具有阳离子表面活性ATRP引发剂的合成

以2-溴异丁酰溴、2-溴乙醇、6-氯-1-己醇及N,N-二甲基正十二烷基胺为主要原料,分别通过两步或三步反应合成了具有阳离子表面活性的原子转移自由基聚合(ATRP)引发剂——N-[2-(2-溴-2-甲基丙酰氧基)乙基]-N,N-二甲基正十二烷基溴化铵或N-[6-(2-溴-2-甲基丙酰氧基)己基]-N,N-二甲基正十二烷基碘化铵,其结构经1H NMR,13C NMR,IR和元素分析表征。     

C(2)-酰胺基-4-芳基-1,5-苯并硫氮杂的合成及抑菌活性的研究

设计合成了三类C(2)酰胺基取代的1,5-苯并硫氮杂衍生物:2-酰胺基(N-芳基)-4-芳基-1,5-苯并硫氮杂、2-酰胺基(N-烷基)-4-芳基-1,5-苯并硫氮杂和2-酰胺基(N,N-二烷基)-4-芳基-1,5-苯并硫氮杂,其结构用元素分析,IR,MS及1H NMR确证.测定了目标化合物的抑真菌活性,结果表明部分化合物对新生隐球菌具有中等强度的抑真菌活性.还研究了2-酰胺基-4-芳基-1,5-苯并硫氮杂的合成反应条件.     

N-甲基丙烯酰-N′-嘧啶基哌嗪及其聚合物敏化的丙烯腈光聚合

我们曾报道过同一分子中含有给电子生色基团和电子受体基团的一类功能性单体,如甲基丙烯酸-4-N,N-二甲氨基苄酯(DMABMA),N-(4-N′,N′-二甲氨基苯基代丙烯酰胺,N-(4-N′、N′)-二甲氨基苯基代甲基丙烯酰胺(DMAPMA),8-丙烯酰氧喹啉(AQ),N-丙烯酰-N′-苯基哌嗪(APP)的合成、聚合以及单独或与过氧化二酰构成氧化还原体系以引发烯类单体的聚合研究。N-甲基丙烯酰-N′-嘧啶基哌嗪(MPMP)     

含荧光基团的烯类单体的合成、聚合及其荧光行为

本论文合成了三个新型功能单体,即N-(4-N’,N’-二甲氨基苯基)马来酰亚胺(DMAPMI)、N-(4-N’,N’-二甲氨基苯基)衣糠酰亚胺(DMAPII)和N-(2-乙烯氧乙基)-1,8-萘二甲酰亚胺(VOENI),研究了它们的聚合、引发、光敏化作用及荧光行为。     

N-芳基马来海枞酸单甲酯二酰亚胺位阻异构化反应及其动力学特性

在合成松香基手性试剂(4a~4f)的过程中,首次发现N-(1-萘基)-马来海枞酸二酰亚胺(4f)的位阻异构现象,而与其结构类似的N-苯基-马来海枞酸二酰亚胺(4a)、N-(2-羧基苯基)-甲酯化马来海松酸二酰亚胺(4b)、N-(2-硝基苯基)-甲酯化马来海松酸二酰亚胺(4c)、N-(2-氯苯基)-甲酯化马来海松酸二酰亚胺(4d)和N-[1-(2-氨基)-苯基]-甲酯化马来海松酸二酰亚胺(4e)则没有该位阻异构现象.化合物4a~4f的结构通过核磁共振、质谱和红外光谱等方法进行了表征.采用变温条件下的1H NMR谱图研究了化合物4f的位阻异构化动力学特性.     

双核铁(Ⅱ)配合物的合成、晶体结构及与分子氧反应性能

合成了一个双核铁(Ⅱ)配合物[Fe2L{O2P(OPh)2}](ClO4)2Et2O(1) (L表示双核配体: N-Et-HPTB, N, N, N′, N′-四双(N-乙基-2-苯并咪唑甲基) -2-羟基-1, 3-二氨基丙烷). 测定了其晶体结构, 三斜晶系, 空间群P1, a = 1.526 8(3) nm, b = 1.259 8(3) nm, c = 1.563 0(3) nm, α = 94.41(3)°,β = 115.31(3)°, β = 99.90(3)°, V = 3.267(1) nm3 , Z = 2; R = 0.084 7, Rw = 0.177 8. Fe(Ⅱ)离子被一个烷氧原子和一个磷酸酯桥联, Fe-μ-O-Fe 键角为131.20(3)°, Fe-Fe距离为0.364 9 nm. 两个Fe(Ⅱ)均具有三角双锥几何构型. 低温下(-60℃) Fe(Ⅱ)配合物与分子氧反应生成稳定的分子氧加合物1/O2, 该加合物展示可见吸收光谱最大在606 nm, 共振Raman光谱显示两个特征吸收带, 478((Fe-O)和897 cm-1((O-O). 后者是 μ-1,2-peroxo物种的典型特征. 即在低温下铁(Ⅱ)配合物与分子氧生成了过氧化物桥联的双核铁(Ⅲ)氧加合物. 模拟了生物体内某些非血红素蛋白的活性中心的结构和功能.     

