期刊文献+
共找到25篇文章
< 1 2 >
每页显示 20 50 100
2-苯基/环己基环十二酮的还原选择性及trans-1,2-二取代环十二烷的构象分析 被引量:2
1
作者 杨明艳 张莉 +1 位作者 王道全 王明安 《高等学校化学学报》 SCIE EI CAS CSCD 北大核心 2015年第3期489-498,共10页
通过研究2-苯基/环己基环十二酮在不同还原剂和温度下的还原反应证实了2-取代环十二酮的还原反应具有cis-选择性.在此基础上,通过2-取代环十二酮的Na BH4还原反应、1,2-环氧环十二烷的开环反应及cis-2-苯基环十二醇的Mitsunobu反应和水... 通过研究2-苯基/环己基环十二酮在不同还原剂和温度下的还原反应证实了2-取代环十二酮的还原反应具有cis-选择性.在此基础上,通过2-取代环十二酮的Na BH4还原反应、1,2-环氧环十二烷的开环反应及cis-2-苯基环十二醇的Mitsunobu反应和水解反应制备了一系列trans-1,2-二取代环十二烷;采用1H NMR、13C NMR、X射线衍射和量子化学计算等方法对其优势构象进行了分析.结果表明,trans-1,2-二取代环十二烷的优势构象为[3333]方形构象,1个取代基位于边碳外向位(Side-exo),另1个位于角碳反向位(Corneranti).cis-2,12-二取代环十二酮的Li Al H4还原产物的X射线衍射分析结果表明,生成的1,2,3-三取代环十二烷保持了环十二烷的[3333]方形构象,2个取代基位于边碳外向位,羟基位于角碳顺向位(Corner-syn),取代基呈现出cis-cis关系. 展开更多
关键词 2-苯基/环己基环十二酮 trans-1 2-二取代环十二烷 1 2 3-三取代环十二烷 构象分析
下载PDF
被修饰环糊精模版控制的trans-2-苯乙烯吡啶的分子内环化
2
作者 马丽雅 张喜子 《煤炭与化工》 CAS 2014年第11期8-10,共3页
环糊精(CDs)是由6,7或8吡喃葡萄糖与上下环绕的羟基组成的环状低聚糖,具有内疏水外亲水的结构特征。合成了一种酰化的γ-环糊精(CDs),并将酰化的环糊精衍生物与trans-2-苯乙烯吡啶分子包合,比较了固态、液态及凝胶态中包合物的光反应结... 环糊精(CDs)是由6,7或8吡喃葡萄糖与上下环绕的羟基组成的环状低聚糖,具有内疏水外亲水的结构特征。合成了一种酰化的γ-环糊精(CDs),并将酰化的环糊精衍生物与trans-2-苯乙烯吡啶分子包合,比较了固态、液态及凝胶态中包合物的光反应结果,发现修饰的环糊精对其分子内光环化产物的生成具有选择性,其中固态产物的选择性最好,可以得到产率较高的苯并[f]喹啉。 展开更多
关键词 修饰环糊精 trans-2-苯乙烯吡啶 分子内环化
下载PDF
Solubility of trans-1,2-Cyclohexanediol in Some Solvents 被引量:4
3
作者 ZHOU Cairong(周彩荣) +3 位作者 WANG Haifeng(王海峰) JIANG Denggao(蒋登高) 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2005年第4期560-563,共4页
The solubility of trans-1,2-cyclohexanediol in water, methyl acetate, acetic ester, propyl acetate, butyl acetate, methyl acrylate, ethyl acrylate, 2-pentanone and acetoacetic ester was measured at temperatures rangin... The solubility of trans-1,2-cyclohexanediol in water, methyl acetate, acetic ester, propyl acetate, butyl acetate, methyl acrylate, ethyl acrylate, 2-pentanone and acetoacetic ester was measured at temperatures ranging from about 300 K to 330 K, using a modification of the experimental technique of laser monitoring observation system. The solubilities were calculated by λh method, in which new parameters were introduced to express the activity coefficients of trans-1,2-cyclohexanediol, and determined from the experimental data. The new parameters provide good calculated results. The experimental data were also correlated with a simple model, and results were compared with present λh model. 展开更多
关键词 soiid- liquid equilibrium SOLUBILITY trans-1 2-cyclohexanediol ACETATE ACRYLATE ACETOACETATE
下载PDF
Solid-Liquid Equilibria of trans-1,2-Cyclohexanediol+Butyl Acetate+ Water Ternary System 被引量:4
4
作者 周彩荣 石晓华 +2 位作者 王海峰 高玉国 蒋登高 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2007年第3期449-452,共4页
Using a laser observation technique,the solubilities of trans-1,2-cyclohexanediol in butyl acetate+wa- ter were measured at the temperature range from 298.15K to 323.15K by a synthetic method at atmospheric pres- sure... Using a laser observation technique,the solubilities of trans-1,2-cyclohexanediol in butyl acetate+wa- ter were measured at the temperature range from 298.15K to 323.15K by a synthetic method at atmospheric pres- sure.It is shown that the solubilities of trans-1,2-cyclohexanediol in butyl acetate+water were affected greatly by the proportion of butyl acetate and water,and presented maximum value at given temperature.The UNIFAC model was used to correlate the experimental data.The average relative deviation(ARD)between experimental and calculated values is 3.03%. 展开更多
