Abstract
The hydrolysis of the bay-region syn- and anti-diol epoxides of 7-methylbenz[c]acridine (7MBAC) has been studied in aqueous solution. The rates of reaction have been measured at low ionic strength in the absence and presence of DNA, as a function of pH and temperature, by spectrophotometry and high-pressure liquid chromatography. The major products are the corresponding tetrols, but the syn diastereomer also undergoes rearrangement to a keto diol. The hydrolysis reaction is catalyzed by both acid and DNA and conforms to a mechanism in which a physical association complex is formed between diol epoxide and DNA, followed by two parallel pathways in which the diol epoxide either is hydrolyzed or becomes covalently bound to the DNA. The rate constants are significantly lower than the corresponding ones for the diol epoxides of benzo[a]pyrene. However, the extent of covalent binding of 7MBAC diol epoxides to DNA was found to be 12-30%, depending on the pH of reaction, values that are 2-3 times greater than for the benzo[a]pyrene diol epoxides reacted under the same conditions of low ionic strength. The very small changes (2 nm) in spectroscopic characteristics observed for the covalently bound adduct as compared to the free tetrol suggest that the binding occurs with little intercalation of the compound between the base pairs of DNA.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
