Absorption Spectra and Resonance Rayleigh Scattering Spectra of Cu(Ⅱ)-Fluoroquinolone Chelates with Tetrachlorotetraiodo-fluoresceindisodium Salt System and Their Analytical Applications

在pH 4.2～4.8的B-R缓冲介质中,莫西沙星(MXFX)和加替沙星(GTF)等氟喹诺酮类抗生素(FLQs)能与铜(Ⅱ)形成螯合阳离子,进一步与虎红(Tf)阴离子通过静电引力和疏水作用形成FLQs∶Cu(Ⅱ)∶Tf为1∶1∶1的离子缔合物,体系反应导致共振瑞利散射(RRS)显著增强并出现新的RRS光谱.两种药物的反应产物具有相似的光谱特征,最大RRS峰位于373 nm处,并在590 nm处有1个较小的散射峰.在373 nm处一定浓度的抗生素与散射增强(△I)成正比,MXFX和GTF的线性范围分别为0.031 ～7.8 mg/L和0.029～9.0 mg/L.据此建立了测定氟喹诺酮类药物的新方法,方法用于胶囊和人尿液中FLQs的测定并取得满意结果.同时对反应机理及RRS增强原因进行了讨论.     

氟喹诺酮类抗生素与磷钨酸体系的共振瑞利散射光谱研究及其分析应用

在5.0 mol/L的HCl缓冲介质中,磷钨酸（Pwa）与莫西沙星(MXFX)和加替沙星（GTF）等氟喹诺酮类抗生素(FLQs)相互作用形成摩尔比1∶1离子缔合物,导致体系的共振瑞利散射(RRS)显著增强并出现新的RRS光谱。 MXFX和GTF的反应产物具有相似的光谱特征,最大散射波长位于320 nm附近,且药物浓度与散射增强(ΔI)成正比,2种氟喹诺酮类药物的线性范围分别为0.025~6.0 mg/L（MXFX）和0.023~9.0 mg/L（GTF）。 据此可建立用于测定氟喹诺酮类药物的简捷快速灵敏的新方法,方法用于胶囊和人尿液中的FLQs测定并取得满意结果。 并对反应机理和RRS增强的原因进行了讨论。     

铜（Ⅱ)-氟喹诺酮类抗生素螯合物与虎红体系的吸收和共振瑞利散射光谱及其分析应用研究

在pH 4.2~4.8的B-R缓冲介质中,莫西沙星（MXFX)和加替沙星（GTF)等氟喹诺酮类抗生素（FLQs)能与铜（Ⅱ)形成螯合阳离子,进一步与虎红（Tf)阴离子通过静电引力和疏水作用形成FLQs∶Cu（Ⅱ)∶Tf为1∶1∶1的离子缔合物,体系反应导致共振瑞利散射（RRS)显著增强并出现新的RRS光谱。两种药物的反应产物具有相似的光谱特征,最大RRS峰位于373 nm处,并在590 nm处有1个较小的散射峰。在373 nm处一定浓度的抗生素与散射增强（ΔI)成正比,MXFX和GTF的线性范围分别为0.031~7.8 mg/L和0.029~9.0 mg/L。据此建立了测定氟喹诺酮类药物的新方法,方法用于胶囊和人尿液中FLQs的测定并取得满意结果。同时对反应机理及RRS增强原因进行了讨论。     

氟喹诺酮类抗生素与钴(Ⅱ)和刚果红三元配合物的共振瑞利散射光谱研究及其分析应用

在pH 4.5～6.5的Bdtton-Robinson缓冲溶液中,钴(Ⅱ)与环丙沙星(CIP)、诺氟沙星(NOR)、氧氟沙星(OF)和左氧氟沙星(LEV)等氟喹诺酮类抗生素(FLQs)能形成螯合阳离子,它们能通过静电引力和疏水作用与刚果红(CR)阴离子反应,形成1:2:1(Co2 :FLQs:CR)三元离了缔合配合物.此时将引起溶液的共振瑞利散射(RRS)显著增强,并出现新的RRS光谱.不同抗生素具有相似的光谱特征,其最大散射波长均位于560 nm处,并在382和278 nm处有2个较小的散射峰.一定浓度的抗生素与散射增强(△成正比,对不同氟喹诺酮类药物的线性范围和检出限(3σ)分别是0.026～2.64 μg·mL-1和7.68 μg·mL-1(CIP),0.045～3.20 μg·mL-1和13.00 ng·mL-1(NOR),0.037～4.00μg·mL-1和11.24 ng·mL-1(OF),0.039～4.00 μg·mL-1和11.80 ng·mL-1(LEV),据此提出了一种以RRS技术测定氟喹诺酮抗牛素的新方法.方法不仅灵敏度高,而且简单、快速,并有良好的选择性和重复性,可用于片剂、针剂、滴眼液和人尿液中氟喹诺酮类药物的测定.文中还对反应机理和RRS增强的原因作了讨论.     

