Synthesis of4-aminoantipyrine Schiff bases and their antimicrobial activities

Various compounds of 4-aminoantipyrine Schiff bases (M1-M12) were synthesized via a condensation reaction of 4-aminoantipyrine with different benzaldehydes through a conventional method of refluxing the mixture for 3-4 h.The synthesized Schiffbases were characterized bY using elemental analyses,FT-IR,UV-Vis,Mass,1H and 13C NMR spectroscopy.The antimicrobial activity of the synthesized Schiff bases was investigated against 12 bacterial strains (Mycobacterium smegmatis,Bacillus cereus,Bacillus subtilis,Enterococcus faecalis,Staphylococcus epidermidis,Klebsiella pneumonia,Escherichia coli,Enterobacter cloacae,Klebsiella oxytoca,Proteus vulgaris,Enterobacter aerogenes,and Pseudomonas aeruginosa),and antifungal activities were tested against seven fungal strains (Aspergillus flavus,Aspergillus carbonarious,Aspergillus parasiticus,Aspergillus fumigatus,Aspergillus niger,Fusarium verticillioides and Fusarium proliferatum).The antimicrobial activities of the synthesized compounds were compared with standard streptomycin and nalidixic acid.The results obtained from antibacterial assay indicated that M1-M12 inhibited potential growth of Proteus vulgaris with minimum inhibitory concentrations (MICs) ranging from 15.6-250 μg/mL compared with the standard nalidixic acid with an MIC of 500 μg/mL.Moreover,we could conclude that most of the tested compounds experienced mild to low activities at 15.6 μg/mL.Their activities could be attributed to their low concentration s.The antifungal analysis showed that the tested fungi were not sensitive to the prepared Schiffbases at the prepared concentration of 500 tg/mL.Therefore,we recommended further analysis on both cytotoxicity and minimum bactericidal concentration (MBC) to ascertain their potential effects against human cells.

The inhibition of acetylcholinesterase (ACHE) activity has been widely used as a biomarker in an animal exposed to the pesticides. However, the interaction of extensively used organocarbamate insecticide, carbofuran, with the nervous system of the aquatic organisms is not properly studied. AChE is a key enzyme which catalyses the hydrolysis of acetylcholine, a neurotransmitter at the neuromuscular junctions, and thus regulates the neurotransmission system. In the present study, we have evaluated the impact of sub-acute concentrations (0.01 and 0.02 mg/L i.e. 1/20th and 1/10th of LC50) of carbofuran on the activity of acetylcholinesterase,from different tissues of Clarias batrachus, a fresh water teleost, after 96 hr and 15 days exposure periods in vivo. The carbofuran significantly reduced the activity of AChE in different tissues of C. batrachus at both concentrations and periods of exposure. The greater inhibition of AChE activities were recorded in fish tissues at higher carbofuran concentration (0.02 mg/L) after longer (15days) treatment period. The inhibition of AChE activity in all fish tissues tested was dependent on pesticide concentration and the duration of treatment. AChE from the tissues of C. batrachus was found to be a true cholinesterase as it was completely inhibited by the small concentration (nM) of eserine as tested in vitro. It was found that carbofuran at very low concentration exerted significant inhibitory effect on AChE activity in fish tissues.

肝细胞刺激因子对肝癌细胞和大鼠肝细胞增生作用的研究

目的探讨肝细胞刺激因子(HSS)对正常大鼠肝细胞和人肝癌细胞的作用特点.方法应用自制的HSS分别与正常大鼠肝脏细胞和人传代肝癌细胞共同培养不同时间,以促进肝细胞增生的IL-6为对照组,采用3H-TdR掺入法,观察HSS对大鼠肝细胞和人肝癌细胞分裂增生和细胞形态变化的影响.结果在培养早期HSS对正常大鼠肝细胞和人肝癌细胞均具有刺激增生的作用,随后HSS对这些细胞的增生具有明显的抑制作用,并伴随着细胞的死亡形态改变.结论HSS对人肝癌细胞和正常大鼠肝细胞的增生不仅有促进作用,而且具有较强的抑制作用,此对进一步研究HSS的生物学活性和临床应用具有重要意义.