Unraveling the phenolic profiles of Clinopodium bolivianum (Benth.) Kuntze and Minthostachys mollis (Benth.) Griseb.: A comprehensive LC-QtoF metabolomic study of underexplored Peruvian medicinal plants

Medicinal plants remain a primary healthcare resource worldwide, particularly in regions with strong cultural traditions and limited economic development. In Peru, muña [Minthostachys mollis (Benth.) Griseb.] and inca muña [Clinopodium bolivianum (Benth.) Kuntze], both Lamiaceae species used for gastrointestinal and anti-inflammatory purposes, are poorly characterized at the metabolomic level, limiting the availability of phytochemical data required to ensure the quality and authenticity of commercial preparations. This study aimed to unravel and comprehensively characterize the phenolic metabolomes of both species and evaluate their antioxidant capacity, providing novel chemical evidence for species differentiation assessment. The samples underwent a two-stage solid-liquid extraction, and the resulting extracts were analyzed using Folin-Ciocalteu, FRAP and ABTS assays, and extensively profiled by LC-ESI-QToF based metabolomics. Morphological characterization was performed by light microscopy. The results showed that inca muña had a higher phenolic content, expressed as milligrams of gallic acid equivalents (mg GAE) per 200 mL of infusion (201 vs. 134 mg GAE/200 mL, and superior antioxidant capacity in FRAP and ABTS assays. A total of fifty-one phenolic compounds were tentatively identified, predominantly flavonols, flavones, hydroxybenzoic acids, and hydroxycinnamic acids. Multivariate metabolomic analysis revealed distinct phenolic profiles between species, highlighting clear interspecific differences. Muña stood out for phenylacetaldehyde, galloyl sucrose, and isoflavones, while inca muña showed higher levels of cudraflavone and naringenin, proposed as potential discriminant biomarkers. Together, these findings unravel the phenolic metabolomes of two underexplored Peruvian medicinal plants, support their antioxidant potential, and provide a comprehensive metabolomic basis for chemical differentiation and paved the way to a more accurate authenticity assessment in commercial herbal preparations.