15 and 16 Many copper complexes have been shown to cleave DNA in the presence of H2O2 due to their ability to behave like a Fenton catalyst.17 The ability of present complexes to effect DNA cleavage was monitored by gel electrophoresis using supercoiled pUC19 DNA in Tris–HCl buffer. Fig. 1 shows the electrophoretic
pattern of plasmid DNA treated with copper(II) complex. Control experiments suggest that untreated DNA and DNA incubated with either complex or peroxide alone did not show any significant DNA cleavage (lanes 1–3). However, in the presence of peroxide, see more copper complex was found to exhibit nuclease activity. Cleavage of DNA from supercoiled form to nicked form by the complex takes place at a concentration of 12 μM of complex and 300 μM of peroxide (lane 4). It is believed that when the present redox active copper
complexes were interacted with DNA in the presence of hydrogen peroxide as an oxidant hydroxyl radicals might be produced.18, 19, 20 and 21 ZD1839 mouse These hydroxyl radicals are responsible for cleavage of DNA. In order to establish the reactive species responsible for the cleavage of DNA, we carried out the experiment in the presence of histidine and DMSO (Dimethyl sulphoxide). When the standard hydroxyl radical scavenger DMSO was added to the reaction mixture of the complex and DNA, the DNA cleavage activity of 1 decreases significantly (lane 5). Interestingly, on addition of histidine to the reaction mixture, the DNA cleavage activity was not inhibited greatly (lane 6). This conclusively shows the involvement of the hydroxyl radical in the observed nuclease activity of complex 1in the presence of peroxide. In the present work a mononuclear copper(II) complex of tridentate reduced Schiff base ligand 1-(1H-benzimidazol-2-yl)-N-(tetrahydrofuran-2-ylmethyl)methanamine has been
isolated and characterized by various physico-chemical Adenylyl cyclase techniques. DNA cleavage was brought about by the copper complex in the presence of hydrogen peroxide. Also the active species responsible for DNA cleavage was studied. All authors have none to declare. The authors thank the Head, Department of Chemistry, UDC for the laboratory facilities. “
“Essential oils are recognized as volatile oily liquids obtained from plant that chemically constituted by variable mixture of constituent such as monoterpenes, sesquiterpenes and also aromatic compounds called phenylpropanes.1 They are known for their antimicrobial, virucidal, fungicidal, analgesic, sedative, anti-inflammatory, spasmolytic and locally anesthetic properties.2 Application of essential oils could control the growth of food-borne bacteria and other pathogenic microorganisms.3 Anethole and carvone occur naturally in many essential oils, and they have antimicrobial activity. Anethole ((E)-1-methoxy-4-(1-propenyl) benzene), a phenylpropene, is a clear and colorless to pale-yellow liquid with freezing and boiling points of 20 °C and 234 °C, respectively.