Highest Amount Of Essential Oil Research Articles

Effect of common horsetail extract on growth characteristics, essential oil yield and chemical compositions of basil (Ocimum basilicum L.)

To investigate the effect of horsetail extract containing high silicon on morphological traits, growth, content, and compositions of essential oil of sweet basil (Ocimum basilicum L.) an experiment turned into carried out in the shape of a randomized complete block design with three replications. Foliar treatment of horsetail extract with zero, 0.5, 1, and 2% concentrations was applied on 6–8 leaf plants. The assessed traits include plant height, number of leaves per plant, number of sub-branches, leaf area index, plant fresh weight, plant dry weight, total anthocyanin, the content of total phenol and total flavonoid, antioxidant activity, essential oil content, and compounds were measured. The findings demonstrated that the increase of silicon-containing horsetail extract enhanced the improved increase in growth and phytochemical trait values. The use of horsetail extract in the 2% treatment increased plant height, the number of leaves per plant, the number of sub-branches, leaf area index, fresh weight, and dry weight of the plant by 49.79, 45.61, 91.09, 99.78, 52.78 and 109.25%, respectively, compared to the control. The highest content of total phenol (2.12 mg GAE/g DW), total flavonoid (1.73 mg RE/g DW), total anthocyanin (0.83 mg C3G/g DW), and antioxidant activity (184.3 µg/ml) was observed in the 2% extract treatment. The content of essential oil increased with increasing the concentration of horsetail extract, so the highest amount of essential oil was obtained at the concentration of 2%, which increased by 134.78% compared to the control. By using GC–MS, the essential oil was analyzed. The main components of the essential oil include methyl eugenol (12.93–25.93%), eugenol (17.63–27.51%), 1,8-cineole (15.63–20.84%), linalool (8.31–19.63%) and (Z)-caryophyllene (6.02–14.93%). Increasing the concentration of horsetail extract increased the compounds of eugenol, 1,8-cineole, and linalool in essential oil compared to the control, but decreased the compounds of methyl eugenol and (Z)-caryophyllene. Foliar spraying of horsetail extract, which contains high amounts of silicon, as a stimulant and biological fertilizer, can be a beneficial ingredient in increasing the yield and production of medicinal plants, especially in organic essential oil production.

Impact of different drying approaches on VOCs and chemical composition of Mentha spicata L. essential oil: A combined analysis of GC/MS and E-nose with chemometrics methods

Given the significance spearmint (Mentha spicata L.), there is an increased demand for dry medicines and high-quality aromatic mint. In this study, a non-destructive technique based on electronic nose was used in combination with a GC/MS method and chemometrics to determine the quality of spearmint essential oil under eight drying methods. It was found that hot air drying (HAD) method yielded the highest amount of essential oil and its compounds. So that its highest amount was obtained in HAD1a method and equal to 1.380%. However, the amount decreased with increasing drying temperature and air velocity. In addition, sun drying performed worst its value was equal to 0.663%. The highest percentage of the obtained essential oil compounds was related to the three main components of carvone (64.30–7.45%), limonene (24.21–6.59%), and carveol (18.34–1.92%). Furthermore, the Nu-SVM classification algorithm with the sigmoid function provided an accuracy of 0.975 for classifying eight essential oil groups. In light of the limited knowledge about the effects of drying on the qualitative and quantitative characteristics of medicinal plants, a new method for essential oil evaluation was proposed in this study. The results could provide a theoretical reference to choose the best drying method and quickly determine the quality of mint essential oils.

Chemical Composition and Anti-Candida Activity of Mentha suaveolens Ehrh. Essential Oils Obtained by Different Distillation Processes.

A comparative study on essential oils extracted from Mentha suaveolens Ehrh. from Italy is reported. Two extraction procedures were investigated: hydrodistillation and steam distillation, carried out as a continuous and fractionated procedure. Fresh and dried plant material from two harvests was used. The hydrodistillation method yielded a higher amount of essential oil. The dried plant was significantly richer in essential oil per kg of starting plant material. Gas chromatography-mass spectrometry analysis of 112 samples showed that the essential oils belong to the piperitenone oxide-rich chemotype. In addition, piperitenone, p-cymen-8-ol, and limonene were among the most abundant compounds in the different samples. A higher amount of piperitenone oxide was obtained by hydrodistillation, while steam distillation gave a higher percentage of piperitenone and limonene. The essential oils were characterized for their anti-Candida albicans activity; higher potency was observed for the samples rich in piperitenone oxide, with MIC values ranging from 0.39 to 0.78 mg·mL-1 (0.039% and 0.078% p/v). The results of this work provide a deep insight into the methodology of essential oil extraction and the associated chemical variability of M. suaveolens Ehrh. Some of the essential oils are potent against C. albicans and could be considered for potential use in therapy.

