1H- and 13C-NMR Study of Some 6,7-Dihaloquinolone Nucleosides and Their Derivatives

The ¹H- and ¹³C-NMR spectra of 6,7-dihalo-1,4-dihydro-4-oxo-1-(2,3,5-tri-0-benzoyl-pβ-D-ribofuranosyl)quinoline-3-carboxylic acids (3), (4), the ester (3a), 6-chloro-1-(2-deoxy-3,5-di-O-tolouyl-α- and β-D-erythropentofuranosyl)-7-fluoro-1,4-dihydro-4-oxo-quinoline-3-carboxylic acid (5), and its free a-nucleoside (5a) have been investigated. Resonance signals were assigned by homo- and heteronuclear two dimensional NMR methods (DQF-COSY, HMQC, and HMBC) for (3), (4), (5), and (5a). Ribosylation sites and anomeric configurations were identified from ROESY spectra.     

核磁共振波谱法测定药物基准物质的绝对含量

探讨在新药基准物质的确定过程中,利用核磁共振法测定药物绝对含量的可行性。以环丙沙星、安妥沙星、卡德沙星、加替沙星、左氧氟沙星、氧氟沙星、诺氟沙星、依诺沙星和洛美沙星9种喹诺酮类抗生素化学对照品为例,其中安妥沙星和卡德沙星为国家一类新药。采用重水、氘代二甲基亚砜或氢氧化钠的重水溶液为溶剂,对苯二酚或顺丁烯二酸为内标,用喹诺酮母核上的质子峰进行定量,以内标法和外标法计算含量。核磁共振法测定结果与各对照品标签示值的误差约为1％,内标法和外标法的计算结果一致。该方法专属、准确、简便、快速,适用于对药物基准物质绝对含量的测定。     

Synthesis of 6-chloro and 6-fluoro-4-hydroxyl-2-quinolone and their azo disperse dyes

<正>In this study,6-chloro-4-hydroxy-2-quinolone and 6-flouro-4-hydroxy-2-quinolone were synthesized from corresponding dianilides.These compounds were coupled with some diazotized aromatic amines to give the corresponding azo disperse dyes.The structures of the quinolone derivatives and new azo dyes were confirmed by UV-vis,FT-IR,~1H NMR and elemental analysis.     

一种强阴离子交换树脂的制备及用于蜂蜜中喹诺酮类药物的富集检测

采用沉淀聚合法,合成了对氯甲基苯乙烯-二乙烯基苯共聚物(VBC-DVB),并通过与三甲胺修饰反应,获得了一种含季铵基团的强阴离子交换树脂(SAX)。表征结果显示,树脂是呈单分散形态的微球,平均粒径为(3.8±1.5)μm,且具有较高的离子交换容量(0.83 meq/g)及良好的选择性吸附性能,对5种喹诺酮类药物(诺氟沙星、环丙沙星、洛美沙星、加替沙星、司帕沙星)的饱和吸附容量明显高于同类型商品化Oasis MAX固相萃取柱。将其用于蜂蜜样品中5种喹诺酮药物的选择性富集和HPLC分析。结果显示,该方法在一定范围内线性关系良好(r2≥0.998 9),平均加标回收率为86.8%~120.3%,日内重复性RSD不大于7.0%,日间RSD不大于8.5%。研究结果表明,所制备的SAX材料可用于复杂基质中喹诺酮类药物残留的高效前处理分析。     

Syntheses and Structures of Two Novel Interdigitated Metal‐Quinolone Complexes: [Cu2(cfH)2(bptc)(H2O)]·4H2O and [Zn2(levofH)2(odpa)]·5.5H2O

Two novel interdigitated metal‐quinolone complexes, namely [Cu₂(cfH)₂(bptc)(H₂O)] · 4H₂O ( 1 ) and [Zn₂(levofH)₂(odpa)] · 5.5H₂O ( 2 ) (bptc = 3,3′,4,4′‐benzophenonetetracarboxylate, cfH = ciprofloxacin, odpa = 4,4′‐oxydiphthalate, levofH = levofloxacin) were synthesized hydrothermally and characterized by elemental analyses, IR spectra, UV/Vis spectra, TG analyses, powder X‐ray diffraction, and single‐crystal X‐ray diffraction. Moreover, solid‐state photoluminescence property of compound 2 was also investigated at room temperature. Compound 1 exhibits a novel interdigitated architecture, which is built from 1D chains with side arms. The structure of compound 2 consists of 1D chains with dangling levofloxacin ligands protruding from both sides of the chain, and these chains are interdigitated with each other to generate a interdigitated framework.     

Gold-catalyzed heteroannulation and allyl migration: synthesis of highly functionalized indole derivatives

Highly substituted indole derivatives have been prepared in good to excellent yields by a novel gold-catalyzed cyclization accompanied by [3,3]-migration of the allyl strategy. We have been able to introduce an allyl group at the C1 position of pyrano[3,2-e]indol-6(7H)-one and pyrrolo[3,2-f]quinolin-7(6H)-one moieties that provide a scope for further transformation.     

