Khan Salman Ahmad, Saleem Kishwar, Khan Zaheer
Department of Chemistry, Jamia Millia Islamia, Jamia Nagar, New Delhi 110025, India.
Eur J Med Chem. 2007 Jan;42(1):103-8. doi: 10.1016/j.ejmech.2006.07.006. Epub 2006 Sep 25.
Herein, we report the synthesis of different steroidal thiazolo quinoxaline derivatives as antibacterial agents against Escherichia coli. Steroidal ketone thiosemicarbazones (4-6) were obtained from corresponding ketones (1-3) by refluxing with thiosemicarbazide. The thiosemicarbazones on reaction with 2,3-dichloroquinoxalines at 80 degrees C gives 3beta-acetoxy-5alpha-cholestan-6-[thiazolo(4,5-b)quinoxaline-2-yl-hydrazone] (7), 3beta-chloro-cholestan-6-[thiazolo(4,5-b)quinoxaline-2-yl-hydrazone] (8), and 5alpha-cholestan-6-[thiazolo(4,5-b)quinoxaline-2-yl-hydrazone] (9). The structures of the compounds were evident by elemental, IR, (1)H NMR and FAB mass spectral analyses. The antibacterial activities of these compounds were evaluated by disk diffusion method against the culture of E. coli and the results were compared with the standard drug amoxicillin. The results reveal that the compounds are better antibacterial agents as compared to amoxicillin. Among all the three compounds (7-9), compound 8 showed better zone of inhibition.
在此，我们报道了不同甾体噻唑并喹喔啉衍生物作为抗大肠杆菌抗菌剂的合成。甾体酮缩氨基硫脲（4 - 6）通过相应的酮（1 - 3）与氨基硫脲回流反应制得。缩氨基硫脲在80℃下与2,3 - 二氯喹喔啉反应得到3β - 乙酰氧基 - 5α - 胆甾烷 - 6 - [噻唑并(4,5 - b)喹喔啉 - 2 - 基腙]（7）、3β - 氯 - 胆甾烷 - 6 - [噻唑并(4,5 - b)喹喔啉 - 2 - 基腙]（8）和5α - 胆甾烷 - 6 - [噻唑并(4,5 - b)喹喔啉 - 2 - 基腙]（9）。通过元素分析、红外光谱、¹H NMR和FAB质谱分析确定了化合物的结构。采用纸片扩散法对这些化合物针对大肠杆菌培养物的抗菌活性进行了评估，并将结果与标准药物阿莫西林进行了比较。结果表明，与阿莫西林相比，这些化合物是更好的抗菌剂。在所有三种化合物（7 - 9）中，化合物8表现出更好的抑菌圈。
