Pyridine and p-Nitrophenyl Oxime Esters with Possible Photochemotherapeutic Activity: Synthesis, DNA Photocleavage and DNA Binding Studies
Milena Pasolli,
Konstantinos Dafnopoulos,
Nicolaos-Panagiotis Andreou,
Panagiotis S. Gritzapis,
Maria Koffa,
Alexandros E. Koumbis,
George Psomas,
Konstantina C. Fylaktakidou
Affiliations
Milena Pasolli
Laboratory of Organic, Bioorganic and Natural Product Chemistry, Molecular Biology and Genetics Department, Democritus University of Thrace, University Campus, Dragana, GR-68100 Alexandroupolis, Greece
Konstantinos Dafnopoulos
Laboratory of Organic, Bioorganic and Natural Product Chemistry, Molecular Biology and Genetics Department, Democritus University of Thrace, University Campus, Dragana, GR-68100 Alexandroupolis, Greece
Nicolaos-Panagiotis Andreou
Laboratory of Organic, Bioorganic and Natural Product Chemistry, Molecular Biology and Genetics Department, Democritus University of Thrace, University Campus, Dragana, GR-68100 Alexandroupolis, Greece
Panagiotis S. Gritzapis
Laboratory of Organic, Bioorganic and Natural Product Chemistry, Molecular Biology and Genetics Department, Democritus University of Thrace, University Campus, Dragana, GR-68100 Alexandroupolis, Greece
Maria Koffa
Laboratory of Cellular Biology and Cell Cycle, Molecular Biology and Genetics Department, Democritus University of Thrace, University Campus, Dragana, GR-68100 Alexandroupolis, Greece
Alexandros E. Koumbis
Laboratory of Organic Chemistry, Chemistry Department, Aristotle University of Thessaloniki, GR-54124 Thessaloniki, Greece
George Psomas
Laboratory of Inorganic Chemistry, Chemistry Department, Aristotle University of Thessaloniki, GR-54124 Thessaloniki, Greece
Konstantina C. Fylaktakidou
Laboratory of Organic, Bioorganic and Natural Product Chemistry, Molecular Biology and Genetics Department, Democritus University of Thrace, University Campus, Dragana, GR-68100 Alexandroupolis, Greece
Compared to standard treatments for various diseases, photochemotherapy and photo-dynamic therapy are less invasive approaches, in which DNA photocleavers represent promising tools for novel “on demand” chemotherapeutics. A series of p-nitrobenzoyl and p-pyridoyl ester conjugated aldoximes, amidoximes and ethanone oximes were subjected to UV irradiation at 312 nm with supercoiled circular plasmid DNA. The compounds which possessed appropriate properties were additionally subjected to UVA irradiation at 365 nm. The ability of most of the compounds to photocleave DNA was high at 312 nm, whereas higher concentrations were required at 365 nm as a result of their lower UV absorption. The affinity of selected compounds to calf-thymus (CT) DNA was studied by UV spectroscopy, viscosity experiments and competitive studies with ethidium bromide (EB) revealing that all compounds interacted with CT DNA. The fluorescence emission spectra of the pre-treated EB-DNA exhibited a moderate to significant quenching in the presence of the compounds indicating the binding of the compounds to CT DNA via intercalation as concluded also by DNA-viscosity experiments. For the oxime esters the DNA photocleavage and affinity studies aimed to clarify the role of the oxime nature (aldoxime, ketoxime, amidoxime) and the role of the pyridine and p-nitrophenyl moieties both as oxime substituents and ester conjugates.