12-钨磷酸钙与丁二酰亚胺加合物的制备和性质研究

本文研究了12-钨磷酸钙与丁二酰亚胺和邻苯二甲酰亚胺的加合反应,制备了12-钨磷酸钙的丁二酰亚胺加合物Ca_(3/2)PW_(12)O_(40)·4(CH_2CO)_2NH·7H_2O,测定了加合物的红外光谱、拉曼光谱和热重差热分析曲线,用X射线粉末衍射方法研究了加合物的结晶学特征.结果表明.配体丁二酰亚胺以一个羰基氧与金属阳离子配位,加合物的形成对杂阴离子的Kcggin结构没有明显影响.但WO_6八面体发生一定的畸变.其中W-O_d键减弱,W-O_c键增强.加合物属单斜晶系,晶胞参数为:a=25.839(6).b=13.223(2),c=18.438(2)(?),β=97.06(2)°,V=6251.88(?)~3,可能的空间群为C_2h~5-P2_1/c或C_2h~2-P2_1/m或C_2~2-P2_1,品质因子F_(30)=54(0.012,45).     

具有Gemini表面活性ATRP引发剂的合成

以2-溴异丁酰溴、N,N-二甲基乙醇胺、1,6-二溴己烷为主要原料,通过两步反应合成了一种新型具有Gemini表面活性的ATRP引发剂——N1,N6-双[2-(2-溴异丁酰氧基)乙基]-N1,N1,N6,N6-四甲基己烷-1,6-二溴化铵,总收率70%,其结构经1H NMR,IR和元素分析表征。     

用N-苯甲酰β-苯胲乙酸酯均匀沉淀鈮及沉淀的组成

利用N-苯甲酰β-苯胺乙酸酯在酒石酸溶液中的水解作用,可以自均匀溶液析出結晶状的N-苯甲酰β-苯胲-鈮絡合物。在65—70°加热二小时可定量沉淀,此时溶液的pH值自8.0降至5.0,放置过夜后沉淀的粗成为NbO(C_(13)H_(10)O_2N)_3。 N-苯甲酰β-苯胲乙酸酯可由BPHA的吡啶溶液与乙酸酐制得。     

1,1,1-三氯-2-取代肼基-3-硝基丙烷及其衍生物的合成

叙述了以1,1,1-三氯-2-乙酰氧基-3-硝基丙烷和1,1,1-三氯-2-肼基-3-硝基丙烷为原料,合成脂肪和芳香肼类、酰肼类、偶氮类以及腙类等四十三个新化合物的方法,将N-芳基-N'-[2-(1,1,1-三氯-3-硝基)丙基]肼用N-溴代丁二酰亚胺氧化成1,1-二氯-2-芳偶氮基-3-硝基丙烯后,不经分离直接加入过量的醇和定量的水继续反应,可方便地获得β-硝基丙酮酸酯腙类化合物,收率达60%以上。初步抑菌活性测定结果表明,大多数化合物呈现不同程度的抑菌活性,其中以肼类和偶氮类化合物的活性最高,丙酮酸酯腙类化合物次之。     

The Reaction of 2-Methylindole with Pyruvic Acid

The reaction of 2-methylindole with pyruvic acid was studied. Two products are found to be depending on experimental conditions, including the 2:2 condensation adduct and the 2:1 condensation adduct. The reaction mechanism evidently involves a 1:1 adduct of 2-hydroxy-2-(2-methylindol-3-yl)-propionic acid as an intermediate.     

