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Essential Oils: Extraction, Chemical Composition, and Biological Activity

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A special issue of Separations (ISSN 2297-8739). This special issue belongs to the section "Analysis of Natural Products and Pharmaceuticals".

Deadline for manuscript submissions: closed (20 June 2023) | Viewed by 13802

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Prof. Dr. Ahmed Mohamed Abd-ElGawad

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Department of Botany, Faculty of Science, Mansoura University, Mansoura 35516, Egypt
Interests: plant ecology; chemical ecology; plant–plant interactions; plant facilitation; plant conservation; allelopathy
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Prof. Dr. Abdelsamed I. Elshamy

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Chemistry of Natural Compounds Department, National Research Centre, 33 El Bohouth St., Dokki, Giza 12622, Egypt
Interests: natural products; chemistry
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Prof. Dr. Giuliano Bonanomi

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Department of Agricultural Sciences, University of Naples Federico II, Via Università 100, 80055 Portici, Italy
Interests: plant pathology; soilborne pathogens; botany; ecology; microbiology; soil organic matter dynamics
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Dear Colleagues,

Essential oils (volatile oils) are promising natural products that possess several biological activities such as antioxidant, antimicrobial, allelopathic, anti-inflammatory, anticancer, insect repellent, etc. The essential oils from natural products attract the attention of researchers and scientists worldwide as they can be integrated into agricultural, industrial, pharmaceutical, and cosmetic applications. The essential oils can be extracted with different techniques such as water distillation (hydrodistillation), steam distillation, solvent extraction, CO₂ extraction, cold-press extraction, maceration, microwave extraction, etc. Thousands of chemical compounds of these essential oils were identified from natural resources, including plants, microorganisms, and animals. The natural products of essential oils are characterized by diversity, fewer side effects, eco-friendly, and safety.

Topics of interest include but are not limited to the ones listed below.

Extraction and separation techniques of essential oils.
Identification and characterization of essential oil composition.
Aromatic plants and their applications.
Biological activities of the essential oils.
Factors affecting the essential oil composition in plants.
Modes of action and mechanisms of essential oil activities.

Prof. Dr. Ahmed Mohamed Abd-ElGawad
Prof. Dr. Abdelsamed I. Elshamy
Prof. Dr. Giuliano Bonanomi
Guest Editors

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Keywords

essential oils
extraction techniques
new bioactive compounds
biological activities
volatile oils
antimicrobial
phytotoxicity
antioxidants
terpenes
green chemistry
natural products, phytochemicals
chemical ecology
green chemistry

Published Papers (8 papers)

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Research

14 pages, 4988 KiB

Open AccessArticle

Anticorrosive Effects of Essential Oils Obtained from White Wormwood and Arâr Plants

by Ghada Beniaich, Mustapha Beniken, Rajae Salim, Nadia Arrousse, Elhachmia Ech-chihbi, Zakia Rais, Asmae Sadiq, Hiba-Allah Nafidi, Yousef A. Bin Jardan, Mohammed Bourhia and Mustapha Taleb

Separations 2023, 10(7), 396; https://doi.org/10.3390/separations10070396 - 10 Jul 2023

Cited by 2 | Viewed by 1263

Abstract

This article is part of the contribution to the development of two medicinal plants widely used by the Moroccan population: white wormwood (Artemisia herba-alba) andArâr (Juniperus phoenicea), species belonging to the Asteraceae and Cupressaceae families, respectively. The present work was conducted to investigate the chemical composition and anticorrosive properties of essential oils (EOs) extracted from these plants. The chemical analysis of the essential oils (EOs) was carried out by GC-MS/MS. Potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), and quantum chemical calculations by density-functional theory at B3lYP were used to study the anticorrosive effect of the researched oils on mild steel in 1 M hydrochloric acid solution. Moreover, SEM-EDX analysis was used to identify the surface morphology of mild steel surface. GC-MSMS results showed the presence of 32 potentially active compounds in the EOs of Artemisia herba-alba. The average yield of the EOs was about 1.39 ± 0.17 mL/100 g dry matter. Beta thujone (30.07%) and alpha thujone (13.32%) are the main components, while for the EOs of Juniperus phoenicea, the study showed the presence of 30 constituents, with alpha-pinene (43.61%) and manoyl oxide (11.5%) as the main components. The average yield of HE was 1.10 ± 0.03 mL/100 g dry matter. The findings demonstrated an important anticorrosive action of EOs from Artemisia herba-alba and Juniperus phoenicea. Notably, the experimental results showed good efficiency of the studied essential oils and correlated well with the density-functional theory (DFT) calculations. The results of potentiodynamic polarization measurements showed that hydrazone acted as a mixed-type inhibitor. The EIS results showed an increase in charge transfer resistance accompanied by a noticeable decrease in C_dl values, revealing that both studied oils were effective as reliable inhibitors for the protection of mild steel in 1 M HCl solution. Also, the efficiency decreased with decreasing inhibitor concentrations. Surface studies ensure the effectiveness of both investigated oils and the reduction of the surface roughness of mild steel. Furthermore, DFT results of the major constituents of Artemisia herba-alba and Juniperus phoenicea EOs revealed insights into the chemical reactivity of the tested oils while supporting the experimental conclusions and showed outstanding adsorption ability of both investigated EOs on the steel surface. Full article