关键词 trans-1 2-cyclohexanediol solid-liquid equilibria laser monitoring technique SOLUBILITY UNIFAC
下载PDF
Determination of trans-4-hydroxy-2-alkenals in thermally treated soybean oil by SPE-HPLC 被引量:1
5
作者 Hongying Hua Shimin Wu Xin Ma 《Grain & Oil Science and Technology》 2022年第3期107-113,共7页
Trans-4-hydroxy-2-hexenal(4-HHE) and trans-4-hydroxy-2-nonenal(4-HNE) are secondary lipid peroxidation products in edible oils, which are cytotoxic and genotoxic. They could covalently bind with protein, phospholipids... Trans-4-hydroxy-2-hexenal(4-HHE) and trans-4-hydroxy-2-nonenal(4-HNE) are secondary lipid peroxidation products in edible oils, which are cytotoxic and genotoxic. They could covalently bind with protein, phospholipids and DNA, further disrupting the normal function of liver, lung and brain.Derivation process was generally conducted during pretreatment before detection and quantification of 4-HHE and 4-HNE. However, the derivation procedures were time consuming and chemical degradation may occur during the process. Hence, this paper aims to establish a simple solid phase extractionhigh performance liquid chromatography(SPE-HPLC) method to determine the 4-HHE and 4-HNE contents in thermally treated soybean oil. C18 solid phase extraction was applied in the pretreatment process. Firstly, the reliability of the method was evaluated. Good linearity was observed in the range of 0.1–0.5 μg/m L and 0.5–10 μg/m L for 4-HHE and 4-HNE. The limit of detection(LOD) of 4-HHE and 4-HNE were 0.0486 and 0.0129 μg/m L, respectively. And the limit of quantitation(LOQ) of4-HHE and 4-HNE were 0.1458 and 0.0431 μg/m L, respectively. Recovery rate were in the range of89.11%–91.58% and 71.83%–79.40% for 4-HHE and 4-HNE, respectively. The method achieved the extraction, purification and detection of 4-HHE and 4-HNE simultaneously and had the advantages of simple operation, effectiveness, high precision, good repeatability. Then, the method was applied to monitor the concentrations of 4-HHE and 4-HNE in soybean oil heated at 180 °C for 40 h. The contents of 4-HHE and 4-HNE were 0–0.32 μg/g and 0–6.97 μg/g, respectively, which provided guidance for evaluating health risks of thermally treated soybean oil during heating. 展开更多
关键词 trans-4-hydroxy-2-hexenal trans-4-hydroxy-2-nonenal Soybean oil
下载PDF
Synthesis and Crystal Structure of Trans-4-[(5-(2,4-Dichlorophenoxy)-3-methyl-1-phenyl-1H-pyrazol-4-yl)methyleneamino]-1,5-dimethyl-2-phenyl-1,2-dihydropyrazol-3-one 被引量:4
6
作者 孙凤梅 田孟魁 +1 位作者 杨靖华 连照勋 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2008年第7期789-792,共4页
