A series of novel imidazo[1,5-a]pyridine-hydrazone derivatives were synthesized and characterized by infrared spectroscopy (IR), 1H NMR, 13C NMR and high resolution mass spectrometer (HRMS). Typically, the spatial structure of compound 3j was determined using X-ray diffraction analysis. The UV-vis absorption and fluorescence spectral characteristics of the compounds in dichloromethane and acetonitrile were investigated. Absorption peaks could be observed in the wavelength range 290-450 nm. It can also be seen that they display very similar maximum emission. The group attached to hydrazone hardly influenced the maximum emission. Furthermore, all the compounds were evaluated for antibacterial activity and were found to be more effective against Staphylococcus aureus, Listeria monocytogenes, Escherichia coli, Salmonella typhimurium, Pseudomonas aeruginosa and Shigella compared with chloramphenicol.

Paris Polyphylla Smith is widely used in traditional Chinese medicine. For its effective of antipyretic detoxicate, its active component is steroid saponin[1]. The present study was designed to evaluate the antioxidative effect of extracts of Paris Polyphylla Smith (PPSE) and its capacity to protect human umbilical vein endothelial cells (HUVECs) against oxidative damage induced by oxidized low density lipoprotein (ox-LDL). Cytotoxicity was determined by MTT assay. Flow cytometer (FCM) demonstrated that the increased apoptosis induced by oxidized low density were inhibited, and the blocked transition of cells from static phase (G0/G1) to DNA synthesis (S) were restored by PPSE, these effect were all in a dose-dependent manner. The actions by PPSE to reduce apoptosis may help protect endothelial function and inhibit atherogenesis, while the novel actions to mitigates oxidative stress may weaken the ability of endothelial injury. Further studies are needed to identify the chemical compounds responsible in order to develop its clinical application.