(This article belongs to the Special Issue Essential Oils: Extraction, Chemical Composition, and Biological Activity)

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15 pages, 3894 KiB

Open AccessArticle

Chemical Characterization, Antioxidant, Insecticidal and Anti-Cholinesterase Activity of Essential Oils Extracted from Cinnamomum verum L.

by Ghada Beniaich, Otmane Zouirech, Aimad Allali, Mohammed Bouslamti, Imane Maliki, Abdelfattah El Moussaoui, Mohamed Chebaibi, Hiba-Allah Nafidi, Yousef A. Bin Jardan, Mohammed Bourhia and Mustapha Taleb

Separations 2023, 10(6), 348; https://doi.org/10.3390/separations10060348 - 09 Jun 2023

Cited by 3 | Viewed by 1361

Abstract

This study is aimed at evaluating the potential of the essential oil of Cinnamomum verum (EOCV) as an antioxidant, as an insecticide against Callosobruchus maculatus and for its anti-acetylcholinesterase activity. To this end, EOCV was extracted via hydrodistillation from this plant, and the identification of the phytochemicals was performed using gas chromatography–mass spectrometry (GC–MS). The antioxidant power was determined via in vitro tests, the insecticidal ability was tested via exposing C. maculatus to EOCV, and molecular docking was used to evaluate the anti-cholinesterase ability. The results of these GC–MS analyses show that the main composition of EOCV comprises Cinnamaldehyde dimethyl acetal (64.50%), cinnamicaldehyde (35.04%) and α-Copaene (0.11%). The insecticidal potential of the studied OEs, determined by using the inhalation test, and expressed as the concentration of EOs required for the death of 50% of the insects (LC50) and that required the death of 95% of adults (LC95) after 96 h of exposure, was 3.99 ± 0.40 and 14.91 ± 0.10 μL/L of air, respectively. In the contact test, 96 h of exposure gave an LC50 and LC95 of 3.17 ± 0.28 and 8.09 ± 0.05 μL/L of air, respectively. A comparison of the antioxidant activity of EOCV to that of ascorbic acid via DPPH free radical scavenging ability and Ferric Reducing Antioxidant Power (FRAP) revealed the IC50 and EC50 values of EOCV to be much higher than that obtained for ascorbic acid, and the molecular docking simulation revealed Coumarin, Piperonal, Cinnamaldehyde dimethyl and alpha-Copaene as possessing potential inhibitory activities against human acetylcholinesterase. However, further experimental validation is needed to enhance the prospects of this study. Full article

(This article belongs to the Special Issue Essential Oils: Extraction, Chemical Composition, and Biological Activity)

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16 pages, 3030 KiB

Open AccessArticle

Phytochemistry and Biological Activities of Essential Oils from Satureja calamintha Nepeta

by Rajae El Brahimi, Azeddin El Barnossi, Abdelfattah El Moussaoui, Mohamed Chebaibi, Rabie Kachkoul, Asmae Baghouz, Hiba-Allah Nafidi, Ahmad Mohammad Salamatullah, Mohammed Bourhia and Amina Bari

Separations 2023, 10(6), 344; https://doi.org/10.3390/separations10060344 - 05 Jun 2023

