Essential Oil Yield Research Articles

Sequential Extraction and Characterization of Essential Oil, Flavonoids, and Pectin from Industrial Orange Waste.

Orange is one of the primary fruits processed into juice and other products worldwide, leading to a vast amount of waste accumulation. Such waste has been considered as an attractive candidate for upcycling to obtain bioactive components remaining. The present study investigated the extraction of essential oil (EO), flavonoids, and pectin from industrial orange waste with a holistic approach. To maximize EO yield and d-limonene concentration, hydrodistillation (HD) conditions were selected to be 5.5 mL water/g solid for 180 min. Remaining solids were further used for flavonoid extraction where conventional solvent, sequential ultrasound + solvent, and ultrasound-assisted extraction (UE) were applied. UE applied for 50 min with 120 mL solvent/g solid yielded the highest total phenolic (TPCs) and total flavonoid contents (TFCs), antioxidant capacity, and hesperidin and neohesperidin concentrations. In terms of TPC, TFC, antioxidant capacity, and antibacterial activity, both EO and flavonoid fractions demonstrated moderate to high bioactivity. At the final step, ethanol precipitation was applied to obtain the pectin that was solubilized in hot water during HD and it was characterized by Fourier transform infrared, degree of esterification, and galacturonic acid content. Practical application: to ensure utilization in the food, pharmaceutical, and cosmetic industries, this study presents a combined method to obtain several value-added compounds from industrial orange waste. Bioactive EO and flavonoids obtained could have applications in functional food, supplements, or cosmetic formulations, whereas extracted pectin can be used in many formulated foods and drugs.

Evaluation of monthly changes in essential oil yield and components of cherry laurel (Prunus laurocerasus L.) leaf

This research was carried out to examine the monthly changes in both the volatile oil content and volatile components of cherry laurel leaves by taking samples every month for 12 months in Turkey. Harvest periods significantly affected volatile oil content (P < 0.01). Depending on harvest periods, volatile oil ratios ranged from 0.19 to 0.35%. The months of August, July, and September yielded the highest volatile oil ratios. Benzaldehyde, phenol, benzoic acid, benzeneacetonitrile, pentadecanone, 1,54-dibromotetrapentacontane and, tetrapentacontane were determined as components in the volatile oil. The ratio of benzaldehyde, the main active ingredient, varied between 83.89 and 94.41%, depending on the harvest time. The cherry laurel leaf should be harvested in July, August, and September for high essential oil ratios and in May, June, and July for high benzaldehyde ratios. Due to the high concentration of benzaldehyde in its volatile oil, cherry laurel evergreen leaf can be considered a valuable source of raw materials for the fragrance and pharmaceutical sectors.

Co-application of titanium nanoparticles and melatonin effectively lowered chromium toxicity in lemon balm (Melissa officinalis L.) through modifying biochemical characteristics.

Chromium (Cr) toxicity can negatively affect plant growth and development, impacting agricultural productivity and posing risks to human health. Metallic nanoparticles (MNPs) such as titanium dioxide (TiO2) and natural growth regulators such as melatonin (MT) become a promising technology to manage heavy metal-contaminated soils and promote safe food production. The present work was conducted to find the effect of foliar application of TiO2 NPs (15 mg L-1) and MT (100 µM) on growth, biochemical attributes, and Cr accumulation in plant tissues of Melissa officinalis L. under Cr toxicity (50 and 100 mg Cr kg-1 soil). The results showed that Cr toxicity led to decreased plant performance, where 100 mg Cr kg-1 soil led to notable decreases in shoot weight (28%), root weight (27%), essential oil (EO) yield (34%), chlorophyll (Chl) a + b (33%), while increased malondialdehyde (MDA, 30%), superoxide dismutase (SOD) activity (51%), and catalase (CAT) activity (122%). The use of TiO2 NPs and MT, particularly their co-application, remarkably reduced Cr toxicity by enhancing plant weight, Chl content, and lowered MDA and antioxidant activity. Total phenolic content (TPC), total flavonoid content (TFC), EO percentage, and rosmarinic acid in plants treated with Cr at 50 mg Cr kg-1 soil and co-application of TiO2 NPs and MT were relatively higher than in other treatments. Under 100 mg Cr kg-1 soil, the synergic effect of TiO2 NPs and MT-enhanced rosmarinic acid content (22%) but lowered Cr accumulation in roots (51%) and shoots (72%). Heat map analysis showed that CAT, SOD, MDA, and EO yield had the maximum variability under Cr, TiO2 NPs, and MT. Exogenous TiO2 NPs and MT can be recommended to modulate Cr toxicity in lemon balm under soil Cr toxicity.