Modeling and optimizing concentration of exogenous application of γ-aminobutyric acid on NaCl-stressed pineapple mint (Mentha suaveolens) using response surface methodology: an investigation into secondary metabolites and physiological parameters

Salinity, a severe worldwide issue, compromises the economic production of medicinal plants including mints and causes drug-yield decline. γ-Aminobutyric acid (GABA) is a tolerance-inducing signaling bio-molecule in various plant physiological processes. Pineapple mint (Mentha suaveolens Ehrh.) is a valuable medicinal herb with an exhilarating scent of citrus fruit. Piperitenone oxide is the major bioactive constituent of its essential oil, having significant demand by pharmaceutical industries. Nonetheless, modeling and optimizing the effective concentration of GABA remain within twin foci of interest. Therefore, a two factor-five level (NaCl 0-150 mM and GABA 0-2.4 mM) central composite design was conducted to model and optimize drug yield and physiological responses of M. suaveolens. Based on the design of experiments (DoE) approach, different linear, quadratic, cubic, and quartic models were assigned to the response variables. Change trends of shoot and root dry weights followed a simple linear model, whereas sophisticated models (i.e., multiple polynomial regression) were fitted to the other traits. NaCl stress inevitably reduced root and shoot dry weight, piperitenone oxide content, relative water content, pigments content, and maximum quantum yield of PSII. However, content of malondialdehyde (MDA) and total flavonoid, and DPPH radical scavenging activity were increased under salinity. Under severe NaCl stress (150 mM), the essential oil content (0.53%) was increased three times in comparison with control (0.18%). Optimization analysis demonstrated that the highest amount of essential oil (0.6%) and piperitenone oxide (81%) as a drug yield-determining component would be achievable by application of 0.1–0.2 mM GABA under 100 mM NaCl. The highest dry weight of root and shoot was predicted to be achieved at 2.4 mM GABA. Overall, extremely severe NaCl stress (i.e., more than 100 mM) in which a sharp drop in yield components value was observed seemed to be out of M. suaveolens salinity tolerance range. Hence, it is rationale to compensate the decrease of drug yield by foliar application of a dilute GABA solution (i.e., 0.1–0.2 mM) under 100 mM NaCl stress or lower levels.

Essential oil yield and composition of Ocimum basilicum L. at different phenological stages, plant density and post-harvest drying methods

• CIM-Sukhda is a linalool rich cultivar of basil. • Densely grown plants have better height and canopy • Higher amount of essential oil is produced in full bloom stage • Post harvest drying methods influence essential oil composition Ocimum basilicum L., popularly known as "sweet basil," is native to South Africa, America, and Asia. In India, numerous cultivars and varieties of O. basilicum have been released for commercial cultivation, which are rich in specific essential oils. In this study, the effects of phenological stages and plant density on the productivity of high-quality essential oil of CIM-Sukhda cultivar of O. basilicum and the effects of drying methods on essential oil quality were investigated. In the present study, four plant spacing (45cm × 30cm, 45cm × 40cm, 45cm × 45cm, 45cm × 60cm), four growth stages (vegetative, semi-flowering, full flowering and seed formation) and drying up to one month were compared. A total of 20 compounds were identified by GC and GC-MS, with linalool (66.9-84.2%), geranial (1.1-9.0%), neral (0.8-7.0%) and 1,8-cineole (0.5-3.4%) as the main constituents. The results showed that both plant density and growth stages affected herb and essential oil yield. The essential oil yield of CIM-Sukhda plants is higher at the time of full flowering (106.2 kg ha −1 ) with > 75.0% linalool content in the essential oil.

