Search Results (70)

Frankincense is a natural oleo-gum resin obtained from several Boswellia tree species, playing important roles in supporting the spiritual, cultural, and socioeconomic livelihoods of communities across East Africa. Despite their cultural and economic value, the Ethiopian market still lacks scientifically based criteria to evaluate and properly classify this raw material, with traditional grading relying on gum size, color, collection area, and impurity content. Frankincense-derived essential oil value is much higher than that of gum, making this valorization route very enticing. This work compares the extraction potential and chemical profiles of hydrodistilled essential oils from various commercial grades and also different Ethiopian harvest locations (Afar, Humera, Assosa, Shire, Metema, South Omo, Borena and Jigjiga). The essential oils were extracted using hydrodistillation with a Clevenger-type apparatus, and their chemical composition was identified with GC-MS. The results revealed no substantial quantitative and qualitative differences among commercial grades, showing that essential oils can be obtained indiscriminately from classification. As for harvesting locations, both the extraction yield and essential oil compositions varied substantially. With the economic value of frankincense essential oil around six times that of the raw resin required to obtain it, these results show the importance of revising the commercial grading system to reflect chemical composition and promote the value-added processing of both black and white frankincense, rather than relying mainly on raw resin exports. Full article

The genus Eugenia (Myrtaceae) is widely distributed in Brazil and is known for producing diverse secondary metabolites with various biological activities, although several species remain poorly explored. This study aimed to characterize the chemical composition of essential oils (EOs) from the leaves of seven Eugenia species (E. brasiliensis, E. involucrata, E. longipedunculata, E. myrcianthes, E. neoverrucosa, E. pyriformis, and E. uniflora), compare their chemical profiles using multivariate analysis, and evaluate their insecticidal activity against the flea Ctenocephalides felis felis. EOs were obtained from dried leaves by hydrodistillation using a Clevenger apparatus and analyzed by gas chromatography–mass spectrometry (GC–MS). Principal component analysis (PCA) was applied to compare chemical compositions, and contact bioassays were conducted to assess insecticidal activity against adult fleas. The EOs showed distinct chemical compositions, with major constituents varying by species, including α-pinene, (E)-caryophyllene, viridiflorene, β-selinene, limonene, and germacrone. PCA revealed clear differences among species, particularly highlighting oils dominated by α-pinene and sesquiterpene-derived compounds. In the bioassays, E. uniflora showed the highest insecticidal activity, reaching 95.1% mortality at 800 µg·cm⁻² and presenting an LC₅₀ of 9.12 µg·cm⁻², whereas E. brasiliensis showed moderate activity (LC₅₀ = 157.82 µg·cm⁻²). These findings expand the chemical knowledge of the genus and indicate the potential of E. uniflora EO as a natural source of insecticidal compounds against C. felis felis. Full article

This study comprehensively characterised the volatile composition of hydrolates obtained as by-products of the hydrodistillation of orange, mandarin, and clementine peels. Enzymatic pretreatments using pectinase, cellulase, xylanase, or their mixture were applied in purified water or citrate buffer (pH 5) prior to Clevenger hydrodistillation, and volatile profiles were analysed by HS–SPME GC–MS. Across all citrus species, hydrolates were dominated by oxygenated monoterpenes and alcohols, with α-terpineol and linalool identified as the principal constituents. Statistical analysis suggested differences in hydrolate volatile composition following enzymatic pretreatment in citrate buffer with cellulase, xylanase, or their combination (p < 0.05); notably, α-terpineol content in mandarin hydrolates nearly doubled after these treatments. Enzyme-free reflux extraction in water also led to observable changes in volatile profiles (p < 0.05), highlighting the importance of including both untreated and enzyme-free controls when evaluating enzymatic effects. The study also illustrates the distinct distribution of dominant volatiles between hydrolates with prevailing α-terpineol. These findings demonstrate the potential of enzymatic hydrodistillation for the valorisation of citrus peel by-products by enabling modulation of hydrolate volatile composition and supporting more sustainable use of citrus processing residues. Full article

