Delineating oxidative processes of aqueous C60 preparations: role of THF peroxide.
The oxidative reactivity of THF derivatives formed during THF/nC60 synthesis was evaluated with indigo dye as a model compound. The results showed that the formation of previously undetected oxidizing agents during THF/nC60 synthesis accounted for the degradation of indigo dye by THF/nC60 (THF/nC60/unwashed), while THF/nC60 after vigorous washing (THF/nC60/washed) and nC60 prepared without the use of THF were not reactive. gamma-Butyrolactone (GBL) was detected by GC-MS in the THF/nC60/unwashed as one of THF derivatives, but showed no reactivity with indigo dye. An organic peroxide was detected in the THF/nC60/unwashed by HPLC, and was reactive with indigo dye. This compound was found to also account for the elevated antibacterial and bactericidal activities of THF/nC60/unwashed on E. coli. Analysis by LC/(+ESI)MS and 1H NMR showed that the detected THF peroxide was tetrahydro-2-(tetrahydrofuran-2-ylperoxy)furan. The formation of THF peroxide during the preparation of aqueous stable C60 aggregates provides another potential explanation for the reactivity and oxidative stress mechanisms of THF/nC60 system reported in the literature, although it does not exclude the potential reactivity and toxicity of nC60 itself.
Zhang
Bo
B
School of Civil and Environmental Engineering, Georgia Institute of Technology, 200 Bobby Dodd Way, Atlanta, Georgia 30332, USA.
Cho
Min
M
Fortner
John D
JD
Lee
Jaesang
J
Huang
Ching-Hua
CH
Hughes
Joseph B
JB
Kim
Jae-Hong
JH
D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001419:Bacteria / Q000187:drug effects; D002498:Centrifugation; D002849:Chromatography, Gas; D002851:Chromatography, High Pressure Liquid; D004396:Coloring Agents / Q000737:chemistry; D004926:Escherichia coli / Q000187:drug effects; D005374:Filtration; D037741:Fullerenes / Q000737:chemistry* / Q000494:pharmacology; D005663:Furans / Q000737:chemistry* / Q000494:pharmacology; D007203:Indigo Carmine; D007211:Indoles / Q000737:chemistry; D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D008826:Microbial Sensitivity Tests; D050296:Microbial Viability / Q000187:drug effects; D010084:Oxidation-Reduction / Q000187:drug effects; D010545:Peroxides / Q000737:chemistry*; D014867:Water / Q000737:chemistry*
D000900:Anti-Bacterial Agents; D004396:Coloring Agents; D037741:Fullerenes; D005663:Furans; D007211:Indoles; D010545:Peroxides; D014867:Water; C018674:tetrahydrofuran; D007203:Indigo Carmine