Chemical Composition and Antimicrobial Activity of Essential Oils

A special issue of Plants (ISSN 2223-7747). This special issue belongs to the section "Phytochemistry".

Deadline for manuscript submissions: closed (28 February 2022) | Viewed by 49304

Special Issue Editor

Special Issue Information

Dear Colleagues,

Essential oils are volatile and colorless liquids representing the finest aromatic extracts obtained by steam distillation from plants. Each oil is characterized by aromatic chemically pure constituents at room temperature and is subjected to restricted standards of purity. The composition is rich and complex and consists of compounds belong to various chemical classes: terpenes, mostly monoterpenes and sesquiterpenes; terpenoids namely oxygenated compounds such as phenols, alcohols, aldehydes, ketones or ethers and aromatic and aliphatic constituents with low molecular weights. In essential oils there are also a series of minor compounds that can modulate the biological action. Each of bioactive component could show several biological activities including antibacterial and bactericidal ones which have shown growing interest in recent years, proving effective even on strains resistant to several drugs used in the medical field. The antibacterial activity of essential oils depends on their chemical composition and the quantity of each individual compound. In this context it is crucial to carry out a chemical characterization of essential oils in order to describe a volatile profile and identify the possibly responsible molecules of the antimicrobial effect.

This Special Issue is designed to collect scientific papers on essential oils antimicrobial activities and their chemical composition. For this aim, wil be appreciated papers dealing with biological essays to test the activity against microorganisms and chemical analysis techniques to characterize essential by the identification and quantification of individual compounds and their mixtures will be appreciated.

Dr. Stefania Garzoli
Guest Editor

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Keywords

  • essential oils
  • antimicrobial agents
  • minimum inhibitory concentration (MIC)
  • minimum bactericidal concentration (MBC)
  • volatile compounds
  • chemical analyses
  • GC-MS
  • HPLC-MS

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Editorial

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5 pages, 216 KiB  
Editorial
Chemical Composition and Antimicrobial Activity of Essential Oils
by Stefania Garzoli
Plants 2023, 12(4), 800; https://doi.org/10.3390/plants12040800 - 10 Feb 2023
Cited by 1 | Viewed by 1495
Abstract
This Special Issue entitled “Chemical Composition and Antimicrobial Activity of Essential Oils” focuses on the chemical characterization of essential oils (EOs) through analytical techniques that are necessary for the identification and quantification of individual compounds [...] Full article
(This article belongs to the Special Issue Chemical Composition and Antimicrobial Activity of Essential Oils)

