Batibay, Gonul S.; Keser Karaoglan, Gulnur; Gumrukcu Kose, Gulsah; Ozcelik Kazancioglu, Elif; Metin, Eyup; Danisman Kalindemirtas, Ferdane; Erdem Kuruca, Serap; Arsu, Nergis

The interaction of a multi-component system consisting of benzene-1,4-diyldimethanimine-bridged dimeric zinc-phthalocyanine groups (4OMPCZ) with calf thymus DNA (ct-DNA) was investigated using UV–Vis absorption, fluorescence emission spectroscopy methods, and viscosity measurements. The binding constant, Kb, which is an important parameter to gain information about the binding mode, was found as 9.7 × 107 M−1 from the UV–Vis absorption studies. Another important spectrophotometric tool is competitive displacement assays with Ethidium bromide and Hoechst 33342. Through this experiment, a higher KSV value was obtained with Hoechst for the phthalocyanine derivative, 4OMPCZ, and the ct-DNA complex than with ethidium bromide. Additionally, molecular docking studies were conducted to calculate the theoretical binding constant and visualize the interactions of 4OMPCZ with a model DNA. According to docking results, although the interactions are mainly located in the major groove of the DNA helix, due to the wrapping, these interactions can also be extended to the minor groove of the DNA. Spectrophotometric, molecular docking, and viscosity studies revealed that the interaction of 4OMPCZ with DNA is likely to be via the major and minor grooves. The in vitro cytotoxic activity of 4OMPCZ was evaluated by MTT assay on human colon cancer cells (HT29) after 72 h of treatment. 4OMPCZ indicated significant cytotoxic activity when stimulated with UV light compared to the standard chemotherapy drugs, fluorouracil (5-FU), and cisplatin on HT29 colon cancer cells. The IC50 value of 4OMPCZ displayed considerably lower concentrations compared to the standard drugs, 5-FU, and cisplatin.

Yildirim, Berat; Beşer, Burcu Meryem; Çolak, Nevin Ulaş; Altay, Ahmet; Yaşar, Ahmet

A novel chalcone derivative (4-(5-(pyridin-2-yl)-4,5-dihydro-1H-pyrazol-3-yl) phenol (PDP) was synthesized, characterized and investigated for its potential as a fluorescent probe. The structure of the synthesized molecule was determined by FTIR, 1H NMR, 13C NMR and LC-MS/MS. The interactions of PDP with fluorescent dyes in aqueous SDS environment and HSA were studied by using fluorescence resonance energy transfer (FRET) technique and steady-state and time-resolved fluorescence spectroscopy techniques. In addition, the cytotoxic effects of PDP against various cell lines (MCF -7, HT −29, and 3 T3-L1) as well as their corresponding healthy cell lines were tested by MTT assay and visualization of FRET efficiency of PDP in vitro was monitored by confocal microscopy. MTT assay showed that PDP has no significant cytotoxic effect on HT −29 cancer cells and moderate cytotoxicity on MCF -7 and 3 T3-L1 cells even at a concentration of 250 μM. Combining confocal microscopes with the FRET technique showed that PDP significantly stained the cytoplasm of MCF -7 cell lines. These results suggest that PDP could be used in fluorescence microscopy for cell staining.