Chemical profiling and bioactivity of Aloysia citriodora essential oils from four localities in Tunisia

ABSTRACT The goal of this work was to investigate the chemical composition of Aloysia citriodora essential oil and its biological activities as antioxidant, antibacterial, antifungal and anti-inflammatory potentials depending on the collection region. The highest essential oil yields were in Gabes and Kairouan at the Arid bioclimatic zone. Sixty volatile compounds were identified by GC-FID-MS. The major compounds were limonene and spathulenol in Gabes at the Middle Arid. However, (E)-citral (known as geranial) was the major compound of Belli and Kairouan belonging to the Upper Semi-Arid and Upper Arid areas, respectively. The essential oil extracted from the inferior sub-humid bioclimatic zone (Boussalem) had spathulenol and caryophyllene oxide as predominant components. Inversely to DPPH and ABTS, the antioxidant activities using reducing power assay of A. citriodora essential oils significantly increased from the inferior sub-humid (Boussalem) to the Upper Arid (Kairouan) bioclimatic areas. Independently of region, A. citriodora essential oil exhibited an interesting antibacterial, antifungal and anti-inflammatory potential.

Synthetic polyploidization induces enhanced phytochemical profile and biological activities in Thymus vulgaris L. essential oil

Essential oil from Thymus vulgaris L. has valuable therapeutic potential that is highly desired in pharmaceutical, food, and cosmetic industries. Considering these advantages and the rising market demand, induced polyploids were obtained using oryzalin to enhance essential oil yield. However, their therapeutic values were unexplored. So, this study aims to assess the phytochemical content, and antimicrobial, antioxidant, and anti-inflammatory activities of tetraploid and diploid thyme essential oils. Induced tetraploids had 41.11% higher essential oil yield with enhanced thymol and γ-terpinene content than diploid. Tetraploids exhibited higher antibacterial activity against all tested microorganisms. Similarly, in DPPH radical scavenging assay tetraploid essential oil was more potent with half-maximal inhibitory doses (IC50) of 180.03 µg/mL (40.05 µg TE/mg) than diploid with IC50 > 512 µg/mL (12.68 µg TE/mg). Tetraploids exhibited more effective inhibition of in vitro catalytic activity of pro-inflammatory enzyme cyclooxygenase-2 (COX-2) than diploids at 50 µg/mL concentration. Furthermore, molecular docking revealed higher binding affinity of thymol and γ-terpinene towards tested protein receptors, which explained enhanced bioactivity of tetraploid essential oil. In conclusion, these results suggest that synthetic polyploidization using oryzalin could effectively enhance the quality and quantity of secondary metabolites and can develop more efficient essential oil-based commercial products using this induced genotype.

Formulation and Evaluation of Physical Quality of Peel-Oof Masks of Essential Oils of Galam Kalimantan Plants

The Kalimantan galam plant (Melaleuca cajuputi subsp cajuputi) has been used for generations but its use is very limited, only as wooden piles which form the basis of buildings in swamps (cerucuk), pillars for building construction, stakes (supports for newly planted seedlings) and siring. Street. The use of galam essential oil as an active ingredient in peel-off mask preparations can be efficacious in reducing inflammation and infection of acne or other skin problems. Facial masks in the form of peel-off itself have many advantages, namely their practical use and are easy to remove or lift like elastic membranes compared to conventional masks which leave residue. This study aims to design a peel-off mask formulation by utilizing the active ingredient in the essential oil of the galam plant. The preparations were then tested for physical quality requirements including organoleptic tests, homogeneity tests, pH tests, drying time tests, spreadability and adhesion tests. The results of the tests that have been carried out include the extraction of essential oils as the active substance. The yield of essential oil obtained was 0.12%. Organoleptic quality tests showed changes in color, smell and shape in the three formulations. The homogeneity test for formulas I and II remained homogeneous, while for formula III the consistency changed to 2 layers. The pH test showed that all formulations met the pH requirements for topical preparations, namely 4-8. The drying time test for formula I was more difficult to remove, formula II was not too stiff while formula III was stiffer. Spreadability test on formulas I, II and III 5-7 cm. The gel viscosity test decreased and the adhesion test on formulation I was easily released, formulas II and III were not easily released while the irritation test of 30 people did not experience redness in 3 formulas.