Cited by 4 | Viewed by 1162

Abstract

Satureja calamintha nepeta (S. calamintha) has a history of successful use in the treatment of bacterial and fungal diseases. The present study was designed to investigate the chemical composition and antioxidant and antimicrobial activities of essential oils extracted from wild S. calamintha (EOSS) and domesticated S. calamintha (EOSD) for comparison purposes. Hydrodistillation was used to extract the essential oils (EOs), while GC/MS was used for chemical analysis. Antioxidant activity was studied using DPPH and FRAP assays. Antifungal activity was performed against Candida albicans, Aspergillus niger, Aspergillus flavus, and Fusarium oxysporum), while antibacterial activity was tested against clinically resistant bacteria, namely Staphylococcus aureus, Escherichia coli, Bacillus subtilis, and Proteus mirabilis. By using ab=n in silico approach, the antioxidant and antimicrobial activities of the main compounds of EOSS and EOSD were also investigated. The yields obtained of EOSS and EOSD were 2.80% and 1.95%, respectively, with a dominance of eucalyptol, pulegone and rotundifolone. Concerning the antioxidant power, the IC50 values recorded by the use of the DPPH assay were in the range of 23.03 ± 4.30 and 24.09 ± 4.38 μg/mL for EOSS and EOSD, respectively, while by using the FRAP assay, the EC₅₀ values were in the range of 55.38 ± 2.16 and 60.72 ± 7.71 μg/mL for EOSS and EOSD, respectively. Importantly, both essential oils of EOSS and EOSD exhibited good antibacterial activity against all studied bacteria; notably, the inhibition zone ranged from 14 ± 0.00 to 48.67 ± 1.15 mm and the MICs ranged from 0.37 ± 0.00 to 5.96 ± 0.00 µg/mL. Similarly, the studied EOs showed important antifungal activities compared to all the studied fungi, wherein the inhibition percentage ranged from 47.33 ± 1.15 to 89.18 ± 0.75%, while the MICs ranged from 0.18 ± 0.00 to 2.98 ± 0.00 µg/mL. The molecular docking results showed that piperitenone and pulegone strongly inhibited human acetylcholinesterase, whereas (+)-Isomenthone and piperitenone strongly inhibited S. aureus nucleoside diphosphate kinase, and E. coli beta-ketoacyl-[acyl carrier protein] synthase, respectively. The outcome of this article suggests that EOs of S. calamintha can be developed as alternative agents to manage drug-resistant phenomena and free radical issues. Full article

(This article belongs to the Special Issue Essential Oils: Extraction, Chemical Composition, and Biological Activity)

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18 pages, 11220 KiB

Open AccessArticle

Promising Insecticidal Properties of Essential Oils from Artemisia aragonensis Lam. and Artemisia negrei L. (Asteraceae) by Targeting Gamma-Aminobutyric Acid and Ryanodine Receptor Proteins: In Vitro and In Silico Approaches

by Khalid Chebbac, Zineb Benziane Ouaritini, Aimad Allali, Burak Tüzün, Otmane Zouirech, Mohammed Chalkha, Abdelfattah El Moussaoui, Soufyane Lafraxo, Hiba-Allah Nafidi, Yousef A. Bin Jardan, Mohammed Bourhia and Raja Guemmouh

Separations 2023, 10(6), 329; https://doi.org/10.3390/separations10060329 - 26 May 2023

Cited by 4 | Viewed by 1535

Abstract

Artemisia negrei (A. negrei) and Artemisia aragonensis (A. aragonensis) are in the family Asteraceae, which has been used in traditional medicine. The use of plant-derived insecticides has become a promising strategy to reduce the harmful effects of synthetic insecticides and overcome the bio-resistance of pest insects to insecticides. In this regard, the purpose of the current study was to determine the chemical composition and evaluate insecticidal effects of essential oils (EOs) extracted from A. negrei (EON) and A. aragonensis (EOA). Notably, all chemical constituents present in the EOs were identified through GC-MS analysis, whilst the insecticidal properties against Callosobruchus maculatus Fab. (C. maculatus) were investigated by use of in vitro an in silico approaches. The obtained results showed that both tested EOs present a significant insecticidal effect against C. maculatus, which increased significantly upon the dose used in both contact and inhalation tests. The lethal concentrations (LC₅₀) for the inhalation test were found to be 2.1 and 2.97 μL/L, while in the contact test they were 2.08 and 2.74 μL/L of air for EON and EOA, respectively. At 5 μL/L of air, the spawn reduction rate was 88.53 % and 77.41%, while the emergence reduction rate was 94.86% and 81.22% by EON and EOA, respectively. With increasing doses of up to 20 μL/L of air, the reduction in individual emergence reached 100% by the two oils tested after 36 h of treatment. In addition, Molecular docking (MD) simulations supported the in vitro findings and indicated that certain identified components in EOA and EON exhibited stronger hydrogen bonding interactions with the target receptors. Interestingly, the prediction of ADMET properties indicates that the molecules investigated have great pharmacokinetic profiles with no side effects. Taken together, our findings suggest that EOA and EON may exert both potential contact and inhalation insecticidal actions and could be used as an alternative tool for the control of this major insect pest of stored products. Full article