Variation in Essential Oil Content and Chemical Composition of Rosemary (Rosmarinus officinalis L.) at Various Growth Stages in the Mediterranean Region

Rosemary is an aromatic shrub native to the coasts of the Mediterranean region. Understanding the changes of chemical composition of essential oil is critical for more targeted rosemary harvesting, which can lead to higher-quality essential oils for agro-food, medicinal, and cosmetics uses. Therefore, rosemary plants were harvested at pre-flowering, full-flowering, and post-flowering stage grown in the experimental area of the Department of Field Crops at Çukurova University in order to determine the most suitable harvest time for the highest amount of essential oils and their important compounds. Essential oil content decreased slightly from the pre-flowering to post-flowering. The highest essential oil content (1.68%) was determined at the pre-flowering stage. Twenty-eight compounds were found representing 95.74%-96.74% of the total essential oil. The major compounds for rosemary were camphor (28.43%-32.74%), 1,8-cineol (20.80%-22.61%), isoborneol (6.05%-7.28%), verbenol (5.17%-6.98%), and limonene (5.71%-6.23%), respectively. Consequently, the optimal harvest time in terms of essential oil content, as well as camphor, 1,8-cineole and limonene content, may be considered as pre-flowering stage.

Essential oil content and components, antioxidant activity and total phenol content of rosemary (Rosmarinus officinalis L.) as affected by harvesting time and drying method

BackgroundPreharvest and postharvest conditions of medicinal plants strongly affect the quantity and quality of their secondary metabolites. Here, the effect of different harvesting times (5 am, 12 noon and 5 pm) and different drying methods (shade at 25 °C, oven at 60 °C and microwave at 180 W) on essential oil content and components, total phenol content and antioxidant activity of rosemary was monitored.ResultsHarvesting time only had a significant effect on the essential oil content and components; however, all investigated traits were significantly affected by drying methods. The essential oil content of plants harvested at 5 am and 5 pm was higher than those harvested at 12 noon. The highest amount of essential oil was obtained from shade (0.85–1.12%) and oven (0.66–1.04%) dried plants, respectively. Total phenol and antioxidant activity of oven dried plants were significantly lower than shade and microwave-dried plants. The number, type and amount of essential oil components were affected by harvesting time and drying method. α-Pinene, verbenone and camphor were the major components of the essential oils. Oxygenated monoterpenes were the main group of essential oil compounds in all treatments. The results of biplot and cluster analysis, based on the measured traits, placed the treatments in three separate clusters; I: shade dried, II: oven-dried, and III: microwave-dried plants.ConclusionGenerally, to obtain the higher essential oil content, phenol and antioxidant activity, harvesting at 5 am and 5 pm and also shade drying are recommended; however, for reaching to essential oil with specific quality, different harvesting time and drying method could be used.

Essential Oil Composition of Lavender (Lavandula angustifolia Mill.) at Various Plantation Ages and Growth Stages in the Mediterranean Region

demand for its essential oil continues to grow on a global scale. The fact remains that harvesting at the right time of growth is critical to maximizing the rate of active ingredients found in the plant. Thus, in the current study, L. angustifolia plants were collected at various growth stages (pre-flowering, mid-flowering, and post-flowering) from Adana, Turkey in order to determine the most suitable harvest time for the highest amount of essential oils and its important compounds. The highest flower essential oil content (7.50 mL 100 g-1) was obtained at mid-flowering of the third year of plantation. The major compounds for L. angustifolia were linalyl acetate (25.63-31.63%), linalool (16.33-24.79%), nerol (8.83-13.43%), beta-farnesene (3.67-5.70%), β-cis-ocimene (1.76-8.14%), respectively. The obtained data have been inquired by principal components analysis (PCA), allowing differentiation of plantation ages and growth stages. Compared to the plantation ages, essential oil content and linalool content increased significantly in the third year of cultivation. As a result, the most suitable harvest time may be considered as mid-flowering in terms of essential oil content and in terms of high linalyl acetate and linalool content.