β-环糊精构筑氨基酸氧化酶的研究

报道了用β-环糊精二间羧基苯磺酸酯与三氯化铁形成的配合物的构筑模拟氨基酸氧化酶, 将苯丙氨酸氧化脱氨生成苯丙酮酸, 在过量H2O2的存在下, 苯丙酮酸进一步被氧化脱羧生成苯乙酸, 若此反应体系是在N, N-二甲基甲酰胺(以下缩写DMF)的弱碱性条件下, 反应则是将苯氨酸氧化成酪氨酸。     

SF(4)·N(C(2)H(5))(3): the first conclusively characterized SF(4) adduct with an organic base

Sulfur tetrafluoride and triethylamine react at low temperatures to form a 1?:?1 adduct. The unambiguous characterization of the SF(4)·N(C(2)H(5))(3), which is only stable at low temperature, proves the Lewis acid property of SF(4) towards organic Lewis bases. The S-N bond has a length of 2.384(2) ? and is an archetypical example of a dative S(IV)← N bonding modality.     

Pork Heart Tissue‐Based Chemiluminescence Biosensor for Pyruvic Acid

Abstract

A novel chemiluminescence (CL) animal tissue‐based sensor for pyruvic acid is presented in this paper. Pork heart tissue was chopped into small pieces and packed into a mini‐glass column as the recognition element. When pyruvic acid passed through the column, hydrogen peroxide was produced under the catalytic oxidation of oxygen by pyruvic acid oxidase present in the pork heart tissue. This produced hydrogen peroxide could react with luminol in alkaline solution to produce chemiluminescence in the presence of potassium hexacyanoferrate(III). The developed sensor system promises simplicity, fastness, stability, and sensitivity. Under the optimum conditions, CL intensities are proportional to the concentration of pyruvic acid in the range of 0.02–12 µmol/L, with a detection limit of 0.004 µmol/L (3σ). RSD is 2.3% for 0.5 µmol/L pyruvic acid (n=11). The sensor could be stable for 150 min by more than 100 times determination. The proposed method has been applied successfully to the analysis of pyruvic acid in biological samples. The results obtained by the proposed method are consistent with those obtained by spectrophotometry.     

Pb-Pt/AC催化甘油一步法制备丙酮酸

生物质能具有绿色环保、可再生、来源广泛和安全性高等优点,成为当前的研究热点.作为生物柴油的主要副产物,甘油是一种重要的生物质平台化合物.甘油的高效利用,不仅能够获得重要的精细化学品及聚合物,也可以延长生物柴油的产业链,降低其生产成本,增加其市场竞争力.丙酮酸是一种弱有机酸,为生物体内葡萄糖分解代谢的中间产物,在生物能量代谢和物质代谢过程中起着重要的枢纽作用.同时,由于它同时含有羧基和酮羰基,具有很强的反应性,可参与多种化学反应,在化学工业中有广泛应用.目前,工业上主要采用酒石酸脱水脱羧法生产丙酮酸,丙酮酸收率可达50–55%,但生产过程需要消耗大量的KHSO4粉末,生产成本高,且高耗能高污染,不符合可持续发展的要求.因此,利用可再生资源甘油在温和条件下生产丙酮酸显现出良好的应用前景.目前,由甘油一步法获得丙酮酸仅可通过发酵法实现,但是其规模化生产存在效率低、废弃物污染等问题.因此,研究化学方法由甘油一步制备丙酮酸可行也十分必要.本课题组以Pt/AC或Cu-Pt/AC为催化剂进行甘油氧化制备乳酸的研究,所得产物中几乎未检出丙酮酸;当以Pb-Pt/C为催化剂进行乳酸脱氢氧化制备丙酮酸,可获得较高选择性的丙酮酸.因此,本文通过向Pt/AC催化剂中引入Pb助剂,以期调变甘油氧化的产物分布,从而获得相对高的丙酮酸选择性.通过浸渍-沉积沉淀法(Im-DP)制备了一系列不同Pb载量(1–7.0 wt%)的xPb-5Pt/AC-Im-DP催化剂,并采用不同方法制备了一系列5Pb-5Pt/AC催化剂,用于在温和条件下甘油选择性氧化制备丙酮酸反应中.结果表明,Pb载量和催化剂制备方法都对其催化活性有显著影响.当xPb-5Pt/AC-Im-DP催化剂中Pb载量为1%时,甘油转化率和丙酮酸选择性均较单金属5Pt/AC催化剂高,但当Pb载量继续升高至3%及以上时,甘油转化率明显下降.我们推测这与Pb3(CO3)2(OH)2物种的形成有关.采用该方法制备催化剂时,Pb载量宜为5.0 wt%.保持Pt和Pb载量均为5.0 wt%,采用共沉积沉淀(Co-DP)、共浸渍(Co-Im)、以及对催化剂进行500oC氩气焙烧等,制备了具有Pb3(CO3)2(OH)2物种、铂铅合金物种(PtPb和PtxPb)和两物种均没有的5Pb-5Pt/AC催化剂.通过评价它们的催化性能,进一步探究了Pb3(CO3)2(OH)2物种、铂铅合金物种、表面金属价态与催化剂活性的关系.实验表明,Pb3(CO3)2(OH)2和表面Pb0物种不利于甘油的转化,铂铅合金对甘油转化有一定的促进作用,对丙酮酸生成显现出明显促进作用.通过对Co-DP、Im-DP催化剂进行500oC氩气焙烧,能够除去Pb3(CO3)2(OH)2物种,同时形成铂铅合金.综上,本文在温和条件下,采用Pb-Pt/AC催化剂进行甘油选择性氧化制备丙酮酸反应.采用优化的方法制备的5Pb-5Pt/AC催化剂在90oC条件下反应10 h,丙酮酸收率可达18.4%,这是目前甘油一步法氧化制备丙酮酸的最高值.进一步优化反应条件、催化剂组成与结构,探索反应机理仍十分必要.     

