Interaction of chromium(III) complex of chiral binaphthyl tetradentate ligand with DNA.
Since conformation of the molecule plays a vital role in the activity of drug, we have investigated the DNA interaction of a chromium(III) complex with ligands in two conformations. Chromium(III) complexes derived from chiral binaphthyl Schiff base ligands, viz. R- and S-2,2'-bis(salicylideneamino) 1,1'-binaphthyl, have been synthesized and characterized by mass, IR, and electronic spectra. The interaction of these R- and S-binaphthyl Schiff base chromium(III) complexes with CT-DNA was investigated with the goal of examining whether the chirality has an influence on the chromium(III)-DNA binding properties. The difference in chirality of the ligand did not show any striking difference in binding properties. The binding constants for R and S conformers were estimated to be 18 (+/-0.4) x 10(3) and 9.4 (+/-0.3) x 10(3) M(-1), respectively, through spectroscopic titrations. All the experimental results are suggestive that both the isomers are DNA groove binders. The results of steady-state as well as time-resolved fluorescence experiments, however, suggest that the R conformer has restricted mobility when bound to DNA because it is more deeply buried in the groove of DNA compared to the S isomer.
Vijayalakshmi
Rajamanickam
R
Chemical Laboratory, Central Leather Research Institute, Adyar, Chennai 600020, India.
Kanthimathi
Mookandi
M
Parthasarathi
Ramakrishnan
R
Nair
Balachandran Unni
BU
D002857:Chromium / Q000737:chemistry*; D004247:DNA / Q000737:chemistry* / Q000378:metabolism; D008024:Ligands; D008958:Models, Molecular; D008968:Molecular Conformation; D009281:Naphthalenes / Q000737:chemistry* / Q000378:metabolism; D009942:Organometallic Compounds / Q000138:chemical synthesis* / Q000737:chemistry*; D012394:Rosaniline Dyes / Q000737:chemistry; D013237:Stereoisomerism
D008024:Ligands; D009281:Naphthalenes; D009942:Organometallic Compounds; D012394:Rosaniline Dyes; C476677:Schiff's reagent; D002857:Chromium; D004247:DNA