Essential oil composition of Mentha longifolia from wild populations growing in Tajikistan

Mentha longifolia selections, collected from three different sites in south-central Tajikistan, were analyzed to determine essential oil constituency. Essential oils were extracted by hydrodistillation of the plants and subsequently analyzed by gas chromatography – mass spectrometry. A total of 82 compounds were identified, representing 84.5-99.0% of total oil composition. Although qualitatively similar, the Tajikistan M. longifolia samples did show quantitative differences. The major components and their percentage of the oil were cis-piperitone epoxide (7.8-77.6%), piperitenone oxide (1.5-49.1%), carvone (0.0-21.5%), pulegone (0.3-5.4%), menthone (0.016.6%), thymol (1.5-4.2%), β-thujone (0.2-3.2%), carvacrol (0.0-2.7%), and (E)-caryophyllene (0.92.5%). INTRODUCTION The mints, Mentha species belonging to the family Labiatae (Lamiaceae), are widely distributed in Eurasia, Australia, and South and North Africa (Gulluce et al., 2007; Lange and Croteau, 1999). Various species of Mentha have been used as folk remedies for treatment of bronchitis, flatulence, anorexia, ulcerative colitis and liver complaints, due to their anti-inflammatory, carminative, antiemetic, diaphoretic, antispasmodic, analgesic, stimulant, emmenagogue, and anticatharral activities (Al-Bayati, 2009; Džamic et al., 2010; Gulluce et al., 2007; Hajlaoui et al., 2010; Hussain, 2009; Mimica-Dukic et al., 1991; Mkaddem et al., 2009; Oyedeji and Afolayan, 2006; Rasooli and Rezaei, 2002; Viljoen et al., 2006). The active virtues of the mints depend on the abundant volatile oils that contain a wide variety of terpenes and terpenoids. The mint species, Mentha longifolia (L.) Huds., has been commonly used as a kitchen and medicinal plant for centuries. Known as wild mint and horse mint, the plant can reach to 1.5 m high in favorable conditions. The plant has a strong aroma. The objectives of this study were to analyze the composition of the oil of Mentha longifolia growing wild in different areas of Tajikistan. In this report, the essential oil compositions of five samples collected at three sites in south-central Tajikistan. To our knowledge, no previous reports on M. longifolia essential oil in this area have been made. MATERIALS AND METHODS Plant material. Aerial parts of M. longifolia were collected from the three regions of Tajikistan. Samples numbered 1, 2, and 4 were gathered in the area of Korvon village, Dushanbe (38.506044N, 68.751535E, 800 m above sea level), on 25 April 2010. Sample number 3 was gathered in the area of Khonaobod village, Muminobod region (38.107547 N, 69.966431 E, 1200 m above sea level), on 7 May 2010, and sample number 5 was gathered in the Chormaghzak village area, Yovon region, (38.417502 N, 69.172175 E, 1300 m above sea level), on 25 July 2010. The plants were identified by F. S. Sharopov, Sharopov et al.: Essential oil composition of Mentha longifolia from wild populati