic acid; Ln = La, Ce, Pr, Nd, Sm Eu, ... Eight rare earth metal ( Ⅲ ) complexes with 2- ( ((4,6-dimethyl)-2-pyrimidinyl) thio)-acetic acid, LnL3· n H2O [HL = 2-(((4,6-dimethyl)-2-pyrimidinyl)thio)-acetic acid; Ln = La, Ce, Pr, Nd, Sm Eu, Gd, Tb; n = 4 or 5], were prepared and characterized by elemental analysis, complexometric titration, thermal analysis, conductivity, IR and ^1H- NMR. The results reveal that carboxyl group of the hgand coordinates with rare earth ions in bidentate mode after deprotonated. The water molecules exist as crystal water in the complexes. The anti-tumour activities of HL and some complexes were tested by both the MTT and SRB methods. The results show that the suppression ratios of some complexes against the tested tumour cells (HL-60 human leukemia cell lines, BGC-823 human gastric carcinoma cell lines, hela human cervix adenocarcinoma cell lines and Bel-7402 human hepatic carcinoma cell lines) are superior to HL. 展开更多
关键词 2-(((4 6-dimethyl)-2-pyfimidinyl) thio)-acetic acid COMPLEXES anti-tumour activities rare earths
下载PDF
Synthesis and Crystal Structure of 3-(Pyrrole-2′-carboxamido)propanoic Acid·(1/2)H_(2)O 被引量:1
13
作者 ZENG Xiang-Chao XU Shi-Hai +1 位作者 GU Jian LIU Po-Run 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2005年第7期779-782,737,共5页
3-(Pyrrole-2?-carboxamido)propanoic acid I has been synthesized from the reaction of β-alanine methyl ester with 2-trichloroacetylpyrrole followed by saponifying and acidating in 85.4% yield, and the crystal structur... 3-(Pyrrole-2?-carboxamido)propanoic acid I has been synthesized from the reaction of β-alanine methyl ester with 2-trichloroacetylpyrrole followed by saponifying and acidating in 85.4% yield, and the crystal structure of 3-(pyrrole-2?-carboxamido)propanoic acid· (1/2)H2O (C8H11N2O3.5, Mr = 191.19) was obtained and determined by X-ray diffraction method. The crystal is of monoclinic, space group C2/c with a = 19.010(4), b = 8.3515(17), c = 13.788(3) ?, β = 125.88(3)o, V = 1773.6(6) ?3, Z = 8, Dc = 1.432 g/cm3, λ = 0.71073 ?, μ(MoKα) = 0.114 mm?1 and F(000) = 768. The structure was refined to R = 0.0354 and wR = 0.0942 for 1642 observed reflections with I > 2σ(I). It is revealed that the title compound has one pyrrole ring and one propionic acid subchain linked by an amido bond at C(4), and there are 8 molecules of com- pound I and 4 crystal water molecules in each unit cell. The supramolecular layers are stabilized by the hydrogen bonds of N(2) H…O(2), N(1) H…O(4), O(4) H(1W)…O(2) and O(3) H…O(1). 展开更多
关键词 3-(pyrrole-2-carboxamido)propanoic acid 2-trichloroacetylpyrrole crystal structure
下载PDF
Long-term and combined effects of N-[2-(nitrooxy)ethyl]-3-pyridinecarboxamide and fumaric acid on methane production,rumen fermentation, and lactation performance in dairy goats 被引量:1
14
作者 Zongjun Li Xinjian Lei +3 位作者 Xiaoxu Chen Qingyan Yin Jing Shen Junhu Yao 《Journal of Animal Science and Biotechnology》 SCIE CAS CSCD 2022年第3期852-863,共12页
Background:In recent years,nitrooxy compounds have been identified as promising inhibitors of methanogenesis in ruminants.However,when animals receive a nitrooxy compound,a high portion of the spared hydrogen is eruct... Background:In recent years,nitrooxy compounds have been identified as promising inhibitors of methanogenesis in ruminants.However,when animals receive a nitrooxy compound,a high portion of the spared hydrogen is eructated as gas,which partly offsets the energy savings of CH4mitigation.The objective of the present study was to evaluate the long-term and combined effects of supplementation with N-[2-(nitrooxy)ethyl]-3-pyridinecarboxamide(NPD),a methanogenesis inhibitor,and fumaric