53555-67-2Relevant academic research and scientific papers
Radical cations of benzo[a]pyrene and 6-substituted derivatives: Reaction with nucleophiles and DNA
Stack,Cremonesi,Hanson,Rogan,Cavalieri
, p. 755 - 760 (2007/10/03)
1. Oxidation of benzo[a]pyrene (BP) by I2 in the presence of AgClO4 in benzene generates the BP.+ ClO4- · AgI complex. This same method was used to produce radical cations from 6-FBP, 6-ClBP, 6-BrBP and 6-CH3BP. 2. Reaction of the BP,6-FBP,6-ClBP and 6-BrBP radical cation perchlorates with H2O produced BP 1,6-, 3,6- and 6,12- dione, whereas 6-CH3BP.+ClO4- · AgI yielded 6-CH2OHBP. 3. When BP.+ClO4- · AgI and 6-FBP.+ClO4- · AgI were reacted with NaOAc in H2O/CH3CN (9:1), 6-OAcBP was formed, in addition to the quinones. In the case of 6-CIBP.+ClO4- · AgI, a small amount of 1-OAc-6-ClBP and 3-OAc-6-ClBP was formed in, addition to the diones, whereas for 6-BrBP and 6-CH3BP the reaction products were BP diones and 6-CH2OHBP respectively. 4. These results confirm the localization of charge in the BP.+ at C-6, followed by C-1 and C-3. 5. The reaction of BP with NOBF4 in CH2Cl2 produced BP.+ BF4-, radical cation free of complexation with inorganic salts. 6. Reaction of BP.+BF4- with DNA produced the depurinating adducts BP-6-C8Gua, BP-6-C8dGua and BP-6-N7Gua.
Chemical Oxidation of Nitrated Polycyclic Aromatic Hydrocarbons: Hydroxylation with Superoxide Anion Radical
Fukuhara, Kiyoshi,Miyata, Naoki
, p. 27 - 33 (2007/10/03)
Nitrated polycyclic aromatic hydrocarbon (nitroPAH) is a potent mutagen which is reductively and/or oxidatively metabolized. Biological oxidation of nitroPAH, such as hydroxylation and epoxidation, is known, but chemical oxidation has been reported in only a few papers. NitroPAH is barely oxidized by various chemical oxidants because of the electron deficient property of the aromatic ring with the nitro substituent. Nucleophilic reactivity of superoxide anion radical is known, and thus the oxidation of nitroPAH with the chemically generated superoxide anion radical was carried out in this study. When 1-nitropyrene was reacted with KO2/18-crown-6 in dimethylformamide, 5-, 6-, 8-, and 9-hydroxy-1-nitropyrenes and 1-hydroxypyrene were obtained in preparative yields. Three isomeric dinitropyrenes, 3-nitrofluoranthene, 6-nitrobenzopyrene, and 6-nitrochrysene, were oxidized to hydroxy derivatives, some of which correspond to the oxidative metabolite of nitroPAH. The oxidation of dinitropyrenes with trifluoroperacetic acid gave K-region oxidized products.
Radical Cations of Benzopyrene and 6-Substituted Derivatives: Synthesis and Reaction with Nucleophiles
Cremonesi, Paolo,Stack, Douglas E.,Rogan, Eleanor G.,Cavalieri, Ercole L.
, p. 7683 - 7687 (2007/10/02)
Radial cations of benzopyrene (BP) and 6-substituted derivatives were synthesized by two methods: reaction of the hydrocarbon with I2 and AgClO4 in benzene, and reaction of the hydrocarbon with NOBF4 in CH3CN/CH2Cl2.Both the radical cation perchlorates and tetrafluoroborates were stable for prolonged periods of time when stored under argon at subzero temperatures.The radical cations were reacted with nucleophiles of various strengths, namely H2O, AcO(1-) and F(1-), as a means of best characterizing these intermediates, as well as determining their chemical properties.Reaction of BP, 6-FBP, 6-ClBP, and 6-BrBP radical cation perchlorates with H2O produced BP 1,6-, 3,6-, and 6,12-dione, whereas the radical cation derived from 6-CH3BP yielded 6-CH2OHBP.When BP(.1+)ClO4(1-) and 6-FBP(.1+)ClO4(1-) were reacted with NaOAc in H2O/CH3CN (9:1), 6-OAcBP was formed, in addition to the quinones. 6-ClBP(.1+)ClO4(1-) formed a small amount of 1-OAc-6-ClBP and 3-OAc-6-ClBP, in addition to the diones, whereas for 6-BrBP(.1+)ClO4(1-) and 6-CH3BP(.1+)ClO4(1-) the reaction products were BP diones and 6-CH2OHBP, respectively.Reactions conducted under anhydrous conditions, using tetramethylammonium acetate in CH3CN, gave similar results, except that no quinones were formed.These results confirm the reactivity of nucleophiles at the postions of high charge localization in the BP(.1+), i.e.C-6, followed by C-1 and C-3.
