TY - JOUR
T1 - Synthesis and structure determination of the adducts formed by electrochemical oxidation of dibenzo[a,l]pyrene in the presence of adenine
AU - Li, Kai Ming
AU - Byun, Jaeman
AU - Gross, Michael L.
AU - Zamzow, Dan
AU - Jankowiak, Ryszard
AU - Rogan, Eleanor G.
AU - Cavalieri, Ercole L.
PY - 1999
Y1 - 1999
N2 - Because the radical cations of polycyclic aromatic hydrocarbons (PAH) are involved in tumor initiation, determination of the structures of biologically formed PAH-DNA adducts is important and relies on comparison of their properties with those of synthesized adducts. One of the possible sites of adduct formation is the N-3 position of Ade, but this depurinating adduct is not obtained by one-electron oxidation of dibenzo[a,l]pyrene (DB[a,l]P) in the presence of deoxyadenosine. Therefore, we turned to electrochemical oxidation of DB [a,l] P in the presence of Ade in dimethylformamide and produced the following adducts: DB [a,l] P-10-N1Ade (47%), DB[a,l]P-10-N3Ade (5%), DB[a,l]P-10-N7Ade (2%), and DB[a,l]P-10-N6Ade (6%). In Me2SO, this reaction afforded the same four adducts, but in slightly different yields: DB[a,l]P-10-N1Ade (44%), DB[a,l]P-10-N3Ade (9%), DB[a,l]P-10-N7Ade (1%), and DB[a,l]P-10-N6Ade (3%). These adducts were purified by reverse-phase HPLC, and the subtle differences between the isomers were revealed by NMR, tandem mass spectrometry, and fluorescence line-narrowing spectroscopy. The relative yields of the N1Ade, N3Ade, and N7Ade adducts reflect the nucleophilicity and steric accessibility of these three nitrogen atoms in Ade.
AB - Because the radical cations of polycyclic aromatic hydrocarbons (PAH) are involved in tumor initiation, determination of the structures of biologically formed PAH-DNA adducts is important and relies on comparison of their properties with those of synthesized adducts. One of the possible sites of adduct formation is the N-3 position of Ade, but this depurinating adduct is not obtained by one-electron oxidation of dibenzo[a,l]pyrene (DB[a,l]P) in the presence of deoxyadenosine. Therefore, we turned to electrochemical oxidation of DB [a,l] P in the presence of Ade in dimethylformamide and produced the following adducts: DB [a,l] P-10-N1Ade (47%), DB[a,l]P-10-N3Ade (5%), DB[a,l]P-10-N7Ade (2%), and DB[a,l]P-10-N6Ade (6%). In Me2SO, this reaction afforded the same four adducts, but in slightly different yields: DB[a,l]P-10-N1Ade (44%), DB[a,l]P-10-N3Ade (9%), DB[a,l]P-10-N7Ade (1%), and DB[a,l]P-10-N6Ade (3%). These adducts were purified by reverse-phase HPLC, and the subtle differences between the isomers were revealed by NMR, tandem mass spectrometry, and fluorescence line-narrowing spectroscopy. The relative yields of the N1Ade, N3Ade, and N7Ade adducts reflect the nucleophilicity and steric accessibility of these three nitrogen atoms in Ade.
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U2 - 10.1021/tx9801965
DO - 10.1021/tx9801965
M3 - Article
C2 - 10490495
AN - SCOPUS:0032877481
SN - 0893-228X
VL - 12
SP - 749
EP - 757
JO - Chemical Research in Toxicology
JF - Chemical Research in Toxicology
IS - 9
ER -