| Quinolones gets more and more use in the clinic for its advantages of high activity ,broad spectrum and the convenience in the taking, et al. At the same time , it also has some disadvantages, so develop new quinolones which has the high activity and low side-effect is the point of research. But the development is hindered by the high cost and long period. So , the QSAR (Quantity Structure Activity Relationship) study base on existent Quinolones Database is very important which can tell us the pharmacophore , the pharmacodyt et al, and we can analyze the candidate medicine, forecast the activity of the new compound . So QSAR can enable us to realize reasonable drug design which will greatly reduce blindness during the development of new medicine, cut down the cost and shorten the development period. Ant at the same time , the QSAR conduce us developing new medicine with high activity and low side-effect. The dissertation performed the study of Fluorescence spectrum character and QSAR based on charge transfer and hydrogen bond. The main content include four parts:First part:The charge transfer reaction and Fluorescence Spectrum between Ofloxacin(OFLX) and chloranil in the ethanol is studied, point out that electron donor is a electron donor, the reaction conditions are found , the max excitation wavelength is 329. 3nm, the max emission wavelength is 474. Onm, the complex ratio chloranil:ofloxacin is 1:2, Beer' s law is obeyed in the range 0.8?X 10~7mol/L, the minimal detection limit is 1. 84X10~8mol/L. And the determination of ofloxacin capsule is performed. The method has convenient operation, good stability, high sensitivity, and the recovery ratio meets the requirement.The experiment results prove that OFLX is a strong electron donor. We can conclude that OFLX works through reaction with electron acceptor.Second part:Studied the Fluorescence Spectrum of ternary system Mg(II) , amino acid(include serine and leucine) and OFLX in the NH3桸H4Cl buffer solution, the results indicate that Mg(II) has Fluorescence quenching effect to OFLX, amino acid has no obvious effect. But Mg(II) has Fluorescence sensitization in the ternary system, which show that Mg(II), amino acid and OFLX have synergetic effect. Theresult prove that Mg(II) has important function in the process of pharmacody .The experiments also make out that serine has stronger Fluorescence sensitization than leucine, and we know that there is the variation of from serine to leucine in DNA topoisomerase through the study of molecular biology, we can say that the site that take place variation is the activity site, and along with the variation of topoisomerase, the ability to form hydrogen bond falls sharply. So we conclude that Quinolones works through hydrogen bond.Third part:The QSAR through multivariant regression is performed on 18 substituent Quinolones in N-1 site. The parameters that used are calculated with AMI (Austin Model) and MNDO(modified neglect diatomic overlap) method by Mopac97 and Gaussian98 software. The regression results indicate that the main factors that influence the anti-bacterial activity are HOMO, Al(4~site ketone oxygen) and A2(3~site carboxyl ketone oxygen). Thereinto HOMO and Al support the electron donor function mechanism which illuminate the electron donor function mechanism of Quinolones wholly .And we can see that AMI method is better than MNDO method. Which is correspond concerned with that the AMI method includes hydrogen bond ingredient. The results imply that hydrogen bond is a important reason of Quinolones' activity.Fourth part:The forecast of 69 Quinolones' activity is performed through ANN (artifical neural net) , the method that used includes BP(Back propagate), LM(LM algorithms) and RBF(Radial Basis Function) neural net. For the anterior two method , the most feasible number of nerve cell is 15. The RBF method has the best speed that it can get the training aim no more than 100 iteration, the forecast accuracy rate is 100% to the training set. As for the test sets, the accuracy...
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