N-溴代琥珀酰亚胺-荧光素体系流动注射能量转移化学发光法测定妥布霉素

在碱性条件下,N-溴代琥珀酰亚胺(NBS)氧化妥布霉素,在荧光素增敏作用下发生化学发光。基于此,结合流动注射技术,建立了测定痕量妥布霉素的流动注射化学发光分析法。在优化的实验条件下,体系对妥布霉素的测定线性范围为0．2—100mg／L;检出限(3σ)为0．07mg／L;对5．0mg／L妥布霉素进行11次平行测定,其相对标准偏差为2．1％。将本法用于制剂和血样中妥布霉素的分析,结果令人满意。     

离子交换-脉冲积分安培法分离检测氨基糖苷类抗生素

用离子交换柱分离氨基糖苷类抗生素妥布霉素、新霉素B和西梭霉素,用脉冲积分安培电化学检测器进行检测。其流动相不同于一般抗生素的离子对色谱法,它配制简单,仅需使用NaOH-水体系;对两种检测电位波形进行了对比,并选取了表现优良的检测电位。方法对妥布霉素、新霉素B和西梭霉素的检出限分别为8、5、47 ng/mL,在0.1~100μg/mL范围内表现良好线性关系(r=0.9990~0.9996)。该方法应用于市售鲜奶的检测,3种氨基糖苷类抗生素的回收率为85.0%~98.5%。     

离子色谱-脉冲安培电化学检测引流组织液中的妥布霉素

建立了一种离子色谱(IC)分离,脉冲安培电化学法(PAD)直接检测人体引流组织液中妥布霉素的分析方法.采用高交换容量阴离子交换柱和低浓度KOH在线淋洗分离,不需要采用衍生化和离子对-柱后加碱等实现分离,并可在短时间内完成妥布霉素的测定.采用本方法测定的妥布霉素线性范围为0.05～10 mg/L,线性相关系数为0.9997,保留时间、峰面积和峰高的相对标准偏差分别为0.14％,0.38％和0.81％,检出限为7.11 μg/L.本方法成功应用于骨髓炎患者引流组织液中妥布霉素的测定,样品实际加标回收率为100.8％.     

大孔弱酸树脂对妥布霉素纯化的工艺研究

工业生产中妥布霉素发酵液粗提物的纯度只能达到50~60%,通常采用强酸树脂进行纯化,但纯化纯度很难达到国家药典要求。本文比较了5种阳离子交换树脂对妥布霉素的吸附性能,利用静态吸附与动态吸附实验优选出了大孔弱酸树脂HZ-3B,并对其纯化妥布霉素工艺进行了进一步的优化:选用浓度为5mg/m L,pH值为6.8~7.2的妥布霉素溶液以9BV/h的流速进行上样,上样200BV;然后利用0.125mol/L的氨水溶液作为解吸液,以6BV/h的流速进行解吸,合并解吸液。HPLC分析结果显示,妥布霉素纯度由50~60%提升到了97.15%,收率为89.52%,且无其他氨基糖苷类抗生素杂质,达到了国家药典的要求。     

高效毛细管电泳-电导检测对四环素衍生物分离测定的研究

运用毛细管电泳-电导检测方法对4种四环素衍生物——土霉素(OTC)、金霉素(CTC)、强力霉素(DOC)和四环素(TC)的分离进行了研究。在3．5mmol/L三羟基氨基甲烷(Tris)-7．5mmol/L柠檬酸(Cit)pH4．0的运行缓冲液中，4种四环素衍生物在15min内获得完全分离。四环素衍生物的线性范围分别为5．0-500μg/mL OTC，3．6-420μg/mL CTC，4.5-470μg/mL DOC和2.5-400μg/mL TC。检测限(S／N＝3)分别为OTC2．0μg/mL，CTC 1．8μg／mL，DOC2．5μg/mL和TC1．0μg/mL。采用本法对实际样品强力霉素片中强力霉素和土霉素片中土霉素进行测定，回收率分别为97．2％和96.4％。     

镧-水溶对氮蒽蓝光度法测定庆大霉素及妥布霉素

硫酸庆大霉素（GEN）、妥布霉素（TOB）是一类多羟基抗菌素。庆大霉素及妥布霉素的测定方法常规采用抗生素微生物检定法,此外有HPLC、荧光法和吸光光度法等。本文利用金属镧和GEN、TOB与水溶对氮蒽蓝（ABWS）易于形成离子缔合物的性质,进行了硫酸庆大霉素和妥布霉素的分光光度测定研究。     

基于适体修饰的金纳米粒子分光光度法测定牛奶中妥布霉素的残留量

在没有妥布霉素存在时,适体包覆在金纳米粒子(AuNPs)表面可以防止盐诱导的聚集;在妥布霉素存在时,由于适体与妥布霉素的亲和力较高,适体与妥布霉素结合并从AuNPs表面脱离,导致AuNPs在适当含量的盐中发生聚集,反应体系颜色由红色变为蓝紫色.采用基于适体修饰的金纳米粒子分光光度法测定牛奶中妥布霉素的残留量.优化的试验...     

柱前衍生高效液相色谱法测定血清中克拉霉素的含量

建立了2，4-二硝基苯肼柱前衍生反相高效液相色谱紫外检测法测定血清中克拉霉素的含量，将在碱性条件下甲基叔丁基醚的血清萃取物，与2，4-二硝基苯肼在55％酸性条件下反应30min，然后用乙腈-0．05mol/LpH7．2磷酸盐缓冲液（48：52）在Alltima C18色谱柱上进行分离，在340nm检测衍生物。方法的线性范围为0．05～3．2mg／L（r=0．9993）；检出限为30μg/L，绝对回收率大于89％，相对标准差小于10％。本方法已用于克拉霉素在健康受试者中的药代动力学研究。     

单扫描示波极谱法测定药物中的苯妥英钠

建立了测定苯妥英钠的新方法。在0．016mol／L B-R(pH 7．0)缓冲溶液中,本妥英钠产生一还原波,峰电位为-1．18V。该还原波二阶导数峰电流与苯妥英钠浓度呈线性,线性范围为2．5～50μg／mL,检出限为2．0μg／mL。该方法用于片剂中笨妥英钠含量的测定,结果满意。     

奋乃静和氟奋乃静的毛细管电泳柱端喷壁式安培检测

应用自组装毛细管电泳．安培检测装置，建立了同时分离检测抗精神病药奋乃静与氟奋乃静的新方法。在1050mV(vs．Ag／AgCl)检测电位下，奋乃静与氟奋乃静的检出限分别达0．060mg／L与0．075mg／L。在最佳检测条件下，两组分的响应电流与浓度之间有着良好的线性关系，线性范围为0．75～75mg／L。将方法用于药物片剂以及模拟尿样和血清样品中奋乃静和氟奋乃静的测定，结果令人满意。     

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.