acid(FUM),a hydrogen sink,on enteric CH4production,rumen fermentation,bacterial populations,apparent nutrient digestibility,and lactation performance of dairy goats.Results:Twenty-four primiparous dairy goats were used in a randomized complete block design with a 2×2factorial arrangement of treatments:supplementation without or with FUM(32 g/d)or NPD(0.5 g/d).All samples were collected every 3 weeks during a 12-week feeding experiment.Both FUM and NPD supplementation persistently inhibited CH4yield(L/kg DMI,by 18.8%and 18.1%,respectively)without negative influence on DMI or apparent nutrient digestibility.When supplemented in combination,no additive CH4suppression was observed.FUM showed greater responses in increasing the molar proportion of propionate when supplemented with NPD than supplemented alone(by 10.2%vs.4.4%).The rumen microbiota structure in the animals receiving FUM was different from that of the other animals,particularly changed the structure of phylum Firmicutes.Daily milk production and serum total antioxidant capacity were improved by NPD,but the contents of milk fat and protein were decreased,probably due to the bioactivity of absorbed NPD on body metabolism.Conclusions:Supplementing NPD and FUM in combination is a promising way to persistently inhibit CH4emissions with a higher rumen propionate proportion.However,the side effects of this nitrooxy compound on animals and its residues in animal products need further evaluation before it can be used as an animal feed additive. 展开更多
关键词 Bacterial populations Dairy goat Fumaric acid Lactation performance Methane emissions N-[2-(nitrooxy)ethyl]-3-pyridinecarboxamide Rumen fermentation
下载PDF
Enantioselective esterification of(R,S)-2-(4-methylphenyl)propionic acid via Novozym 435:Optimization and application 被引量:1
15
作者 Xin Yuan LujunWang +2 位作者 Panliang Zhang Weifeng Xu Kewen Tang 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2020年第7期1816-1823,共8页
This paper reports on the resolution of(R,S)-2-(4-methylphenyl)propionic acid(MPPA)enantiomers by enzymatic esterification in organic solvent.Novozym 435(CALB)has the best catalytic performance compared with other lip... This paper reports on the resolution of(R,S)-2-(4-methylphenyl)propionic acid(MPPA)enantiomers by enzymatic esterification in organic solvent.Novozym 435(CALB)has the best catalytic performance compared with other lipases.Of the alcohols screened,n-hexanol is the best acyl acceptor and gives the highest enzyme activity and enantioselectivity in n-hexane.Response surface methodology(RSM)was used to evaluate the influence of the factors,such as temperature,enzyme amount,substrate concentration and reaction time on the substrate conversion(c)and enantiomeric excess(ee).The correlation coefficient R2 for enantiomeric excess and the conversion are 0.9827 and 0.9910,respectively,indicating that can accurately predict the experimental results.By simulation and optimization,the optimal conditions were obtained,involving 600 mmol·L^-1 MPPA concentration(0.60 mmol),850 mmol·L^-1 hexanol concentration(0.85 mmol),58 mg enzyme amount,75℃temperature and 4.5 h reaction time,respectively.Under the optimized conditions,the experimental values of conversion and enantiomeric excess were 89.34%and 97.84%,respectively,which are in good agreement with the model predictions. 展开更多
关键词 (R S)-2-(4-Methylphenyl)propionic acid Novozym 435 ESTERIFICATION kinetic resolution Response surface methodology
下载PDF
Synthesis and Crystal Structure of 4-(4,6-dimethoxyl -pyrimidin-2-yl)-3-thiourea Carboxylic Acid Methyl Ester 被引量:1
16
作者 HUANG Jie SONG Ji-Rong REN Ying-Hui XU Kang-Zhen MA Hai-Xia 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2006年第2期168-172,共5页
