Journal of the Brazilian Chemical Society
On-line version ISSN 1678-4790
FORMENTON-CATAI, Ana Paula; MACHADO, Rosecler Pereira; LANCAS, Fernando M. and CARRILHO, Emanuel. Solid-Phase purification of deoxyguanosine-benzo[a]pyrene diol epoxide adducts from genomic DNA adduct synthesis. J. Braz. Chem. Soc. [online]. 2005, vol.16, n.4, pp.808-814. ISSN 1678-4790. http://dx.doi.org/10.1590/S0103-50532005000500020.
Polycyclic aromatic hydrocarbons are compounds widely present in the environment and well known to have carcinogenic and/or mutagenic properties. These substances when present in an organism are metabolized and can bind to DNA forming an adduct. Such adduct can induce replication errors that may cause carcinogenic tumor or genetic mutation. As a consequence, the determination of such adducts can be helpful in determining the risk for cancer development. In the present study, a synthesis of DNA adduct formed from the reaction of (±)-anti-7,8,9,10-tetrahydrobenzo[a]pyrene -7,8-diol 9,10-epoxide (BPDE) with calf thymus DNA has been carried out. The major product formed in this reaction is the binding of BPDE with the guanosine base. Since the reaction was conducted utilizing genomic DNA, a purification protocol for the adducts was necessary to isolate the main adduct. Solid phase extraction method was developed for isolation and purification of the adduct. The results have shown that a step gradient of water/methanol was needed to elute the adduct. Capillary zone electrophoresis with laser-induced fluorescence detection was used for monitoring the step-by-step purification procedure development and the analytical-grade adduct was characterized by UV/Vis and fluorescence spectroscopy, and electrospray ionization mass spectrometry.
Keywords : BPDE; biomarkers; carcinogens; capillary electrophoresis; mass spectrometry.