Related Experiment Video
Updated: Aug 18, 2026

Formation of Covalent DNA Adducts by Enzymatically Activated Carcinogens and Drugs In Vitro and Their Determination by 32P-postlabeling
Published on: March 20, 2018
Photoaddition of thienocoumarin derivatives to DNA: stoichiometry and kinetics of binding
Lisa Dalla Via1, Vito Di Noto, Ornella Gia
1Department of Pharmaceutical Sciences, University of Padova, Via Marzolo 5, 35131 Padova, Italy. lisa.dallavia@unipd.it
Abstract:
Photoreaction of the 6,9-dimethyl-4-methoxymethyl-2H-thieno[3,2-g]-1-benzopyran-2-one (compound I) and 4-acetoxymethyl-6,9-dimethyl-2H-thieno[3,2-g]-1-benzopyran-2-one (compound II) to DNA was studied. The quantitative evaluation of the photobound molecules was performed by means of inductively coupled plasma atomic emission spectrometry (ICP-AES), exploiting the presence of the sulphur atom inside the tricyclic chromophore. The concurrent estimation of the phosphorus atom, present exclusively in the macromolecule, allowed possible intercalation sites to be identified and their involvement in the photoaddition reaction to be determined. The development of a kinetic model made it possible to discriminate and evaluate the single kinetic events that constitute the overall photoaddition process of I and II to DNA.
Related Concept Videos
Conjugate Addition (1,4-Addition) vs Direct Addition (1,2-Addition)
Conjugate addition results in a thermodynamically stable product. The reaction retains the stronger C=O bond at the expense of the weaker C=C π bond. The process is slow as the β carbon is less electrophilic than the carbonyl carbon.
Direct addition products are formed faster owing to...
The Equilibrium Binding Constant and Binding Strength
Cycloaddition Reactions: MO Requirements for Thermal Activation
Cycloaddition Reactions: MO Requirements for Photochemical Activation
Conjugate Addition to α,β-Unsaturated Carbonyl Compounds
Cooperative Binding of Transcription Regulators

