Cyclic Voltammograms of Estrogen Quinones
Advisor Information
Douglas Stack
Location
Milo Bail Student Center Ballroom
Presentation Type
Poster
Start Date
8-3-2013 9:00 AM
End Date
8-3-2013 12:00 PM
Abstract
Estrogen is considered the strongest risk factor for breast and other human cancers. Oxidative metabolism of estrogen (Figure 1) generates o-quinones (Qs) that can damage DNA. The most genotoxic oquinone is E2-3,4-Q. Cyclic voltammetry (CV) was done on E2-2,3-Q, E2-3,4-Q, and 1-n-butyl- E2-3,4,Q in order to gain insight into their possible role as redox cycling metabolites. The first reduction potential of E2-2,3-Q, E2-3,4-Q, and 1-n-butyl- E2-3,4,Q was measured at -0.275, -0.495, and -0.965 V, respectively versus a silver/silver chloride reference electrode. The second reduction potential of E2-2,3-Q, E2- 3,4-Q, and 1-n-butyl-E2-3,4,Q was measured at -0.930, -0.935, and -1.440 V, respectively. All reduction potentials became more positive (more easily reduced) at lower pH. 1-n-butyl- E2-3,4,Q reduction potential was significantly made more positive when converted to its conjugate acid (-0.965V vs. +0.275 V). These results indicate that E2-2,3-Q is more easily reduced than E2-3,4-Q. While E2-3,4-Q has more a reversible CV profile indicating it a more likely candidate for redox cycling.
Cyclic Voltammograms of Estrogen Quinones
Milo Bail Student Center Ballroom
Estrogen is considered the strongest risk factor for breast and other human cancers. Oxidative metabolism of estrogen (Figure 1) generates o-quinones (Qs) that can damage DNA. The most genotoxic oquinone is E2-3,4-Q. Cyclic voltammetry (CV) was done on E2-2,3-Q, E2-3,4-Q, and 1-n-butyl- E2-3,4,Q in order to gain insight into their possible role as redox cycling metabolites. The first reduction potential of E2-2,3-Q, E2-3,4-Q, and 1-n-butyl- E2-3,4,Q was measured at -0.275, -0.495, and -0.965 V, respectively versus a silver/silver chloride reference electrode. The second reduction potential of E2-2,3-Q, E2- 3,4-Q, and 1-n-butyl-E2-3,4,Q was measured at -0.930, -0.935, and -1.440 V, respectively. All reduction potentials became more positive (more easily reduced) at lower pH. 1-n-butyl- E2-3,4,Q reduction potential was significantly made more positive when converted to its conjugate acid (-0.965V vs. +0.275 V). These results indicate that E2-2,3-Q is more easily reduced than E2-3,4-Q. While E2-3,4-Q has more a reversible CV profile indicating it a more likely candidate for redox cycling.