Research

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15 pages, 2334 KiB  
Article
Gas Chromatography-Mass Spectrometry (GC-MS) Metabolites Profiling and Biological Activities of Various Capsicum annum cultivars
by Rizwan Ahmad, Aljawharah Alqathama, Mohammed Aldholmi, Muhammad Riaz, Ashraf N. Abdalla, Ahmed Mostafa, Hamdi M. Al-Said, Abdulmalik M. Alqarni, Riaz Ullah, Sami S. Asgher, Mohd Amir, Heba Shaaban and Wasim Ahmad
Plants 2022, 11(8), 1022; https://doi.org/10.3390/plants11081022 - 9 Apr 2022
Cited by 5 | Viewed by 2825
Abstract
This study evaluates the quality variation for twenty-seven capsicum fruit (CF) samples, in terms of their volatile oil composition and biological activities. The GCMS analysis revealed the presence of seventy one chemical compounds from different chemical classes with an average (%) composition of: [...] Read more.
This study evaluates the quality variation for twenty-seven capsicum fruit (CF) samples, in terms of their volatile oil composition and biological activities. The GCMS analysis revealed the presence of seventy one chemical compounds from different chemical classes with an average (%) composition of: 26.13 (alcohols) > 18.82 (hydrocarbons) > 14.97 (esters) > 3.08 (ketones) > 1.14 (others) > 1.07 (acids) > 0.72 (sugar) > 0.42 (aldehydes) > 0.15 (amino compounds). Alcohols and hydrocarbons were the most abundant in these CF samples with 1-Decanol, 2-octyl- and docosanoic acid, docosyl ester as the major components, respectively. The % inhibition in cytotoxicity assays was observed in the range of 9–47 (MCF7) and 4–41 (HCT116) whereas, the zone of inhibition (mm) for the antimicrobial activity was found to be 0.0–17 (P. aeruginosa) > 0.0–13 (E. coli and S. aureus). Moreover, the samples with the largest zone of inhibition in the agar-well-diffusion method (C16, C19, and C26) upon further evaluation presented the least MIC and MBC values against P. aeruginosa with an MIC and MBC (µg/mL) of 6.3 and 12.5, respectively. The outcome for GCMS and biological activities were further supported by statistical tools of PCA and K-mean cluster analysis which confirmed the C16 CF sample with the best activity followed by C5, C13 (the best cytotoxic), and C19, C26 (the best antimicrobial). The statistical analysis exhibited a high Chi-square value of 5931.68 (GCMS) and 32.19 (biological activities) with p = 0.00 for KMO and Bartlett’s Test of Sphericity. The 27-CF samples were effectively distinguished based on quality variation, and the C16 CF sample exhibited significant potential for further study. Full article
(This article belongs to the Special Issue Chemical Composition and Antimicrobial Activity of Essential Oils)
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21 pages, 38736 KiB  
Article
Agathis robusta Bark Essential Oil Effectiveness against COVID-19: Chemical Composition, In Silico and In Vitro Approaches
by Maged E. Mohamed, Nora Tawfeek, Samar S. Elbaramawi and Eman Fikry
Plants 2022, 11(5), 663; https://doi.org/10.3390/plants11050663 - 28 Feb 2022
Cited by 18 | Viewed by 2640
Abstract
Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV2), the causative agent of Coronavirus Disease 2019 (COVID-19), has seriously threatened global health. Alongside the approved vaccines, the discovery of prospective anti-COVID-19 drugs has been progressively targeted. Essential oils (EOs) provide a rich source of compounds [...] Read more.
Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV2), the causative agent of Coronavirus Disease 2019 (COVID-19), has seriously threatened global health. Alongside the approved vaccines, the discovery of prospective anti-COVID-19 drugs has been progressively targeted. Essential oils (EOs) provide a rich source of compounds with valuable antiviral activities that may contribute as effective agents against COVID-19. In this study, the EO of Agathus robusta bark was investigated for its chemical composition and its antiviral activity against SARS-CoV2. Overall, 26 constituents were identified by gas chromatography-mass spectrometry (GC-MS) analysis. α-Pinene, tricyclene, α-terpineol, limonene, d-camphene, trans-pinocarveol, α-phellandren-8-ol, L-β-pinene and borneol were the major components. In silico docking of these constituents against viral key enzymes, spike receptor-binding domain (RBD), main protease (Mpro) and RNA-dependent RNA polymerase (RdRp), using Molecular Operating Environment (MOE) software revealed good binding affinities of the components to the active site of the selected targets, especially, the RBD. In Vitro antiviral MTT and cytopathic effect inhibition assays demonstrated a promising anti SARS-CoV2 for A. robusta bark EO, with a significant selectivity index of 17.5. The results suggested using this EO or its individual components for the protection against or treatment of COVID-19. Full article