КОЛИЧЕСТВЕННЫЕ И КАЧЕСТВЕННЫЕ ХАРАКТЕРИСТИКИ ЭФИРНОГО МАСЛА ИЗ СОЦВЕТИЙ И ЛИСТЬЕВ CANNABIS SATIVA СОРТА МАРИЯ, ПОЛУЧЕННЫХ РАЗНЫМИ СПОСОБАМИ ФЕРМЕНТАЦИИ

The purpose of the study is to evaluate samples of the Cannabis sativa plant for the possibility of using them as a source of essential oils. Objectives: to establish methods for hydrodistillation of essential oil from samples of Cannabis sativa variety Maria, obtained by different fermentation methods, to determine the most effective method for obtaining essential oil that meets the requirements for the mass fraction of essential oil and physicochemical parameters; to determine the qualitative and quantitative characteristics of the essential oil of the studied objects of research. The objects of the study are fresh leaves and inflorescences of Cannabis sativa variety Maria, collected in September 2023 from a plantation in the Sukhobuzimsky district of the Krasnoyarsk Region, and fermented leaves and inflorescences of Cannabis sativa variety Maria, collected from a plantation in the Ermakovo District of the Krasnoyarsk Region in 2021. Two methods were used for fermentation: natural and with specified parameters. The hydrodistillation process was studied on a standard Clevenger-type apparatus for 5 hours, the obtained samples of essential oils were studied by volume of output in accordance with the method of isola¬ting essential oils, quality indicators and the mass fraction of essential oils were determined. The volume of essential oil obtained in experimental samples directly depends on the time of the distillation process and the conditions of Cannabis sativa fermentation. The largest amount of hemp essential oil was obtained from fresh leaves and inflorescences of Cannabis sativa variety Maria (0.42 %) from the average value of the samples. The organoleptic and physicochemical characteristics of the essential oil obtained as a result of fermentation meet the requirements for essential oils. The use of different methods of fermentation of leaves and inflorescences of Cannabis sativa affects not only the yield of essential oil, but also to a large extent its quality.

Aroma profile, antioxidant and anti-inflammatory properties of cinnamomum camphora L. essential oil as affected by various drying techniques

ABSTRACT The aim of the study was to examine the effect of drying on the aroma profile and bioactivity of Cinnamomum camphora L. leaf. Clevenger was used to extract essential oils and were analyzed by GC and GC-MS. Principal component analysis (PCA) was used to visualize the variance in the aroma profile. These oils were tested for their antioxidant and anti-inflammatory potential. Fresh oil was found to be rich in camphor, limonene, α-pinene and myrcene. Camphor, limonene and α-pinene were the major constituents of all the oils under different drying conditions. The content of camphor increased significantly upon drying. Shade drying could be used as the most prominent drying method for C. camphora L. as it was found to have the highest camphor content (67.30 %), essential oil yield (0.34 %) and in-vitro anti-inflammatory activity potential (IC50: 7.46 μg mL−1). Monoterpene hydrocarbons might be responsible for the antioxidant activity.

Chemical compositions of the essential oils of endemic wild Origanum majorana var. tenuifolium collected from three different locations during flowering and post-flowering phases in North Cyprus, Multivariate Statistical Analyses