The title compound trans-4-[(5-(2,4-dichlorophenoxy)-3-methyl- 1-phenyl-1H-pyrazol-4-yl)methyleneamino]- 1,5-dimethyl-2-phenyl-1,2-dihydropyrazol-3-one 3 (C28H23Cl2N5O2, Mr = 532.41) has been synthesized and its... The title compound trans-4-[(5-(2,4-dichlorophenoxy)-3-methyl- 1-phenyl-1H-pyrazol-4-yl)methyleneamino]- 1,5-dimethyl-2-phenyl-1,2-dihydropyrazol-3-one 3 (C28H23Cl2N5O2, Mr = 532.41) has been synthesized and its crystal structure was determined by single-crystal X-ray diffraction analysis. It crystallizes in triclinic, space group P1- with a = 8.9438(4), b = 11.6065(5), c = 14.2215(6)A, α = 112.566(1), β = 92.324(2), γ = 102.91(1)°, V= 1315.65(10) A^3, Z = 2, Dc = 1.344 g/cm^3,μ(MoKa) = 0.282 mm^-1, λ = 0.71073 A, F(000) = 552, the final R = 0.0587 and wR = 0.1578 for 5071 observed reflections (I 〉 2σ(I)). X-ray analysis reveals that the product is a thermodynamically stable trans isomer. Intra- and intermolecular C( 12)-H(12)…O(1) and C(28)-H(28)...O(1)# 1 hydrogen bonds were observed in the title compound. 展开更多
关键词 trans-4-[ 5-(2 4-dichlorophenoxy)-3-methyl- 1-phenyl- 1H-pyrazol-4-yl)methylene amino]-1 5-dimethyl-2-phenyl-1 2-dihydropyrazol-3-one synthesis crystal structure
下载PDF
Dimer of Bis[trans-5-methyl-2-[2-(4-methoxylphenyl)ethenyl]-benzoxazole]di-μ-nitratosilver(I)
7
作者 LIUHui-Min ZHANGWei XINYing ZHANGWen-Qin 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2004年第5期532-536,共5页
The title complex [AgNO3(C17H15NO2)2]2 was synthesized and characterized by X-ray diffraction analysis. The compound crystallizes in triclinic, space group P with a = 11.226(7), b = 11.906(7), c = 12.144(7) , = 99.79... The title complex [AgNO3(C17H15NO2)2]2 was synthesized and characterized by X-ray diffraction analysis. The compound crystallizes in triclinic, space group P with a = 11.226(7), b = 11.906(7), c = 12.144(7) , = 99.796(10), = 91.631(10), = 101.225(10), V = 1565.6(16) 3, Z = 1, Mr = 1400.96, Dc = 1.486 g/cm3, F(000) = 716 and (Mo-K? = 0.697 mm-1. The final R and wR are 0.0401 and 0.0995, respectively for 5492 independent observable reflections with I > 2(I). The results show that the central Ag atom is four-coordinated with two O atoms from two distinct NO3- anions and two N atoms from two trans-5-methyl-2-[2-(4-methoxylphenyl)ethenyl]- benzoxazole ligands, and the two Ag atoms bridged with two O atoms give an interesting Ag-O-Ag-O parallelogram structure. The coordination sphere of Ag atom exhibits a heavily distorted tetrahedral geometry and the coordination angles lie in the range of 66.73(12)~129.59(10). The intra- molecular dihedral angles between the benzoxazolyl and phenyl planes are 4.1(3) and 2.9(3), respectively. 展开更多
关键词 synthesis crystal structure trans-2-styrylbenzoxazole silver complex
下载PDF
Mechanistic Study on the Monofunctional Binding of Hydrolysis Products of Non-planar Heterocyclic Complexes Trans-[PtCl_2NH_3(piperidine)] and Trans-[PtCl_2(piperidine)_2] to DNA Purine Bases
8
作者 陈鋆晖 周立新 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2010年第10期1536-1546,共11页