(This article belongs to the Special Issue Chemical Composition and Antimicrobial Activity of Essential Oils)
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13 pages, 1760 KiB  
Article
Brocchia cinerea (Delile) Vis. Essential Oil Antimicrobial Activity and Crop Protection against Cowpea Weevil Callosobruchus maculatus (Fab.)
by Abdelkrim Agour, Ibrahim Mssillou, Hamza Mechchate, Imane Es-safi, Aimad Allali, Azeddin El Barnossi, Omkulthom Al Kamaly, Samar Zuhair Alshawwa, Abdelfattah El Moussaoui, Amina Bari, Badiaa Lyoussi and Elhoussine Derwich
Plants 2022, 11(5), 583; https://doi.org/10.3390/plants11050583 - 22 Feb 2022
Cited by 13 | Viewed by 2422
Abstract
Antibiotics and synthetic pesticides are now playing a role in the spread of resistant pathogens. They continue to have negative consequences for animal and plant health. The goal of this work is to identify the chemical composition of Brocchia cinerea (Delile) Vis. essential [...] Read more.
Antibiotics and synthetic pesticides are now playing a role in the spread of resistant pathogens. They continue to have negative consequences for animal and plant health. The goal of this work is to identify the chemical composition of Brocchia cinerea (Delile) Vis. essential oil (EO) using GC-MS(Gas Chromatography-Mass Spectrometer), evaluate its antimicrobial properties, and investigate its insecticidal and repellent effectiveness against Callosobruchus maculatus (C. maculatus). The GC-MS indicated the presence of 21 chemicals, with thujone (24.9%), lyratyl acetate (24.32%), camphor (13.55%), and 1,8-cineole (10.81%) being the most prominent. For the antimicrobial assay, the yeast Candida albicans was very sensitive to the EO with a growth inhibition diameter of (42.33 mm), followed by Staphylococcus aureus (31.33 mm). Fusarium oxysporum is the mycelia strain that appeared to be extremely sensitive to the utilized EO (88.44%) compared to the two species of Aspergillus (A. flavus (48.44%); A. niger (36.55%)). The results obtained in the microdilution method show that Pseudomonas aeruginosa was very sensitive to the EO, inhibited by a very low dose (0.0018 mg/mL). The minimum inhibitory concentration (MIC) results were between 0.0149 and 0.06 mg/mL. B. cinerea EO also demonstrated a potent insecticidal effect and a medium repulsive effect against C. maculatus. Thus, the LC50 value in the contact test was 0.61 μL/L of air, lower than that observed in the inhalation test (0.72 μL/L of air). The present study reveals that B. cinerea EO has the potential to be an antimicrobial and insecticidal agent with a better performance against several pathogenic microorganisms. Full article
(This article belongs to the Special Issue Chemical Composition and Antimicrobial Activity of Essential Oils)
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18 pages, 1974 KiB  
Article
Lavandula dentata L.: Phytochemical Analysis, Antioxidant, Antifungal and Insecticidal Activities of Its Essential Oil
by Youness El Abdali, Abdelkrim Agour, Aimad Allali, Mohammed Bourhia, Abdelfattah El Moussaoui, Noureddine Eloutassi, Ahmad Mohammed Salamatullah, Abdulhakeem Alzahrani, Lahcen Ouahmane, Mourad A. M. Aboul-Soud, John P. Giesy and Abdelhak Bouia
Plants 2022, 11(3), 311; https://doi.org/10.3390/plants11030311 - 25 Jan 2022
Cited by 33 | Viewed by 4979
Abstract
Antioxidant, antifungal and insecticidal activities of essential oil (EO) extracted from the Moroccan lavender (Lavandula dentata) were investigated and their chemical constituents determined. Gas chromatography with flame ionization detection (GC-FID) and gas chromatography-mass spectrometry analyses (GC-MS) were used to examine the [...] Read more.
Antioxidant, antifungal and insecticidal activities of essential oil (EO) extracted from the Moroccan lavender (Lavandula dentata) were investigated and their chemical constituents determined. Gas chromatography with flame ionization detection (GC-FID) and gas chromatography-mass spectrometry analyses (GC-MS) were used to examine the phytochemical composition of EO. Antioxidant potential was examined in vitro by use of three tests: DPPH inhibition, reducing power (FRAP) and total antioxidant capacity (TAC). Antifungal activity was assessed by calculating inhibition of growth of Alternaria alternata, Botrytis cinerea and Fusarium oxysporum. Repellent potential and toxicity of EO by contact and inhalation were performed against Callosobruchus maculatus. Sixteen constituents were detected in the EO of Lavandula dentata. The major component was linalool (45.06%) followed by camphor (15.62%) and borneol (8.28%). EO exhibited a significant antioxidant activity, as measured by DPPH and FRAP assays, with IC50 and EC50 