Heteroleptic cobalt complex augments antifungal activity with fluconazole and causes membrane disruption in .

Heteroleptic metal complexes containing Cu, Co, and Zn, incorporating curcumin and a Schiff base ligand (L), were synthesized and characterized, and their antifungal activity was evaluated. Their antifungal activities were investigated individually and in combination with fluconazole. Utilizing various analytical techniques such as UV-Vis, FT-IR, NMR, ESI-MS, TGA-DTG, elemental analyses, conductance, and magnetic susceptibility measurements, complex C1 ([Cu(Cur)LCl(HO)]) was assigned a distorted octahedral geometry, while complexes C2 ([Co(Cur)LCl(HO)]) and C3 ([Zn(Cur)LCl(HO)]) were assigned octahedral geometries. Among these complexes, C2 exhibited the highest inhibitory activity against both FLC-susceptible and resistant strains of . Furthermore, C2 demonstrated candidicidal activity and synergistic interactions with fluconazole, effectively inhibiting the growth and survival of both FLC-resistant and FLC-sensitive strains. The complex displayed a dose-dependent inhibition of drug efflux pumps in FLC-resistant strains, indicating its potential to disrupt the cell membrane of these strains. The significant role of membrane efflux transporters in the development of antifungal drug resistance within species has been extensively documented and our findings indicate that complex C2 specifically targets this crucial factor, thereby playing a pivotal role in mitigating drug resistance in .