Phytochemicals, antioxidant activity and essential oil components of Mentha longifolia genotypes

Abstract

Mentha longifolia is one of the most important aromatic and native plants of Iran and has a wide range of applications in the pharmaceutical, food and cosmetic industries. In the present study, the phytochemicals and essential oil components, and antioxidant activity of 30 genotypes of M. longifolia were studied. The maximum amount of chlorophyll a (0.40 mg g− 1 DW), chlorophyll b (0.23 mg g− 1 DW) and total carotenoid content (18.59 µg g− 1 DW) were obtained in G26, while beta carotene (0.026 µg g− 1 DW) was obtained in G27. Total phenol content, flavonoid content and antioxidant activity by DPPH method ranged between 5.97–16.06 mg GAE g− 1 DW, 0.59–3.60 mg quercetin g− 1 DW and 3.34–15.72 mg AAE g− 1 DW, respectively. The highest levels of total anthocyanin content (9.30 µmol g− 1 DW) and soluble carbohydrate content (2.01 mg g− 1 DW) were recorded in G10 and G29, respectively. GC-MS analysis revealed that piperitenone oxide (from1.17 to 69.12%), pulegone (from 2.97 to 67.82%), cis-piperitenone oxide (from 0.78 to 24.89%), thymol (from 0.14 to 22.90%) 1, 8-Cineole (from 0.97to 22.54%), p-menthone (from 0.17 to 15.42%) were as the main ingredients in 30 studied genotypes. Genotypes were divided into four classes based on Hierarchical cluster heat map analysis. Correlation analysis also showed a good relationship between essential oil constituents and evaluated phytochemical compounds. According to the results of this study, the essential oil of M. Longifolia genotypes can be a suitable candidate for use in various pharmaceutical, food and cosmetic industries.