Enzymatic pretreatment is a promising method for modulating essential oil isolation. This study evaluated the effects of pectinase, cellulase, xylanase, and their mixture, applied in purified water or citrate buffer before Clevenger hydrodistillation, on the yield and volatile composition of essential oils from orange, mandarin, and clementine peels. Essential oil yield increased slightly for orange and mandarin peels (up to approximately 2%) compared to non-enzymatic controls, while clementine yield was unaffected. Limonene remained the dominant compound in all oils, reaching 81.16% in orange, 77.50% in mandarin, and 75.29% in clementine. Enzyme pretreatment particularly affected the secondary components: mandarin peel showed increased sesquiterpenes (up to 60.52%) and aldehydes (up to 4.86%), while clementine oils exhibited higher oxygenated monoterpenes after buffer-based enzymatic treatments. These results indicate that enzyme-assisted pretreatment can modulate the volatile profile of citrus essential oils, although overall yield gains are modest. The inclusion of no-enzyme and no-pretreatment controls is crucial for the reliable assessment of enzymatic effects under laboratory conditions. This systematic approach provides insight into enzyme-assisted extraction, highlighting its potential to influence essential oil quality and composition rather than dramatically increase yield, and offers a foundation for further optimization research. Full article

In the present study, the yield, chemical composition, and biological activities of Lavandula angustifolia flower essential oil (LAFEO) and leaves (LALEO) under different shade nets (pearl, red, blue) with 40% shading index compared with non-shading (control-open field) plants were investigated. The essential oil (EO) was isolated using a Clevenger-type hydrodistillation and the chemical composition of isolated EO was determined by GC/MS and GC/FID analyses. The antioxidant activity was determined using the DPPH and FRAP assay. The highest EO yield was recorded in flowers from plants grown under pearl shade nets (4.62 mL/100 g p.m.) and in leaves under red nets (0.99 mL/100 g p.m.). The lowest EO content occurred in plant leaves (0.50 mL/100 g p.m.) and flowers (3.17 mL/100 g p.m.) from non-shaded (control) plants. The composition of lavender EO depended on both plant part and light conditions. Among the 47–59 identified compounds in LAFEO, the major constituents were 1,8-cineole (27.4–32.2%), linalool (24.7–27.3%), borneol (18.0–21.9%), and camphor (7.5–8.6%). In LALEO, 55–65 compounds were identified, with 1,8-cineole (30.4–39.8%), borneol (21.9–26.5%), camphor (11.3–13.9%), and linalool (6.0–8.6%) as the dominant constituents. Flower samples from non-shaded (control) plants showed moderate antioxidant activity, with EC₅₀ values decreasing over time, indicating the highest activity among treatments tested. Conversely, plant leaves under pearl nets showed the lowest activity among samples, with an EC₅₀ value of 42.40 mg/mL at 120 min, still within the moderate antioxidant activity range. LALEO showed higher FRAP values than flower oils, confirming a stronger reducing capacity. The highest activity was found in plant leaves under red nets (0.72 mg EFe²⁺/g) and in non-shaded plants (0.68 mg EFe²⁺/g), while the lowest occurred in flower samples from red (0.28 mg EFe²⁺/g) and pearl nets (0.33 mg EFe²⁺/g). Unlike the FRAP results, the DPPH assay showed relatively higher activity in flowers compared to leaves, though all samples exhibited moderate antioxidant capacity. Shading significantly increased essential oil yield; however, the effects of different color nets on essential oil quality require further investigation, although preliminary results indicate a potential reduction in undesirable constituents. Full article

