氧氟沙星甲基化物的核磁共振波谱研究

结合1H NMR,13C NMR,DEPT,HSQC,HMBC谱和碳氟偶合裂分行为,对氧氟沙星(ofloxacin,OFL)哌嗪部分的甲基化产物-甲基氧氟沙星(methyl-ofloxacin,Me-OFL)的结构进行归属,并探讨了Me-OFL在酸性及碱性溶液中的1H和13C谱的变化。碱性溶液中,5H的化学位移较酸性向高场移动1.02,推测此变化与形成C—H…O弱氢键有关。6C、13C、羰基碳7C和羧基碳15C分别向低场位移12.04,7.46,4.33,2.88 ppm,推测此变化与羧基和羧酸根的转变有关。另外,还比较了OFL哌嗪环4’N上质子化产物与烷基化产物的正电荷分布。当哌嗪环质子化形成季铵盐时,正电荷分布在氢原子上;当其烷基化形成季铵盐时,正电荷分布在氮原子上。

去甲基左氧氟沙星对映体的手性分离

目的建立去甲基左氧氟沙星手性分离的高效液相色谱方法。方法色谱柱采用十八烷基硅烷键和硅胶为填充剂,流动相为L-异亮氨酸硫酸铜溶液-甲醇(85:15),流速为1.0mL/min;检测波长330nm,柱温:40℃。结果在此条件下,去甲基左氧氟沙星及其对映体能够达到基线分离,分离度为2.7。结论简单快速,重现性好,能够用于去甲基左氧氟沙星对映体的分离和纯度考察。

自制左氧氟沙星羧甲基壳聚糖缓释微球体内结肠靶向释放的实验

目的:制备左氧氟沙星羧甲基壳聚糖(LVFX/CMC)微球并检测其在大鼠体内结肠靶向释药的性能。方法:色谱柱:KromasilRKR100-5C18(250 mm×4.6 mm),流动相:乙腈-0.1%三氟醋酸溶液(20:80),柱温:50℃,激发波长:295 nm,发射波长:495 nm,流速:1.0 ml/min。SD大鼠60只,随机分为2组,分别以LVFX/CMC微球(含40 mg左氧氟沙星)及等量左氧氟沙星溶剂灌胃,以高效液相色谱法对LVFX/CMC微球和左氧氟沙星(LVFX)灌胃后大鼠胃、小肠、盲肠、结肠及血液中药物浓度进行定量检测。结果:灌胃后LVFX/CMC微球组5 h盲肠、结肠药量分别达(3.394±0.197)和(1.873±0.216)mg,远高于LVFX组的(0.489±0.123)和(0.078±0.002)mg(P<0.01)。在9 h时LVFX/CMC微球组盲肠和结肠药量仍分别达到(1.580±0.234)和(0.713±0.073)mg,明显高于LVFX组的(0.105±0.023)和(0.054±0.016)mg(P<0.01)。LVFX/CMC微球组血药浓度于5 h后达到最高,而LVFX组1 h后即达最高血药浓度峰。微球组盲肠和结肠内容物的药量在7、9 h时段均明显大于胃和小肠内的药量。结论:左氧氟沙星羧甲基壳聚糖微球在体内实验中的释放符合结肠靶向释药的特点。

Antimicrobial Susceptibilities of Salmonella spp. Isolated from Chicken Meat Samples

The aim of this study was to determine presence of Salmonella spp. in chicken meat samples collected from Ankara, Turkey and determine the susceptibility of the Salmonella isolates to some antimicrobial agents. For this purpose, 127 chicken samples were collected from local markets. Investigation of Salmonella was done according to horizontal method, the guidelines of the method recommended by International Standards Organization （ISO）. Antimicrobial susceptibilities of Salmonella spp. was performed with microdilution method according to the guidelines of CLSI M100-SI8. Ampicillin, gentamicin sulphate, ofloxacin, levofloxacin, ciprofloxacin, enrofloxacin, tetracycline, ceftriaxon, amoxicillin/clavulanic acid and trimethoprim/sulfamethoxazole were used in the study. Salmonella spp. was isolated from 5 （3.94%） of the 127 chicken meat samples. Although our findings are not within Turkish Food Codex （TFC） values, lower number of samples that involve Salmonella spp. indicates an improvement in the hygienic conditions in Turkey. Among 5 isolates, one isolate was sensitive to all antimicrobial agents tested. 2 isolates exhibited multidrug resistance. Successfully, all the isolates were sensitive to quinolones as a good result in spite of the reported reduced susceptibility from different regions of the world. However, this study should be improved with more chicken samples and Salmonella spp. isolate numbers to support these results.