虾肉中呋喃它酮代谢物化学发光酶免疫分析方法的建立

采用对碘苯酚增强的HRP-鲁米诺-H2O2化学发光体系,建立了虾肉中呋喃它酮代谢物5-吗啉甲基-3-氨基-2-恶唑烷基酮(AMOZ)残留的间接竞争化学发光酶免疫分析(icCLEIA)检测方法。检测所用抗体是基因重组的抗AMOZ衍生物单链抗体。优化的icCLEIA最佳工作条件为:AMOZA-OVA包被浓度62.5μg/L,抗AMOZ衍生物单链抗体最佳稀释度为1∶10,竞争免疫反应时间45 min,HRP酶标记羊抗鼠抗体最佳稀释度为1∶10000,孵育时间50 min。本方法的IC50为1.38μg/L;灵敏度为0.09μg/L;线性范围为0.26～9.08μg/L(IC20～IC80);批内和批间相对标准偏差均小于15%;抗AMOZ衍生物单链抗体与其它硝基呋喃类抗生素及其代谢物均没有交叉反应,特异性良好。4个不同添加量的AMOZ加标样品的平均回收率分别为72.2%,73.4%,72.6%和78.6%。与HPLC-MS/MS法测定值进行比较发现,两种方法相关性良好(R2=0.9997)。本方法可用于水产品中AMOZ残留的快速检测。     

呋喃它酮代谢物时间分辨荧光免疫分析法的建立与应用

建立了Eu3+标记的间接竞争时间分辨荧光免疫分析法( Indirect competitive time-resolved fluoroimmu-noassay , ic-TRFIA)用于鱼肉样品中呋喃它酮代谢物AMOZ的检测。通过单因素实验考察了包被抗原浓度、抗体稀释倍数、竞争反应时间等参数对方法灵敏度的影响。结果表明,ic-TRFIA的最佳反应条件为：包被抗原浓度为0.25μg/mL,抗体稀释5×104倍,最佳竞争时间为50 min。在优化的条件下,方法的检出限( LOD, IC10)为0.01 ng/mL,半抑制浓度(IC50)为0.26 ng/mL,线性范围(IC20~IC80)为0.025~2.83 ng/mL,对鱼样中AMOZ回收率在78.0%~86.0%之间,各样品变异系数均小于15%,与HPLC-MS/MS对比检测结果显示相关性良好。本方法灵敏度高、特异性好,能够满足实际样品的检测需求。     

化学发光酶免疫法检测猪肉中氯丙嗪残留

采用棋盘滴定法确定包被抗原浓度和抗体稀释倍数,通过单因素实验优化了竞争反应时间、磷酸盐缓冲液浓度、甲醇含量、pH值等参数,建立了氯丙嗪的间接竞争化学发光酶免疫检测方法,并考察了方法的特异性、灵敏度和稳定性.结果表明,最佳反应条件为包被抗原浓度为0.05 μg/L;氯丙嗪抗体稀释32000倍;体系缓冲液为含10％甲醇、0.1 mol/L磷酸盐缓冲液(pH 7.0).本方法的IC50为0.12 μg/L;检出限为0.02 μg/L;线性范围0.02～24.78 μg/L;批内和批间相对标准偏差均小于10％.与其它结构类似物没有明显交叉反应.猪肉检测的平均回收率为87.4％～105.6％,与高效液相色谱方法的相关性良好.本方法具有较高的灵敏度和较好的稳定性.     

细交链孢菌酮酸酶联免疫吸附分析方法研究

采用水合肼和乙醛酸依次对细交链孢菌酮酸(Tenuazonic acid,TeA)进行衍生化,设计合成了含有氮杂共轭双键偶联手臂,可增强免疫效果的半抗原TeAHGA.通过偶联载体蛋白BSA后的免疫原TeAHGABSA免疫新西兰大白兔,成功制备了特异性识别TeA水合肼衍生物TeAH的多克隆抗体;优化确立了ELISA最佳反应条件(TeAH-OVA为异源包被原、包被浓度0.156 μg/L、药物稀释及反应缓冲液为PBS、一抗反应时间40 min、二抗反应时间20 min),建立了TeA间接竞争ELISA(icELISA)检测方法,其抑制中浓度(IC50)为1.61 μg/L,检出限(LOD)为0.08 μg/L,定量线性检测范围为0.19～12.89 μg/L (IC20～IC80).番茄、面粉样品平均添加回收率分别为67.2％～89.8％和74.8％～93.7％.     

