Synthesis and antitumor and antibacterial evaluation of fluoroquinolone derivatives(Ⅲ):Mono- and bis-Schiff-bases

To further explore an efficient modified route for the shift from an antibacterial fluoroquinolone to an antitumor one,mono-Schiff bases 6a-6h related to ciprofloxacin C3 carbonylhydrazone and bis-Schiff bases 4a-4h corresponding to C3/C7 carbonylhydrazone/hydrazone attached on a skeleton of ciprofloquinolone were designed and synthesized,and their in vitro antitumor activity against CHO,HL60,L1210 cells and antibacterial activity against Staphylococcus aureus and Escherichia coli were also reported.     

Development and validation of an LC/MS/MS method for simultaneous determination of shionone and epi‐friedelinol in rat plasma for pharmacokinetic study after oral administration of Aster tataricus extract

A rapid and sensitive liquid chromatography tandem mass spectrometry (LC/MS/MS) method was developed and validated using spinasterol as the internal standard (IS) for the simultaneous determination of shionone and epi‐friedelinol in rat plasma. Plasma samples were pretreated using liquid–liquid extraction with ethyl ether. Chromatographic separation was achieved on a C₁₈ column (100 × 2.1 mm, 5 μm) with an isocratic elution consisting of acetonitrile–0.1% formic acid water (75:25, v/v) at a flow rate of 0.30 mL/min. Detection was performed under the selected reaction monitoring scan using an electrospray ionization in the positive ion mode. The mass transitions were as follows: m/z 427.4 → 95.1 for shionone, m/z 411.4 → 205.2 for epi‐friedelinol and m/z 395.3 → 105.2 for IS. All calibration curves exhibited good linearity (r > 0.995) over the concentration range for both components. The intra‐ and inter‐day precisions at three QC and lower limit of quantitation levels were both <10.21% in terms of relative standard deviation, and the accuracy ranged from ?7.13 to 8.02% in terms of relative error. The extraction recoveries of the compounds ranged from 82.07 to 89.81%. The developed method was successfully applied to the pharmacokinetic study of shionone and epi‐friedelinol after oral administration of Aster tataricus extract to rats. Copyright © 2015 John Wiley & Sons, Ltd.     

Biomimetic design of amphiphilic polycations and surface grafting onto polycarbonate urethane film as effective antibacterial agents with controlled hemocompatibility

The synthetic polycations are ideal candidates as antimicrobial agents, because they resemble natural antimicrobial peptides, but to render hemocompatibility to these materials is a great challenge. Herein, we used 2‐(tert‐butyl‐aminoethyl) methacrylate (TBAEMA), to synthesize its homopolymer and pegylated random and diblock copolymers with polyethyleneglycol methacrylate (PEGMA, M_n = 360 Da) by single‐electron transfer–living radical polymerization (SET‐LRP). In the second step, the secondary amino groups in the precursor polymers were quaternized with iodomethane and bromohexane, to obtain three series of quaternized polymers. The antimicrobial properties of these quaternized polymers were evaluated against Escherichia coli (E. coli), by studying the minimum inhibitory concentrations (MICs) which ranged between 32 and 200 mg L^?1 and showed higher values for the quaternized random than the diblock copolymers. In addition to, we have also demonstrated the grafting of these polycations onto polycarbonate urethane film surfaces, which showed good killing efficacy against E. coli. Furthermore, the hemolysis of these materials was investigated against human red blood cells, which indicated that except the quaternized homopolymers that showed highest hemolysis, all other amphiphilic polycations exhibited very low hemolytic activity. Therefore, our designed materials with controlled structures and functionality, synthesized from cheaply available resources could serve as useful agents in the field of biomedicines and implantable materials. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 3166–3176     

A Facile Route to Synthesize α,α′-bis(Substituted-benzylidene) Cycloalkanones Promoted by SmI3

Promoted by SmI₃ cycloalkanone trimethylsilyl enol ethers were reacted with aldehydes to give α,α′-bis (substituted-benzylidene) cycloalkanones.     

变限积分的求导方法

结合实例归纳总结不同类型变限积分的求导方法．