铈(Ⅳ)与氟喹诺酮类抗生素相互作用的共振瑞利散射光谱及其分析应用

在pH4.0～5.0的弱酸性介质中,Ce(Ⅳ)能与诺氟沙星(NOR)、环丙沙星(CIP)、培氟沙星(PE)、洛美沙星(LOM)和司帕沙星(SPA)等氟喹诺酮类抗生素(FLQs)反应,并最终形成Ce(HL)(OH)4型的三元混配络合物.此时,仅能引起吸收光谱的微小变化和摩尔吸光系数(ε)的少量提高,但是却能导致共振瑞利散射(RRS)的显著增强,5种体系的最大散射波长均位于381nm附近,并在534nm处出现一个较小的散射峰,散射增强(ΔI)在一定范围内与FLQs的浓度成正比,方法有高灵敏度,对不同的FLQ其检出限(3σ)除SPA(16.0μgmL-1)之外,其余FLQs在1.9～5.3ngmL-1之间.研究了Ce(Ⅳ)与FLQs相互作用对RRS光谱的影响,反应的适宜条件和影响因素,考察了共存物质的影响,表明方法有良好的选择性,可用于某些样品中FLQs的测定.还结合吸收光谱的变化和量子化学计算,讨论了反应机理及散射增强的原因.     

共振瑞利光散射法测定人体尿液和血浆中的氟罗沙星

提出了共振瑞利光散射法测定氟罗沙星的新方法。在pH5.3～5.6的Britton-Robinson缓冲溶液中,氟罗沙星(FLE)与钴(II)能形成螯合阳离子,它可进一步与刚果红(CR)反应形成2∶1∶1(FLE∶Co2+∶CR)三元离子缔合物,导致共振瑞利散射(RRS)显著增强并出现新的RRS光谱,其最大散射波长分别位于372和560nm。在372nm处,氟罗沙星的浓度在0.03～3.69μg/mL范围内,与RRS强度有良好的线性关系,检出限(3σ)为6.0ng/mL。方法用于片剂、尿液和人血清中氟罗沙星的测定。     

氟喹诺酮类抗生素与钴(II)和刚果红三元配合物的共振瑞利散射光谱研究及其分析应用

在pH 4.5～6.5的Britton-Robinson缓冲溶液中, 钴(II)与环丙沙星(CIP)、诺氟沙星(NOR)、氧氟沙星(OF)和左氧氟沙星(LEV)等氟喹诺酮类抗生素(FLQs)能形成螯合阳离子, 它们能通过静电引力和疏水作用与刚果红(CR)阴离子反应, 形成1∶2∶1 (Co^2＋∶FLQs∶CR)三元离子缔合配合物. 此时将引起溶液的共振瑞利散射(RRS)显著增强, 并出现新的RRS光谱. 不同抗生素具有相似的光谱特征, 其最大散射波长均位于560 nm处, 并在382和278 nm处有2个较小的散射峰. 一定浓度的抗生素与散射增强(ΔI)成正比, 对不同氟喹诺酮类药物的线性范围和检出限(3s)分别是0.026～2.64 μg•mL^－1和7.68 ng•mL^－1 (CIP), 0.045～3.20 μg•mL^－1和13.00 ng• mL^－1 (NOR), 0.037～4.00 μg•mL^－1和11.24 ng• mL^－1 (OF), 0.039～4.00 μg•mL^－1和11.80 ng•mL^－1 (LEV), 据此提出了一种以RRS技术测定氟喹诺酮抗生素的新方法. 方法不仅灵敏度高, 而且简单、快速, 并有良好的选择性和重复性, 可用于片剂、针剂、滴眼液和人尿液中氟喹诺酮类药物的测定. 文中还对反应机理和RRS增强的原因作了讨论.     

某些蒽环类抗癌药物与刚果红相互作用的吸收、荧光和共振瑞利散射光谱研究

在pH 2.5左右的酸性介质中, 刚果红与表柔比星、柔红霉素和米托蒽醌等蒽环类抗生素反应形成离子缔合物时, 仅能引起吸收光谱和荧光光谱的微小变化, 但却能导致共振瑞利散射(RRS)的显著增强并产生新的RRS光谱, 与此同时也观察到二级散射(SOS)和倍频散射(FDS)的增强. 最大RRS峰位于370 nm附近, 并在280 nm附近有另一散射峰. 而它们的SOS峰均在530 nm附近, 最大FDS峰均位于353 nm处. 其中RRS法灵敏度最高, 它对表柔比星、柔红霉素和米托蒽醌的检出限分别为0.054, 0.058和0.033 μg/mL, 而其线性范围分别为0.05～12.0, 0.05～12.0和0.04～7.5 μg/mL. 文中研究了反应产物的吸收、荧光和RRS光谱特征, 适宜的反应条件及分析化学性质, 据此发展了一种用RRS技术灵敏、简便、快速测定蒽环类抗癌药物的新方法.     