The title compound 4-(4,6-dimethoxylpyrimidin-2-yl)-3-thiourea carboxylic acid methyl ester was synthesized by the reaction of 2-amino-4,6-dimethoxyl pyrimidine, potassium thiocyanate and methyl chloroformate in eth... The title compound 4-(4,6-dimethoxylpyrimidin-2-yl)-3-thiourea carboxylic acid methyl ester was synthesized by the reaction of 2-amino-4,6-dimethoxyl pyrimidine, potassium thiocyanate and methyl chloroformate in ethyl acetate. Single crystals suitable for X-ray measurement were obtained by recrystallization with the solvent of dimethyl formamide at the room temperature. The structure was characterized by elemental analysis and IR and determined by X-ray diffraction analysis' Crystallographic data: C9H12N4O4S, Mr = 272.29, monoclinic, space group C2/m with a = 1.6672(3), b = 0.66383(12), c = 1.1617(2) nm, β = 109.275(2)°, V = 1.2136(4) nm^3, Dc = 1.490 g/cm^3,μ = 0.281 mm^-1, F(000) = 568, Z = 4, R1 = 0.0341and wR2 = 0.1042. 展开更多
关键词 4-(4 6-dimethoxylpyrimidin-2-yl)-3-thiourea carboxylic acid methyl ester synthesis X-ray diffraction
下载PDF
Synthesis and Crystal Structure of 1-H-Pyrrole-2-carboxylic Acid [2-(Naphthalen-1-ylamino)-ethyl]-amide 被引量:1
17
作者 YIN Zhen-Ming WANG Jian-Ying 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2006年第7期771-774,共4页
1-H-Pyrrole-2-carboxylic acid [2-(naphthalen-1-ylamino)-ethyl]-amide has been synthesized and characterized. Its crystal is of monoclinic, space group P2 1/n with a = 5.930(6), b = 12.144(13), c = 20.10(2) , ... 1-H-Pyrrole-2-carboxylic acid [2-(naphthalen-1-ylamino)-ethyl]-amide has been synthesized and characterized. Its crystal is of monoclinic, space group P2 1/n with a = 5.930(6), b = 12.144(13), c = 20.10(2) , A, β = 95.709(17)°, V= 1441(3) ,A, Z= 4, C17H17N3O, Mr= 279.34, Dc= 1.288 g/cm^3, F(000) = 592, μ(MoKa) = 0.083 mm^-1, S = 1.019, R = 0.0473 and wR = 0.1181 for 1713 observed reflections with I 〉 2 σ(I). X-ray diffraction reveals that two molecules of the title compound form a dimer through a pair of N-H…O hydrogen bonds. 展开更多
关键词 1-H-pyrrole-2-carboxylic acid [2-(naphthalen-l-ylamino)-ethyi]-amide crystal structure hydrogen bonds
下载PDF
A One-dimensional Cd(Ⅱ)Coordination Polymer Constructed from 1,4-Benzene-dicarboxylic Acid and 3-(2,6-Di(pyrazin-2-yl)pyridin-4-yl)-1H-indole:Synthesis,Structure and Photoluminescence 被引量:2
18
作者 谢玲 卢丽萍 朱苗力 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2016年第10期1606-1614,共9页
A new coordination polymer {[Cd(C_(21)H_(14)N_6)(C_8H_4O_4)]·H_2O}_n(1) was synthesized by an elaborate design via the reaction of 3-(2,6-di(pyrazin-2-yl)pyridin-4-yl)-1H-indole(bppi),1,4-benzene-... A new coordination polymer {[Cd(C_(21)H_(14)N_6)(C_8H_4O_4)]·H_2O}_n(1) was synthesized by an elaborate design via the reaction of 3-(2,6-di(pyrazin-2-yl)pyridin-4-yl)-1H-indole(bppi),1,4-benzene-dicarboxylic acid(H2bdc) and cadmium(Ⅱ) nitrate in CH_3OH/H_2O mixed solvents. Complex 1 crystallizes in orthorhombic,space group Ccca with a = 20.012(4),b = 31.881(6),c = 19.808(4) ?,V = 12638(4) ?~3,Z = 16,C_(29)H_(20)CdN_6O_5,M_r = 644.91,D_c = 1.356 g·cm^(-3),μ = 0.735 mm^(-1),F(000) = 5184,GOOF = 1.046,the final R = 0.0405 and wR = 0.1063 for 6870 observed reflections(I 〉 2σ(I)). The Cd(Ⅱ) centre is hepta-coordinated by three N and four O atoms from one bppi terminal ligand and two bdc2– ligands,respectively,displaying a capped trigonal prism geometry. Structure extension gives coordination polymeric chains,in which the bdc2– linkers connect Cd(Ⅱ) cations into a one-dimensional(1D) coordination polymer along the c axis,giving zigzag chains with the Cd···Cd separation of 11.178(1) ?. The adjacent bppi terminal ligands in the chains are anti-periplanar conformation. The three-dimensional(3D) structure is stabilized by π···π stacking and hydrogen-bonding interactions to form a supramolecular self-penetrating network with 1D channels. In 1,there are voids 2999.7 ?~3 with 23.7% of per unit cell volume. Thermal analysis indicates that the framework of 1 is stable until 651 K and the photoluminescence of 1 in the solid shows very weak fluorescence at 382 and 560 nm upon excitation at 310 nm. 展开更多