The monofunctional substitution reactions between trans-[PtCl(H2O)(NH3)(pip)]+,trans-[Pt(H2O)2(NH3)(pip)]2+,trans-[PtCl(H2O)(pip)2]+,trans-[Pt(H2O)2(pip)2]2+ (pip = piperidine) and adenine/gu... The monofunctional substitution reactions between trans-[PtCl(H2O)(NH3)(pip)]+,trans-[Pt(H2O)2(NH3)(pip)]2+,trans-[PtCl(H2O)(pip)2]+,trans-[Pt(H2O)2(pip)2]2+ (pip = piperidine) and adenine/guanine nucleotides are explored by using B3LYP hybrid functional and IEF-PCM salvation models. For the trans-[Pt(H2O)2(NH3)(pip)]2+ and trans-[PtCl(H2O)(NH3)(pip)]+ complexes,the computed barrier heights in aqueous solution are 13.5/13.5 and 11.6/11.6 kcal/mol from trans-Pt-chloroaqua complex to trans/cis-monoadduct for adenine and guanine,and the corresponding values are 20.7/20.7 and 18.8/18.8 kcal/mol from trans-Pt-diaqua complex to trans/cis-monoadduct for adenine and guanine,respectively. For trans-[PtCl(H2O)(pip)2]+ and trans-[Pt(H2O)2(pip)2]2+,the corresponding values are 21.5/21.3 and 19.4/19.4 kcal/mol,and 26.0/26.0 and 20.7/20.8 kal/mol for adenine and guanine,respectively. Our calculations demonstrate that the barrier heights of chloroaqua are lower than the corresponding values of diaqua for adenine and guanine. In addition,the free energies of activation for guanine in aqueous solution are all smaller than that for adenine,which predicts a preference of 1.9 kcal/mol when trans-[PtCl(H2O)(NH3)(pip)]+ and trans-[Pt(H2O)2(NH3)(pip)]2+ are the active agents and ~1.9 and ~ 5.3 kcal/mol when trans-[PtCl(H2O)(pip)2]+ and trans-[Pt(H2O)2(pip)2]2+ are the active agents,respectively. For the reaction of trans-Pt-chloroaqua (or diaqua) to cis-monoadduct,we obtain the same transition-state structure as from the reaction of trans-Pt-chloroaqua (or diaqua) to trans-monoadduct,which seems that the trans-Pt-chloroaqua (or diaqua) complex can generate trans-or cis-monoadduct via the same transition-state. 展开更多
关键词 DFT trans-[PtCl2NH3(piperidine)] and trans-[PtCl2(piperidine)2] DNA bases transition state activation energy
下载PDF
Facile synthesis of 9-(N-amino-4-fluoromethyl-3-pyrrolidinyl)-2-fluoro-6-aminopurine from trans-4-hydroxy-L-proline
9
作者 Ye Qing Li Ming Lu Chun Xu Lu Sai Jian Zhu Qi Fa Liu 《Chinese Chemical Letters》 SCIE CAS CSCD 2007年第11期1313-1315,共3页
A novel and simple procedure for synthesis of azanucleoside by Mitsunobu reaction between N-(p-nitrobenzyloxycarbonyl)- trans-4-hydroxy-D-proline methyl ester obtained from trans-4-hydroxy-L-proline after six-step r... A novel and simple procedure for synthesis of azanucleoside by Mitsunobu reaction between N-(p-nitrobenzyloxycarbonyl)- trans-4-hydroxy-D-proline methyl ester obtained from trans-4-hydroxy-L-proline after six-step reaction and 2-fluoro-6-azidopurine is described, and azanucleoside is fluorinated by new fluridizer 2,2-difluoro-1,3-dimethylimidazolidine (DFI). All reactions could be carried out under mild condition. 展开更多
关键词 trans-4-Hydroxy-D-proline 2-Fluoro-6-azidopurine Fluoride azanucleosides Mitsunobu reaction DFI
下载PDF
N-[反式-2-(3,4-~3H-吡咯基)-环己基]-N-甲基-3,4-二氯-苯乙酰胺盐酸盐的合成
10
作者 李德有 马斯才 +2 位作者 李健国 王崇铨 沈德存 《中国药物化学杂志》 CAS CSCD 1990年第1期66-68,共3页
N-[反式-2-(1-吡咯基)环己基]-N-甲基-3,4-二氯-苯乙酰胺盐酸盐(简称U-50488H(K-I))是近年来报道的高选择性的K-阿片受体激动剂,动物实验结果表明:该化合物具有较强的镇痛活性,且成瘾性较低,呼吸抑制较弱,无吗啡样副作用的新型麻醉镇痛... N-[反式-2-(1-吡咯基)环己基]-N-甲基-3,4-二氯-苯乙酰胺盐酸盐(简称U-50488H(K-I))是近年来报道的高选择性的K-阿片受体激动剂,动物实验结果表明:该化合物具有较强的镇痛活性,且成瘾性较低,呼吸抑制较弱,无吗啡样副作用的新型麻醉镇痛剂。为研究它的药理作用,我们用氚标记了U-50488(K-I)。合成该化合物开始原料是N-甲基-反式-2-(1-△~3-吡咯啉基)环己基胺,按一般还原法以氧化铂为催化剂,通氚进行氚化反应,未经分离与3,4一二氯苯乙酸在二环己基碳二亚胺(DCC)存在下进行缩合脱水反应,生成N-[反式-2-(3,4-~3H-吡咯基)环己基]-N-甲基-3,4-二氯-苯乙酰胺,再用氯化氢乙醚处理,制得了氚化的U-50488(K-I)。合成途径如下: 展开更多