Wild growing Origanum majorana L. var. tenuifolium Weston was collected from three different locations (Om1: Avtepe, Om2: Alevkayası, Om3: Kozanköy) in North Cyprus. The essential oils were hydrodistilled and chemical composition analyses were simultaneously performed by GC-FID and GC-MS. The average yields of essential oils were 5.46-8.14%. Major compounds of flowering Om1 oil were cis-sabinene hydrate (45.0%) and terpinen-4-ol (11.1%) while those of Om3 (Kozanköy) oil were cis-sabinene hydrate (33.3%), terpinen-4-ol (12.3%) and α-terpineol (11.5%). In the post-flowering stage, the major compounds for Om1 and Om3, respectively, were cis-sabinene hydrate (16.7% and 18.8%), terpinen-4-ol (18.1% and 14.5%) and α-terpineol (23.9% and 20.0%). However, the main compound of the essential oils of the flowering and post-flowering oil of Om2 was α-terpineol (76.9% and 51.6%). Statistical Principal Component (PCA) and Hierarchical Cluster Analyses (HCA) tools demonstrated the composition variations of the essential oils at different times and locations. Om1 and Om3 (HCA similarity level: 98.98%) were similar while Om2 (HCA similarity level: 46.32%) was discordant.

Chemical composition, enzyme inhibitory activities, and molecular docking studies of essential oil of Knema globularia leaves from Vietnam

In the present work, chemical composition, enzyme inhibitory activities, and molecular docking studies of essential oil (EO) of Knema globularia leaves collected from Vinh Phuc Province, Vietnam, were investigated. The EO from the leaves of K. globularia was obtained by hydrodistillation and analyzed by gas chromatography-mass spectrometry (GC-MS) analysis. The leaf EO yield was 0.14 ± 0.01% (w/w), comprising 39 identified components, constituting 96.77% of the EO content. Notable constituents included β-caryophyllene (54.11%), α-humulene (12.67%), and (E)-β-ocimene (8.82%). Enzyme inhibitions were assessed via the α-amylase inhibitory assay (IC50 = 282.71 ± 10.06 μg/mL) and tyrosinase inhibitory assay (IC50 = 993.92 ± 37.40 μg/mL). The molecular docking method has been employed to observe valuable binding interactions and binding energy with the main compounds on the target enzymes α-amylase and tyrosinase. Caryophyllene oxide exhibits the strongest affinity with α-amylase among the other major compounds. Meanwhile, viridiflorene shows the best binding energy with the tyrosinase enzyme. This is the first study providing valuable scientific data on the in vitro inhibitory activities of α-amylase and tyrosinase enzymes of the leaf EO of K. globularia and evaluating its main compounds through a molecular docking approach on these enzyme targets.

Antioxidant and antibacterial activities of geranium (pelargonium graveolens L’Hér.) essential oil as affected by the growing biotope

ABSTRACT This study investigated the variability of antioxidant and antibacterial activities of essential oil (EO) from geranium (Pelargonium graveolens) aerial parts, collected from four Tunisian regions. The highest EO yield was obtained in Korba, followed by Beja, Tozeur and Sfax. In all regions, geranium EO was rich in oxygenated monoterpenes mainly due to the predominance of citronellol and geraniol. Antioxidant potential of geranium EO was evaluated by DPPH, ABTS, iron reducing power and β-carotene bleaching assays. Independently of region, geranium EO showed a weak antioxidant potential as compared to the positive control BHT. However, geranium EO was endowed with important antibacterial properties. In fact, Escherichia coli and Staphylococcus aureus were the most sensitive strains than Serratia marcescens, Pseudomonas aeruginosa, Pseudomonas aeruginosa and Enterococcus hirae. These findings suggested that geranium EO could be used as new and rich potential sources of many future multipurpose products for food preservation, pharmaceutical, and industrial applications.

Interactive effects of number of plants and nitrogen fertilization on quality parameters of Salvia officinalis L. cultivated in semi-arid environments

This research aimed to elucidate the interplay between number of plants and nitrogen dose on the agronomic attributes, as well as the essential oil yield and composition of Salvia officinalis L. (sage) in the challenging ecological conditions of Mardin, situated in South Eastern Anatolia. A split-plot experimental design was employed during 2018-2019, manipulating the variables of number of plants and nitrogen application rates. The experiment identified camphor, 1,8-cineole, α-thujone, and β-thujone as the major components. The PCA analysis unveiled statistically significant inverse correlations between the concentration of camphor and 1,8-cineole, as well as α- and β-thujone. The results demonstrated that the combination of lower plant number with elevated nitrogen levels yielded higher fresh herb dry herb and dry leaf. While lower plant number and higher nitrogen application independently exerted positive influences on essential oil production and yield, the interactive impact of these treatments yielded inconclusive results. Specifically, nitrogen treatments led to an increase in camphor content while reducing α- and β-thujone contents in the essential oil. Conversely, lower plant numbers resulted in decreased camphor content and an increase in thujone content within the oil. In light of these findings, it is recommended that, under semi-arid conditions, optimal yields can be achieved by employing plant number of 50000 plants ha−1 and a nitrogen fertilizer rate of 120 kg ha−1. This research sheds light on the intricate relationship between agronomic factors and the quality of sage cultivation, offering valuable insights into sustainable agricultural practices in semi-arid regions.

