本文旨在评价抗结核分枝杆菌先导化合物E在体外抗H37Ra的活性，为新型抗结核药物筛选提供参考依据。应用96孔板微稀释法测定化合物E单独及与异烟脱(INH) 、利福平(RIF)联合应用时对H37Ra的最小抑菌浓度(MIC)。从肉眼未见细菌生长孔取培养物涂Middlebrook 7H10-ADC平板，以没有细菌生长所对应孔的浓度为化合物E的最小杀菌浓度(MBC) 。并采用棋盘滴定法计算分级抑菌指数(FICI)，评价化合物E与其他抗结核药物之间是否存在协同作用。采用药物暴露法，将培养10 d，6周的H37Ra暴露于不同浓度的化合物E中3d，涂板测定化合物E对不同生长时期H37Ra的杀菌作用。同法测定化合物E在酸性缺氧条件下对不同生长时期H37Ra的杀菌作用。测定H37Ra对化合物E、INH的耐药频率并分离耐药菌株。结果显示，化合物E对H37Ra的MIC为0.078μg/ml , MBC为0.312μg/ml; 与一线抗结核药物INH和RIF联合应用时，MIC分别降至单独应用化合物E的1/2 MIC、1/10MIC, FICI分别为0.6 、0.27，表明化合物E与INH联用有相加作用，与RIF联用有协同作用。药物暴露实验结果表明，在正常条件下新型小分子化合物E对生长活跃期(10 d) 结核分枝杆菌有明显的杀菌活性;在酸性缺氧条件下，化合物E对生长2个月的结核分枝杆菌具有较好的杀菌活性。3轮实验均未筛选出耐化合物E的H37Ra菌株，而H37Ra对INH的耐药频率为3 .4 X 10^-6 。这些结果显示，化合物E具有较好的体外抗结核分枝杆菌的活性，值得进一步研究。

In order to evaluate the antituberculous activities of leading compound E in vitro and provide the evidence for further studies, the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of compound E , isoniazid (INH) and rifampicin (RIF) against Mycobacterium tuberculosis H37Ra were determined by standard methods. Synergy between compound E and INH/RIF was determined by chequerboard titration in 96-well microtitre plates. According to MICs of the drugs alone and in combination , the fractional inhibitory concentration index (FICI) was calculated to find out that if there was synergy between the drugs. The elimination rate of non-growing H37Ra under normal as well as hypoxic and acidic conditions were determined by drug exposure in 3 days. Drug-resistant mutants of H37Ra and drug-resistant frequencies were obtained by Middlebrook 7H10-ADC agar containing compound E or INH.The results indicated that compound E was active against H37Ra with MIC of 0.078μg/ml ， and MBC of 0.312μg/ml. There was an additive effect between compound E and INH (FICI = 0.6) and a synergistic effect between E and RIF (FICI = 0. 27). The results also indicated that compound E showed better antituberculous activity against 10-day-old H37Ra than 6-week-old H37Ra under normal growth condition, but more active against 2-month-old H37Ra than 3-week-old H37Ra under hypoxic and acidic condition. No H37Ra resistant to compound E was detected after three independent repeats while the INH-resistant frequency was 3.4 x 10-⁶.