Hydrocinnamic Acid From Candida albicans: Isolation, Characterization, and Antibacterial Activity Against Multidrug-Resistant Bacteria.

Microbial secondary metabolites remain an important source of structurally diverse bioactive compounds with huge therapeutic potential. Yeasts, particularly Candida albicans, possess remarkable metabolic plasticity; thus, it paves the way for identifying antibacterial substances from their extracellular metabolome as it remains underexplored. In the present study, a semi-preparative high-performance liquid chromatography (HPLC) method was developed and optimized for the efficient isolation and purification of hydrocinnamic acid (3-phenylpropionic acid) from the extracellular metabolite extract of C. albicans. The purified compound was characterized using UV-Vis, FTIR, NMR (1H and 13C), GC-MS, and X-ray diffraction analyses. This study represents the first report of hydrocinnamic acid isolated and purified from the extracellular metabolites of C. albicans. The antibacterial potential of the purified hydrocinnamic acid was assessed against multidrug-resistant (MDR) strains of Staphylococcus aureus, Enterobacter cloacae, and Escherichia coli, which exhibited concentration-dependent inhibition against all tested pathogens, with distinct activity against S. aureus and E. cloacae. The minimum inhibitory concentrations were 10 μg/mL for S. aureus, 15 μg/mL against E. cloacae, and 40 μg/mL against E. coli. Collectively, these results underscore the unexplored antibacterial potential of C. albicans-derived extracellular metabolites and position hydrocinnamic acid as a promising natural candidate for combating multidrug-resistant bacteria.