Evaluation of some lavender genotypes with high ornamental potential for essential oil properties and antimicrobial activities

ABSTRACT Lavender, a member of the Lamiaceae family, is an essential plant worldwide with high medicinal aromatic value and ornamental properties. In this study, 75 lavender genotypes belonging to Lavandula angustifolia Miller and Lavandula hybrida L. species, which were selected from several segregating populations and had high agronomic features as ornamental and medicinal aromatic plants, were evaluated in terms of essential oil properties. The essential oil ratios varied between 1.08% and 7.00%. The essential oil yield of lavender genotypes varied between 0.6 and 9.0 liter/decare. The highest components were determined as linalool and linalyl acetate. Lavender genotypes were also evaluated for their antimicrobial activities, and the inhibition zone diameter of Escherichia coli, a Gram (-) bacterium, varied between 10 and 44 mm. While the zone diameter for Staphylococcus aureus was in the range of 27–44 mm, the zone diameter value for Candida albicans was found to be in the range of 37–42 mm. This study indicated that segregating populations had great potential for improving lavender genotypes with higher oil ratios and antimicrobial activity. Genotypes that could be cultivar candidates were determined.

Elevating morphology and essential oil in cumin genotypes through polyploidy induction

Polyploidy induction is a valuable tool for improving plant breeding outcomes, influencing key plant characteristics. This study investigates the effects of induced polyploidy on various traits in five genotypes of cumin (Cuminum cyminum L.), contributing novel insights to the ongoing research in this domain. Employing varied colchicine concentrations (0.025, 0.05, 0.1, and 0.2 w/v) targeted at the apical meristem, successful chromosome doubling in tetraploid plants (2n = 4x = 28) is achieved, with the optimal induction observed at 0.05 % colchicine. Beyond conventional cytological assessments (chromosome counts, flow cytometry and cytological traits), the investigation extends to elucidate the impact of polyploidy on morphological characteristics and essential oil (EO) content across the cumin genotypic spectrum in the field. Tetraploid plants exhibit a noteworthy enhancement in EO yield (30–100 %) among the five cumin genotypes compared to their diploid counterparts, presenting a promising avenue for practical applications in medicinal plant cultivation. Chemical analysis by GC–MS reveals the role of induced polyploidy in modulating specific essential oil components. Cuminaldehyde, a key constituent, demonstrates heightened levels in tetraploid plants, shedding light on potential commercial implications for the pharmaceutical and spice industries. This study not only contributes to the scientific understanding of polyploidy induction in cumin genotypes but also introduces novel insights into optimization strategies, morphological alterations, and chemical composition.

Novel Electromagnetic Heat Hydrodistillation for Extraction of Essential Oil from Tangerine Peel.

A novel electromagnetic heat method is presented for green extraction of natural compounds from peel residue. In the processing cavity obtained through 3D printing, a core made of amorphous alloy was applied to strengthen the magnetic flux. During the process, an induced electric field was produced in the extract medium owing to an oscillating magnetic field at 50 kHz rather than a pair of electrodes; thus, electrochemical reactions could be avoided. A thermal effect and temperature rise were observed under the field, and essential oil was obtained via this electromagnetic heat hydrodistillation. In addition, the numerical relationships between magnetic field, induced electric field (IEF), induced current density, and temperature profile were elaborated; they were positively correlated with the extraction yield of essential oils. It was found that the waveforms of the magnetic field, induced electric field, and excitation voltage were not consistent. Using a higher magnetic field resulted in high current densities and terminal temperatures in the extracts, as well as higher essential oil yields. When the magnetic field strength was 1.39 T and the extraction time was 60 min, the maximum yield of essential oil reached 1.88%. Meanwhile, conventional hydrodistillation and ohmic heating hydrodistillation were conducted for the comparison; all treatments had no significant impact on the densities. In addition, the essential oil extracted by electromagnetic heat had the lowest acid value and highest saponification value. The proportion of monoterpenoids and oxygen-containing compounds of essential oil extracted by this proposed method was higher than the other two methods. In the end, the development of this electromagnetic heat originating from magnetic energy has the potential to recover high-value compounds from biomass waste.

