Electron paramagnetic resonance, kinetics of formation and decomposition studies of (bis(hydroxyethyl)amino-tris(hydroxymethyl)-methane)oxochromate(V): a model chromium(V) complex for DNA damage studies.

A new chromium complex, (bis(hydroxyethyl)amino-tris(hydroxymethyl)methane)oxochromate(V), has been characterized by epr spectroscopy. The chromium(V) complex was formed by the ligand displacement reaction of bis(2-ethyl-2-hydroxybutanato) oxochromate(V) with bis(hydroxyethyl)amino-tris(hydroxy-methyl)methane (BT). Both epr and kinetic data indicate that the reaction proceeds through a chromium(V) intermediate.

Mechanisms of DNA damage by chromium(V) carcinogens.

Reactions of bis(2-ethyl-2-hydroxy-butanato)oxochromate(V) with pUC19 DNA, single-stranded calf thymus DNA (ss-ctDNA), a synthetic oligonucleotide, 5'-GATCTATGGACTTACTTCAAGGCCGGGTAATGCTA-3' (35mer), deoxyguanosine and guanine were carried out in Bis-Tris buffer at pH 7.0. The plasmid DNA was only nicked, whereas the single-stranded DNA suffered extensive damage due to oxidation of the ribose moiety.