Abstract: Fluorescence spectroscopy, UV spectroscopy, viscosity measurement and other experiments was used to study interaction of rufloxacin with the DNA .Under the temperature of 293K and 310K , the quenching constants were measured to discusse the mechanism of fluorescence quenching. In the determination of the viscosity experiment, rufloxacin did not distort the DNA backbone. In the UV absorption spectrum,equal absorption point did not appear by the addition of rufloxacin With the increasing rufloxacin concertration,EB-DNA fluorescence intensity was weakened less than 50% suggested that rufloxacin did not compete the EB binding sites.In the fluorescence quenching of KI experiment, the results were almost same under the simply rufloxacin system and the coexistence of CT-DNA with rufloxacin system.The result suggested that rufloxacin was protected by the DNA bases . In conclusion, rufloxacin interacted with CT-DNA with the quenching constant of 2.89×103L ·mol-1. The interaction is exothermic with a Van’t Hoff enthalply of -12.91KJ·mol-1. Rufloxacin interacted with CT-DNA in the mode of groove binding .
Key words: Rufloxacin; DNA; Fluorescence quenching; Groove bonding
