超滤管净化/高效液相色谱-串联质谱法测定动物源食品中喹诺酮类药物残留

建立了超滤管净化技术结合高效液相色谱-串联质谱同时测定动物源食品中10种喹诺酮类药物残留的新方法。样品经酸化乙腈提取后,采用50 m L Millipore超滤管(截留分子量3 k D)净化,离心液氮吹复溶后,经Waters Xbridge C18色谱柱进行分离,以0.1%甲酸-乙腈作为流动相进行梯度洗脱,电喷雾正离子(ESI+)模式电离,多反应监测(MRM)模式检测,外标法定量。结果表明,10种喹诺酮类药物在5.0~100μg/kg浓度范围内线性关系良好,方法的检出限为0.15~0.75μg/kg,定量下限为0.49~2.59μg/kg,在5.0,10,50μg/kg 3个加标水平下的回收率为71.4%~85.9%,相对标准偏差(n=6)为3.9%~10.7%。方法简便快速、灵敏度高、重复性好,可用于动物源食品中10种喹诺酮类药物残留的快速确证和定量分析。     

A catalytic asymmetric ring-expansion reaction of isatins and α-alkyl-α-diazoesters: highly efficient synthesis of functionalized 2-quinolone derivatives

Asymmetric expansion: A catalytic asymmetric ring-expansion reaction of the title compounds occurs in the presence of a Sc(OTf)(3) catalyst bearing an N,N'-dioxide-based ligand. Highly functionalized 2-quinolone derivatives containing a chiral C4-quaternary stereocenter were obtained in high yields and high levels of selectivity under mild reaction conditions (see scheme; Tf=trifluoromethanesulfonyl).     

1H and 13C NMR spectral characterization of some antimalarial in vitro 2,4‐diamino‐10‐methylpyrimido[4,5‐b]‐5‐quinolone derivatives

We report the ¹H NMR and ¹³C NMR chemical shifts and J(H,H), J(H,F) and J(C,F) coupling constants of 13 2,4‐diamino‐10‐methylpyrimido[4,5‐b]‐5‐quinolone derivatives, some of them with moderate activity against Plasmodium falciparum in vitro. They were characterized and assigned on the basis of ¹H, ¹³C and ¹³C–¹H (short‐ and long‐range) correlated spectra. Copyright © 2002 John Wiley & Sons, Ltd.     

Synthese von chinolin-kondensierten 2-Chinolonen und Cumarinen via Azidoverbindungen

Coumarins and 2-quinolones (1), having a 4-azido-3-benzyl-moiety, can easily by cyclized by thermo- or photolysis to 3,4-fused quino-coumarins and quino-2-quinolones (2,3).

     

Bacterial Alkyl-4-quinolones: Discovery,Structural Diversity and Biological Properties

The alkyl-4-quinolones (AQs) are a class of metabolites produced primarily by members of the Pseudomonas and Burkholderia genera, consisting of a 4-quinolone core substituted by a range of pendant groups, most commonly at the C-2 position. The history of this class of compounds dates back to the 1940s, when a range of alkylquinolones with notable antibiotic properties were first isolated from Pseudomonas aeruginosa. More recently, it was discovered that an alkylquinolone derivative, the Pseudomonas Quinolone Signal (PQS) plays a key role in bacterial communication and quorum sensing in Pseudomonas aeruginosa. Many of the best-studied examples contain simple hydrocarbon side-chains, but more recent studies have revealed a wide range of structurally diverse examples from multiple bacterial genera, including those with aromatic, isoprenoid, or sulfur-containing side-chains. In addition to their well-known antimicrobial properties, alkylquinolones have been reported with antimalarial, antifungal, antialgal, and antioxidant properties. Here we review the structural diversity and biological activity of these intriguing metabolites.     

通过式固相萃取净化-液相色谱-串联质谱法测定豆芽中10种喹诺酮类抗生素

建立了超高效液相色谱-串联质谱(UPLC-Ms/Ms)快速检测豆芽中10种喹诺酮类抗生素(QNs)的方法。样品用乙腈-0.1%甲酸水溶液提取后,经PRiME HLB快速净化,氮吹浓缩后,用电喷雾离子源正离子-多反应监测(MRM)模式串联质谱进行检测。在0.25~100μg/L范围内,10种目标物的线性关系良好,其相关系数均大于0.997。方法对两种豆芽基质进行前处理并测定,检出限为1.0μg/kg和2.0μg/kg,定量限为3.0μg/kg和6.0μg/kg。回收率实验结果表明:10种目标物回收率范围为78.1%~106.4%,RSD<8.1%。方法能有效地避免杂质的干扰。     

环境友好型方法快速检测牛奶中的六种喹诺酮残留

本文建立了一种环境友好型、同时分离检测牛奶中六种喹诺酮类药物的高效液相色谱分析法。方法采用反相Chromatorex C18色谱柱,二极管阵列检测器,检测波长为280 nm。实验表明,适当浓度的柠檬酸和硫酸铵溶液作为提取液时可使牛奶中的蛋白质发生缓慢而彻底的变性,释放出与其结合的喹诺酮类药物,从而提高了从牛奶中提取喹诺酮类药物的提取效率。然后通过对提取液进行加热沉淀蛋白质、加入PSA(N-丙基乙二胺修饰的硅胶)净化,即可实现样品的快速前处理。该方法用于牛奶中六种喹诺酮类抗生素残留的测定,回收率均在82.0%～117.8%之间,方法检出限为34.5～85.0 ng·g-1。本文提出的样品前处理方法可靠、快速、环保、易于操作。