Oxidation with permanganate in strong alkaline medium. Oxidation of pyruvic and lactic acids

The reaction of permanganate ion with pyruvic acid and lactic acid has been studied in aqueous solutions containing 0.10–2.0 mol dm^?3 alkali. In this range of HO^? concentration the reaction is followed slowly by the reduction of manganate, thus, the above process can be studied separately. In the case of lactic acid (LA), the reactive species is alkoxy anion, and the deprotonation constant could be calculated from the kinetic data. A mechanism based on electron abstraction from the alkoxy anion has been proposed. In the case of pyruvic acid (PA) oxidation may proceed with participation of enolate anion, or hydrate anion, or an adduct. These three possibilities have been investigated. © John Wiley & Sons, Inc.     

Characterisation of estrone-nucleic acid adducts formed by reaction of 3,4-estrone-o-quinone with 2'-deoxynucleosides/deoxynucleotides using capillary liquid chromatography/electrospray ionization mass spectrometry

Xenobiotic and endobiotic molecules can react with DNA leading to formation of so-called DNA adducts. This modified DNA can be repaired enzymatically, but, if not, these modifications are believed to be responsible for the initiation of carcinogenic processes. Hence, we studied the interaction of 2'-deoxynucleosides and 2'-deoxynucleotides with 3,4-estronequinone (3,4-E(1)Q), a metabolite of estrone (E(1)) and a supposed carcinogen. These estrone-nucleic acid adducts were analysed by capillary liquid chromatography (CapLC) coupled to electrospray ionization mass spectrometry (ESI-MS). Knowledge of their behaviour from in vitro studies is a prerequisite for detecting adducts in in vivo studies. Our initial attempts to synthesise nucleos(t)ide adducts of 3,4-E(1)Q in an aprotic solvent (dimethylformamide) yielded no adducts. However, under acidic aqueous conditions, adducts were obtained. With dGuo, a dGuo adduct was found in addition to a Gua adduct. Earlier publications on adduct formation in protic solvents failed to report formation of any adduct with dAdo. A N(3)-Ade adduct was reported upon reaction of 3,4-E(1)Q with Ade base and with DNA. With dAdo, we obtained two nucleoside adducts and six Ade adducts due to loss of 2'-deoxyribose. Thus, contrary to general belief that only 2,3-E(1)Q can form stable adducts, we showed formation of substantial amounts of intact DNA adducts with 3,4-E(1)Q in addition to deglycosylated adducts. Adducts were also obtained with dGMP and dAMP, but no phosphate alkylation was found. Adducts of dCyd, dCMP, dThd, and dTMP were not detected. Using chromatographic-MS data a structural relationship between the 2'-deoxynucleoside, 2'-deoxynucleotide and base adducts was found in the various reaction mixtures. The adducts of dGuo and dGMP reaction mixtures were alkylated at the same N(7)-position of the nucleobase, as indicated by the occurrence of a rapid deglycosylation reaction. In dAdo and dAMP reaction mixtures, 14 adducts were detected; their relationships from the LC and MS data reduced the number of structures to six adenine base alkylated adducts with respect to alkylation between N(1), N(3), N(7) and/or N(6) in the adenine and C(1), C(2) and/or C(6) in 3,4-E(1)Q. We could infer, in addition, whether they had an A ring attachment or a C(6) attachment on the estrone moiety.     

