Synthesis, crystal structure, antitumor activity and DNA-binding study on the Mn(II) complex of 2H-5-hydroxy-1,2,5-oxadiazo[3,4-f]1,10-phenanthroline

The complex [Mn(L)(NO3)(2)(H2O)(2)] (1) (L = 2H-5-hydroxy-1,2,5-oxadiazo[3,4-f]1,10-phenanthroline) was synthesized and characterized by elemental analysis, IR and UV. The crystal and molecular structure of I was determined by single-crystal X-ray diffraction; crystal data: light yellow, monoclinic, space group P2(1)/n, Z = 4, a = 7.432(2) Angstrom, b = 9.582(3) Angstrom, c = 23.445(7) Angstrom, beta = 90.519(5)degrees. The Mn atom in 1 is hexa-coordinated in a distorted octahedral arrangement by two N atoms of the ligand L and four 0 atoms of two water molecules and two nitrate anions. Biological tests in vitro showed that I has significant antitumor activity against HL-60, KB, Hela and BGC-823 cells. The interaction of 1 with calf thymus DNA was investigated by absorption titration, thermal denaturation and viscosity measurements. The results suggest that 1 binds with DNA by intercalating via the ligand L. (C) 2002 Elsevier Science Inc. All rights reserved.