4-Acetamidophenol Binding Mechanism with DNA by UV-Vis and FTIR Techniques Based on Binding Energy, LUMO and HOMO Orbitals and Geometry of Molecule

Abstract

Abstract Present study was conducted to appraise the interaction mechanism of 4-acetamidophenol (4-AP) with DNA based on UV-Vis and FTIR techniques based on binding energy, isolated atomic energy, LUMO and HOMO orbitals gap and geometry of molecule. Analysis revealed the groove binding and intercalation mode of interaction between 4-AP and DNA since hyperchromic and bathochromic shifts were observed in response of interaction of DNA. The planar part of interacting molecule intercalated with DNA and non-planar part of 4-acetamidophenol bounded with DNA (groove binding). The constants for binding between 4-AP and DNA were calculated and 20.12 × 103 mol−1 dm3 binding constant was recorded at pH 4.7, whereas this value was 5.32 × 103 mol−1 dm3 for the pH 7.4. The binding constant value for interaction of 4-AP with DNA revealed the possibility of oral administration of 4-AP. The 4-AP binding with DNA is spontaneous process, which was confirmed from negative value of free energy at room temperature. FTIR study revealed that C–H and C=C (aromatic) functional groups were involved in binding at pH 4.7 and C=O (amide) was involved in groove binding, whereas C–H (aromatic) was responsible for intercalation at pH 7.4 and C–H (alkaline) and C=O (amide) were responsible for groove binding at pH 4.7.