Spectroscopic and molecular modeling study on the interaction of ctDNA with 3′-deoxy-3′-azido doxorubicin

The method of synthesizing 3′-deoxy-3′-azido doxorubicin (ADOX) directly from doxorubicin has been developed. This study presents the interaction between ADOX and calf thymus deoxyribonucleic acid (ctDNA) by using spectroscopic methods and molecular modeling techniques. Iodide quenching, fluorescence polarization, viscosity and molecular modeling studies of ADOX-ctDNA interactions indicated that ADOX was an intercalator of ctDNA and preferentially bound to C-G rich regions of ctDNA. Simultaneously, spectroscopic results indicated that the quenching mechanism of ADOX-ctDNA was a static quenching. According to thermodynamic parameters, electrostatic force played roles in the interaction of ADOX with ctDNA.