Multidisciplinary Approach to Determine the Optimal Time and Period for Extracting the Essential Oil from Mentha suaveolens Ehrh

Abstract

A comprehensive study on essential oils (EOs) extracted from some Mentha suaveolens L. samples, collected in the countryside of Tarquinia, is reported. In this study, the procedure for essential oil preparation, in terms of harvesting and extraction time, was analyzed in detail for the first time. The GC/MS analysis, carried out on 18 samples, revealed that piperitenone oxide (PO), the main essential oils' chemical constituent, is primarily responsible for the related antifungal activity. Nevertheless, EOs with lower PO content indicate that other chemicals, such as para-cymenene, may participate in exerting OPEN ACCESSMolecules 2015, 20 9641 the EOs' antifungal effect. Furthermore, the bacterial reverse mutation assay highlighted lack of mutagenic effect in all tested samples. Analysis of the results indicated that for higher activity, the essential oils should be produced with 3 h maximum hydrodistillation, regardless of the harvesting time. Differently, the maximum essential oil yield can be obtained in August and the highest piperitenone oxide percentage is obtainable in July.

Essential Oil Extraction, Chemical Analysis and Anti-Candida Activity of Calamintha nepeta (L.) Savi subsp. glandulosa (Req.) Ball—New Approaches

“…The results indicate that PUL is likely not the only chemical component responsible for the antifungal activities, although it is always the dominant one, on the other hand, this is just an observation as advanced chemometric and statistical analyses need to be carried out. Looking at Tables S1–S4, it is evident that other minor constituents are capable of microbiological activity as well and might be involved in the inhibition process with some synergistic mechanism resembling the one recently described [8]. This is in compliance with the phytocomplex hypothesis discussed elsewhere [40,41].…”

“…A comprehensive study on the EO, considering both extraction time and period of harvesting, from wild Mentha suaveolens Ehrh. (MS) has been reported recently [8]. Analogously, as in the MS study, we report herein a detailed study on C. nepeta (L.) Savi subsp.…”

“…Similarly, as previously reported [8] fresh plant material (2.5 kg) was subjected to steam distillation separating EOs at an interval time of 1, 2, 3, 6, 12 and 24 h and worked out to furnish six fractions of yellow paled EOs. In addition, EOs mixtures were prepared by mixing each fraction as follows: M1 (1 + 2 h of extraction), M2 (1 + 2 + 3 h), M3 (1 + 2 + 3 + 6 h), M4 (1 + 2 + 3 + 6 + 12 h) and M5 (1 + 2 + 3 + 6 + 12 + 24 h).…”

“…Considering the increased interest in natural substances, the deepening of the knowledge of the potential of different aromatic plants can lead to important results in the discovery of both sustainable and effective drug treatment. In line with our previous studies on MS [8], a 24-h extraction procedure was applied to CG in terms of a different harvesting period (four months) and extraction duration. In this study, we investigated the chemical composition of 44 TEOCG samples, showing that the PUL/MEN chemotype was represented in Tarquinia, but the ratio varied greatly according to the growth phase of the plant.…”

“…The gas chromatographic/mass spectrometric (GC/MS analysis was carried out with a GC-MS and flame ionization detector (FID) as previously reported [8]. The analyses were carried out twice showing reproducible results.…”