values of 12.95 ± 1.300 mg/mL and 11.88 ± 0.23 mg/mL, respectively. EO of lavender exhibited total antioxidant capacity of 81.28 ± 2.28 mg AAE/g EO. EO of lavender showed an inhibitory effect on mycelial growth against tested fungi and was 100% in the case of B. cinerea. EO caused total mortality of adult C. maculatus from 5 µL/L air with LC50 value of 4.01 µL/L air. Significant reduction in numbers of eggs laid (99.2%) and emergence (100%) was observed in a dose-dependent manner up to maxima of 100% and 99.2%, respectively. EO of lavender also showed a moderate potency to repel insects with a mean of 34.44%. EO of Moroccan Lavandula dentata has potential to be an effective natural agent against free radical damage and could be an environmentally friendly alternative bio-fungicide and bio-insecticide. Full article
(This article belongs to the Special Issue Chemical Composition and Antimicrobial Activity of Essential Oils)
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17 pages, 1391 KiB  
Article
Apiaceae Essential Oils: Boosters of Terbinafine Activity against Dermatophytes and Potent Anti-Inflammatory Effectors
by Adriana Trifan, Simon Vlad Luca, Andra-Cristina Bostănaru, Mihai Brebu, Alexandra Jităreanu, Romeo-Teodor Cristina, Krystyna Skalicka-Woźniak, Sebastian Granica, Monika E. Czerwińska, Aleksandra Kruk, Hélène Greige-Gerges, Elwira Sieniawska and Mihai Mareș
Plants 2021, 10(11), 2378; https://doi.org/10.3390/plants10112378 - 4 Nov 2021
Cited by 7 | Viewed by 2756
Abstract
Dermatophyte infections represent an important public health concern, affecting up to 25% of the world’s population. Trichophyton rubrum and T. mentagrophytes are the predominant dermatophytes in cutaneous infections, with a prevalence accounting for 70% of dermatophytoses. Although terbinafine represents the preferred treatment, its [...] Read more.
Dermatophyte infections represent an important public health concern, affecting up to 25% of the world’s population. Trichophyton rubrum and T. mentagrophytes are the predominant dermatophytes in cutaneous infections, with a prevalence accounting for 70% of dermatophytoses. Although terbinafine represents the preferred treatment, its clinical use is hampered by side effects, drug–drug interactions, and the emergence of resistant clinical isolates. Combination therapy, associating terbinafine and essential oils (EOs), represents a promising strategy in the treatment of dermatophytosis. In this study, we screened the potential of selected Apiaceae EOs (ajowan, coriander, caraway, and anise) to improve the antifungal activity of terbinafine against T. rubrum ATCC 28188 and T. mentagrophytes ATCC 9533. The chemical profile of EOs was analyzed by gas chromatography. The minimal inhibitory concentration (MIC) and minimal fungicidal concentration (MFC) of EOs/main compounds were determined according to EUCAST-AFST guidelines, with minor modifications. The checkerboard microtiter method was used to identify putative synergistic combinations of EOs/main constituents with terbinafine. The influence of EOs on the viability and pro-inflammatory cytokine production (IL-1β, IL-8 and TNF-α) was determined using an ex vivo human neutrophils model. The binary associations of tested EOs with terbinafine were found to be synergistic against T. rubrum, with FICI values of 0.26–0.31. At the tested concentrations (6.25–25 mg/L), EOs did not exert cytotoxic effects towards human neutrophils. Anise EO was the most potent inhibitor of IL-1β release (46.49% inhibition at 25 mg/L), while coriander EO displayed the highest inhibition towards IL-8 and TNF-α production (54.15% and 54.91%, respectively). In conclusion, the synergistic combinations of terbinafine and investigated Apiaceae EOs could be a starting point in the development of novel topical therapies against T. rubrum-related dermatophytosis. Full article
(This article belongs to the Special Issue Chemical Composition and Antimicrobial Activity of Essential Oils)
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21 pages, 3730 KiB  
Article
Antimicrobial Potential and Phytochemical Profile of Wild and Cultivated Populations of Thyme (Thymus sp.) Growing in Western Romania
by Rodica Beicu, Ersilia Alexa, Diana Obiștioiu, Ileana Cocan, Florin Imbrea, Georgeta Pop, Denisa Circioban, Cristian Moisa, Andreea Lupitu, Lucian Copolovici, Dana Maria Copolovici and Ilinca Merima Imbrea
Plants 2021, 10(9), 1833; https://doi.org/10.3390/plants10091833 - 3 Sep 2021
Cited by 10 | Viewed by 3038
Abstract
The purpose of this study was to analyze the chemical composition and antimicrobial activity of some thymus populations collected from five different locations in Western Romania. The chemical compositions of the essential oils (EOs) were studied through GC–MS, and the biological activities were [...] Read more.