关键词 ANALGESIC activity N-[trans-2-(3 4-~3H-pyrrolyl)-cyclohexyl)-N-methyl-3 4-dichloro-benzenacetamide hydrochloride
下载PDF
Identification and functional characterization of ApisOr23 in pea aphid Acyrthosiphon pisum 被引量:1
11
作者 HUANG Tian-yu ZHANG Rui-bin +4 位作者 YANG Lu-lu CAO Song Frederic FRANCIS WANG Bing WANG Gui-rong 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2022年第5期1414-1423,共10页
Pea aphid,Acyrthosiphon pisum,is a serious pest of many different leguminous plants,and it mainly relies on its odorant receptors(Ors)to discriminate among host species.However,less is known about the role that Ors pl... Pea aphid,Acyrthosiphon pisum,is a serious pest of many different leguminous plants,and it mainly relies on its odorant receptors(Ors)to discriminate among host species.However,less is known about the role that Ors play in the host plant location.In this study,we identified a novel conserved odorant receptor clade by phylogenetic analysis,and conducted the functional analysis of ApisOr23 in A.pisum.The results showed that the homologous Ors from A.pisum,Aphis glycines and Aphis gossypii share 94.28% identity in amino acid sequences.Moreover,conserved motifs were analyzed using the annotated homologous Or23 from eight aphid species,providing further proof of the high conservation level of the Or23 clade.According to the tissue expression pattern analysis,ApisOr23 was mainly expressed in the antennae.Further functional study using a heterologous Xenopus expression system revealed that ApisOr23 was tuned to five plant volatiles,namely trans-2-hexen-1-al,cis-2-hexen-1-ol,1-heptanol,4’-ethylacetophenone,and hexyl acetate.Among them,trans-2-hexen-1-al,which is one of the main volatile organic compounds released from legume plants,activated the highest response of ApisOr23.Our findings suggest that the conserved Or23 clade in most aphid species might play an important role in host plant detection. 展开更多
关键词 Acyrthosiphon pisum odorant receptor phylogenetic analysis two-electrode voltage clamp trans-2-hexen-1-al
下载PDF
Synthesis and Crystal Structure of Cobalt(II) Complex [Co(H_2O)_2(bpe)(OAc)_2]·4,4'-dpdo
12
作者 ZHAOQi-Huaa LIHui-Qiong FANGRui-Bin 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2004年第11期1305-1307,共3页
The reaction of Co(OAc)2 with bpe and 4,4?-dpdo in an aqueous-alcohol solution affords the formation of red crystals of [Co(H2O)2(bpe)(OAc)2]?4,4?-dpdo (bpe = trans-1,2-bis(4- pyridyl)ethylene, 4,4?-dpdo = 4,4?-dipyri... The reaction of Co(OAc)2 with bpe and 4,4?-dpdo in an aqueous-alcohol solution affords the formation of red crystals of [Co(H2O)2(bpe)(OAc)2]?4,4?-dpdo (bpe = trans-1,2-bis(4- pyridyl)ethylene, 4,4?-dpdo = 4,4?-dipyridyl N,N?