Tansy (Tanacetum vulgare L.)—A Wild-Growing Aromatic Medicinal Plant with a Variable Essential Oil Composition

Tansy (Tanacetum vulgare L.) is an aromatic medicinal plant whose use is limited by the presence of toxic thujone. This research aimed to evaluate the morphological and chemical properties of tansy plants growing in various natural habitats. The research determined the content and chemical composition of the essential oil, the contents of flavonoids and phenolic acids, and the antioxidant activity levels of methanol extracts from tansy inflorescences. The highest amount of essential oil (1.05 mL·kg−1) was found in the raw material collected from the reclaimed area (R). Forty-seven compounds were identified in tansy oil, among which camphor (31.21–1.27%) and trans-chrysanthenyl acetate (76.09–0.09%) dominated, while the concentration of trans-thujone was low (2.67% on average). The highest amounts of flavonoids (0.52%) were found in the raw material collected from the ruderal (W) and reclaimed (R) sites, while the highest amount of phenolic acids (2.42%) was found in the raw material from the ruderal site (W). Tansy inflorescence extracts showed high antioxidant potential (88.41%). The reasons for the variability of the chemical composition of tansy were environmental and genetic variability factors.

Yield and Essential Oil Composition of Thymus eigii (M. Zohary & P.H. Davis) Jalas Leaves and Flowers at Various Growth Stages in the Mediterranean Region

Thymus eigii is a perennial shrub from Lamiaceae family and it is found as wild in Adana and Hatay provinces, Turkey. The potential use of Thymus spp. in the prevention of viral diseases is making its demand rise. In this study, T. eigii plants were collected at various growth stages (pre-flowering, mid-flowering, and full-flowering) from Adana, Turkey in order to determine the most suitable harvest time for the highest amount of essential oil and yield. Full-flowering resulted in the highest plant height (36.11 cm), plant diameter (57.30 cm), fresh herb yield (251.31 g plant-1), fresh flower yield (158.24 g plant-1), dry herb yield (84.73 g plant-1), and dry flowers yield (53.63 g plant-1), whereas the highest fresh leaves yield (38.97 g plant-1) and dry leaves yield (16.72 g plant-1) were found at mid-flowering. While the highest flower essential oil rate (4.75 ml 100 g-1) was obtained at mid-flowering, the highest leaves essential oil rate (2.77 ml 100 g-1) was found at pre-flowering. The major compounds were carvacrol (70.87-77.98%), p-Cymene (3.39-7.46%), β-Caryophyllene (3.90-5.17%), γ-Terpinene (0.58-5.15%), and isoborneol (0.30-3.58%). As a result, the most suitable harvest time was determined as pre-flowering in terms of dry leaf yield and full-flowering in terms of flowers essential oil yield.

English

Thyme is one of the most important medicinal plants in wild rangeland in Iran that has lots of benefits. Pseudomonas flourescence is one of the effective plant growth promoting bacteria (PGPR) as a bioinoculant for medicinal plants. This study aims to survey three inoculation techniques with PGPR on growth and oil content in Thymus kotschyanus for organic cultivation. For this research, an experiment was conducted in Randomized Complete Block Design at Research Institute Forest and Rangelands, Tehran, Iran, with four treatments and three replications. In the first method, thyme seed was treated in liquid bacterial suspension for 3 h, in the second method bacterial suspension injected around the root before cultivation in farm and in the third method both seed and root have been treated by the bacterial suspension. In all three methods of inoculation of P. fluorescence, an increase in growth and the amount of essential oil was determined. The highest amount of root volume (30 mL) compared to the control (15 mL) was significant at the level of P=0.05 and the highest amount of essential oil (1.74%) was obtained by using the third inoculation method. It could be concluded that the microbial inoculation method has a great influence on the yield of T. kotschyanus and bacterial inoculation of seeds and roots had a greater effect, rather than inoculated separately for organic cultivation.   Keywords: Inoculation method, biofertilizer, thymus, plant growth promoting.

Physiological response and secondary metabolites of three lavender genotypes under water deficit