One-Electron Oxidation of Dibenzopyrenes by Manganic Acetate
Cremonesi, Paolo,Hietbrink, Bruce,Rogan, Eleanor G.,Cavalieri, Ercole L.
, p. 3309 - 3312 (2007/10/02)
The dibenzopyrenes (DBPs) are carcinogenic polycyclic aromatic hydrocarbons (PAH) found as environmental pollutants.DBP is the most potent carcinogenic PAH ever tested.To investigate the bioactivation of DBPs by one-electron oxidation, oxidation of DBP, DBP, DBP, DBP, and anthanthrene with Mn(OAc)3 was conducted and compared to that of benzopyrene (BP).All five DBPs produced monoacetoxy derivatives, and all of them except DBP also produced diacetoxy derivatives.Kinetic studies of the formation of monoacetoxy and diacetoxy derivatives of DBPs were carried out and the results were compared to those of the parent compound BP.DBP was similar to BP.DBP reacted inefficiently to form monoacetoxy and diacetoxy products.The other three DBPs resembled one another.These results provide preliminary essential information for studies of the bioactivation of the very potent carcinogen DBP to form DNA adducts.
One-Electron Oxidation of 6-Substituted Benzopyrenes by Manganic Acetate. A Model for Metabolic Activation
Cremonesi, Paolo,Cavalieri, Ercole L.,Rogan, Eleanor G.
, p. 3561 - 3570 (2007/10/02)
Radical cations of benzopyrene (BP) and 6-substituted derivatives were generated by one-electron oxidation with 2 equiv of Mn(OAc)3*2H2O.Some of the properties of these radical cations were investigated by nucleophilic trapping with acetate ion.BP produced predominantly 6-OAcBP and small amounts of BP 1,6-, 3,6-, and 6,12-dione. 6-FBP yielded 6-OAcBP, a mixture of 1,6-(OAc)2BP and 3,6-(OAc)2BP, and BP diones.In the case of 6-ClBP and 6-BrBP the major products obtained were a mixture of the 1-OAc and 3-OAc derivatives, and BP diones, while substantial starting material remained unreacted. 6-CH3BP afforded mostly 6-OAcCH2BP, a mixture of 1-OAc and 3-OAc derivatives of 6-CH3BP, and a mixture of 1-OAc and 3-OAc derivatives of 6-OAcCH2BP.These results indicate that nucleophilic substitution of BP-radical-cation and 6-FBP-radical-cation occurs exclusively at C-6.For 6-ClBP-radical-cation and 6-BrBP-radical-cation substitution at C-1 and C-3, which are the positions of second highest charge density in their radical cations after C-6, complete successfully for nucleophilic substitution.For 6-CH3BP-radical-cation charge localization at C-6 activates the methyl group rendering it the most reactive toward nucleophilic attack.Competitive acetoxylation of 6-CH3BP-radical-cation also occurs to a minor extent at C-1 and C-3.These mechanistic studies have been useful in clarifying some aspects of the metabolism of BP and its halogeno derivatives by cytochrome P-450 and peroxidases.Furthermore, this chemistry can provide some guidance in understanding the mechanism of tumor initiation by these compounds.
PREPARATION, PROPERTIES, AND SOME CHEMICAL REACTIONS OF PHENALENOFURAN
Weeratunga, Gamini,Austrup, Mona,Rodrigo, Russell
, p. 3169 - 3174 (2007/10/02)
The synthesis of hitherto unknown phenalenofuran (1), in 11 percent overall yield from 2-naphthol, has been achieved.Its (1)H and (13)C n.m.r. spectra have been fully assigned by means of heteronuclear 2D correlations.The furanoid moiety of (1) displays Diels-Alder diene reactivity in its reactions with benzyne, dimethyl acetylenedicarboxylate, and singlet oxygen.The furan ring of (1) also suffers oxidation by m-chloroperbenzoic acid and undergoes catalytic hydrogenation.This chemistry appears to be more characteristic of naphthofuran than of naphthofuran although both structural units co-exist in structure (1).