-oxide). The molecular and crystal structures were determined by single-crystal X-ray diffraction. The crystal is of triclinic, space group P1 with a = 7.6146(9), b = 8.6691(11), c = 10.3440(11) ?, α = 88.311(3), β = 76.992(3), γ = 75.809(3)°, V = 644.76(13) ?3, Z = 1, C26H28CoN4O8, Mr = 583.45, Dc = 1.503 g/cm3, μ = 0.724 mm-1, F(000) = 303, T = 223(2) K, the final R = 0.0477 and wR = 0.1177 for 3199 observed reflections with I > 2σ(I). In the crystal the cobalt atom is six-coordinated by oxygen atoms from two carboxylic molecules, two nitrogen atoms from the bpe ligands and two water molecules, completing an octahedral geometry. The structure of the title complex consists of neutral chains containing cobalt(II) ions bridged by mutually trans bpe molecules. The adjacent chains are connected through weak hydrogen bonds to form a two-dimensional structure. 展开更多
关键词 cobalt complex trans-1 2-bis(4-pyridyl)ethylene crystal structure
下载PDF
Use of Cucurbit [6] Uril as a Modifier in the Electrochemical Determination of Antitumor Platinum (II) Complex: <i>Trans</i>-[PtCl<sub>2</sub>(Dimethylamine) (Isopropylamine)]. Application to Biological Samples
13
作者 Carmen S. H. Domínguez Pedro Hernández 《American Journal of Analytical Chemistry》 2013年第6期314-322,共9页
A square wave voltammetry (DPV) method for trans-Pt[Cl2(Dimethylamine)(isopropylamine)] determination is developed. To this end, all the chemical and instrumental variables affecting the determination of trans-Pt[Cl2(... A square wave voltammetry (DPV) method for trans-Pt[Cl2(Dimethylamine)(isopropylamine)] determination is developed. To this end, all the chemical and instrumental variables affecting the determination of trans-Pt[Cl2(Dimethylamine) (isopropylamine)] are optimized. From studies of the mechanisms governing the electrochemical response of trans-Pt[Cl2(Dimethylamine)(isopropylamine)], it was concluded that it was an electrochemically reversible system with an adsorptive oxidation phenomenon. Under optimal conditions, the variation of analytical signal (Ip) with trans-Pt[Cl2(Dimethylamine)(isopropylamine)] concentration was linear in the 0.05 μg·mL-1 to 10 μg·mL-1 range, with a LOD 91 μg·mL-1 of and a LOQ of 303 μg·mL-1, a RSD 1.10% and Er 0.72%. The optimized method was applied to the determination of trans-Pt[Cl2(Dimethylamine)(isopropylamine)] in biological fluids, in human urine and synthetic urine. 展开更多
关键词 trans-[PtCl2(Dimethylamine)(Isopropylamine)] Differential Pulse VOLTAMMETRY (DPV) Square Wave VOLTAMMETRY (SWV) Biological Fluids Human Urine
下载PDF
皂角刺中黄酮类化学成分的分离鉴定 被引量:21
14
作者 李万华 李琴 +1 位作者 王小刚 赵文明 《西北大学学报(自然科学版)》 CAS CSCD 北大核心 2005年第6期763-765,770,共4页
目的研究中药材皂角刺中黄酮类化合物化学成分。方法用溶剂萃取、反复柱层析方法,分离纯化皂角刺中黄酮类化合物,通过NMR,MS等波谱技术确定其化学结构,并进行细胞模型的体外活性筛选。结果从皂角刺中分离得到两种黄酮类化合物,结构鉴定... 目的研究中药材皂角刺中黄酮类化合物化学成分。方法用溶剂萃取、反复柱层析方法,分离纯化皂角刺中黄酮类化合物,通过NMR,MS等波谱技术确定其化学结构,并进行细胞模型的体外活性筛选。结果从皂角刺中分离得到两种黄酮类化合物,结构鉴定为(+)trans-2R,3R-3′,4′,5,7-tetrahydroxyflavanonol(1)和8-C-glucopyranosyl-3,4′,7-trihydroxyflavone(2),化合物2显示出明显的组织蛋白酶B抑制活性(CAT-B模型)。结论该两种化合物均为首次从皂角刺中分离得到的单体黄酮类化合物,且发现化合物2具有组织蛋白酶B抑制活性。 展开更多
关键词 皂角刺 (+)trans-2R 3R-3’ 4’ 5 7-tetrahydroxyflavanonol 8-C—glucopyranosyl-3 4’ 7-trihydroxyflavone
下载PDF
炔丙型硫Ylide环丙烷化反应及其立体选择性 被引量:1
15
作者 刘文剑 路慧哲 +5 位作者 肖玉梅 王明安 杜凤沛 付滨 李楠 覃兆海 《高等学校化学学报》 SCIE EI CAS CSCD 北大核心 2009年第7期1357-1360,共4页
