ABSTRACT
Gatifloxacin (GFX) is a kind of chiral fluoroquinolones compound due to the methyl group at the C-3 position of the piperazine ring[1]. Although the enantiomers of GFX show similar levels of antimicrobial activity and pharmacokinetics[2], the other biological activities (i.e., toxicity or enantioselective recognition to various receptors in vivo) of GFX enantiomers have not yet been studied. With this in mind, we developed a rapid and cost-effective high performance liquid chromatographic (HPLC) separation procedure for GFX enantiomers with a pre-column esterification strategy. With significant enhancement of drug solubility and optimization for chromatographic conditions, the proposed method was scaled up to preparative HPLC to obtain optical active S-(-)- and R-(+)-GFX. The antibacterial activities of GFX enantiomers after preparative separation were further verified by measuring the Minimum Inhibitory Concentration (MIC) values against Escherichia coli ATCC 25922. In addition, the binding selectivity of GFX enantiomers to protein receptor were evaluated by antibody using enzyme-linked immunosorbent assay (ELISA) for the first time.
Subject(s)
Anti-Bacterial Agents , Chemistry , Pharmacology , Escherichia coli , Esterification , Fluoroquinolones , Chemistry , Pharmacology , Microbial Sensitivity Tests , Molecular Structure , Structure-Activity RelationshipABSTRACT
Objective To study the changes of somatostatin(SOM) in plasma and cerebrospinal fluid (CSF) of children with convulsive diseases.Methods Sixty-seven children with convulsive diseases were studied as following:obtaining the samples of plasma in the 1st and 7th day after being in hospital,and the samples of CSF in the 1st after being in hospital.We investigated the changes of SOM in plasma and CSF with radioimmunoassay(RIA).Results 1.Convulsive group:the concentration of SOM in plasma in the 7th day(29.47?9.40 ng/L) was significant lower than that in the 1st day(39.23?11.00 ng/L)(t=21.530 P0.05).The concentration of SOM in plasma in the 1st day in control group was(19.58?6.04) ng/L.There were significant differences in convulsive group and encephalitis group without convulsion, control group(t= 6.847,7.921 P