Lavandula genus is a considerable medicinal plant in pharmaceutical and cosmetics industries. Considering increasing threat of drought in the world, it is important to identify genotypes which can tolerate drought. It is also important to characterize quantity and quality of essential oils, and tolerance indicators of these genotypes against drought stress. Therefore, an experiment was conducted in Gorgan University of Agricultural Sciences and Natural Resources, Iran, during 2017 and 2018, to investigate these factors. It was a factorial experiment based on randomized complete block design with two treatments, three genotypes (Lavandula angustifolia cv. Hidcote, Lavandula angustifolia cv. Munstead, and Lavandula stricta), and four levels of drought stress (irrigation regimes) (I1: 100–90% (control), I2: 80–70%, I3: 60–50% and I4: 30–40% of field capacity) which was done with three repetitions. Drought increased amount of proline in leaves, antioxidant activity, activity of catalase, peroxidase, ascorbate peroxidase, and superoxide enzymes, malondialdehyde content, total flavonoids, total phenol, total sugar and essential oil percentage. The PCA analysis of different irrigation regimes showed that in the first component, the best traits are antioxidant enzymes CAT, SOD, APX, while in the second component, only the trait Catalase is the best trait. The results of PCA analysis in lavender genotypes showed that L. stricta exhibits the most affected physiological changes while trying to adjust to changes in the water status of the environment, under the imposed conditions and shows the highest resistance. But it reduced dry weight of aerial parts, relative water content of leaves, and efficacy of essential oil. Lavandula stricta genotype had the highest amount of essential oil, but the highest dry weight of the aerial parts and essential oil yield were related to L. angustifolia cv. Hidcote and L. angustifolia cv. Munstead genotypes. In all evaluated genotypes, with increasing drought stress, monoterpene compounds were decreased and sesquiterpene compounds were increased. Totally it was shown that drought effect on evaluated traits depends on genotype and nature of traits; this indicates that by choosing drought-tolerant genotypes in breeding programs, high quantity and quality of essential oil, as well as tolerance to drought stress can be achieved.

Effects of using humic acid and selenium on some morphophysiological characteristics of Calendula officinalis L. under salinity stress

Salinity stress is one of the most important factors in reducing the crop yield in the world. The application of humic acid along with selenium can improve the plant yield under salinity stress conditions by increasing the antioxidant capacity. To evaluate the effects of humic acid and selenium application under salinity stress conditions in Calendula officinalis L., a factorial greenhouse experiment was conducted in a completely randomized design with three replications in Islamshahr city in 2018. The experimental treatments included sodium chloride (0, 50, and 100 mg l-1), humic acid (0, 100, and 200 mg l-1), and selenium (0, 5, and 10 mg l-1) and their combined effects. The results showed that increasing the salinity significantly reduced the fresh and dry weight of shoots and roots and number of flowers per plant. The foliar application of 200 mg l-1 humic acid and 10 mg l-1 selenium improved carotenoids content of the petals and total chlorophyll of the leaves at all salinity levels. Also, with increasing the sodium chloride level up to 100 mg l-1, the amount of proline increased significantly. Meanwhile, the interaction treatments of humic acid and selenium had significant effects (P≤0.0.1) on improving the activity of superoxide dismutase and peroxidase enzymes at different salinity levels. The highest amount of essential oil (1.37%) was obtained in the interaction treatment of 200 mg l-1 humic acid and 10 mg l-1 selenium under salinity stress of 50 mg l-1 sodium chloride. In general, the results of this study showed that the foliar application of 200 mg l-1 humic acid and 10 mg l-1 selenium could be effective in reducing the negative effects of salinity stress on C. officinalis.

Quantity and Quality of Hyssop (Hyssopus officinalis L.) Affected by Precision Harvesting

The amount of active compounds of medicinal plants (e.g. essential oil) varies in different plant parts. Thus, it is important to harvest those parts containing the highest levels of active compounds. In the present study the effect of harvest height on quantity and quality of Hyssopus officinalis was investigated based on a randomized complete block design with three replications. Treatments included four harvest heights including 15, 25, 35, and 45 cm (in basipetal order) and the residual stalks. After measuring the essential oil, the component values analyzed by GC and GC/MS. Regarding essential oil content (% v/w), yield and dry matter of different heights, the 15 cm height had the highest amount of essential oil (1.02±0.01%) and the lowest yield (2.17±0.13 g/m2) and dry matter (213.72±15.32 g/m2). On the contrary, the 45 cm height had the lowest amount of essential oil (0.75±0.01%) and the highest yield (5.7±0.57 g/m2) and dry matter (757.52±63.5 g/m2). For all harvest heights, cis-pinocamphone (53.93-44.6%), β-pinene (15.33-12.5%) and trans-pinocamphone (12.2-8.17%) had the highest levels among the compounds of the essential oil. The findings obtained from present study revealed that, if the quality is the matter, the essential oil extracted from the top 15 cm had the highest quality and purity although it was less in quantity.

Growth responses and essential oil profile of Salvia officinalis L. Influenced by water deficit and various nutrient sources in the greenhouse.

