Synthesis, spectral characterization, in vitro microbial and cytotoxic studies of lanthanum(III) and thorium(IV) complexes with 1,2,4-triazole Schiff bases

Abstract

A series of metal complexes of La(III) and Th(IV) have been synthesized with newly derived biologically active ligands. These ligands were synthesized by the condensation of 3-substituted-4-amino-5-hydrazino-1,2,4-triazole with 8-formyl-7-hydroxy- 4-methylcoumarin. The structure of the complexes has been proposed by elemental analyses, spectroscopic data i.e. i.r., ¹H nmr, Uv-Vis, FAB-mass and thermal studies. The elemental analyses of the complexes conform to the stoichiometry of the type [La(L)·3H₂O]·2H₂O and [Th(L)(NO₃)·2H₂O]·2H₂O where (L = L^I-L^IV). All the complexes are soluble in DMF and DMSO and are non-electrolytes in DMF and DMSO. All these ligands and their complexes have also been screened for their antibacterial (Escherichia coli, Staphylococcus aureus, Staphylococcus pyogenes and Pseudomonas aeruginosa) and antifungal activities (Aspergillus niger, Aspergillus flavus and cladosporium) by the MIC method. The brine shrimp bioassay was also carried out to study their invitro cytotoxic properties.

Keywords::

• Synthesis
• biological activity
• cytotoxic
• 1,2,4-triazole
• coumarin
• La(III) and Th(IV) complexes

Acknowledgements

The authors are grateful to the Chairman, Department of Chemistry, Karnatak University, Dharwad for the facilities. One of the authors (GBB) grateful to Karnatak University, Dharwad for grant of University Research Studentship.

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.