In Vitro Metabolism Of Valne Mulin Derivatives And The Study On The Anti-bacterial Activity

In this paper,the in vitro and in vivo antibacterial activity of a compound of Valnemulin prodrug(?)and its in vitro metabolism in three biological substrates were reported.The minimal inhibitory concentration(MIC)of the six strains of Staphylococcus aureus,7 strains of Escherichia coli strain,3 Streptococcus strains and Mycoplasma gallisepticum were determined by micro-broth dilution method.The results showed that the derivatives(MIC)was 0.003~0.007?g/ mL,and the minimum inhibitory concentration(MIC)of the strain was 0.0156~0.03(P <0.05).The minimum inhibitory concentration(MIC)was 0.003 ~ 0.007 ?g / mL for 6 strains of Staphylococcus aureus(MIC)was 0.008 ?g / mL,and the minimum inhibitory concentration(MIC)of 7 strains of Escherichia coli was4~32?g/mL.Derived(?)on Staphylococcus aureus,Streptococcus in vitro antibacterial activity is excellent,the antibacterial effect is better than the control group(Wo N i Miao Lin);on the in vitro antibacterial activity of Mycoplasma gallisepticum and Werner Miaolin quite.In this study,we established a model of Staphylococcus aureus infection in mice with granulocytopenia and a streptococcus,? on Staphylococcus aureus ATCC 25923 and Streptococcus 10373 in both models?The results showed that the effect of compound ? on Staphylococcus aureus in mice was significant,and the bacteriostatic effect was comparable to that of Valnemulin(P>0.05).The antibacterial effect of compound ? on Streptococcus was excellent and Dose dependent and antimicrobial activity was comparable to that of Valnemulin(P>0.05).In this study,high performance liquid chromatography-tandem mass spectrometry(HPLC-MS/MS)method for the determination of compound ? and compound Valnemulin was carried out.The two drugs were tested simultaneously.The sample was purified by centrifugation with acetonitrile,and the supernatant was 0.22?m.The CNW C8 column was selected to separate the two analytes by gradient elution.The mobile phase consisted of a gradient of 0.1% formic acid aqueous solution(A)and acetonitrile(B).The API4000 triple quadrupole mass spectrometer with an electrospray ionization(ESI)source w as used to detect both analytes in a positive electrospray ionization mode.Triple quadrupole for multiple reaction monitoring(MRM)mode.A calibration curve for matrix matching was prepared and used for quantification.In the concentration range of 2~500ng / mL showed good linearity,the correlation coefficient(r2)is greater than 0.99.The sensitivity of the method evaluated by the detection limit(LOD)and the limit of quantification(LOQ),LOD no more than 2 ng / g,LOQ no more than 5 ng / g.The evaluation results show that the method is stable,the sensitivity and accuracy are high,and the reproducibility is good,which meets the requirement of sample detection.The results showed that compound ? did not metabolize in the liver homogenate and its content did not change significantly.It was proved that compound ? did not change in the liver homogenate.The results showed that compound ? did not change in the liver homogenate,in the artificial gastric juice and artificial intestinal fluid,the content of the prodrug compound ? was reduced,and the production of the target compound Valnemulin was proved.The prodrug compound ? could be metabolized in the artificial gastrointestinal fluid and could be converted into.The target metabolite Valnemulin,after calculation,compound ? in artificial gastric juice and artificial intestinal fluid maximum metabolic rate can reach 78.4% and 72.2%.