Peppermint belongs to one of most popular medicinal plants in pharmacy as well as in the food industry.
Aim: For the conventional usage, the aerial part, especially leaves, is used. This investigation was aimed at the determination of phenolic compound in peppermint rhizomes infusion and the comparison with the phenolics in leaves infusions.
Methods: For the separation and identification of the phenolic compounds, the Sykam HPLC-DAD connected with Microsaic 4500MiD®, a single quadrupole mass spectrometer, was used.
Results: Three compounds in rhizomes and eight compounds in leaves were identified and quantified. In rhizomes, rosmarinic acid was determined as the main secondary metabolite, but its content was three times lower than that in leaves. Infusion of peppermint leaves was richer in flavonoids content with eriocitrin as a major phenolic compound.
Conclusion: Rhizomes of peppermint may also be used as a potential source of rosmarinic acid and caffeic acid derivatives.
 Dorman DJH, Kosar M, Kahlos K, Holm Y, Hiltunen K. Phenolic Profile and antioxidant evaluation of Mentha × pipretia L. (peppermint) extracts. Nat Prod Commun. 2009;4:535-542.
 Dorman HJD, Kosar M, Kahlos K, Holm Y, Hiltunen R. Antioxidant properties and composition of aqueous extracts from Mentha species, hybrids, varieties, and cultivars. J Agric Food Chem. 2003;51:4563–4569;
 Fialová S, Prinz S, Zehl M, Tekeľová D, Reznicek G, Grančai D, Kopp B. Polyphenolic fingerprint of methanolic extracts of Mentha sp. cultivated in Slovakia. Planta Med. 2009;75:SL24.