Journal of the Korean Chemical Society 2010, Vol. 54, No. 5 Printed in the Republic of Korea DOI 10.5012/jkcs.2010.54.5.573 -573- 요약. 본 연구에서는 염화제1철을 2,4-디히드록시살로펜과 조합하여 2,4-디히드록시살로펜-염화철을 합성하였다. 이 복합체 를 자외선-가시광선 분광법, IR 분광법으로 분석하였고, 천연의 송아지 흉선 DNA (ct-DNA)와 2,4-디히드록시살로펜-염화철 의 상호작용을 자외선-가시광선 분광법, 형광분광법, 열변성 분석법, 점성측정법을 이용하여 조사하였다. 분광학적 적정실험 으로 밝힌 2,4-디히드록시살로펜-염화철과 ct-DNA 사이의 결합상수는 (1.6 ± 0.2) × 10 3 M -1 이었다. 형광분광분석을으로 브롬 화 에티디움의 DNA 결합이 2,4-디히드록시살로펜-염화철에 의하여 저해되는 것을 관찰하였다. 이 저해효과는 2,4-디히드록 시살로펜-염화철의 농도에 따라 선형의 Stern-Volmer 방정식을 따른다. 열변성 실험으로 2,4-디히드록시살로펜-염화철이 DNA의 녹는점을 약 4.3 o C 증가시킨다는 것을 관찰하였다. 이 결과들은 2,4-디히드록시살로펜-염화철이 대부분 ct-DNA의 큰고랑과 상호작용한다는 모델을 잘 설명하여 준다. 주제어: DNA, 쉬프염기, 상호작용, 형광, 자외선-가시광선 분광법 ABSTRACT. In this study, iron(III)-2,4-dihydroxysalophen chloride (Fe(2,4-DHSalophen)Cl), has been synthesized by combina- tion of 2,4-dihydroxysalophen (2,4-DHSalophen) with FeCl2 in a solvent system. This complex combination was characterized using UV-vis and IR spectroscopies. Subsequently, the interaction between native calf thymus deoxyribonucleic acid (ct-DNA) and Fe(2,4-DHSalophen)Cl, was investigated in 10 mM Tris/HCl buffer solution, pH 7.2, using UV-visible absorption and fluorescence spectroscopies, thermal denaturation technique and viscosity measurements. From spectrophotometric titration experiments, the binding constant of Fe(2,4-DHSalophen)Cl with ct-DNA was found to be (1.6 ± 0.2) × 10 3 M -1 . The fluorescence study represents the quenching effect of Fe(2,4-DHSalophen)Cl on bound ethidium bromide to DNA. The quenching process obeys linear Stern- Volmer equation in extended range of Fe(2,4-DHSalophen)Cl concentration. Thermal denaturation experiments represent the increasing melting temperature of DNA (about 4.3 o C) due to binding of Fe(2,4-DHSalophen)Cl. These results are consistent with a binding mode dominated by interactions with the groove of ct-DNA. Keywords: DNA, Schiff base, Interaction, Fluorescence, UV-vis spectroscopy 천연 DNA와 2,4-디히드록시살로펜-염화철(III)과 의 상호작용 연구 Mohammad-Reza Azani*, Azin Hassanpour, and Abdol-Khalegh Bordbar † Departamento de Química Inorgánica, Facultad de Ciencias, Universidad Autónoma de Madrid, 28049 Madrid, Spain † Laboratory of Biophysical Chemistry, Department of Chemistry, University of Isfahan, Isfahan, 81746-73441, I.R. Iran (접수 2010. 5. 10; 수정 2010. 6. 4; 게재확정 2010. 8. 18) Study of Interaction of Native DNA with Iron(III)-(2,4-Dihydroxysalophen)chloride Mohammad-Reza Azani*, Azin Hassanpour, and Abdol-Khalegh Bordbar † Departamento de Química Inorgánica, Facultad de Ciencias, Universidad Autónoma de Madrid, 28049 Madrid, Spain * E-mail: mr.azani@yahoo.com † Laboratory of Biophysical Chemistry, Department of Chemistry, University of Isfahan, Isfahan, 81746-73441, I.R. Iran (Received May 10, 2010; Revised June 4, 2010; Accepted August 18, 2010) INTRODUCTION The interaction of transition metal complexes, containing multidentate aromatic ligands, with DNA has recently gained much attention following the important biological and medi- cal roles played by potential metallointercalators. 1 Schiff base metal complexes have been recognized as powerful catalysts in a great number of chemical reactions such as, electrochemical reduction of alkyl halides in aprotic sol- vents, 2 oxygenation of indols, phenols, flavones, and others. 3 In addition, some of these complexes are able to bind in a reversible form to molecular oxygen. These complexes have been also investigated as model compounds in the study of the natural oxygen carriers such as, hemoglobin, myoglobin hemocyanin 4 and in the study of the catalytic properties of some cytochromes involved in the biological oxidative reactions. Finally, Schiff base tetradentate com- plexes of iron have been studied as mimetic models of pero- xidases, catalases and superoxide dismutase. 5 In addition to these applications, the synthesis and further structural