The escalating prevalence of multidrug resistance (MDR) worldwide has spurred a critical imperative

to explore and innovate novel therapeutic modalities and potent antimicrobial agents. Amide Schiffbase

ligands (referred to as H3L1 and H3L2) have emerged as promising candidates for combating a

spectrum of pathogens including Gram-negative bacteria, Gram-positive bacteria, and certain

antifungal strains, amid the scarcity of novel antibiotics. Concurrently, β-naphthylamide (PAβN), a

peptidomimetic compound, has garnered attention as an efflux pump inhibitor (EPI) aimed at

surmounting efflux-mediated multidrug resistance. In this investigation, the antibacterial efficacy of

two Schiff base ligands synthesized through the condensation of (N-(2-amino phenyl)-2-

hydroxybenzamide) with hydroxybenzaldehyde, and (N-(2-aminoethyl)-2-hydroxybenzamide) with

hydroxybenzaldehyde, alongside their respective complexes [H3L1.Cu(OAc)2].2H2O,

[H3L1CuCl2].2H2O, [H3L1Ag2(SO4)], [H3L1Hg(SO4)(H2O)]·2H2O, [H3L2Cu(OAc)2]·2H2O, and

[H3L2CuCl2]·3H2O). The ligands and their complexes were characterized using elemental and

spectroscopic techniques such as IR, UV-VIS, Mass Spectra, 1H-NMR and ESR measurements as well

as Magnetism, Conductivity, Thermal Analyses (DTA and TGA) and Electronic microscope. The

conductivity measurements confirmed non electrolytic in nature, however, The electron microscope

data indicate that, the complexes were found in nano-form. ESR spectra for Cu(II) complexes showed

axial type with d(x2-y2) ground state. The compounds were assessed individually against a spectrum of

bacteria including Escherichia coli (ATCC:10536), Klebsiella pneumoniae (ATCC:10031),

Staphylococcus aureus (ATCC:13565), Streptococcus mutans (ATCC:25175), and Candida albicans

(ATCC:10231), encompassing antibiotic-susceptible strains. Preliminary results of minimum inhibition

concentration (MIC) assays revealed notable antimicrobial activity exhibited by the complexes

[H3L1.Cu(OAc)2].2H2O, [H3L1CuCl2].2H2O, [H3L1Ag2(SO4)], [H3L1Hg(SO4)(H2O)]·2H2O,

[H3L2Cu(OAc)2]·2H2O, and [H3L2CuCl2]·3H2O) when compared to the ligands in isolation. Further

analysis via fractional inhibitory concentration (FIC) indices demonstrated enhanced MIC values

indicative of additive and synergistic effects upon combining Nano metal amide Schiff base complexes

with H3L1 and H3L2. These findings underscore the therapeutic promise inherent in the combined

utilization of these metal complexes.