The purpose of this study was to analyze the chemical composition and antimicrobial activity of some thymus populations collected from five different locations in Western Romania. The chemical compositions of the essential oils (EOs) were studied through GC–MS, and the biological activities were evaluated using the microdilution method. The EO yield ranged between 0.44% and 0.81%. Overall, 60 chemical compounds were identified belonging to three chemotypes: thymol (three populations), geraniol (one population) and carvacrol (one population). Thymus vulgaris L. is distinguished by a high content of thymol, while species of spontaneous flora (Th. odoratissimus and Th. pulegioides) contain, in addition to thymol, appreciable amounts of carvacrol and geraniol. The antimicrobial activity of each the five oils was tested on Staphylococcus aureus (ATCC 25923), Streptococcus pyogenes (ATCC 19615), Esherichia coli (ATCC 25922), Pseudomonas aeruginosa (ATCC 27853), Shigella flexneri (ATCC 12022), Salmonella typhimurium (ATCC 14028), Haemophilus influenzae type B (ATCC 10211), Candida albicans (ATCC 10231) and Candida parapsilopsis (ATCC 22019). The EOs showed biological activity on Gram-positive/Gram-negative/fungal pathogens, the most sensitive strains proving to be S. pyogenes, S. flexneri, S. typhimurium and C. parapsilopsis with an MIC starting at 2 µL EO/100 µL. The species sensitive to the action of Thymus sp. from culture or spontaneous flora are generally the same, but it should be noted that T. odoratissimus has a positive inhibition rate higher than other investigated EOs, regardless of the administered oil concentration. To date, there is no research work presenting the chemical and antimicrobial profiling of T. odoratissimus and the correlations between the antimicrobial potential and chemical composition of wild and cultivated populations of thyme (Thymus sp.) growing in Western Romania. Full article
(This article belongs to the Special Issue Chemical Composition and Antimicrobial Activity of Essential Oils)
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12 pages, 797 KiB  
Article
Metabolomic Profiles of Essential Oils from Selected Rosa Varieties and Their Antimicrobial Activities
by Esraa A. Elhawary, Nada M. Mostafa, Rola M. Labib and Abdel Nasser Singab
Plants 2021, 10(8), 1721; https://doi.org/10.3390/plants10081721 - 20 Aug 2021
Cited by 18 | Viewed by 2822
Abstract
This study aimed to analyze the essential oils of the aerial parts (A) and flowers (F) of Rosa banksiae var. banksiae Ait. (RBW), Rosa polyantha Thunb. “orange fairy” (RPO) and Rosa polyantha Thunb. “white fairy” (RPW), family Rosaceae, and perform multivariate data analyses [...] Read more.
This study aimed to analyze the essential oils of the aerial parts (A) and flowers (F) of Rosa banksiae var. banksiae Ait. (RBW), Rosa polyantha Thunb. “orange fairy” (RPO) and Rosa polyantha Thunb. “white fairy” (RPW), family Rosaceae, and perform multivariate data analyses and antimicrobial activity evaluations. The essential oil analyses were performed by GC/FID and GC/MS. Principal component analysis (PCA), hierarchical cluster analysis (HCA), and clustered heat map were used for the multivariate analyses. The antimicrobial activity was evaluated by the well-diffusion method against four bacteria and four fungi. Two hundred fifty-three compounds were identified from the six oil samples. The major components in RBW-A, RPO-A, and RPW-A were n-undecane (14.40, 19.36, and 9.21%) n-dodecane (14.54, 22.13, and 8.39%), and yomogi alcohol (8.41, 10.53, and 6.28%), respectively, whereas RBW-F, RPO-F and RPW-F contained n-heptadecane (16.70%), n-undecane (7.98%), and β-phellandrene (22.78%), respectively. The tested essential oils showed moderate antifungal activity against Aspergillus fumigatus compared to amphotericin B. PCA and HCA revealed five main clusters. The six samples carried close chemical profiles and can be regarded as fruitful sources of safe antifungal agents. Full article
(This article belongs to the Special Issue Chemical Composition and Antimicrobial Activity of Essential Oils)
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13 pages, 29394 KiB  
Article
Assessing the Control of Postharvest Gray Mold Disease on Tomato Fruit Using Mixtures of Essential Oils and Their Respective Hydrolates
by Conny Brito, Henrik Hansen, Luis Espinoza, Martín Faúndez, Andrés F. Olea, Sebastián Pino and Katy Díaz
Plants 2021, 10(8), 1719; https://doi.org/10.3390/plants10081719 - 20 Aug 2021
Cited by 12 | Viewed by 3456
Abstract
Gray mold disease, which is caused by Botrytis cinerea Pers ex. Fr., results in serious economic losses to Lycopersicum esculentum (tomato) crop productivity. In this study, we explored the possibility that mixtures of essential oils (EOs) and their respective hydrolates (HYSs) could be [...] Read more.