(This article belongs to the Special Issue Essential Oils: Extraction, Chemical Composition, and Biological Activity)

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12 pages, 2505 KiB

Open AccessArticle

Fractionation of Marigold Waxy Extract Using Supercritical CO₂

by Alessandra Zanotti, Lucia Baldino, Mariarosa Scognamiglio and Ernesto Reverchon

Separations 2023, 10(5), 298; https://doi.org/10.3390/separations10050298 - 08 May 2023

Viewed by 1621

Abstract

Marigold oil is a product of great industrial interest thanks to its wide range of medicinal and wound-healing properties. In this work, supercritical carbon dioxide was used to recover marigold essential oil from the hexane solvent extract of marigold flowers, the floral “concrete”. This starting material was mixed with synthetic paraffinic waxes to heighten its melting point and viscosity, thus, improving material processability. Supercritical fluid extraction and fractionation of the modified marigold “concrete” was carried out, and the effect of pressure and CO₂ mass flow rate was studied. The pressure was varied from 80 to 180 bar, keeping the temperature constant at 40 °C: the higher the pressure, the larger the CO₂ solvent power and extraction yield (up to 9.40% w/w). Nevertheless, the optimum between productivity and process selectivity was found at 100 bar. By changing the CO₂ mass flow rate (from 1.20 to 1.50 kg/h), we noted that mass transfer resistance was located externally. GC-MS analysis showed that the most abundant compounds in the oil were δ-cadinene (25%), γ-cadinene (16%), τ-muurolol (6.5%), and α-muurolene (6%). Moreover, the traces of oil and waxes showed no mutual contamination between lighter species and waxes, meaning that the fractionation step was successful. Full article

(This article belongs to the Special Issue Essential Oils: Extraction, Chemical Composition, and Biological Activity)

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26 pages, 4444 KiB

Open AccessArticle

Influence of Season and Habitat on the Essential Oils Composition, Allelopathy, and Antioxidant Activities of Artemisia monosperma Delile

by Ahmed M. Abd-ElGawad, Abdulaziz M. Assaeed, Saud L. Al-Rowaily, Mohamed S. Alshahri, Giuliano Bonanomi and Abdelsamed I. Elshamy

Separations 2023, 10(4), 263; https://doi.org/10.3390/separations10040263 - 17 Apr 2023

Cited by 4 | Viewed by 1201

Abstract

Plants belonging to the Artemisia genus (Asteraceae) are widely distributed worldwide and have many ethnopharmacological, traditional, therapeutic, and phytochemical aspects. Artemisia monosperma is an important aromatic plant due to its traditional and therapeutic uses and phytochemical diversity, including essential oils (EOs). The EO chemical profile of aromatic plants has been reported to be affected by exogenous and endogenous factors. Geographic and seasonal variations are crucial factors shaping the chemical composition of the EO. Herein, the variations of the yields, chemical profiles, and allelopathic and antioxidant activities of A. monosperma EOs collected from three regions in four seasons were assessed. A slight variation in the oil yields was observed among regions and seasons, while the chemical profile, characterized via GC-MS, exhibited significant quantitative and qualitative variation among either regions or seasons. Sesquiterpenes were the main components of all EOs, with significant variation in concentration. In most EO samples, the summer-plant samples had the highest concentration of sesquiterpenes, followed by spring, winter, and autumn. The 7-epi-trans-sesquisabinene hydrate, 6-epi-shyobunol, dehydro-cyclolongifolene oxide, isoshyobunone, diepicedrene-1-oxide, dehydro-aromadendrene, and junipene were the main compounds of all the EO samples. The extracted EOs of the A. monosperma samples showed considerable allelopathic activity against the weed Dactyloctenium aegyptium and the crop Lactuca sativa. A significant variation in allelopathic activity was observed among samples collected during different seasons, while the samples of the autumn and summer seasons had more potential. Also, L. sativa was more affected by the EO compared to D. aegyptium, reflecting that weeds are more resistant to allelochemicals. In this context, the EOs of A. monosperma samples exhibited substantial antioxidant activity with the same pattern of allelopathic activity, whereas the samples of the autumn and summer seasons showed higher antioxidant activity. These biological activities of the EOs could be ascribed to the higher content of oxygenated compounds. The present study revealed that seasons have a substantial effect on EO production as well as composition. In consequence, the biological activities varied with the variation of the chemical profile of the EO. These results show the importance of season/timing for sampling aromatic plants. Full article