Mango fruits are one of the strategic fruit crops in different countries that are attacked by several serious pests such as Cryptoblabes gnidiella and Scirtothrips mangiferae. Natural extracts, especially essential oils, provide several promising insecticide agents to control different insects as an alternative to synthetic insecticides. Using Clevenger-type hydrodistillation, the essential oils of five thyme plants—Thymus vulgaris, Origanum vulgare, Thymus argenteus, Thymus citriodorus, and Origanum syriacum—from Saudi Arabia and Egypt were extracted, and GC/MS analysis was performed. In addition, some chemical parameters of the five species were determined, such as chlorophyll a, chlorophyll b, β-carotene, total antioxidant capacity, total phenols, and total flavonoids. Two compounds, thymol and carvacrol, were identified in T. vulgaris and O. vulgare at ratios of 69.45 and 64.82%, respectively. These major compounds were isolated and identified using ¹H NMR analysis. The insecticidal potentials of the five essential oils and their pure isolated compounds were evaluated on C. gnidiella and S. mangiferae on mango inflorescences. The results showed that T. vulgaris and O. vulgare oils were the most potent against C. gnidiella (LC₅₀, 183.33 and 164.68 ppm, respectively) and S. mangiferae (18.93 and 16.93 ppm, respectively). Thymol and carvacrol had the highest effect on both insects. Furthermore, the effect of thymol and carvacrol at LC₅₀ values on some biochemical parameters of C. gnidiella was determined. Therefore, thymol and carvacrol from Thymus species are promising compounds that could be used as insecticides against the harmful insects C. gnidiella and S. mangiferae on mango inflorescences. Full article

Background: Myrtus communis L. is a typical aromatic species of the Mediterranean basin, whose leaves are rich in essential oil known for its biological properties. Methods: The essential oil of Tunisian Myrtus communis L. leaves was extracted via hydrodistillation using a Clevenger-type apparatus and optimized using a complete factorial design including three factors with two different modalities and one factor with three modalities, hence the total number of experiments N_total = 2³ × 3¹. This optimization concerns the yield, the terpene composition by GC-MS and the antioxidant activity by the two radical scavenging assays, DPPH and ABTS. Four factors were retained, namely, the type of leaf used (dry or fresh sample), the leaf granulometry (whole or ground), the extraction time (1 h 30 min, 2 h 30 min and 3 h 30 min) and the water volume/plant material ratio (1/4 and 1/10). Results: The dry and whole leaves, duration 3 h 30 min, and V/M 1/10 modalities gave the best yield of essential oil (0.77%). The optimal contents of the majority of the terpene compounds, 1,8-cineole (37.23%), α-pinene (54.79%), myrtenyl acetate (23.43%) and limonene (17.77%), were recorded using the modalities dry and whole leaves, duration 2 h 30 min, V/M 1/10; dry and ground leaves, duration 1 h 30 min, V/M 1/4; fresh and whole leaves, duration 3 h 30 min, V/M 1/4; and fresh and whole leaves, duration 3 h 30 min, V/M 1/4, respectively. The antioxidant activity of the essential oil of myrtle leaves was optimized for the two DPPH (7.477 mg TE/g EO) with the GDL, duration 3 h 30 min, V/M 1/4 and ABTS assays (14.053 mg TE/g EO) with WDL terms, duration 3 h 30 min, V/M 1/10. Conclusions: Optimizing essential oil extraction is of significant interest to the cosmetic, perfumery, and pharmaceutical industries, which are constantly seeking optimal conditions to enhance essential oil yield and to ensure a high concentration of terpenic compounds, valued for their aromatic qualities and diverse biological activities. Full article

The composition of an essential oil (EO) depends on both the plant’s genetic constitution and environmental factors. In this study, the leaves of female bay laurel (Laurus nobilis L., family Lauraceae) plants were collected each month in the period from 15 January to 15 December 2022. Twelve obtained leaf samples were hydrodistilled in a Clevenger apparatus and analyzed using gas chromatography–mass spectrometry (GC-MS). A total of 44 compounds were detected in EO and 39 compounds were identified based on MS spectra and RIs (retention indices), accounting for 99.44–99.94% of the oil. The EO consisted almost entirely of monoterpenes (95.56–99.28%) and small quantities of phenylpropanoids, sesquiterpenes and other compounds. The major volatile compound was 1,8-cineole (49.79–64.94%), followed by α-terpinyl acetate (7.14–11.96%), sabinene (3.16–9.01%), linalool (1.77–8.03%), α-pinene (1.46–4.49%), β-pinene (1.55–3.69%) and α-terpineol (0.99–4.77%). The ANOVA indicated statistically significant changes in the composition of the EO over one year. The contents of eugenol, methyl eugenol and elemicin, which are responsible for the spicy aroma of the leaves, were highest during flowering (March) and at the time of fruit ripening (October, November). The harvest time of the leaves can be adjusted to obtain leaves rich in the desired compounds according to whether they are to be used as a spice, medicine or repellent. Full article