关键词 1 4-benzenedicarboxylic acid 3-2 6-di(pyrazin-2-yl)pyridin-4-yl)-1H-indole one-dimensional cadmium(Ⅱ) coordination polymer π···π stacking interactions photoluminescence
下载PDF
Synthesis,Crystal Structure and Antitumor Activity of a Novel Zn(Ⅱ)Complex with 2-(Nicotinoyloxy)acetic Acid Ligand 被引量:1
19
作者 台夕市 郭洪梅 郭芊沁 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2018年第7期1052-1056,共5页
A novel Zn(Ⅱ) complex, [ZnL2(H2O)4]·H2O(1, HL = 2-(nicotinoyloxy)acetic acid), was synthesized using Zn(OAc)2·2H2O and 2-(nicotinoyloxy)acetic acid as raw materials. Its structure has been eluci... A novel Zn(Ⅱ) complex, [ZnL2(H2O)4]·H2O(1, HL = 2-(nicotinoyloxy)acetic acid), was synthesized using Zn(OAc)2·2H2O and 2-(nicotinoyloxy)acetic acid as raw materials. Its structure has been elucidated by elemental analysis, IR and single-crystal X-ray diffraction. The structural analysis revealed that complex 1 crystallizes in triclinic, space group P1 and the Zn(Ⅱ) atom is six-coordinated with two N atoms from two different 2-(nicotinoyloxy)acetate anion ligands and four O atoms from coordinated water molecules. Complex 1 forms a 3D network structure by O–H···O hydrogen bonds. The antitumor activities of 2-(nicotinoyloxy)acetic acid ligand and its Zn(Ⅱ) complex were evaluated against human lung adenocarcinoma A549 cells, human hepatoma SMMC-7721 cells and human colon carcinoma Wi Dr cells. 展开更多
关键词 2-(nicotinoyloxy)acetic acid ligand Zn(Ⅱ) complex SYNTHESIS crystal structure antitumor activity
下载PDF
Synthesis,Crystal Structure,and Magnetic Property of One 3D Nickel Coordination Polymer Based on 2-Hydroxy-5-(3',5'-terephthalic acid)Pyridine and 1,4-Bis(1-imdazoly)benzene 被引量:1
20
作者 TANG Pei-Qin HAO Lu-Jiang +3 位作者 FAN Li-Ming LIU Xin-Zheng LI Bin ZHANG Xiu-Tang 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2015年第10期1519-1524,共6页
One novel nickel coordination polymer, {[Ni(OTP)(bib)1.5(H2O)]·2H2O}n(1, H2 OTP = 2-hydroxy-5-(3',5'-terephthalic acid) pyridine, bib = 1,4-bis(1-imdazoly)benzene), has been synthesized and characte... One novel nickel coordination polymer, {[Ni(OTP)(bib)1.5(H2O)]·2H2O}n(1, H2 OTP = 2-hydroxy-5-(3',5'-terephthalic acid) pyridine, bib = 1,4-bis(1-imdazoly)benzene), has been synthesized and characterized by elemental analysis(EA), IR, powder X-ray diffraction(PXRD), and thermogravimetric(TG) analyses. The crystal of 1 crystallizes in monoclinic, space group P21/n with a = 12.2860(5), b = 13.8246(6), c = 19.0140(8) A, β = 104.3870(1)°, V = 3128.2(2) A3, Z = 4, C32H28N7 Ni O8, Mr = 697.32, Dc = 1.481 g/cm^3, F(000) = 1444 and μ(Mo Kα) = 0.684 mm-1. The final R = 0.0704 and w R = 0.1764 for 5485 observed reflections with I 2σ(I) and R = 0.1087 and wR = 0.2010 for all data. Topology analysis reveals that complex 1 is a 3D 2-fold interpenetrated {4^4·6^6}-nov net based on the 1D [Ni(OTP)]n chain and the 2D [Ni2(bib)3]n sql sheet. And the variable-temperature magnetic susceptibility measurements exhibit weak antiferromagnetic coupling interaction. 展开更多
关键词 2-hydroxy-5-(3' 5'-terephthalic acid)pyridine 1 4-bis(1-imdazoly)benzene NICKEL topology magnetic property
下载PDF
上一页 1 2 6 下一页 到第
使用帮助 返回顶部