Conserved and Divergent Phytochemical Profiles in Native and Micropropagated Micromeria croatica (Pers.) Schott: An LC-HRMS Study Across Solvent Extracts

<i>Micromeria croatica</i> (Pers.) Schott is a Balkan endemic of the Lamiaceae family, valued for its aromatic and medicinal properties, but it is threatened by its limited natural distribution. Micropropagation offers a sustainable method for securing biomass and provides material for chemical studies. In this work, we present the first LC-HRMS profiling of extracts (in methanol, ethyl acetate, and hexane) obtained from both native and micropropagated plants. A total of 29 metabolites were identified. A diverse spectrum of secondary metabolites was identified, including phenolic acids (gallic acid monohydrate, vanillic acid, trans-cinnamic acid), flavonoids (luteolin-7-O-rutinoside, diosmetin-7-O-glucoside, kaempferol-O-rutinoside, eriocitrin), and terpenoids (ursolic acid, tanshinone I, riligustilide). The analysis revealed that all compounds detected in native plants were also present in micropropagated material, demonstrating the preservation of the characteristic phytochemical profile in vitro. Moreover, several compounds, such as apigenin, apigenin-7-O-glucuronide, isomaltopaeoniflorin, and methoxylated flavones, were found exclusively in micropropagated samples, indicating that tissue culture may enhance the chemical diversity of the species. Ethyl acetate extracts showed the highest degree of overlap between native and in vitro plants, whereas methanol and hexane extracts contained a greater number of unique metabolites in micropropagated material. This first comprehensive phytochemical report on <i>M. croatica</i> highlights the importance of micropropagation as a sustainable strategy for conserving rare species while ensuring a reliable source of bioactive metabolites.