Constituents of Melittis melissophyllum subsp. albida.

In this paper, for the first time, we have reported the analysis of the polar fraction of Melittis melissophyllum subsp. albida, a species with ecological relevance which is also used in traditional medicine of Central-Southern Italy. Iridoid glucosides were mainly identified, together with verbascoside, an ubiquitous phenyl-ethanoid glycoside, with chemotaxonomic implications in Lamiales order. The majority of the isolated compounds is endowed with interesting bio- activities and may justify the traditional uses of this plant also from a chemical point of view. Several peculiarities were also recorded in the metabolic pattern of this subspecies, i.e. the presence of virginioside and geniposidic acid, two rare compounds in the Lamiaceae family. The presence of free cinnamic acid was an additional characteristic of this subspecies which showed a specific secondary metabolites content. These phytochemical peculiarities, together with the morphological differences showed by the subsp. albida in respect to the nominal species, may be a base for a reconsideration of the systematic of Melittis melissophyllum subsp. albida.