Detection of biological efficiency of fe(III) complexes with heterocyclic N-donor ligand nicotinamide (nia) using algal assay

Using cultures of the green alga, Scenedesmus quadricauda, the toxicity of a selected number of newly prepared trivalent iron complexes with N-donor ligand (nia) was investigated. Experiments were also conducted using divalent cadmium, divalent zinc, and divalent nickel complexes with nicotinamide. The EC sub(50) values of the complexes and their 95% confidence intervals for growth rate of S. quadricauda after 16 d of cultivation are tabulated. The Fe(III) dichloroacetato complex was found to be biologically more active than similar complexes with anions from mineral acids. Binding of Fe with nicotinamide generally increased the inhibitory effect on alga growth.