ABSTRACT
A high performance liquid chromatographic method was applied to the determination of some phenolic compounds in the leaves of Mentha spicata L. subsp. spicata. Phenolic compounds were known as antioxidants so that the profile of such compounds in the plants are taking more attention. In this study the qualitative and quantitative analysis of the methanolic extract of Mentha spicata subsp. spicata growing in Turkey in terms of phenolic compound characterization were performed by RP-HPLC for the first time. The plant contains caffeic acid, rosmarinic acid and luteolin among the investigated seven compounds and especially the rosmarinic acid content of the plant was found so high as 1.34g/100g. The plant was found to be a really good source of rosmarinic acid and it’s feasible that standardization of the extract of Mentha spicata subsp. spicata could be done via this developed method over rosmarinic acid due to the significant amount in the plant.