Evaluation of mint (Mentha spicata) hydrodistillation aqueous byproducts and its utilization in development of bioactive-rich functional drink

Distillation aqueous byproducts are discarded despite being rich in bioactive components. In this study, the aqueous byproducts (hydrolats and flask water fractions) resulting from the hydrodistillation of fresh and dry mint leaves were compared, with a primary focus on their essential oil yield and bioactive properties. Dry mint leaves yielded approximately eight times more essential oil than fresh leaves. The hydrolat extracted from dried mint leaves (MHD) exhibited higher phenolics (35.5 ± 1.1d mg GAE/100 mL), flavonoids (7.8 ± 0.29d mg QE/100 mL) and 2,2-diphenylpicrylhydrazyl scavenging potential (21.13%), compared to the hydrolat derived from fresh leaves (MHF), which had lower values (7.115 ± 0.9e mg GAE/100 mL, 5.72 ± 0.422d mg QE/100 mL and 6.79%, respectively). Similarly, the flask water fraction from dry mint leaves (FWF2) had a higher concentration of bioactive compounds compared to that from fresh leaves (FWF1). The hydrolat with higher bioactivity (MHD) was selected for infusion to develop a flavored drink and its GCMS profile indicated a relatively abundant presence of D-Carvone. The flavored drink prepared with a 20:100 ratio of hydrolat was preferred for its flavor intensity, a key sensory parameter for determining the hydrolat amount. Additionally, for Gum Arabic, a 2.5:100 ratio in the drink resulted in a more acceptable consistency score.

Physico and Phyto-chemical Evaluation of Seeds and their Extracted Crude Oil’s Characteristic of a Nutritionally important plant Daucus carota Linn

Carrot seed oil and carrot seed essential oil are distinctively different from one another. Carrot seed oil is pressed from wild carrot seeds, while carrot seed essential oil is steam-distilled and may come from either the seeds or the carrot itself. It has a unique aroma, but carrot seed oil may be found in many formulas dealing with skin conditions ranging from revitalizing and toning to eczema and can also be directly on the skin as another way to take advantage of its many benefits e. g. analgesic, androgenic, anti-Alzheimer, anorexic, anti-arcane, anti-aging anti-asthmatic activity. The present study has been taken up to establish the physical and phytochemical properties of carrot (Daucus carota L.) seeds and their oil which was extracted in the laboratory with the help of Soxhlet apparatus. The seeds were evaluated for successive extractive values, moisture content, crude protein, crude fiber, total ash, acid-insoluble ash, total carbohydrate, essential oil, mineral contents, and weight of 1000 seeds. Also, relative density, refractive index, free fatty acids, peroxide value, iodine value, saponification number, and unsaponifiable matter were determined in the seed oil. Other parameters studied, arefluorescence behaviour, qualitative and quantitative analysis of inorganic and phytoconstituents etc. Besides, thin layer chromatography of different solvent extracts of seeds and their oil was also reported in the present study. The fatty acids identified by gas chromatography were oleic (5.21%), linoleic (11.5%), palmitic (13.50%), and stearic (3.50%) acids. The yield of essential and crude oil from carrot seeds was established as 0.83% and 6.50% respectively.

Variability in Chemical Composition and Biochemical Activities of Mentha x piperita L. Essential Oil, in Response to Mycorrhizal Symbiosis and Heavy Metal Stress.

