Subasi, BilgenGunbatan, TugbaGurbuz, IhanDilmac, ElifBedir, ErdalDemirci, Fatih2025-12-252025-12-2520260378-87411872-7573https://doi.org/10.1016/j.jep.2025.120900https://hdl.handle.net/11147/18776Ethnopharmacological relevance: Achillea biebersteinii Afan. is traditionally utilized as folk medicine for a broad range of therapeutic applications, especially for promoting the maturation of abscesses, wound healing; against inflammation, and rheumatism in T & uuml;rkiye. Aim of the study: The anti-inflammatory potential of A. biebersteinii was evaluated through activity-guided fractionation (AGF) targeting lipoxygenase (15-LOX) inhibition. Materials and methods: Different chromatographic techniques were used for the AGF of the ethyl acetate extract of A. biebersteinii aerial parts. The in vitro 15-LOX inhibitory activity evaluation was performed to address the antiinflammatory activity. The structures of purified compounds from the fractions were confirmed by LC-HRMS, 1H NMR, and 13C NMR analyses, respectively. Results: The fractionation and isolation process culminated in the identification of three key flavonoids namely; patulitrin, axillarin, quercetagetin-7-O-beta-glucopyranoside, and 4,5-dicaffeoylquinic acid, which showed statistically remarkable 15-LOX inhibitory activity with inhibition rates of 82.27%, 96.81 %, 84.65% and 77.47 %, respectively. Two flavonoids were isolated by using the AGF method, where quinic acid was spotted to have significant 15-LOX inhibitory activity. Conclusion: These findings support the future therapeutic potential of A. biebersteinii as a natural antiinflammatory source.eninfo:eu-repo/semantics/closedAccessAchillea BiebersteiniiPatulitrinAxillarinQuercetagetin-7-O-Beta-Glucopyranosidne4, 5-Dicaffeoylquinic AcidLipoxygenaseAnti-InflammatoryArticle2-s2.0-10502366703610.1016/j.jep.2025.120900