title: Respiratory chain inhibition by fullerene derivatives: hydrogen peroxide production caused by fullerene derivatives and a respiratory chain system.
abstract: Fullerene is a new type of carbon allotrope. We have shown that the fullerene derivative C(60)-bis(N,N-dimethylpyrrolidinium iodide), a regio isomer mixture, inhibited Escherichia coli growth and dioxygen uptake caused by E. coli and glucose. This result indicates that the mechanism of the bacteriostatic effect is the inhibition of energy metabolism. In this study, we isolated two regio isomers of C(60)-bis(N,N-dimethylpyrrolidinium iodide) and studied their effect on E. coli growth and on respiratory chain activity. In dioxygen uptake caused by the inner-membrane and NADH, the effect of fullerene derivatives was biphasic. At low concentrations of both fullerene derivatives, dioxygen uptake was inhibited, whereas at high concentrations, it was increased. At high concentrations, consumed dioxygen was converted to H(2)O(2). An electrochemical study revealed that reduced fullerene derivatives react with dioxygen. This activity was closely related to a redox property of the isomers.
authors.affiliation: Kyoritsu College of Pharmacy, 1-5-30, Minato-ku, Shibakoen, Tokyo 105-8512, Japan. mashino-td@kyoritsu-ph.ac.jp
authors.forename: Tadahiko
authors.initials: T
authors.lastname: Mashino
authors.forename: Noriko
authors.initials: N
authors.lastname: Usui
authors.forename: Kensuke
authors.initials: K
authors.lastname: Okuda
authors.forename: Takashi
authors.initials: T
authors.lastname: Hirota
authors.forename: Masataka
authors.initials: M
authors.lastname: Mochizuki
mesh_terms: D002374:Catalase / Q000494:pharmacology; D004563:Electrochemistry; D004579:Electron Transport / Q000187:drug effects*; D004926:Escherichia coli / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D037741:Fullerenes / Q000494:pharmacology*; D006861:Hydrogen Peroxide / Q000378:metabolism*; D007202:Indicators and Reagents; D007536:Isomerism; D007700:Kinetics; D010100:Oxygen / Q000378:metabolism
chemical_list: D037741:Fullerenes; D007202:Indicators and Reagents; D006861:Hydrogen Peroxide; D002374:Catalase; D010100:Oxygen