中文摘要：

目的寻找由抗菌氟喹诺酮向抗肿瘤氟喹诺酮转化的有效结构修饰途径。方法以抗菌氟喹诺酮药物氧氟沙星1为原料，其相应的酰肼2与二硫化碳缩环合得C-3噁二唑硫醇3中间体，然后分别与5-取代苯基-2-氯甲基-1，3，4-噁二唑4a-4g缩合得含氟喹诺酮骨架的双哄二唑甲硫醚5a-5g，接着用碘甲烷进行季铵化反应得相应的季铵盐6a-6g。用MTF方法评价了目标化合物5a-5g和6a-6g体外对肿瘤细胞的生长抑制活性。结果合成了14个新的目标化合物，体外均显示潜在的抗癌活性（IC50〈25μmol·L^-1），其中季铵盐6a-6g的活性高于相应游离碱5a-5g的活性。结论基于抗菌氟喹诺酮c-3杂环的抗肿瘤氟喹诺酮的设计值得进一步研究。

英文摘要：

OBJECTIVE To explore an efficient structure modification route to transform antibacterial fluoroquinolones to antitumot ones. METHODS Compound A [1,3, 4 ] oxadiazol-5-thiol 3 derived from ofloxacin 1 was subjected to nucleophilic substitution with each of chloromethyl-1,3,4-oxadiazoles 4a-4g gave di-oxadiazolyl methylsulfides 5a- 5g, followed by a quaternization to form the corresponding methiodides 6a -6g, respectively. The in vitro arltitumor activity of the title compounds 5a -5g and 6a -6g against three cancer cell lines was evaluated by MTT method. RESULTS Fourteen title compunds were synthesized and the structures were characterized by corresponding spectral data. The bioactive assay showed that compounds 5a -5g and 6a -6g exhibited a potential an- tieancer activity （IC50 〈 25 μmol·L^-1）. The activity of the quaternary ammoniums 6a -6g was higher than that of the corresponding free bases 5a -5g. CONCLUSION The design and synthesis of antitumor fluoroquinolone based on antibacterial fluoroquinolonc C- 3 heterocycle are worthy of further study.