Investigation of the interactions of rutin, quercitrin and myricitrin flavanoides from the plant Hypericum montbretii Spach. with DNA

Interactions of rutin, quercitrin and myricitrin flavonoids isolated from the Hypericum montbretii plant and their metal complexes with DNA were examined using UV-vis spectroscopy, fluorescence spectroscopy, agarose gel electrophoresis and viscometry. The results showed that the flavonoids interact with DNA in the form of intercalation or partial intercalation. The binding of the flavonoids with DNA were determined by UV titration and fluorescence spectroscopy as follows myricitrin> quercitrin> rutin. In addition, agarose gel electrophoresis results clearly showed that flavonoids could prevent any damage to DNA. It was observed that all three flavonoids inhibited the peroxide induced damage in DNA. Flavonoids in the presence of metals interacted with DNA much better than free flavonoids. The results we obtained from both UV spectroscopy and fluorescence spectroscopy experiments showed that these interactions were caused by intercalation and electrostatic external binding by cationic metals. The highest binding constant was reached in the Myricitrin-Cu+2 complex. The fact that the structure of this complex is more suitable to enter between the base pairs of the DNA may result from the additional hydroxyl group. Unlike flavonoids, the complexes were observed in the gel electrophoresis results in which they did not have any curative effects on DNA damage but in some cases increased damage. In the light of the results obtained, it was determined that all three flavonoids interacted with DNA by intercalation but flavonoid-metal complexes interacted more strongly with DNA. Flavonoids have been observed to have inhibitory effects on DNA damage