USING NMR AND MS IN PLANTS MEDICINE AND NUTRACEUTICS: THE EXAMPLE OF MENTHA AQUATICA L.

In this work, we present our approach for the study of plants with medical and nutraceutical interest also showing the example of Mentha aquatica L. Our methodology consists of four steps: extraction of the studied plant; performance of a preliminary analysis through NMR and MS; isolation and identification of the secondary metabolites constituting the molecular pattern of the species by means of Column Chromatography coupled again with MS and NMR; eventual considerations if the presence of certain compounds may justify the use of that plant in a specific field. Mentha aquatica L. is a perennial plant belonging to the Lamiaceae family, growing along hydrous places like rivers, lakes and swamps in meadows and woods till the altitude of 1200 m a.s.l. and presenting a double use as a food and as a medicine. It’s characterized by an ascending hairy and branched stem. Its leaves are short and opposite with an oblong oval shape. Its flowers are quite big, odorous and hermaphrodite with a color ranging from pink to violet and bloom from June to October. The fruit is formed by four nuculae with a warty surface . Mentha species are traditionally used in several fields for several purposes: in pharmaceutics as a flavor corrective of some drugs; in herbal medicine for their analgesic, antigenotoxic, spasmolytic, antibacterial and astringent properties; in cosmetics as a component of fragrances and of creams and soaps; in alimentation as a condiment , in the preparation of confectioneries and salads or as a flavouring of beverages and sweets . The phytochemical analysis conducted on a sample of this species, collected in the area of the Turano Lake, province of Rieti, Central Italy, (geographic coordinates 42°12'30"N; 12°57'26"E) in July of 2015, evidenced the presence of fourteen compounds namely rosmarinic acid (1) , oleanolic acid (2) , corosolic acid (3) , asiatic acid (4) , caffeic acid (5), quinic acid (6) , one diglyceride (7) , one triglyceride (8) , succinic acid (9) ), glucose (10) , sucrose (11) , alanine (12) , valine (13) and threonine (14) . The presence of these compounds is very important in our context: the triterpenes (1, 2, 3, 4), the hydroxycinnamic acid (5) and the cyclohexane-carboxylic acid (6) are known to possess several interesting pharmacological properties among which the anti-oxidant and anti-inflammatory ones are the most relevant and may suggest the further use of this plant in medicine; on the other side, the glycerides (7, 8), the dicarboxylic acid (9) the sugars (10, 11) and the amino acids (12, 13, 14) are important for their several nutritive properties . This study has then provided a phytochemical rationale for the employment of also this species in the traditional uses of the Mentha genus. Indeed, our approach, with these two combined spectroscopic techniques, has confirmed to be very efficient for the study of plants presenting an alimentary and/or pharmaceutical interest.