RP-HPLC法测定水体表层沉积物中的磺胺类与四环素类抗生素

建立了超声提取-固相萃取/反相高效液相色谱检测水体表层沉积物中磺胺类和四环素类抗生素含量的方法。沉积物样品经冷冻干燥后用甲醇-EDTA/Mc Ilvaine缓冲液(1∶1)超声萃取,于40℃下氮气吹除提取液中有机溶剂后,过Poly-Sery HLB固相萃取小柱净化萃取,以ODS-P C_(18)反相色谱柱、紫外检测器进行色谱分析。结果表明:7种磺胺类抗生素在0.025~0.5 mg/L浓度范围内线性关系良好,相关系数(r2)均大于0.999,3个加标水平下的回收率为71.4%~107.6%,相对标准偏差(RSD,n=3)为1.4%~5.2%,方法检出限(MDL)为0.07~0.29 ng/g;3种四环素类抗生素在0.05~1 mg/L浓度范围内线性关系良好,r~2均大于0.999,3个加标水平下的回收率为62.2%~87.9%,RSD(n=3)为1.1%~4.6%,MDL为0.45~0.58ng/g。应用此方法对某城市湖泊及其引水河道表层沉积物进行检测,10种目标抗生素均被检出。该方法简单快速、精确可靠,适用于水体沉积物中磺胺类和四环素类抗生素的检测。     

Identification of a β1/β2‐Specific Sulfonamide Proteasome Ligand by Crystallographic Screening

The proteasome represents a validated drug target for the treatment of cancer, however, new types of inhibitors are required to tackle the development of resistant tumors. Current fluorescence‐based screening methods suffer from low sensitivity and are limited to the detection of ligands with conventional binding profiles. In response to these drawbacks, a crystallographic screening procedure for the discovery of agents with a novel mode of action was utilized. The optimized workflow was applied to the screening of a focused set of compounds, resulting in the discovery of a β1/β2‐specific sulfonamide derivative that noncovalently binds between subunits β1 and β2. The binding pocket displays significant differences in size and polarity between the immuno‐ and constitutive proteasome. The identified ligand thus provides valuable insights for the future structure‐based design of subtype‐specific proteasome inhibitors.     

Rhodium(III)‐Catalyzed Activation of C?H Bonds and Subsequent Intermolecular Amidation at Room Temperature

Disclosed herein is a Rh^III‐catalyzed chelation‐assisted activation of unreactive C H bonds, thus enabling an intermolecular amidation to provide a practical and step‐economic route to 2‐(pyridin‐2‐yl)ethanamine derivatives. Substrates with other N‐donor groups are also compatible with the amidation. This protocol proceeds at room temperature, has a relatively broad functional‐group tolerance and high selectivity, and demonstrates the potential of rhodium(III) in the promotive functionalization of unreactive C H bonds. A rhodacycle having a SbF₆⁻ counterion was identified as a plausible intermediate.     

Synthesis, complexation studies and biological activity of some novel mono and tricyclic cyclophane amides and cyclophane sulfonamides

A series of mono, tricyclic cyclophane tetraamides and cyclophane sulfonamides have been synthesized and characterized from spectral and XRD studies. All the cyclophane amides form charge transfer (CT) complex with TCNQ. The cyclophane amides show moderate to good anti-inflammatory activity. Some of them were active against Gram positive (Klebsiella pneumonia) and Gram negative (Escherichia coli and Staphylococcus aureus) human pathogens.     

Organic ligand-free alkylation of amines, carboxamides, sulfonamides, and ketones by using alcohols catalyzed by heterogeneous Ag/Mo oxides

Complicated and expensive organic ligands are normally essential in fine chemical synthesis at preparative or industrial levels. The synthesis of fine chemicals by using heterogeneous catalyst systems without additive organic ligand is highly desirable but severely limited due to their poor generality and rigorous reaction conditions. Here, we show the results of carbon–nitrogen or carbon–carbon bond formation catalyzed by an Ag/Mo hybrid material with specific Ag₆Mo₁₀O₃₃ crystal structure. 48 nitrogen‐ or oxygen‐containing compounds, that is, amines, carboxamides, sulfonamides, and ketones, were successfully synthesized through a borrowing‐hydrogen mechanism. Up to 99 % isolated yields were obtained under relatively mild conditions without additive organic ligand. The catalytic process shows promise for the efficient and economic synthesis of amine, carboxamide, sulfonamide, and ketone derivatives because of the simplicity of the system and ease of operation.     

Metal‐based isatin‐bearing sulfonamides: their synthesis,characterization and biological properties

A new series of antibacterial and antifungal isatin bearing sulfonamides and their cobalt (II), copper (II), nickel (II) and zinc (II) metal complexes have been synthesized, characterized and screened for their in vitro antibacterial activity against Bacillus cereus, Corynebacterium diphtheriae, Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Pseudomonas aeruginosa, Salmonella typhi, Shigilla dysentriae and Staphylococcus aureus and for in vitro antifungal activity against Trichophyton schoenleinii, Candid glabrata, Pseudallescheria boydii, Candida albicans, Aspergillus niger, Microsporum canis and Trichophyton mentagrophytes. The results of these studies revealed that all compounds showed moderate to significant antibacterial activity. The brine shrimp bioassay was also carried out to study their in vitro cytotoxic properties. Only three compounds, 2, 11 and 22 displayed potent cytotoxic activity as LD₅₀ = 1.56 × 10^?7, 1.59 × 10^?7 and 1.67 × 10^?7 M /ml respectively, against Artemia salina. Copyright © 2006 John Wiley & Sons, Ltd.     

Sulfur dioxide mediated one-pot, four-component synthesis of polyfunctional sulfones and sulfonamides, including medium-ring cyclic derivatives

In previous papers (Synthesis2002, 232 and J. Org. Chem.2004, 69, 6413), we have shown that the hetero-Diels-Alder addition of sulfur dioxide to 1-oxy or 1,3-dioxy-1,3-dienes generates zwitterions that add to enoxysilanes or allylsilanes giving silyl sulfinates that can be converted in the same pot into polyfunctional sulfones, sulfonamides or sulfonic esters. We are presenting further applications of this method, including the synthesis of new medium-size heterocyclic systems of the type tetrahydro-2H-thiocines and hexahydro-1,2-thiazonine.