铜(II)-氟喹诺酮类抗生素螯合物与赤藓红体系的吸收、荧光和共振Rayleigh散射光谱及其分析应用研究

在pH 4.2~5.0的Britton-Robinson 缓冲溶液中, 环丙沙星(CIP), 诺氟沙星(NOR), 氧氟沙星(OF), 左氧氟沙星(LEV), 洛美沙星(LOM)和司帕沙星(SPA)等氟喹诺酮类抗生素(FLQs) 能与铜(II)形成螯合阳离子, 它们能进一步与赤藓红(Ery)阴离子通过静电引力和疏水作用形成FLQs:Cu(II): Ery为1:1:1的离子缔合物. 此时, 能引起吸收光谱的变化, 并发生明显的褪色作用, 最大褪色波长均位于526 nm处, 反应具有较高的灵敏度, 除NOR的摩尔吸光系数(ε)较低外, 其余5种抗生素的ε值均大于1.0×10⁵ L·mol^-1·cm^-1, 而且LOM和OF体系的ε值均大于3×10⁵ L·mol^-1·cm^-1, 而SPA的e 值高达7.22×10⁵ L·mol^-1·cm^-1, 可用于这类药物的分光光度测定. 离子缔合反应还导致赤藓红的荧光猝灭, 反应也具有高灵敏度, 上述6种FLQs药物的检出限在7.1~12.2 μg·L^-1之间, 为荧光猝灭法测定μg·L^-1级FLQs创造了条件. 离子缔合反应更能导致共振瑞利散射(RRS)的显著增强, 并产生新的RRS光谱. 六种药物的反应产物具有相似的光谱特征, 最大散射波长均位于566 nm处, 并在333 nm和287 nm处有2个较小的散射峰. 在一定条件下散射增强(ΔI)与药物浓度成正比. RRS法较褪色分光光度法和荧光猝灭法具有更高的灵敏度, 对不同的FLQs药物的检出限在1.7 μg·L^-1至3.1 μg·L^-1之间, 更适于痕量的FLQs测定. 研究了反应产物的吸收、荧光和RRS光谱特征, 适宜的反应条件及分析化学性质, 结合量子化学计算方法讨论了离子缔合反应的历程及对光谱特征的影响, 并研究了RRS法 的选择性及分析应用.     

健那绿作光谱探针共振瑞利散射法测定藻酸钠

本文提出了共振瑞利散射法测定藻酸钠的新方法。研究发现在pH=4.0的Britton-Robinson缓冲溶液中,藻酸钠或健那绿单独存在时共振瑞利散射(RRS)强度非常弱,当两者反应形成复合物时,RRS大大增强并产生新的RRS光谱,其最大RRS峰位于560nm,另在328nm和397nm处产生两个强度较低的散射峰。在560nm处,藻酸钠的浓度在0.015～1.0μg/mL范围内与RRS强度有良好的线性关系,检出限(3σ/k)为5ng/mL。方法灵敏度高,选择性好,可用于面条和海带提取液中的藻酸钠测定。     

Furyl- and thienyl-silatranes and germatranes

We review our research on the synthesis and study of the physical and biological properties of furyl- and thienylgermatranes and -silatranes.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 725–732, June, 1992.     

Review and patents and literature

The use of the insect cell/baculovirus expression system for producing recombinant proteins of bacterial, plant, insect, and mammalian origin has become widespread. The popularity of this eukaryotic expression system is due to many factors, including (1) potentially high protein expression levels, (2) ease and speed of genetic engineering, (3) ability to accommodate large DNA inserts, (4) protein processing similar to higher eukaryotic cells (e.g., mammalian cells), and (5) ease of insect cell growth (e.g., suspension growth). The following review of the literature discusses two engineering aspects of recombinant protein synthesis by insect cell cultures: bioreactor scale-up and insect cell line selection. Following this review patent abstracts and additional literature pertaining to expression of recombinant proteins in insect cell culture are listed.     