Objective: In this study, the chemical composition and biological activities of the essential oils extracted from the leaves and fruits of Zanthoxylum mantaro were analyzed. Methods: The essential oils were obtained through hydrodistillation using a Clevenger-type apparatus. Chemical composition was determined by gas chromatography coupled with mass spectrometry (GC-MS) and gas chromatography with a flame ionization detector (GC-FID). The antimicrobial activity was evaluated against four Gram-positive bacteria, three Gram-negative bacteria, and two fungi using the broth microdilution method. Antioxidant activity was assessed using the ABTS (2,2′-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid) and DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging assays. Additionally, the acetylcholinesterase inhibitory effect of the essential oils was measured by a spectrophotometric method. Results and Conclusions: A total of 23 compounds were identified in the essential oil from the fruits, while 47 compounds were found in the essential oil from the leaves. The major constituents of the fruit essential oil were α-thujone (39.85%), β-thujone (25.04%), sabinene (10.71%), and terpinen-4-ol (4.38%), whereas the main compounds in the leaf essential oil were germacrene D (21.75%), nerolidol (E) (12.39%), and pentadecanal (7.14%). The essential oil from the fruits exhibited antifungal activity against Aspergillus niger (ATCC 6275), with a minimum inhibitory concentration (MIC) of 1000 μg/mL. Both the fruit and leaf essential oils showed moderate antioxidant activity in the ABTS assay, with SC₅₀ values of 274.14 ± 1.06 μg/mL and 2798.85 ± 15.69 μg/mL, respectively. Furthermore, the fruit essential oil demonstrated considerable acetylcholinesterase inhibitory activity with an IC₅₀ value of 65.46 ± 1.01 μg/mL, while the leaf essential oil exhibited an IC₅₀ value of 158.2 ± 1.02 μg/mL. Full article

Kumquat is one of the smallest citrus fruits (from the Rutaceae family), and its essential oil’s biological effects have not yet been sufficiently researched, in contrast to the essential oils of its relatives. Therefore, the aim of this large-scale study was to investigate the chemical profile of kumquat essential oils (KEOs) isolated by microwave-assisted distillation (MAD) and Clevenger hydrodistillation using GC-MS analysis. To test the bioaccessibility of their bioactive components, in vitro digestion with commercially available enzymes was performed. The final step of this research was to test their cytotoxic activity against a cervical cancer cell line (HeLa), a human colon cancer cell line (HCT116), a human osteosarcoma cell line (U2OS), and a healthy cell line (RPE1). Two methods were used to test the antioxidant activity: DPPH (2,2-diphenyl-1-picrylhydrazyl) and ORAC (oxygen radical absorbance capacity). The antibacterial activity was tested in relation to the growth and adhesion of Escherichia coli and Staphylococcus aureus on a polystyrene surface. The GC-MS analysis showed that the major compound in both kumquat essential oils was limonene, which was stable before and after in vitro digestion (>90%). The results showed that the cytotoxic activity of the KEOs in all three cancer cell lines tested was IC₅₀ 1–2 mg/mL, and in the healthy cell line (RPE1), the IC₅₀ value was above 4 mg/mL. The antibacterial activity of the KEOs obtained after MAD and Clevenger hydrodistillation was 4 mg/mL against E. coli and 1 mg/mL against S. aureus. The KEOs after MAD and Clevenger hydrodistillation reduced the adhesion of E. coli by more than 1 log, while there was no statistically significant effect on the adhesion of S. aureus to the polystyrene surface. Both KEOs exhibited comparable levels of antioxidant activity using both methods tested, with IC50 values of 855.25 ± 26.02 μg/mL (after MAD) and 929.41 ± 101.57 μg/mL (after Clevenger hydrodistillation) for DPPH activity and 4839.09 ± 91.99 μmol TE/g of EO (after MAD) and 4928.78 ± 275.67 μmol TE/g of EO (after Clevenger hydrodistillation) for ORAC. The results obtained show possible future applications in various fields (e.g., in the food, pharmaceutical, cosmetic, and agricultural industries). Full article

