In recent years, great interest has been focused on Fe(II) Schiff base amino acid complexes as cytotoxic
and antitumor drugs. Thus a series of new iron(II) complexes based on Schiff bases amino acids ligands
have been designed and synthesized from condensation of 5-bromosalicylaldehyde (bs) and a-amino
acids (L-alanine (ala), L-phenylalanine (phala), L-aspartic acid (aspa), L-histidine (his) and L-arginine
(arg)). The structure of the investigated iron(II) complexes was elucidated using elemental analyses,
infrared, ultraviolet–visible, thermogravimetric analysis, as well as conductivity and magnetic susceptibility
measurements. Moreover, the stoichiometry and the stability constants of the prepared complexes
have been determined spectrophotometrically. The results suggest that 5-bromosalicylaldehyde amino
acid Schiff bases (bs:aa) behave as dibasic tridentate ONO ligands and coordinate to Fe(II) in octahedral
geometry according to the general formula [Fe(bs:aa)2]nH2O. The conductivity values between 37 and
64 ohm1 mol1 cm2 in ethanol imply the presence of nonelectrolyte species. The structure of the complexes was validated using quantum mechanics calculations based on accurate DFT methods. Geometry optimization of the Fe-Schiff base amino acid complexes showed that all complexes had octahedral coordination.
In addition, the interaction of these complexes with (CT-DNA) was investigated at pH = 7.2, by
using UV–vis absorption, viscosity and agarose gel electrophoresis measurements. Results indicated that
the investigated complexes strongly bind to calf thymus DNA via intercalative mode and showed a different DNA binding according to the sequence: bsari > bshi > bsali > bsasi > bsphali. Moreover, the prepared compounds are screened for their in vitro antibacterial and antifungal activity against three
types of bacteria, Escherichia coli, Pseudomonas aeruginosa and Bacillus cereus and three types of anti