The present paper highlights the effect of Pb/Cd-stress and/or mycorrhizal colonization by Glomus Intraradices on yield, chemical composition, cytotoxicity and antimicrobial activity of Mentha x piperita L. essential oil. Our findings showed that mycorrhizal colonization could be used to improve the essential oil yield of M. x piperita, either in non-stressed or Pb/Cd-stressed plants. GC-MS analysis revealed three chemotypes: linalool/pulegone (32.6/30.8 %) chemotype in essential oils of non-mycorrhizal Pb-stressed plants, menthone/menthyl acetate (30.3/25.1 %) chemotype in essential oils of non-mycorrhizal Cd-stressed plants and menthol (44.6 %) chemotype in essential oils of non-mycorrhizal non-stressed plants, mycorrhizal non-stressed plants and mycorrhizal Pb/Cd-stressed plants. The cytotoxicity of M. x piperita essential oil, evaluated by brine shrimp lethality bioassay, was increased in presence of Pb/Cd-stress (from 379.58 to 72.84 μm/mL) and decreased in mycorrhizal plants (from 379.58 to 482.32 μm/mL). The antimicrobial activity of M. x piperita essential oil, evaluated by disc diffusion method and determination of Minimum Inhibitory Concentration against ten microorganisms, was enhanced by the mycorrhizal colonization and deceased by the Pb/Cd-stress. In conclusion, the inoculation of medicinal plants with mycorrhizal fungi is a real avenue for alleviating abiotic stress and/or increasing the quantity and quality of secondary metabolites in terms of biological activities.

Essential Oils from Azorean Cryptomeria japonica Female Cones at Different Developmental Stages: Variations in the Yields and Chemical Compositions

Cryptomeria japonica (Thunb. ex L.f.) D. Don (Cupressaceae) is widely cultivated in the Azores archipelago (Portugal) for landscaping and timber production, generating a huge amount of biomass residues. Among these, female cones (FC) emerge as a source of particularly valuable essential oils (EOs), namely, as promising broad-spectrum antimicrobial agents. However, phytochemical research on C. japonica FC EOs remains scarce. This study evaluated the EO yields and chemical compositions of immature and mature FC (IFC and MFC) from the same batch of Azorean C. japonica. IFC and MFC EOs, obtained via hydrodistillation, presented different yields (0.72% vs. 1.12% w/w, dry weight), and their composition, determined via gas chromatography/mass spectroscopy, revealed that the monoterpenes class was dominant (51.84% vs. 69.13%), followed by the sesquiterpenes (36.44% vs. 26.28%) and diterpenes (10.96% vs. 3.03%) classes. However, the correspondent oxygen-containing terpenes classes were 1.5–2.0 times higher in IFC. Thus, the maturation process revealed an increase in EO yield and α-pinene content (19.5% vs. 41.3%) but a decrease in other important bioactive terpenes/terpenoids (terpinen-4-ol, bornyl acetate, elemol, γ-eudesmol, phyllocladene, and nezukol) content. In conclusion, IFC and MFC EOs, due to their unique composition, may have differential commercial applications and, consequently, contribute to increasing the commercial potential of C. japonica’s EO industry.

Phytochemical analysis, antiproliferative, antibacterial, antifungal, and antiviral activities of bitter orange (Citrus aurantium) leaf essential oil

The young and old leaves of bitter orange (Citrus aurantium) were examined for their essential oil (EO) compositions, anticancer, antimicrobial, and antiviral activities. The EO yields were 0.77% in young leaves and 0.26% in old leaves. The EO composition showed the predominance of sabinene (37.17%), E-β-ocimene (8.21%), δ-3-carene (7.71%), linalool (7.35%), and limonene (5.43%) in young leaves while of sabinene (47.47%), β-sinensal (5.71%), E-β-ocimene (4.98%), δ-3-carene (4.11%), and β-caryophyllene (4.06%) in old leaves. The EOs of both young and old leaves showed potent cytotoxic activities against human lung carcinoma (A549) and colon adenocarcinoma (DLD-1) cells with IC50 < 0.1 µg/mL. The young leaf EO had higher antibacterial activity than the old leaf EO for all bacterial strains with inhibition zones (IZ) varying from 17 to 45 and 8 to 36 mm, respectively. The EOs of both young and old leaves had strong antifungal activity against all fungal strains with IZ = 90 mm. The young leaf EO was found to be the most active in protecting cells against Herpes simplex virus type-1 (HSV-1) infection during the protection, absorption, and direct periods as compared to the untreated and treated Vero cells except the replication phase.