炔丙型硫Ylide与丙烯酸酯的反应是一个多反应竞争的复杂反应,通常环丙烷化产物收率很低.本文通过对反应底物的优化,成功获得了高收率、高选择性的反式环丙烷化产物.同时利用Gaussian 03程序,选择密度泛函BHHLYP方法,6-31G**基组对反应... 炔丙型硫Ylide与丙烯酸酯的反应是一个多反应竞争的复杂反应,通常环丙烷化产物收率很低.本文通过对反应底物的优化,成功获得了高收率、高选择性的反式环丙烷化产物.同时利用Gaussian 03程序,选择密度泛函BHHLYP方法,6-31G**基组对反应路径及过渡态模型进行了计算,进而采用密度泛函理论中的B3LYP方法,选择6-31G**基组,对顺、反式产物的热稳定性进行了分析,明确了该反应的高非对映选择性是由过渡态的能量差异和产物的热稳定性两个因素共同决定的,而过渡态的能量差异可以归于分子内弱的立体电子效应的不同. 展开更多
关键词 环丙烷化反应 炔丙型硫Ylide trans-2-乙炔基环丙烷羧酸酯 密度泛函理论 过渡态
下载PDF
Powdered activated carbon adsorption of two fishy odorants in water: Trans,trans-2,4-heptadienal and trans,trans-2,4-decadienal 被引量:10
16
作者 Xin Li Jun Wang +1 位作者 Xiaojian Zhang Chao Chen 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2015年第6期15-25,共11页
Powdered activated carbon(PAC) adsorption of two fishy odorants, trans,trans-2,4-heptadienal(HDE) and trans,trans-2,4-decadienal(DDE), was investigated. Both the pseudo first-order and the pseudo second-order ki... Powdered activated carbon(PAC) adsorption of two fishy odorants, trans,trans-2,4-heptadienal(HDE) and trans,trans-2,4-decadienal(DDE), was investigated. Both the pseudo first-order and the pseudo second-order kinetic models well described the kinetics curves, and DDE was more readily removed by PAC. In isotherm tests, both Freundlich and Modified Freundlich isotherms fitted the experimental data well. PAC exhibited a higher adsorption capacity for DDE than for HDE, which could be ascribed to the difference in their hydrophobicity. The calculated thermodynamic parameters(ΔG^0, ΔH^0, and ΔS^0) indicated an exothermic and spontaneous adsorption process. PAC dosage, p H, and natural organic matter(NOM) presence were found to influence the adsorption process. With increasing PAC dosage, the pseudo first-order and pseudo second-order rate constants both increased. The value of p H had little influence on HDE or DDE molecules but altered the surface charge of PAC, and the maximum adsorption capacity occurred at p H 9. The presence of NOM, especially the fraction with molecular weight less than1 k Dalton, hindered the adsorption. The study showed that preloaded NOM impaired the adsorption capacity of HDE or DDE more severely than simultaneously fed NOM did. 展开更多
关键词 Adsorption mechanism Drinking water Trans trans-2 4-decadienal Trans trans-2 4-heptadienal
原文传递
分离提取马蔺子中的化合物 被引量:1
17
作者 侯微 《黑龙江科技信息》 2012年第11期28-28,共1页
目的:分离提取马蔺子中的活性化合物。方法:使用硅胶柱层析梯度洗脱分离化合物,制备型高效液相进一步纯化化合物。结果:从马蔺子中首次分离出白藜芦醇四聚体(r-2-viniferin)和白藜芦醇二聚体(trans-ε-viniferin)。马蔺子是鸢尾科植物... 目的:分离提取马蔺子中的活性化合物。方法:使用硅胶柱层析梯度洗脱分离化合物,制备型高效液相进一步纯化化合物。结果:从马蔺子中首次分离出白藜芦醇四聚体(r-2-viniferin)和白藜芦醇二聚体(trans-ε-viniferin)。马蔺子是鸢尾科植物马蔺的种子,具有清热,利湿,止血,解毒。治黄疸,泻痢,吐血,衄血,血崩,白带,喉痹,痈肿等作用[1,2]。本文使用硅胶柱层析从马蔺子中分离出了白藜芦醇四聚体和二聚体,制备型高效液相纯化这两种化合物,结合液相质谱和核磁共振解析出其化合物的结构。之前很多研究已经发现这两种化合物存在葡萄科等植物中[3],这是首次在马蔺子中提取出来。 展开更多
关键词 马蔺子 r-2-viniferin trans-ε-viniferin
下载PDF
Green,mild and efficient bromination of aromatic compounds by HBr promoted by trans-3,5-dihydroperoxy-3,5-dimethyl-1,2-dioxolane in water as a solvent 被引量:1
18
作者 Kaveh Khosravi Samira Kazemi 《Chinese Chemical Letters》 SCIE CAS CSCD 2012年第4期387-390,共4页