Ground- and excited-state aromaticity and antiaromaticity in benzene and cyclobutadiene

The aromaticity and antiaromaticity of the ground state (S 0), lowest triplet state (T 1), and first singlet excited state (S 1) of benzene, and the ground states (S 0), lowest triplet states (T 1), and the first and second singlet excited states (S 1 and S 2) of square and rectangular cyclobutadiene are assessed using various magnetic criteria including nucleus-independent chemical shifts (NICS), proton shieldings, and magnetic susceptibilities calculated using complete-active-space self-consistent field (CASSCF) wave functions constructed from gauge-including atomic orbitals (GIAOs). These magnetic criteria strongly suggest that, in contrast to the well-known aromaticity of the S 0 state of benzene, the T 1 and S 1 states of this molecule are antiaromatic. In square cyclobutadiene, which is shown to be considerably more antiaromatic than rectangular cyclobutadiene, the magnetic properties of the T 1 and S 1 states allow these to be classified as aromatic. According to the computed magnetic criteria, the T 1 state of rectangular cyclobutadiene is still aromatic, but the S 1 state is antiaromatic, just as the S 2 state of square cyclobutadiene; the S 2 state of rectangular cyclobutadiene is nonaromatic. The results demonstrate that the well-known "triplet aromaticity" of cyclic conjugated hydrocarbons represents a particular case of a broader concept of excited-state aromaticity and antiaromaticity. It is shown that while electronic excitation may lead to increased nuclear shieldings in certain low-lying electronic states, in general its main effect can be expected to be nuclear deshielding, which can be substantial for heavier nuclei.     

Hard and soft acids and bases: structure and process

Under investigation is the structure and process that gives rise to hard-soft behavior in simple anionic atomic bases. That for simple atomic bases the chemical hardness is expected to be the only extrinsic component of acid-base strength, has been substantiated in the current study. A thermochemically based operational scale of chemical hardness was used to identify the structure within anionic atomic bases that is responsible for chemical hardness. The base's responding electrons have been identified as the structure, and the relaxation that occurs during charge transfer has been identified as the process giving rise to hard-soft behavior. This is in contrast the commonly accepted explanations that attribute hard-soft behavior to varying degrees of electrostatic and covalent contributions to the acid-base interaction. The ability of the atomic ion's responding electrons to cause hard-soft behavior has been assessed by examining the correlation of the estimated relaxation energies of the responding electrons with the operational chemical hardness. It has been demonstrated that the responding electrons are able to give rise to hard-soft behavior in simple anionic bases.     

Determination and study on residue and dissipation of benazolin-ethyl and quizalofop-p-ethyl in rape and soil

A QuEChERS (quick, easy, cheap, effective, rugged, and safe) method for the determination of benazolin-ethyl and quizalofop-p-ethyl in rape and soil by high-performance liquid chromatography-tandem mass spectrometry has been developed in this study. The residue and dissipation of benazolin-ethyl and quizalofop-p-ethyl in rape and soil were determined with the developed method. The half-lives of benazolin-ethyl in rape straw and soil were 3.7–5.1 days and 14.3–26.3 days, respectively. The half-lives of quizalofop-p-ethyl in rape straw and soil were 5.0-6.1 days and 0.3–9.7 days, respectively. The residue of benazolin-ethyl and quizalofop-p-ethyl in rapeseed and soil were below the detection limit (i.e., 0.5?mg?kg^?1, the maximum residue level of European Union for quizalofop-p-ethyl).     

Syntheses and structures of P-anilino-P-chalcogeno- and P-anilino-P-iminodiazasilaphosphetidines and their group 12 and 13 metal compounds

The P-anilino-P-chalcogeno(imino)diazasilaphosphetidines [Me(2)Si(mu-N(t)Bu)(2)P=E(NHPh)] (E = O (3), S (4), Se (5), N-p-tolyl (6)) were synthesized by oxidizing the P-anilinodiazasilaphosphetidine [Me(2)Si(N(t)Bu)(2)P(NHPh)] (2) with cumene hydroperoxide, sulfur, selenium, and p-tolyl azide, respectively. The lithium salt of 4 reacted with thallium monochloride to produce ([Me(2)Si(mu-N(t)Bu)(2)P=S(NPh)-kappaN-kappaS]Tl)(7), which features a two-coordinate thallium atom. Treatment of 4-6 with AlMe(3) gave the monoligand dimethylaluminum complexes ([Me(2)Si(mu-N(t)Bu)(2)P=E(NPh)-kappaN-kappaE]AlMe(2)) (E = S (8), Se (9), N-p-tolyl (10)), respectively. In these complexes the aluminum atom is tetrahedrally coordinated by one chelating ligand and two methyl groups, as a single-crystal X-ray analysis of 8 showed. A 2 equiv amount of 4-6 reacted with diethylzinc to produce the homoleptic diligand complexes ([Me(2)Si(mu-N(t)Bu)(2)P=E(NPh)-kappaN-kappaE](2)Zn)(E = S (11), Se (12), N-p-tolyl (13)). A crystal-structure analysis of 11 revealed a linear tetraspirocycle with a tetrahedrally coordinated, central zinc atom.