Cholinesterase Inhibitory Assay and Antimicrobial Effect of Four Constituents of Lonicera quinquelocularis Against Gram Positive and Gram Negative Bacteria

A phytochemical study on the chloroform soluble fraction of Lonicera quinquelocularis led to the first time isolation of four known compounds (1-4). These compounds were tested against two human Gram-positive bacteria (Staphylococcus aureus, Micrococcus luteus) and four Gram-negative ones (Escherichia coli, Pseudomonas aeruginosa, Enterobacter cloacae, Klebsiella pneumoniae). The agar well diffusion method was used to check the antibacterial activity of these four compounds. The antifungal activity against Aspergillus niger was determined by the agar well diffusion method. Compound (1) showed maximum antimicrobial activities. The MIC of the compound 1 was determined by agar dilution method while the MBC was carried out by viable cell count method. Two different antibiotics (ampicillin and ofloxacin) were used as positive controls. For antifungal activity an effective antifungal "Itraconazole" was used as a control standard. In addition the isolated compounds were assayed for their Acetyl cholinesterase (AChE) and Butyryl cholinesterase (BChE) inhibitory activities. Moreover, the IC (50% inhibitory effect) values of compounds 1 50