Gray mold disease, which is caused by Botrytis cinerea Pers ex. Fr., results in serious economic losses to Lycopersicum esculentum (tomato) crop productivity. In this study, we explored the possibility that mixtures of essential oils (EOs) and their respective hydrolates (HYSs) could be used to control this disease. Thus, EOs and HYSs were obtained from Origanum vulgare, Thymus vulgaris, Citrus limon, and Citrus sinensis by hydrodistillation. In vitro antifungal activities were evaluated, and EC50 values of 15.9 and 19.8 µg/mL were obtained for EOs of thyme and oregano, respectively. These activities are due mainly to volatile compounds, thymol and carvacrol. Results from in vivo assays show that although most tomatoes were infested five days after inoculation, the damage was considerably reduced by the application of an EO/HYS mixture of thyme. The disease incidence indexes of B. cinerea tomato rot, percentage and severity, measured four days after inoculation, were reduced by 70% and 76%, respectively, as compared with the inoculum control. These results suggest that a combination of HYSs and EOs enhances antifungal activity, and that optimization of relative concentrations, volumes, and the nature of the compounds, could design a formulation able to control B. cinerea inoculum on tomato fruits. Full article
(This article belongs to the Special Issue Chemical Composition and Antimicrobial Activity of Essential Oils)
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14 pages, 2143 KiB  
Article
Essential Oils of Sage, Rosemary, and Bay Laurel Inhibit the Life Stages of Oomycete Pathogens Important in Aquaculture
by Anđela Miljanović, Dorotea Grbin, Dora Pavić, Maja Dent, Igor Jerković, Zvonimir Marijanović and Ana Bielen
Plants 2021, 10(8), 1676; https://doi.org/10.3390/plants10081676 - 15 Aug 2021
Cited by 5 | Viewed by 2932
Abstract
Saprolegnia parasitica, the causative agent of saprolegniosis in fish, and Aphanomyces astaci, the causative agent of crayfish plague, are oomycete pathogens that cause economic losses in aquaculture. Since toxic chemicals are currently used to control them, we aimed to investigate their [...] Read more.
Saprolegnia parasitica, the causative agent of saprolegniosis in fish, and Aphanomyces astaci, the causative agent of crayfish plague, are oomycete pathogens that cause economic losses in aquaculture. Since toxic chemicals are currently used to control them, we aimed to investigate their inhibition by essential oils of sage, rosemary, and bay laurel as environmentally acceptable alternatives. Gas Chromatography–Mass Spectrometry (GC–MS) analysis showed that the essential oils tested were rich in bioactive volatiles, mainly monoterpenes. Mycelium and zoospores of A. astaci were more sensitive compared to those of S. parasitica, where only sage essential oil completely inhibited mycelial growth. EC50 values (i.e., concentrations of samples at which the growth was inhibited by 50%) for mycelial growth determined by the radial growth inhibition assay were 0.031–0.098 µL/mL for A. astaci and 0.040 µL/mL for S. parasitica. EC50 values determined by the zoospore germination inhibition assay were 0.007–0.049 µL/mL for A. astaci and 0.012–0.063 µL/mL for S. parasitica. The observed inhibition, most pronounced for sage essential oil, could be partly due to dominant constituents of the essential oils, such as camphor, but more likely resulted from a synergistic effect of multiple compounds. Our results may serve as a basis for in vivo experiments and the development of environmentally friendly methods to control oomycete pathogens in aquaculture. Full article
(This article belongs to the Special Issue Chemical Composition and Antimicrobial Activity of Essential Oils)
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18 pages, 4184 KiB  
Article
Thymus serpyllum Essential Oil and Its Biological Activity as a Modern Food Preserver
by Lucia Galovičová, Petra Borotová, Veronika Valková, Nenad L. Vukovic, Milena Vukic, Margarita Terentjeva, Jana Štefániková, Hana Ďúranová, Przemysław Łukasz Kowalczewski and Miroslava Kačániová
Plants 2021, 10(7), 1416; https://doi.org/10.3390/plants10071416 - 11 Jul 2021
Cited by 28 | Viewed by 4177
Abstract
The aim of this study was to analyze the chemical composition and biological and antibiofilm activity of the essential oil (EO) of Thymus serpyllum with the use of a MALDI-TOF MS Biotyper. The main compounds of the EO were thymol, 18.8%; carvacrol, 17.4%; [...] Read more.