A combination of HBr and trans-3,5-dihydroperoxy-3,5-dimethyl-1,2-dioxolane as anew and powerful oxidant was found effective for facile brotnination of different aromatic compounds at room temperature in water as a gr... A combination of HBr and trans-3,5-dihydroperoxy-3,5-dimethyl-1,2-dioxolane as anew and powerful oxidant was found effective for facile brotnination of different aromatic compounds at room temperature in water as a green solvent.Mild reaction conditions,high selectivity and yield,high reaction rate and non-toxicity are some of the major advantages of this synthetic protocol. 展开更多
关键词 trans-3 5-dihydroperoxy-3 5-dimethyl-1 2-dioxolane HBR BROMINATION Anilines Phenoles
原文传递
Crystal structure of trans-3-phenyl-2-propenoic acid
19
作者 Yucui Ma Liang Xu +1 位作者 Cui Wu Zhimao Chao 《Journal of Chinese Pharmaceutical Sciences》 CAS CSCD 2018年第9期644-648,共5页
The title compound of trans-3-phenyl-2-propenoic acid (C9H802), a main active organic acid of cinnamon bark and styrax, was obtained by oxidization from trans-3-phenyl-2-propenaldehyde and characterized by X-ray dif... The title compound of trans-3-phenyl-2-propenoic acid (C9H802), a main active organic acid of cinnamon bark and styrax, was obtained by oxidization from trans-3-phenyl-2-propenaldehyde and characterized by X-ray diffraction analysis. It crystallizes in monoclinic system, space group P21/n with a = 5.55916(10), b = 17.4870(3), c = 7.70677(13) A, V = 744.89(2) A3, Z= 4, Dc= 1.321 g/cm3, Mr = 148.15, F(000) = 312, and/t μ=0.764 mm-1. A total of 2661 reflections with 1447 unique ones (Rint = 0.0137) were collected, in which 1447 were observed (I〉2σ(/)). There were two C9H802 molecules in an asymmetric unit. The structural unit was a dimer formed by the hydrogen bonding of the oxygen atom of carbonyl group and the hydrogen atom of hydroxyl group. A 3D layer structure was formed through hydrogen bonds and Van der Walls' forces. 展开更多
关键词 trans-3-Phenyl-2-propenoic acid Crystal structure Organic acid Layer structure
原文传递
Investigation on the Coordinate Structures of the Rare Earth Metal Complexes with Edta and Cydta Ligands
20
作者 Wang Jun, Zhang Xiang-dong, Zhang Yang, Liu Zhen-rong Department of Chemistry, Liaoning University, Shenyang 110036, Liaoning, China 《Wuhan University Journal of Natural Sciences》 CAS 2003年第04A期1131-1137,共7页
The crystal and molecular structures of cydta (trans-1, 2-cyclohexanediaminetetraacetic acid) have been determined by single\|crystal X-ray structure analyses. The reasons that RE Ⅲ -edta and RE Ⅲ -cydta compl... The crystal and molecular structures of cydta (trans-1, 2-cyclohexanediaminetetraacetic acid) have been determined by single\|crystal X-ray structure analyses. The reasons that RE Ⅲ -edta and RE Ⅲ -cydta complexes select different coordinate structures were discussed and illustrated through the comparison of the molecular and crystal structures between edta and cydta, (NH_ 4 )\[Y Ⅲ (edta)(H_ 2 O)_ 3 \]\55H_ 2 O and (NH_ 4 )\[Y Ⅲ (cydta)(H_ 2 O)_ 2 \]\55H_ 2 O as well as (NH_ 4 )\[Gd Ⅲ (edta)(H_ 2 O)_ 3 \]\55H_ 2 O and (NH_ 4 )\[Gd Ⅲ (cydta) (H_ 2 O) _ 2 \]\55H_ 2 O complexes. 展开更多
关键词 rare earth edta (ethylenediaminetetraacetic acid) cydta (trans-1 2-cyclohexanediaminetetraacetic acid) COMPLEXES coordinate structures
下载PDF
上一页 1 2 下一页 到第
使用帮助 返回顶部