Salvia officinalis L. is a medicinal plant extensively used in foods, traditional medicine, and the pharmacological industry. In the current study, the effects of different irrigation regimes [irrigation after 70 ± 5 (regular), 105 ± 5 (moderate drought stress), and 140 ± 5 (severe drought stress) mm evaporation] and nutrient sources (control, NPK, farmyard manure, foliar fertilizer, and hydrogel) were investigated on the growth parameters and essential oil (EO) components of S. officinalis in the greenhouse. The plants were harvested two times. The regular irrigation treatment had the most significant effect on plant height (51 cm), fresh and dry herb weight (51.5 and 18.1 g plant−1), and fresh and dry leaf weight (40.1 and 13.1 g plant−1). The highest amount of EO was observed after moderate drought stress (1.48%). The NPK treatment had the greatest effect on plant height (40 cm), branch number (19 per plant), fresh and dry herb weight (53.4 and 18.9 g plant−1), fresh and dry leaf weight (41.2 and 13.6 g plant−1), and EO content (1.67%). The 1st cutting was superior in EO amount, while the 2nd cutting had a high agronomic yield. α-Thujone (from 21.6 to 34.2%) was identified as the predominant compound. Additionally, the content of α-thujone in the 2nd cutting was higher after moderate drought stress, NPK, and hydrogel treatments. Moreover, 1,8-cineole, β-thujone, camphene, α-pinene, α-humulene, viridiflorol, borneol, and bornyl acetate were the other main compounds. As a general result, regular irrigation and NPK treatments improved the agronomic yield of S. officinalis. The plants under drought stress produced high amounts of EO. The farmyard manure also improved plant yield by providing a part of the plant's nutritional needs. Therefore, it could be concluded that it is crucial to determine the effects of limited water availability and various nutrient sources on yield and chemical compositions for medicinal and aromatic plant growth.

Chitosan-Selenium Nanoparticle (Cs-Se NP) Foliar Spray Alleviates Salt Stress in Bitter Melon.

Salt stress severely reduces growth and yield of plants. Considering the positive effects of selenium (Se) and chitosan (Cs) separately against abiotic stress, in these experiments, we synthesized chitosan–selenium nanoparticles (Cs–Se NPs) and investigated their ability to reduce the negative effects of salt stress on growth and some biochemical parameters of bitter melon (Momordica charantia). Bitter melon plants were grown at three NaCl salinity levels (0, 50, and 100 mM) and a foliar spray of Cs–Se NPs (0, 10, and 20 mg L−1) was applied. Some key morphological, biochemical, and physiological parameters in leaf samples and essential oil from fruit were measured at harvest. Salinity decreased growth and yield while foliar application of Cs–Se NPs increased these critical parameters. Furthermore, Cs–Se NPs enhanced bitter melon tolerance to salinity by increasing antioxidant enzyme activity, proline concentration, relative water content, and K+, and decreasing MDA and H2O2 oxidants and Na aggregation in plant tissues. Yield was also improved, as the highest amount of essential oils was produced by plants treated with Cs–Se NPs. Generally, the greatest improvement in measured parameters under saline conditions was obtained by treating plants with 20 mg L−1 Cs–Se NPs, which significantly increased salinity tolerance in bitter melon plants.

Varietal variability of less grown mints: influence on selected antioxidants

Genus Mentha belongs among the important part of spice, aromatic and medical plants. It includes a large amount of varieties and forms which are not spread generally because of low knowledgeability about possibilities of individual varieties using and also about their high content of bioactive substances. Five less-known varieties and forms (Mentha x piperita var. ´Danica´, Mentha x piperita var. ´Chocolate´, Mentha arvensis f. Banana, Mentha sp. f. Mojito, Mentha sp. f. White Grape) with different aroma and plant habitus were chosen to estimate the content of essential oils, chlorophyll a, chlorophyll b and carotenoids. From obtained results varietal variability of individual varieties and forms have been specified and compared with commonly used Mentha x piperita. The content of essential oils was estimated by steam distillation. The pigment content was determined by spectrophotometric measurement of absorbance at a wavelength of 649 nm (chlorophyll a), 665 nm (chlorophyll b) and 450 nm (carotenoids). The results showed that ´Danica´ and ´Chocolate´ varieties have reached the highest amount of essential oils. Most of the chlorophyll a, b and carotenoids content reached commonly used Mentha x piperita, but there wasn´t found significant difference when compared with ´Danica´ and ´Chocolate´. The effect of varietal variability on the content of qualitative characteristics in the case of essential oils, chlorophyll a and b was confirmed according to used statistical analyse (p <0.05). The varietal variability of tested mint forms and varieties on carotenoids content was not confirmed.

