1-环丙基-5-取代-7-(4-甲基哌嗪基）-6,8-二氟-1,4-二氢 -4-氧-3-喹啉羧酸的定量构效关系

通过量子化学AM1和Monte Carlo模拟计算，对1-环丙基-5-取代-7-(4-甲基哌嗪基）-6,8-二氟-1,4-二氢-4-氧-3-喹啉羧酸的定量构效关系进行了研究，结果显示5-位取代基的体积V、表面积S、与母核紧连原子的净电荷、指示变量等对抗菌活性有很大影响，回归得到了相关性好的方程：((4)R=0.9，(5)R=0.94)，(6)R=0.95)。5-位小的取代基、4-位和5-位形成氢键对抗菌活性有利。计算表明5-为被甲基取代后具有更好的抑制金葡萄菌和绿脓杆菌的抗菌活性。

QSAR of 1-Cyclopropyl-5-Substituted- 6,8-Difluoro -7-4-(methyl-1-piperazinyl) -4(1H)-Oxoquinoline-3-Carboxylic Acids

By the method of AM1 and Monte Carlo Simulation calculation, quantitative-activity relationships of 1-cyclopropyl-5-substituted-6, 8-difluoro-7-(methyl-1-piperazinyl)-4(1H)-oxoquinoline-3-arboxylic acids were invest-igated. The results showed than van der Waals Volume V 、dipole moment DM 、 INDEX and the net charge Q (first atom connect to the nucleus)of C-5 group are influence on antibacterial activities in vitro,the correlation coefficients of the regressions are high ((4)R=0.90(5),R=0.94,(6)R=0.95).Small groups（ H、 F、 NH2 et al ) of C-5 are in favor of antibacterial activities. Hydrogen bond between C-4 and C-5 improves the antibacterial activities. C-5 substituted by CH3 group calculated has higher antibacterial activities for S.aureus and P.aeruginosa than others and its antibacterial activity of E.coli NIHJ JC-2 is also high but lower than that of NH2 group.