Untargeted UHPLC-HRMS Metabolomic Profiling of Cornus mas L. Fruits: Impact of Conventional and Emerging Extraction Methods on Phenolic Composition and Bioactivity

A growing number of studies evaluated cornelian cherry (<i>Cornus mas</i> L.) fruits due to their rich phenolic profile. It is obvious that the efficient recovery of these compounds depends on the extraction method used. Thus, this study aimed at comparing conventional (maceration, decoction) and non-conventional (ultrasound-assisted [UAE], enzyme-assisted [EAE]) extractions. Two novel aspects were characterized: the first application of EAE for cornelian cherry fruit phenolic recovery and the use of untargeted UHPLC-HRMS metabolomics. Untargeted UHPLC-HRMS profiling in positive electrospray ionization mode annotated 342 compounds, the broadest chemical analysis of <i>C. mas</i> fruits reported to date, followed by a semi-quantitative assessment of main phenolic compound subclasses using representative standards and multivariate statistical approaches. UAE proved most effective for recovering total flavonoids (433.6 μg eq./g) and phenolic acids (420.2 μg eq./g), while EAE selectively enriched other phenolic category compounds, semi-quantified as oleuropein equivalents (1975.4 μg eq./g). Multivariate analysis further confirmed distinct phytochemical fingerprints across extraction methods: the UAE extract was characterized by isocoumarin 2,4-di-<i>O</i>-methylolivetonide, while two compounds, cardamonin and ellagic acid arabinoside, were specifically up-accumulated in the EAE extract. All extracts showed moderate antioxidant (UAE > decoction > maceration > EAE) and enzyme inhibitory activities, with UAE and maceration being the most promising for multifunctional bioactivity. However, while untargeted UHPLC-HRMS revealed unprecedented complexity, results remain tentative and highlight the need for future targeted validation.