(This article belongs to the Special Issue Essential Oils: Extraction, Chemical Composition, and Biological Activity)

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15 pages, 3322 KiB

Open AccessArticle

Phytochemical Characterization and Antifungal Efficacy of Camphor (Cinnamomum camphora L.) Extract against Phytopathogenic Fungi

by Sherien Sobhy, Abdulaziz A. Al-Askar, Elsayed K. Bakhiet, Mohsen M. Elsharkawy, Amr A. Arishi, Said I. Behiry and Ahmed Abdelkhalek

Separations 2023, 10(3), 189; https://doi.org/10.3390/separations10030189 - 09 Mar 2023

Cited by 8 | Viewed by 3279

Abstract

Cinnamomum camphora methanolic extract was tested for antifungal activity against three common, isolated, widespread phytopathogens: Alternaria alternata, Fusarium solani, and Fusarium oxysporum, which were molecularly identified and assigned accession numbers ON795987, ON795988, and ON795989, respectively. At 4000 µg/mL, the highest concentration of C. camphora methanolic extract inhibits the fungal mycelia weight of F. oxysporum, A. alternata, and F. solani by 60, 49, and 24%, respectively. The presence of several bioactive metabolites in the C. camphora extract could explain its antifungal activity. The presence of numerous phenolic and flavonoid compounds in the extract was revealed by HPLC analysis, including catechin and gallic acid, which had the highest concentrations of 6.21 and 6.98 µg/mL, respectively. Furthermore, osmoprotectants, total amino acids, and glycine betaine were abundant. Furthermore, total antioxidant activities, as measured by PMA and DPPH, were significant. The most abundant compound in the extract, according to GC-MS analysis, was mono(2-ethylhexyl) ester of 1,2-benzene dicarboxylic acid. Based on its in vitro efficacy in inhibiting mycelial growth weight, the tested extract could be recommended as a safe fungicide instead of a chemical treatment. Full article

(This article belongs to the Special Issue Essential Oils: Extraction, Chemical Composition, and Biological Activity)

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17 pages, 3409 KiB

Open AccessArticle

Bioactive Chemical Constituents of Matthiola longipetala Extract Showed Antioxidant, Antibacterial, and Cytotoxic Potency

by Yasser A. El-Amier, Nouf S. Zaghloul and Ahmed M. Abd-ElGawad

Separations 2023, 10(1), 53; https://doi.org/10.3390/separations10010053 - 13 Jan 2023

Cited by 3 | Viewed by 1759

Abstract

The exploration of bioactive compounds from natural resources attracts the attention of researchers and scientists worldwide. M. longipetala is an annual aromatic herb that emits a pleasant odor during the night. Regarding the chemical composition and biological characteristics, M. longipetala extracts are poorly studied. The current study aimed to characterize the chemical composition of M. longipetala methanol extract using GC-MS and determine its biological potencies, including its capacity for cytotoxicity and antioxidant and antibacterial activities. In this approach, 37 components were identified, representing 99.98% of the total mass. The major chemical components can be classified as oxygenated hydrocarbons (19.15%), carbohydrates (10.21%), amines (4.85%), terpenoids (12.71%), fatty acids and lipids (50.8%), and steroids (2.26%). The major identified compounds were ascaridole epoxide (monoterpene, 12.71%) and methyl (E)-octadec-11-enoate (ester of fatty acid, 12.21%). The extract of M. longipetala showed substantial antioxidant activity. Based on the DPPH and ABTS scavenging, the antioxidant activity of the extracted components of M. longipetala revealed that leaf extract is the most effective with IC₅₀ values of 31.47 and 28.94 mg/L, respectively. On the other hand, the extracted plant showed low antibacterial activities against diverse bacterial species, viz., Escherichia coli, Klebsiella pneumonia, Staphylococcus epidermidis, S. haemolyticus, and S. aureus. The most potent antibacterial results were documented for leaf and flower extracts against E. coli and S. aureus. Additionally, the extract’s effectiveness against HepG2 cells was evaluated in vitro using the measures of MTT, DNA fragmentation, and cell proliferation cycle, where it showed considerable activity. Therefore, we can conclude that M. longipetala extract displayed improvement in cytocompatibility and cell migration properties. In conclusion, M. longipetala could be considered a potential candidate for various bioactive compounds with promising biological activities. However, further characterization of the identified compounds, particularly the major compounds, is recommended to evaluate their efficacy, modes of action, and safety. Full article

(This article belongs to the Special Issue Essential Oils: Extraction, Chemical Composition, and Biological Activity)

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