Electrochemical Determination of Salivary N‐Acetylneuraminic Acid by Miniaturized Capillary Electrophoresis Coupled with Sample Stacking

Due to their important biological role as markers for different pathologies, sialic acid (SA) analyses are important for clinical research. In this work, a miniaturized capillary electrophoresis with amperometric detection (mini‐CE‐AD) was developed for the determination of N‐acetylneuraminic acid (NANA), which is the most widespread form of SAs. NANA was first oxidized by periodic acid in an acidic solution, and then the oxidation product β‐formyl pyruvic acid was derivatized with electroactive 2‐thiobarbituric acid (TBA) to form an electroactive NANA‐TBA adduct, which could be readily determined by mini‐CE‐AD. The limit of detection (LOD) of NANA‐TBA could achieve 0.50 µg/mL (1.6 µmol·L^?1, S/N=3) based on an online enrichment approach of moving chemical reaction boundary. The proposed method was successfully applied to the analysis of NANA in human saliva, and the recoveries were in the range of 91.8% –109% with RSDs of 1.8% –3.9%. Due to its simple design and construction, low cost and portability, the mini‐CE‐AD device will possess more practicability in more field work as an alternative to conventional and microchip CE approaches.     

S-oxygenation of thiocarbamides II: Oxidation of trimethylthiourea by chlorite and chlorine dioxide

The kinetics of the oxidation of a substituted thiourea, trimethylthiourea (TMTU), by chlorite have been studied in slightly acidic media. The reaction is much faster than the comparable oxidation of the unsubstituted thiourea by chlorite. The stoichiometry of the reaction was experimentally deduced to be 2ClO2- + Me2N(NHMe)C=S + H2O --> 2Cl- + Me2N(NHMe)C=O + SO4(2-) + 2H+. In excess chlorite conditions, chlorine dioxide is formed after a short induction period. The oxidation of TMTU occurs in two phases. It starts initially with S-oxygenation of the sulfur center to yield the sulfinic acid, which then reacts in the second phase predominantly through an initial hydrolysis to produce trimethylurea and the sulfoxylate anion. The sulfoxylate anion is a highly reducing species which is rapidly oxidized to sulfate. The sulfinic and sulfonic acids of TMTU exists in the form of zwitterionic species that are stable in acidic environments and rapidly decompose in basic environments. The rate of oxidation of the sulfonic acid is determined by its rate of hydrolysis, which is inhibited by acid. The direct reaction of chlorine dioxide and TMTU is autocatalytic and also inhibited by acid. It commences with the initial formation of an adduct of the radical chlorine dioxide species with the electron-rich sulfur center of the thiocarbamide followed by reaction of the adduct with another chlorine dioxide molecule and subsequent hydrolysis to yield chlorite and a sulfenic acid. The bimolecular rate constant for the reaction of chlorine dioxide and TMTU was experimentally determined as 16 +/- 3.0 M(-1) s(-1) at pH 1.00.     

Reactions of 9-substituted guanines with bromomalondialdehyde in aqueous solution predominantly yield glyoxal-derived adducts

Reactions of 9-ethylguanine, 2'-deoxyguanosine and guanosine with bromomalondialdehyde in aqueous buffers over a wide pH-range were studied. The main products were isolated and characterized by (1)H and (13)C NMR and mass spectroscopy. The final products formed under acidic and basic conditions were different, but they shared the common feature of being derived from glyoxal. Among the 1 : 1 adducts, 1,N(2)-(trans-1,2-dihydroxyethano)guanine adduct (6) predominated at pH < 6 and N(2)-carboxymethylguanine adduct (10a,b) at pH > 7. In addition to these, an N(2)-(4,5-dihydroxy-1,3-dioxolan-2-yl)methylene adduct (11a,b) and an N(2)-carboxymethyl-1,N(2)-(trans-1,2-dihydroxyethano)guanine adduct (12) were obtained at pH 10. The results of kinetic experiments suggest that bromomalondialdehyde is significantly decomposed to formic acid and glycolaldehyde under the conditions required to obtain guanine adducts. Glycolaldehyde is oxidized to glyoxal, which then modifies the guanine base more readily than bromomalondialdehyde. Besides the glyoxal-derived adducts, 1,N(2)-ethenoguanine (5a-c) and N(2),3-ethenoguanine adducts (4a-c) were formed as minor products, and a transient accumulation of two unstable intermediates, tentatively identified as 1,N(2)-(1,2,2,3-tetrahydroxypropano)(8) and 1,N(2)-(2-formyl-1,2,3-trihydroxypropano)(9) adducts, was observed.