ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Structural properties and in vitro evaluation of some Ln (III) complexes as potential selective antimicrobial and antioxidant substances

Ahmed K. Hijazi, Ziyad A. Taha, Abdellatif Ibdah, Idris M. Idris, and Waleed M. Al-Momani

Department of Chemical Sciences, Faculty of Science and Arts, Jordan University of Science and Technology, Irbid, Jordan

E-mail: akhijazi@just.edu.jo

Received: 27 January 2021  Accepted: 22 April 2021

Abstract:

Rare metals have been used in pharmaceuticals and for medicinal purposes for long time. Currently, the link between some specific medicinal and biological properties of inorganic drugs has been established. [Ln(NO₃)₃] complexes with N-(2-hydroxynaphthalen-1-yl) methylene) isonicotinohydrazide Schiff base, [Ln(NHIso)₂(NO₃)₂]NO₃, complexes 1–8, were prepared and characterized using different techniques. The expected coordination for prepared complexes is ten, six from the tri-dentate NHIso ligand, and four from the two bi-dentate nitrate groups. DFT calculations on La and its cationic [La(NHIso)₂(NO₃)₂]⁺ complex were carried out at the B3LYP level of theory. The NHIso ligand and its lanthanide complexes were screened for antimicrobial activity, in vitro activity against four gram-negative bacteria Ec: Escherichia coli; Kp: Klebsiella pneumonia; Pm: Proteus mirabilis; Pa: Pseudomonas aeruginosa, with two gram-positive bacteria En: Enterococcus faecalis and Sa: Staphylococcus aureus. Complexes 1, 2, 4, 7 and 8 showed excellent and higher activity against En and Sa Gram-positive bacteria than the free ligand, especially complex 2 with a MIC value of 4 μg/mL. The reported complexes have greater and significant efficiency in quenching DPPH than that of free NHIso ligand, with a scavenging activity between 39 and 65%.

Graphic Abstract

Ln (III) nitrate complexes with N-(2-hydroxynaphthalen-1-yl) methylene) isonicotinohydrazide Schiff base, [Ln(NHIso)2(NO3)2]NO3, were prepared and characterized. They showed very promising antimicrobial and antioxidant activities. Their molecular geometries have been examined using DFT calculations and the obtained results are in good agreement with the experimental data.

Keywords: Hydrazone Schiff base; Lanthanides complexes; DFT; MIC; Antibacterial; Antioxidant

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-021-01676-x

Chemical Papers 75 (9) 4611–4624 (2021)