对硫磷化学发光酶联免疫吸附分析方法的建立和评价

建立了基于多克隆抗体的对硫磷间接竞争化学发光酶联免疫吸附分析方法(icCLEIA)。以三氯硫磷为原料,经三步取代反应合成对硫磷半抗原,通过活泼酯法将半抗原分别与牛血清蛋白(BSA)和卵清蛋白(OVA)偶联,制备免疫抗原和包被抗原。经免疫新西兰大白兔,获得对硫磷抗血清。通过优化条件参数,建立了对硫磷的icCLEIA分析方法。本方法的检测线性范围为0.24～15.83!g/L;半抑制浓度IC50为1.14!g/L;检出限为0.09!g/L;对蔬菜样品和水样品的平均添加回收率为74.6%～121.0%。本方法可用于实际样品中痕量对硫磷残留检测。     

免疫化学方法测定动物组织中呋喃唑酮残留标示物

以自制特异性抗体为核心试剂,建立了以苯甲醛为衍生试剂的呋喃唑酮残留标示物间接竞争ELISA方法.通过方阵滴定法和间接竞争法确定ELISA方法最佳反应条件:抗原最佳包被浓度200 μg/L,抗体最佳稀释倍数1:2.5×105,抗体与药物最佳工作配比40 μL: 60 μL,最佳竞争时间1 h.检出限为0.1 μg/L,检测范围0.1～25.6 μg/L,线性关系良好.在空白组织中(猪肌肉、猪肝脏、鸡肌肉、鸡肝脏、鱼肉)添加0.4、1.0和5.0 μg/kg AOZ,回收率55.8%～96.6%,相对标准偏差均小于20%.测定20份不同组织的空白样品,方法的检出限为0.4～0.5 μg/kg.以100 mg/kg呋喃唑酮饲喂动物,其组织样品同时经HPLC方法和本方法测定,数据表明本方法具有实际检出能力,测定结果与仪器方法的测定结果相近.通过与德国同类试剂盒比较实验表明,本方法的灵敏度、精密度、准确度接近于进口试剂盒水平,可用于动物可食性组织肝脏和肌肉中AOZ筛选.     

食品中罂栗碱金标快速检测试剂条的研究

首先以1-乙基-3-(3-二甲氨基丙基)碳二亚胺盐酸盐(EDC·HCI)方法合成罂粟碱完全抗原;通过改变还原剂加入量,确定纳米金合成条件为每50.0 ml,氯金酸加入1.5 mL柠檬酸三钠;合成金标保护剂量为20.0 mL胶体金溶胶加入1100稀释抗体(12 mg/L)2.0 mL,标记pH值为8.65.以罂粟碱多克隆抗体-纳米金复合物作为分析探针,罂粟碱完全抗原作为竞争抗原,构建分析体系.点样条件抗原质量浓度为1.0 g/L(以蛋白浓度计算);抗原点样量1 μL/条;金标点样量5 μL/条;二抗浓度(羊抗兔)3.3 g/L稀释至13 500;二抗点样量1μL/条.同时在实验中确定了样品提取方法.检测的灵敏度达到10 μg/L,检测时间不超过20 min.与ELISA方法对照结果,对比检测123份样品,准确率100%.     

高效液相色谱串联质谱法测定水体中氨基脲、5-甲基吗啉-3-氨基-2-恶唑烷基酮、1-氨基乙内酰脲和3-氨基-2-唑烷基酮

建立了高效液相色谱三重四极杆串联质谱检测水体中痕量氨基脲(SEM)、5-甲基吗啉-3-氨基-2-恶唑烷基酮(AMOZ)、1-氨基乙内酰脲(AHD)和3-氨基-2-唑烷基酮(AOZ)的分析方法。水样在pH 1.5～3条件下衍生8 h,经乙酸乙酯萃取,氮吹浓缩,流动相溶解后,内标法定量。分析条件为:CAPCELLPAK C18色谱柱,以甲醇和2 mmol/L乙酸铵(含0.1%甲酸)溶液为流动相进行梯度洗脱。结果表明:AMOZ、AHD和AOZ在0.005～1μg/L范围内,SEM在0.01～1μg/L范围内呈现良好的线性关系,相关系数均大于0.9980。AMOZ、AHD和AOZ的定性检测限和定量检测限为分别为0.0025μg/L和0.005μg/L;SEM的定性检测限和定量检测限为分别为0.005μg/L和0.01μg/L。4种化合物在水体中3个不同浓度添加水平下的平均回收率为84.9%～110.4%,相对标准偏差为1.2%～7.8%。方法可用于分析环境水体中4种化合物的残留。     

呋喃西林代谢物荧光偏振免疫检测方法研究

利用新制备的抗体首次建立了呋喃西林代谢物氨基脲(SEM)的荧光偏振免疫分析(FPIA)方法.通过设计合成新的SEM半抗原CEPSEM(2-(4-((2-carbamoylhydrazono)methyl)phenoxy)acetic acid),偶联载体蛋白后免疫新西兰大白兔,制备了亲和力高、特异性好的多克隆抗体.结合新设计合成的荧光示踪物CEPSEM-HDF建立了SEM的FPIA方法.结果表明:在示踪物浓度为0.5 nmol/L,抗体稀释度为1/100的优化条件下,IC50为47.9 μg/L,检出限为8.3 μg/L,线性范围为15.8 ～145.7 μg/L.该方法特异性强(和其它相关兽药交叉反应小于0.1%),稳定性好(批内相对标准偏差小于2.5%,批间相对标准偏差小于6.3%).     