Combined Application of 24-Epibrassinolide and Selenium Improves Essential Oil Content and Composition of Dragonhead (Dracocephalum moldavica L.)

The greenhouse experiment was carried out to investigate the response of Dragonhead (Dracocephalum moldavica L.) to 24-Epibrassinolide (EBL) (0.0 and 0.5 μM) and selenium (Se) (0.0 and 10 μM) foliar applications. The essential oil from the aerial parts of Dragonhead was obtained by hydrodistillation and analyzed by GC/MS. EBL and Se treatments had a promoting influence on essential oil (EO) accumulation and changed chemical constituents of Dragonhead. In general, the highest amount of essential oil was obtained in the plants treated with EBL+Se. The main constituent of the EO was geranial (33.46-36.29 %) followed by neral (24.18-26.03 %) and geranyl acetate (11.67-15.43 %) which the highest percentage of them were obtained in the plants treated with EBL and Se in combination. However, the most abundant chemical class was oxygenated monoterpenes (68.63-78.59 %) compared with the other chemical classes, and the highest percentage of these components was related to EBL-treated plants. Collectively, the present study demonstrates that EBL (5 μM) or Se (10 μM), particularly their combination, can generate the beneficial response in terms of production and compositions of EO in Dragonhead plants.

Extraction and encapsulation of lesser galangal (Alpinia officinarum) essential oil using microwave pretreatment and spray drying

Galangal (Alpinia officinarum) essential oil potentially exerts several health benefits such as antiproliferative, pain relief and fever reduction activities. The essential oil in this study was extracted using the microwave (MW) assisted treatment as an alternative method to conventional extraction. The samples were treated with MW at different power levels (600, 700, and 800 W) for 3 min before subjecting to a hydro distillation extraction. The effect of sample:water ratio (1:1 and 1:0.5) was also investigated. The MW treatment at 600 W and sample:water ratio of 1:1 resulted in the highest amount of essential oil (0.33%). The MW pretreatment had a positive effect on reducing the extraction time (from 3 h to 2.5 h) observed at all MW power levels. The effect of essential oil loading capacity (10, 20 and 30%) on the encapsulation yield was evaluated. The in vitro antioxidative activity of the obtained powder was then measured. The highest encapsulation efficiency (86.5%) was obtained from the 20% loading capacity, suggesting for a suitable amount of essential oil should be loaded for the encapsulation. The in vitro antioxidant activity of the encapsulated essential oil powders was determined. The IC50 of the powder was 2077 μg/mL using DPPH assay

Effect of Phenological Stages on Essential Oil Content, Composition and Rosmarinic Acid in Rosmarinus officinalis L.

Rosemary (Rosmarinus officinalis L.) is an important medicinal plant that contained a wide range of secondary metabolites such as rosmarinic acid. In this study, essential oil content and composition and rosmarinc acid were determined at three phenological stages (before flowering, full flowering and fruit set stages). Hydro distillation method was used for essential oil extraction and GC and GC/MS was used for essential oil composition. On the basis of the obtained results rosemary plants in full flowering stage had higher amount of essential oil (1.99 ml/100 g dry weight) than in before flowering and fruit set stages (1.2 and 1.01 ml/100 per g dry weight, respectively). The extracted essential oil was contained 1,8-cineole, α-pinene, verbenone, camphor, geraniol, borneol acetae, camphene and linalool as major constituents. These constituents were affected by phenological stages. Before flowering, 1,8-cineole, α-pinene and verbenone (13.68%), in full flowering, 1,8-cineole (17.90%) and in fruit set α-pinene (21.77%) were the main constituents of the reosemary essential oil. Using HPLC analysis on leaf extract showed that the highest amount of rosmarinic acid (25.92mg/g DW) was observed in the fruit set stage. In conclusion, for essential oil content full flowering stage can be recommended for harvesting of Rosmarinus officinalis L. and for rosmarinic acid, fruit set stage can be the best time for harvesting of this medicinal plant.