Chemical Composition and Antibacterial Effect of Mentha spp. Grown in Estonia

Abstract

Mentha spp. are used in the food and pharmaceutical industry; the plants are characterized by natural interspecies hybridization. In this study, knowledge of the chemical composition of Mentha spp. was broadened by focusing on plants grown in a geographically small region of Estonia. The antibacterial activity of Mentha spp. essential oils and water extracts was evaluated. Polyphenolic water extracts of M. × villosa Huds., M. × suaveolens Ehrh., and M. × gracilis Sole were tested for the first time on Escherichia coli and Staphylococcus aureus. Leaves of cultivated and wild-grown plants ( n = 33) were collected. The microdistilled essential oil composition reflected the diversity within the genus Mentha. Determined by gas chromatography-mass spectrometry (MS), major compounds were cis-piperitone oxide, carvone, linalool, menthol, and menthofuran. Based on high-performance liquid chromatography-ultraviolet-MS/MS analyses of the water extracts, no species-specific polyphenolic compounds could be proposed. Abundant polyphenols were rosmarinic acid, salvianolic acid B, and eriocitrin. Essential oils exhibited antibacterial activity on E. coli and S. aureus by the broth dilution method. Water extracts showed activity only against S. aureus. This study supports the use of Mentha spp. as health-promoting ingredients in food. However, further studies are still needed to widen the knowledge of the chemical composition of these plants.

LC-MS Identification and Quantification of Phenolic Compounds in Solid Residues from the Essential Oil Industry

“…Compound 10 was present in oregano and lemon balm, whereas compound 11 was detected in all extracts except oregano and sage. Medioresinol was also reported by other authors in spearmint [ 29 ] and in rosemary [ 32 ]. Peaks 16 , 35, 39 and 42 at m / z 537 with characteristic fragment ion at m / z = 493 implied the presence of lithospermic acid isomers, according to other studies [ 30 , 33 ].…”

“…Peak 2 ( m / z 191, UV max 279 nm) was characterized as citric acid, according to MS data of previous studies for similar samples [ 29 ]. Peak 3 ( m / z 197, UVmax 280 nm) was tentatively identified [ 30 , 31 ] as dihydroxyphenyllactic acid (Danshensu) and was present in five of the six extracts (except lemon balm).…”

“…Peak 3 ( m / z 197, UVmax 280 nm) was tentatively identified [ 30 , 31 ] as dihydroxyphenyllactic acid (Danshensu) and was present in five of the six extracts (except lemon balm). This compound however, has been detected in lemon balm infusions [ 30 ] and dry spearmint as well [ 29 , 31 ]. Peaks 10 and 11 with precursor ion at m / z 387 and 305, respectively, in the negative mode, were tentatively characterized as medioresinol and gallocatechin isomer.…”

THE CHEMICAL COMPOSITION AND THE ANTIBACTERIAL ACTIVITY OF ESSENTIAL OILS OBTAINED FROM THREE VARIETIES OF MENTHA x PIPERITA F. CITRATA

“…The genus Mentha (Lamiaceae) includes 23 -30 species and hybrids, which have hundreds of subspecies, varieties and cultivars, widely cultivated in temperate areas around the world, to be used in pharmaceutical, food and dermato-cosmetics industries [6][7][8][9][10][11]. Mentha x piperita f. citrata (Ehrh.)…”

“…Previous studies pointed out antimicrobial, antiinflammatory and antioxidant properties of the essential oils obtained from different varieties of Mentha sp. [5,6,9,10,12,14,19]. In general, agricultural crops of medicinal plants are made with improved varieties that have certain superior characteristics (high yield, important content in valuable active ingredients, fine aroma, resistance to drought, frost, diseases and pests, etc.)…”