呋喃唑酮代谢物单克隆抗体制备及酶联免疫吸附分析方法

本研究针对呋喃唑酮代谢物(AOZ),设计合成了系列半抗原,进一步通过偶联牛血清白蛋白(BSA)免疫Balb/c小鼠、细胞融合、筛选和亚克隆等过程成功获得了源于新颖半抗原H3的具有高亲和力(亲和力常数6.68× 1010L/mol)和高特异性(与其它功能类似物交叉反应小于0.1％)抗AOZ单克隆抗体.同时,基于设计合成的系列同/异源半抗原/包被抗原,考察了不同结构包被原对ELISA方法灵敏度的影响.另外,采用最佳的特征结构异源包被原H5 -OVA,建立了以对硝基苯甲醛(p-NP)为衍生剂的AOZ间接竞争ELISA(icELISA)和直接竞争ELISA(deELISA)检测方法.结果表明:icELISA模式的AOZ检测IC50为0.503 μg/L,定量检测线性范围(IC20～IG80)为0.06～14.0 μg/L,检出限(IC10)达0.017 μg/L; dcELISA模式的AOZ检测IC50为1.19 μg/L,定量检测线性范围为0.14～23.6 μg/L,检出限为0.056 μg/L.两种方法对AOZ的检测灵敏度和定量线性范围均达到相关检测限量要求,可满足不同需求的实际样品检测.     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.     

Synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives

Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.     

Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction

In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.     

CoFe2O4自形成磁性液体场致结构化对磁化的影响

The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.     

Highly regioselective Buchwald–Hartwig amination at C-2 of 2,4-dichloropyridine enabling a novel approach to 2,4-bisanilinopyridine (BAPyd) libraries

The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.     

KMnO4-mediated oxidative CN bond cleavage of tertiary amines: Synthesis of amides and sulfonamides

KMnO₄-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.     

Chemistry of heterocyclic compounds at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, over 50 years (Review)

The review contains a concise historical account and information on the most significant researches undertaken by the staff at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry of Heterocyclic Compounds. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008.     

A general and convenient synthesis of 4-(tosylmethyl)semicarbazones and their use in amidoalkylation of hydrogen,heteroatom, and carbon nucleophiles

A general synthesis of previously unknown semicarbazone-based α-amidoalkylating reagents, 4-(tosylmethyl)semicarbazones, has been developed. The synthesis involved three-component condensation of semicarbazones of aliphatic or aromatic aldehydes with the same or other aldehydes and p-toluenesulfinic acid. The scope and limitations of this reaction were investigated. The compounds obtained were demonstrated to be an efficient α-(4-semicarbazono)alkylating agents. They were reacted with H- (sodium borohydride), O- (sodium methylate), S- (sodium phenylthiolate), N- (pyrrolidine, sodium succinimide), P- (trialkyl phosphites), and C-nucleophiles (sodium diethyl malonate) to give the corresponding products of the tosyl group substitution, 4-substituted semicarbazones, including analogues of nitrofurazone. Among the prepared compounds tested in vitro for antibacterial and antifungal activity, three nitrofuryl-containing semicarbazones exhibited high biological activities with minimum inhibitory concentration (MIC) values of 8–32 μg/mL.     

Sulfur-directed metal-free and regiospecific methyl C(sp3)–H imidation of thioanisoles

Regiospecific and direct imidation of the methyl C(sp³)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products.     

Synthesis of novel chiral bidentate hydroxyalkyl-N-heterocyclic carbene ligands and their application in palladium-catalyzed Mizoroki–Heck couplings and asymmetric addition of diethylzinc to benzaldehyde

A small library of new chiral bidentate hydroxyalkyl-imidazolium salts 1 is conveniently synthesized on multi-gram scale from inexpensive and commercially available chiral pool amino acids. The corresponding carbenes, generated by deprotonation of imidazolium salts 1, in combination with palladium(II) chloride were tested in the Mizoroki–Heck coupling reaction. The most significant results in terms of yields and reactivities were achieved with low catalyst loading. The catalytic activities of these imidazolium salts were also investigated in the asymmetric addition of diethylzinc to benzaldehyde. The use of MgO nanoparticles as an additive in conjunction with these ligands played a crucial role in increasing the efficiency of these reactions.