Rare-Earth Metal Complexes of the Antibacterial Drug Oxolinic Acid: Synthesis,Characterization, DNA/Protein Binding and Cytotoxicity Studies

“Drug repositioning” is a current trend which proved useful in the search for new applications for existing, failed, no longer in use or abandoned drugs, particularly when addressing issues such as bacterial or cancer cells resistance to current therapeutic approaches. In this context, six new complexes of the first-generation quinolone oxolinic acid with rare-earth metal cations (Y³⁺, La³⁺, Sm³⁺, Eu³⁺, Gd³⁺, Tb³⁺) have been synthesized and characterized. The experimental data suggest that the quinolone acts as a bidentate ligand, binding to the metal ion via the keto and carboxylate oxygen atoms; these findings are supported by DFT (density functional theory) calculations for the Sm³⁺ complex. The cytotoxic activity of the complexes, as well as the ligand, has been studied on MDA-MB 231 (human breast adenocarcinoma), LoVo (human colon adenocarcinoma) and HUVEC (normal human umbilical vein endothelial cells) cell lines. UV-Vis spectroscopy and competitive binding studies show that the complexes display binding affinities (K_b) towards double stranded DNA in the range of 9.33 × 10⁴ − 10.72 × 10⁵. Major and minor groove-binding most likely play a significant role in the interactions of the complexes with DNA. Moreover, the complexes bind human serum albumin more avidly than apo-transferrin.     

4‐Styrylquinolines from cyclocondensation reactions between (2‐aminophenyl)chalcones and 1,3‐diketones: crystal structures and regiochemistry

Structures are reported for two matched sets of substituted 4‐styrylquinolines which were prepared by the formation of the heterocyclic ring in cyclocondensation reactions between 1‐(2‐aminophenyl)‐3‐arylprop‐2‐en‐1‐ones with 1,3‐dicarbonyl compounds. (E)‐3‐Acetyl‐4‐[2‐(4‐methoxyphenyl)ethenyl]‐2‐methylquinoline, C₂₁H₁₉NO₂, (I), (E)‐3‐acetyl‐4‐[2‐(4‐bromophenyl)ethenyl]‐2‐methylquinoline, C₂₀H₁₆BrNO, (II), and (E)‐3‐acetyl‐2‐methyl‐4‐{2‐[4‐(trifluoromethyl)phenyl]ethenyl}quinoline, C₂₁H₁₆F₃NO, (III), are isomorphous and in each structure the molecules are linked by a single C—H…O hydrogen bond to form C(6) chains. In (I), but not in (II) or (III), this is augmented by a C—H…π(arene) hydrogen bond to form a chain of rings; hence, (I)–(III) are not strictly isostructural. By contrast with (I)–(III), no two of ethyl (E)‐4‐[2‐(4‐methoxyphenyl)ethenyl]‐2‐methylquinoline‐3‐carboxylate, C₂₂H₂₁NO₃, (IV), ethyl (E)‐4‐[2‐(4‐bromophenyl)ethenyl]‐2‐methylquinoline‐3‐carboxylate, C₂₁H₁₈BrNO₂, (V), and ethyl (E)‐2‐methyl‐4‐{2‐[4‐(trifluoromethyl)phenyl]ethenyl}quinoline‐3‐carboxylate, C₂₂H₁₈F₃NO₂, (VI), are isomorphous. The molecules of (IV) are linked by a single C—H…O hydrogen bond to form C(13) chains, but cyclic centrosymmetric dimers are formed in both (V) and (VI). The dimer in (V) contains a C—H…π(pyridyl) hydrogen bond, while that in (VI) contains two independent C—H…O hydrogen bonds. Comparisons are made with some related structures, and both the regiochemistry and the mechanism of the heterocyclic ring formation are discussed.     

Synthesis of Quinolone Analogues: 7-[(2S,4R)-2-Aminomethyl-4- hydroxypyrrolidin-1-yl] Quinolones

Quinolone antibacterial agents have emerged as one of the dominant classes chemotherapeutic drugs for the treatment of various bacterial infections1. We have focused our attention on the modification of the C-7 basic group of the quinolone which has been most varied. In 1987, Uno et al.2 reported that 3-hydroxypyrrolidine quinolones showed more active antibacterial activities than Norfloxacin in vivo. In 1998, Fujita et al.3 reported that 2-aminomethylpyrrolidine quinolones have the same …     

Facile synthesis of 6,6,8,6,6-ring fused pentacyclic heterocycles: annelation of quinolines to quinoxalines under PTC condition

An efficient and simple synthesis of pentacyclic quinolonoquinoxalinooxazocines in a one-pot sequence has been performed by unique application of phase transfer catalysis. Preparative simplicity and conceptual novelty of the methodology offer an attractive general application for the synthesis of novel quinoline antibiotics.