Chemical constituents and antioxidant and antimicrobial potential of Iphiona discoidea: A stenoendemic species from Iran

Abstract

The hydroethanolic Soxhlet extraction of Iphiona discoidea (Asteraceae), an unstudied endemic species in eastern Iran, was investigated for the first time to evaluate its chemical composition, antioxidant capacity, and antimicrobial potential. The chemical constituents of the extract were identified using gas chromatography coupled with mass spectrometry (GC-MS). Antioxidant and antimicrobial activities were evaluated using the DPPH radical scavenging assay and the broth microdilution and streak plate methods, respectively. GC-MS analysis identified 29 compounds, among which n-hexadecanoic acid (38.755%), and phytol acetate (18.611%) exhibited prominent peaks, suggesting their significant contribution to the extract’s bioactivity. The hydroethanolic extract of Iphiona discoidea yielded an IC₅₀ of 57.84± 5.4 μg/mL, indicating a moderate antioxidant potential compared to ascorbic acid (IC₅₀ = 3.94 μg/mL). The extract exhibited selective antibacterial activity, with the strongest effects observed against Escherichia coli and Bacillus cereus, while no activity was detected against Salmonella enterica or Staphylococcus epidermidis. In addition, among the three fungal strains tested, the extract demonstrated the strongest inhibitory effect against Fusarium oxysporum and the weakest against Aspergillus fumigatus. These findings suggest that I. discoidea possesses promising antioxidant and antimicrobial properties, supporting its potential as a natural source of bioactive compounds for pharmaceutical and nutraceutical applications.