Researchers have designed a few bio-organometallic compounds that can snap DNA in the presence of visible as well as ultraviolet light1. Presence of oxidizing and reducing agents sharpen the activity of these compounds in cleaving DNA and binding to specific proteins. These compounds are potential candidate for photodynamic therapy (PDT) of cancer.
Given the toxicity and drug-resistance of metal-based anti-cancer drugs, researchers have turned their attention to bioorganometallic compounds for use in PDT. For the study, the researchers produced four ferrocene-conjugated copper complexes containing four different bases – bipyridine (bpy), phenanthroline (phen), dipyridoquinoxaline (dpq) and dipyridophenazine (dppz). These compounds were exposed to calf thymus DNA and bovine serum albumin (BSA) protein in solution in the presence of visible as well as ultraviolet light. The researchers used hydrogen peroxide (oxidizing agent) and mercaptopropanoic acid (reducing agent).
Both the dpq and dppz complexes displayed significantly high DNA photocleavage activity in visible light. Of all the complexes, the dppz complex showed significant photocleavage of BSA under physiological reaction conditions. The dpq and dppz complexes showed significant red light induced DNA cleavage activity.
The findings could help design new photoactive metal-based bioorganometallic complexes as anti-cancer agents.