The aim of this study was to analyze the chemical composition and biological and antibiofilm activity of the essential oil (EO) of Thymus serpyllum with the use of a MALDI-TOF MS Biotyper. The main compounds of the EO were thymol, 18.8%; carvacrol, 17.4%; o-cymene, 15.4%; and geraniol, 10.7%. It was found that free-radical scavenging activity was high. The highest antimicrobial activity was observed against Pseudomonas aeruginosa, Salmonella enteritidis, and biofilm-forming bacteria. The changes in the biofilm structure after T. serpyllum EO application confirmed the inhibitory action and the most pronounced effect was observed on Bacillus subtilis biofilm. The antifungal activity of the vapor phase was the most effective against Penicillium crustosum. T. serpyllum should be a suitable alternative to synthetic antioxidants as well as antimicrobials. The EO of T. serpyllum can be used in the vapor phase in the storage of root vegetables as well as a growth inhibitor of Penicillium on bread. Full article
(This article belongs to the Special Issue Chemical Composition and Antimicrobial Activity of Essential Oils)
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17 pages, 2171 KiB  
Article
Laurus nobilis, Salvia sclarea and Salvia officinalis Essential Oils and Hydrolates: Evaluation of Liquid and Vapor Phase Chemical Composition and Biological Activities
by Elisa Ovidi, Valentina Laghezza Masci, Marta Zambelli, Antonio Tiezzi, Sara Vitalini and Stefania Garzoli
Plants 2021, 10(4), 707; https://doi.org/10.3390/plants10040707 - 6 Apr 2021
Cited by 35 | Viewed by 4078
Abstract
Laurus nobilis, Salvia officinalis and Salvia sclarea essential oils (EOs) and hydrolates (HYs) were investigated to define their chemical compositions and biological properties. Gas-chromatography/Mass-spectrometry (GC/MS) and Headspace-GC/MS (HS-GC/MS) techniques were used to characterize the liquid and vapor phase chemical composition of EOs [...] Read more.
Laurus nobilis, Salvia officinalis and Salvia sclarea essential oils (EOs) and hydrolates (HYs) were investigated to define their chemical compositions and biological properties. Gas-chromatography/Mass-spectrometry (GC/MS) and Headspace-GC/MS (HS-GC/MS) techniques were used to characterize the liquid and vapor phase chemical composition of EOs and HYs. 1,8-Cineole (42.2%, 33.5%) and α-pinene (16.7%, 39.0%) were the main compounds of L. nobilis EO; 1,8-cineole (30.3%, 48.4%) and camphor (17.1%, 8.7%) were for S. officinalis EO; linalyl acetate (62.6%, 30.1%) and linalool (11.1%, 28.9%) were for S. sclarea EO for the liquid and vapor phase, respectively. Chemical profile of HYs was characterized by 1,8-cineole (65.1%, 61.4%) as a main constituent of L. nobilis and S. officinalis HYs, while linalool (89.5%) was the main constituent of S. sclarea HY. The antioxidant activity of EOs and HYs was carried out by DPPH and ABTS assays and antimicrobial properties were also investigated by microdilution and the disc diffusion method for liquid and vapor phase against five different bacterial strains such as Escherichia coli ATCC 25922, Pseudomonas fluorescens ATCC 13525 and Acinetobacter bohemicus DSM 102855 among Gram-negative and Bacillus cereus ATCC 10876 and Kocuria marina DSM 16420 among Gram-positive. L. nobilis and S. officinalis EOs demonstrated considerable antibacterial activity, while S. sclarea EO proved to be less effective. Agar diffusion method and vapor phase test showed the EOs activity with the biggest halo inhibition diameters against A. bohemicus and B. cereus. A remarkably high antioxidant activity was determined for L. nobilis showing low EC50 values and also for S. sclarea; good EO results were obtained in both of the used assays. S. officinalis EC50 values were slightly higher to which corresponds to a lower antioxidant activity. Concerning the HYs, the EC50 values for L. nobilis, S. officinalis and S. sclarea were remarkably high corresponding to an extremely low antioxidant activity, as also obtained by expressing the values in Trolox equivalent antioxidant capacity (TEAC). Full article
(This article belongs to the Special Issue Chemical Composition and Antimicrobial Activity of Essential Oils)
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23 pages, 6296 KiB  
Article
Discovering Penicillium polonicum with High-Lytic Capacity on Helianthus tuberosus Tubers: Oil-Based Preservation for Mold Management
by Abdulaziz A. Al-Askar, Ehsan M. Rashad, Khalid M. Ghoneem, Ashraf A. Mostafa, Fatimah O. Al-Otibi and WesamEldin I. A. Saber
Plants 2021, 10(2), 413; https://doi.org/10.3390/plants10020413 - 23 Feb 2021
Cited by 15 | Viewed by 2928 | Correction
Abstract
During preservation, Jerusalem artichoke (JA) tubers are subjected to deterioration by mold fungi under storage, which signifies a serious problem. A new blue mold (Penicillium polonium) was recorded for the first time on JA tubers. Penicillium mold was isolated, identified (morphologically, [...] Read more.