Ocimum gratissimum (OG) is a species rich in essential oils (EO), which is known for its antimicrobial and antioxidant properties. This study aimed to encapsulate the essential oil of Ocimum gratissimum (OGE), determine its chemical composition, and evaluate its antioxidant and antimicrobial activities against six pathogenic bacteria, comparing it with the free essential oil (OGF). The EO was extracted by hydrodistillation using a Clevenger-type apparatus, and an oil-in-water emulsion was prepared using a combination of biopolymers: maltodextrin (MA), cashew gum (CG), and inulin (IN). The chemical profile was identified using gas chromatography–mass spectrometry (GC–MS). Antioxidant activity was assessed using the Oxygen Radical Absorbance Capacity with fluorescein (ORAC-FL) method, while the Minimum Inhibitory Concentrations (MIC) and Minimum Bactericidal Concentrations (MBC) were determined by the microdilution method. Microparticles were formed using the spray-drying method, achieving an encapsulation efficiency of 45.2%. The analysis identified eugenol as the main compound both before and after microencapsulation. The OGE microparticles demonstrated high inhibitory and bactericidal effects against S. aureus, S. choleraesuis, and E. coli, with MIC values of 500 µg·mL⁻¹ and MBC values of 1000 µg·mL⁻¹, as well as antioxidant activity of 1914.0 µmol-TE·g⁻¹. Therefore, it can be inferred that the EO of OG maintained its antimicrobial and antioxidant effects even after microencapsulation by spray-drying, making it a promising natural ingredient. Full article

The essential oil of Salvia officinalis, an aromatic plant belonging to the Lamiaceae family, is very useful in the pharmaceutical, food and cosmetics industries due to its biological properties, which have anti-inflammatory, antioxidant and antimicrobial effects. The present work aims to optimize the extraction of essential oils from commercial samples using an experimental design with two independent variables, the solid/liquid ratio (w/v) and time, followed by an evaluation of the response variables, yield and antioxidant activity. A chemical characterization of the oils was also carried out. For this, the material obtained from local stores in the city of Rio de Janeiro was subjected to hydrodistillation in a Clevenger apparatus, and the identification and quantification of the compounds in the isolated oil were carried out using GC/MS. The antioxidant capacity was determined by calculating the percentage inhibition of the DPPH^● radical, resulting in a variation between 8.7 and 28.3% inhibition. The results show that the number of compounds identified and their respective chemical classes have an impact on the difference in the percentage of inhibition of the radical due to their particular properties. In this work, we chose to evaluate the experiments that presented the best and worst responses in the experimental design, which where obtained in the following conditions: the solid/liquid ratio was 1:14 (w/v) for 180 min and 1:50 (w/v) for 60 min, respectively. The first condition showed the best results, which may be associated with a higher concentration of sesquiterpenes, highlighting β-caryophyllene, which has recognized antioxidant and anti-inflammatory effects. It can therefore be concluded that sage essential oil has significant bioactive properties; however, the differences in extraction conditions have a direct influence on antioxidant activity, since during the process, the conditions applied can lead to the loss of important volatile compounds. Full article

Tanacetum parthenium L. (Asteraceae) is a perennial herbaceous plant with a long-standing historical use in traditional medicine. Recently Tanacetum parthenium L. essential oil has been associated with a promising potential for future applications in the pharmaceutical industry, in the cosmetics industry, and in agriculture. Investigations on the essential oil (EO) have indicated antimicrobial, antioxidant, and repellent activity. The present study aimed to evaluate the chemical composition of Bulgarian T. parthenium essential oil from two different regions, to compare the results to those reported previously in the literature, and to point out some of its future applications. The essential oils of the air-dried flowering aerial parts were obtained by hydrodistillation using a Clevenger-type apparatus. The chemical composition was evaluated using gas chromatography with mass spectrometry (GC-MS). It was established that the oxygenated monoterpenes were the predominant terpene class, followed by the monoterpene hydrocarbons. Significant qualitative and quantitative differences between both samples were revealed. Camphor (50.90%), camphene (16.12%), and bornyl acetate (6.05%) were the major constituents in the feverfew EO from the western Rhodope Mountains, while in the EO from the central Balkan mountains camphor (45.54%), trans-chrysanthenyl acetate (13.87%), and camphene (13.03%) were the most abundant components. Full article

