Title
Synthesis and crystal structure elucidation of new copper(II)–based chemotherapeutic agent coupled with 1,2–DACH and orthovaniline: Validated by in vitro DNA/HSA binding profile and pBR322 cleavage pathway
Author
Mehvash Zaki, Mohd. Afzal, Musheer Ahmad, Sartaj Tabassum
Year
2016
Journal
Journal of Photochemistry and Photobiology B: Biology
Abstract
New copper(II)–based complex (1) was synthesized and characterized by analytical, spectroscopic and single crystal X–ray diffraction. The in vitro binding studies of complex1 with CT DNA and HSA have been investigated by employing biophysical techniques to examine the binding propensity of 1 towards DNA and HSA. The results showed that 1avidly binds to CT DNA via electrostatic mode along with the hydrogen bonding interaction of –NH2 and C = N groups of Schiff base ligand with the base pairs of DNA helix, leads to partial unwinding and destabilization of the DNA double helix. Moreover, the CD spectral studies revealed that complex 1 binds through groove binding interaction that stabilizes the right–handed B–form of DNA. Complex 1 showed an impressive photoinduced nuclease activity generating single–strand breaks in comparison with the DNA cleavage activity in presence of visible light. The mechanistic investigation revealed the efficiency of 1 to cleave DNA strands by involving the generation of reactive oxygen species. Furthermore, the time dependent DNA cleavage activity showed that there was gradual increase in the amount of NC DNA on increasing the photoexposure time. However, the interaction of 1 and HSA showed that the change of intrinsic fluorescence intensity of HSA was induced by the microenvironment of Trp residue.
Instrument
J-815
Keywords
Circular dichroism, Secondary structure, Ligand binding, Inorganic chemistry, Pharmaceutical, Biochemistry