Phytochemical Profile, Chemotaxonomic Studies, and In Vitro Antioxidant Activities of Two Endemisms from Madeira Archipelago: Melanoselinum decipiens and Monizia edulis (Apiaceae).

Melanoselinum decipiens and Monizia edulis (Apiaceae) are two endemic plants from Madeira archipelago, phytochemical compositions of which remains little explored, despite their use in folk medicine. Using liquid chromatography with diode array and electrospray ionization/mass spectrometry analysis, their polyphenolic profile was established for the first time. Fifty-six compounds were identified with 5-O-caffeoylquinic acid, quercetin-O-(malonyl)hexoside, luteolin diacetyl, and quercetin-O-hexoside being the major constituents in the leaves of both plant species (≥ 0.76 mg/g of dry extract). Principal component analysis provided a suitable tool to differentiate targeted plants. Naringenin-6,8-di-C-glucoside, quercetin 3-O-pentosylhexoside, and 1,5-O-dicaffeoylquinic acid can be used as discriminatory taxonomic/geographical markers for M. edulis subspecies from Madeira and Porto Santo populations. This methodology of using polyphenols as chemotaxonomic markers proved to be useful for identification of plant species since the results are consistent with previous taxonomical data. The free-radical scavenging activities of the M. decipiens extracts proved to be higher than those of M. edulis, which correlated well with their phenolic content (R2  > 0.906).