During preservation, Jerusalem artichoke (JA) tubers are subjected to deterioration by mold fungi under storage, which signifies a serious problem. A new blue mold (Penicillium polonium) was recorded for the first time on JA tubers. Penicillium mold was isolated, identified (morphologically, and molecularly), and deposited in GenBank; (MW041259). The fungus has a multi-lytic capacity, facilitated by various enzymes capable of severely destroying the tuber components. An economic oil-based procedure was applied for preserving and retaining the nutritive value of JA tubers under storage conditions. Caraway and clove essential oils, at a concentration of 2%, were selected based on their strong antifungal actions. JA tubers were treated with individual oils under storage, kept between peat moss layers, and stored at room temperature. Tubers treated with both oils exhibited lower blue mold severity, sprouting and weight loss, and higher levels of carbohydrates, inulin, and protein contents accompanied by increased levels of defense-related phytochemicals (total phenols, peroxidase, and polyphenol oxidase). Caraway was superior, but the results endorse the use of both essential oils for the preservation of JA tubers at room temperature, as an economic and eco-safe storage technique against the new blue mold. Full article
(This article belongs to the Special Issue Chemical Composition and Antimicrobial Activity of Essential Oils)
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14 pages, 351 KiB  
Review
River Tea Tree Oil: Composition, Antimicrobial and Antioxidant Activities, and Potential Applications in Agriculture
by Mursleen Yasin, Adnan Younis, Talha Javed, Ahsan Akram, Muhammad Ahsan, Rubab Shabbir, Muhammad Moaaz Ali, Ayesha Tahir, Enas M. El-Ballat, Mohamed S. Sheteiwy, Reda Helmy Sammour, Christophe Hano, Fahad A. Alhumaydhi and Mohamed A. El-Esawi
Plants 2021, 10(10), 2105; https://doi.org/10.3390/plants10102105 - 4 Oct 2021
Cited by 30 | Viewed by 5661
Abstract
Melaleuca is one of the genera of the Myrtaceae family enriched in tea tree oil (TTO). Tea tree oils of Melaleuca bracteata and Melaleuca alternifolia are of prime importance and have antioxidant and antimicrobial properties. Terpinen-4-ol and 1-8 cineole are major constituents of [...] Read more.
Melaleuca is one of the genera of the Myrtaceae family enriched in tea tree oil (TTO). Tea tree oils of Melaleuca bracteata and Melaleuca alternifolia are of prime importance and have antioxidant and antimicrobial properties. Terpinen-4-ol and 1-8 cineole are major constituents of M. alternifolia oil. The percentages of the compounds in the oils can slightly vary according to the region of plant harvest, the distillation technique, or the part of the plant used for oil extraction. TTO has a bactericidal effect against various bacterial species such as Bacillus cereus, B. subtilis, E. coli, Pseudomonas putida, and S. aureus. Several reports proved that this essential oil is also effective against fungal strains of Fusarium, Aspergillus, and Candida species. It also has antioxidant properties such as radical scavenging activity and reducing power. The antioxidant properties of TTO at a concentration of 30 mM were observed to be greater than those of butylated hydroxytoluene (BHT), commonly used as a synthetic antioxidant. TTO is also an effective organic fungicide, herbicide, and insecticide for use in the agriculture sector. Postharvest application of the oil has been found efficient on sweet basil, citrus, and strawberry. It is concluded that tea tree oil has the potential to be used in the food, agriculture, and pharmaceutical industries as a natural antimicrobial and preservative agent. This review provides comprehensive information regarding the antioxidant and antimicrobial activities of tea tree oil and its potential applications in agriculture. Full article
(This article belongs to the Special Issue Chemical Composition and Antimicrobial Activity of Essential Oils)

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1 pages, 166 KiB  
Correction
Correction: Al-Askar et al. Discovering Penicillium polonicum with High-Lytic Capacity on Helianthus tuberosus Tubers: Oil-Based Preservation for Mold Management. Plants 2021, 10, 413
by Abdulaziz A. Al-Askar, Ehsan M. Rashad, Khalid M. Ghoneem, Ashraf A. Mostafa, Fatimah O. Al-Otibi and WesamEldin I. A. Saber
Plants 2021, 10(9), 1905; https://doi.org/10.3390/plants10091905 - 14 Sep 2021
Cited by 4 | Viewed by 1202
Abstract
The authors would like to advise that several corrections have been made to the original article [...] Full article
(This article belongs to the Special Issue Chemical Composition and Antimicrobial Activity of Essential Oils)
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