Synthesis and Biological Activities of Lanthanide (III) Nitrate Complexes with N-(2-hydroxynaphthalen-1-yl) methylene) Nicotinohydrazide Schiff Base

Background: The field of coordination chemistry has registered a phenomenal growth during the last few decades. It is well known that precious metals have been used for medicinal purposes for at least 3500 years. At that time, precious metals were believed to benefit health because of their rarity, but research has now well established the link between medicinal properties of inorganic drugs and specific biological properties. Methods: The current study was designed to explain the synthesis and characterization of the lanthanide (III) nitrate complexes with N-(2-hydroxynaphthalen-1-yl) methylene) nicotinohydrazide schiff base and to evaluate the antibacterial and the antioxidant activities of the schiff base and it's lanthanide ion complexes. Antimicrobial activity of the Lanthanide (III) nitrate complexes with N-(2- hydroxynaphthalen-1-yl) methylene) nicotinohydrazide schiff base was estimated by minimum inhibitory concentration (MIC, μg/mL) using a micro-broth dilution method for different clinical isolates such as Eschereshia coli and Enterococcus faecalis. The antioxidant activities of the ligand and its lanthanide complexes were tested using a UV-Visible spectrophotometer by preparing 5x10-4 M of all tested samples and DPPH in Dimethyl sulphoxide (DMSO). Results: Our present study has shown that moderate antimicrobial activity exists against both ligand and its complexes. There was no significant difference between Gram-positive and Gram-negative bacteria towards the tested ligand and its complexes. The free ligand has scavenging activity between 13-21 % while all complexes are more efficient in quenching DPPH than free ligand. Conclusion: The results obtained herein indicate that the ligand and its complexes have a considerable antibacterial activity as well as antioxidant activity in quenching DPPH.