The fruits of Citrus limon are often purchased for their vitamin C-rich juice, while the fruit peel and the tree leaves are discarded as wastes. This study obtained the chemical profiles of the essential oils (EOs) of C. limon wastes (the peel and leaves), evaluated their medicinal value as antioxidants, their potential for sustainable use in agriculture as an insecticide for post-harvest preservation of grains, and their potential as a bioresource in livestock feed formulations. The EOs were isolated from C. limon leaves and peel using a hydro-distillation method on a Clevenger apparatus. The oil constituents were identified using the gas chromatography-mass spectrometry (GC-MS) hyphenated technique. The oils were evaluated for their in vitro antioxidant activity using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric-reducing antioxidant power methods. An insecticidal study was conducted using contact toxicity, fumigation, and repellence bioassay methods against Sitophilus zeamais (maize weevils). Finally, the predicted income from using lemon peel as an alternative or substitute ingredient for maize in livestock feed formulations was obtained through a conventional simulation method. Chemically, limonene was found to be present in all the EOs analyzed (12–52%), while α-pinene was only found in the fresh leaf and peel oils (13.3% and 10.6%). Caryophyllene oxide was identified as the major component of the dried leaf oil (17.7%). At 20 µg m, the dry peel oil exhibited the highest inhibitory activity (52.41 ± 0.26%) against the DPPH radical, which was comparable to L-ascorbic acid (a standard antioxidant) at 54.25 ± 3.55%. The insecticidal study revealed that the dry peel oil is a better insect repellent (73.33 ± 6.95% at 10 µL) and fumigant (LC₅₀ = 0.17 µL g⁻¹ after 48 h) natural agent compared to the peel oil. Conversely, the dry peel oil showed a better contact activity (LC₅₀ = 1.69 µL g⁻¹) against the maize weevils compared to the dry leaf oil. The simulation study showed the cost of using dry lemon peel as an alternative to maize in livestock feed formulation to be ZAR 2.8 billion, compared against the higher cost of feed formulation with maize, which currently stands at ZAR 24.9 billion. This study has shown that C. limon wastes (the peel and leaves) contain EOs with unique chemical profiles, valuable medicinal properties as free radical scavengers, and considerable insecticidal properties for agricultural use in post-harvest grain preservation, presenting a cost-effective and promising bioresource for livestock feed production. Full article

This study determined the content and composition of dill seed (Anethum graveolens L.) essential oil under varying light conditions: non-shaded plants in open fields and plants covered with pearl shade nets (40% shade index). Essential oil was extracted using Clevenger hydrodistillation. The essential oil content was 4.63% for non-shaded plants and 4.81% for shaded plants. GC/MS analysis revealed twenty-one and twenty-two components in dill seed from non-shaded and shaded plants, respectively. The terpenic fraction of essential oil from non-shaded plants consisted mainly of oxygen-containing monoterpene derivatives (53.6%), with carvone (46.1%) as the primary component, followed by monoterpene hydrocarbons (46.4%), predominantly limonene (43.8%). Essential oil from shaded plants contained a higher content of carvone (49.8%) and a lower content of limonene (37.8%) compared to essential oil from non-shaded plants. Non-shaded plant essential oil exhibited stronger antioxidant activity (EC₅₀ value: 26.04 mg mL⁻¹) than shaded plant essential oil (54.23 mg mL⁻¹). Dill seed essential oil showed the most potent antimicrobial activity (disc diffusion method) against Escherichia coli (inhibition zone: 15–18 mm). Shaded plants demonstrated a positive influence of essential oil against Klebsiella pneumoniae. Carvone and its derivatives, as the main components, hold significant potential in the food industry and alternative medicines. A practical implication of this study could be higher plant densities or intercropping of dill, as it thrives with minimal light. Full article