Interaction of Antiparkinsonian Drug molecule, (-)-3-(3,4-dihydroxyphenyl)-L-alanine with Bioessential Metals Study by Simple Spectrophotometric Method

Due to significance of metals and their high affinity towards oxygen and nitrogen donor ligands, present in the biological system, the interaction of (-)-3-(3,4-dihydroxyphenyl)-L-alanine with few bioessential metals was selected to study, using spectrophotometry. Metal and ligand were mixed in 1:5 ratio of metal and ligand. The complex solutions were then scanned from 300 to 800 nm. Spectra of CrIII, MnVII, MnIV, VV, VIII, FeIII and FeII complexes were recorded on Shimadzu spectrophotometer model UV-160A. ?max of mentioned metal complexes were found to be as 410 & 590 nm for CrIII, 303 & 477 nm for MnVII, 478 nm for MnIV, 510 nm for VV and 460 nm for VIII. While, that of 430 & 730 nm for both FeIII and FeII. In Addition to that the stoichiometry of MnVII, MnIV, FeIII, FeII with LD was evaluated by mole ratio method, providing consistent results. Using stoichiometric data, overall formation constant, log Kf, were evaluated for all complexes. It was found 12.45 for MnVII-LD, 9.64 for MnIV-LD, 9.75 for FeIII-LD and 11.45 for FeII-LD complexes.