Antimicrobial phenolic secondary metabolites from the flowers of Narcissus tazetta L.

Bioassay-guided fractionation of the ethyl acetate antimicrobial fraction from the hydroalcoholic extract of the fresh Narcissus tazetta L. flowers afforded a new antimicrobial compound, tazettin (1), along with 3-caffeoylquinic acid methyl ester (2), methyl-3,4-dihydroxybenzoate (3), and syringic acid (4). The compounds were assigned by NMR and (+)-HRESIMS analyses. Antimicrobial assays revealed that 1 potently inhibited Staphylococcus aureus (18 mm, MIC = 14.9 µM) and Candida albicans (16 mm, MIC = 29.8 µM. Compound 2 exhibited similar potency against S. aureus (16 mm, MIC = 10.8 µM) and C. albicans (18 mm, MIC = 10.8 µM), with moderate Escherichia coli inhibition (11 mm, MIC = 21.7 µM). Compound 3 displayed moderate effects on S. aureus (14 mm, MIC = 40 µM) and C. albicans (16 mm, MIC = 40 µM). Syringic acid (4) was least active against the three microbes (10–15 mm, MIC = 80.8 µM). Overall, 1–3 selectively targeted S. aureus and C. albicans, highlighting N. tazetta metabolites as promising antimicrobial leads.