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Antimicrobial Activity of Plant Volatiles in Vapor Phase

A special issue of Molecules (ISSN 1420-3049). This special issue belongs to the section "Flavours and Fragrances".

Deadline for manuscript submissions: closed (31 December 2022) | Viewed by 30480

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Special Issue Editor

Department of Crop Sciences and Agroforestry, Faculty of Tropical AgriSciences, Czech University of Life Sciences Prague, Prague 6-Suchdol, Czech Republic
Interests: biologically active natural products; phytochemistry; food and agricultural chemistry; ethnobotany and ethnopharmacology

Special Issue Information

Dear Colleagues,

Plant volatile agents (PVA) are abundant chemicals that are emitted as an important factor, allowing communication and interaction among plants and their environment. This relatively large group of natural products consisting of lipophilic compounds of low molecular weight and high vapor pressure is divided into several chemical classes, including terpenoids, phenylpropanoids, fatty acids derivatives, and amino acid-derived products in addition to a few specific compounds not represented in those major classes, such as alkanes, alkenes, alcohols, esters, aldehydes, and ketones. Essential oils (EOs), aromatic liquids of complex composition, including aliphatic hydrocarbons, terpenoids, and phenylpropanoids are one of the most important representatives of PVA. As they often possess a broad spectrum of biological effects, EOs and their constituents have been widely used in the medicine, perfumery, cosmetic, and food industries since ancient times.

In recent years, the vapors of PVA have been intensively studied for their inhibitory effects against various microorganisms involved in the pathogenesis of human and plant diseases as well as in contamination and deterioration of food and agricultural products. The main advantage of PVA vapors is that they do not need to be applied systemically to the body or directly to the product, and they naturally tend to be regularly distributed in the air conditions of the targeted area. In addition, EOs are a typical example of complex mixtures producing an antimicrobial synergistic effect, which is currently considered as an effective tool for overcoming microbial resistance. Although they are considered relatively safe and environmentally friendly agents, it should be noted that respiratory, allergic, or immune effects associated with inhalation of essential oils and their constituents have been observed, especially in infants and children. Therefore, detailed safety evaluation of novel PVA through appropriate methods is necessary before their introduction to practical use.

The papers in this Special Issue will provide up-to date literature analysis and newly generated experimental data on antimicrobial effectiveness of PVA, including innovative approaches for evaluating their activities in vapor phase. This information should be useful for medicinal, pharmaceutical, food, and agricultural experts working in areas related to the management of infectious diseases (especially respiratory and skin infections), food preservation (e.g., active packaging), and protection of agriculture products (e.g., controlled atmosphere). It may also stimulate the interest of the pharmaceutical, cosmetic, food, and agriculture industries in the research and development of new antibacterial and antifungal agents of natural origin. The issue will therefore appeal to communities of industrial stakeholders, pharmacists, physicians, food experts, agriculturists, and researchers in related areas such as pharmacology, medicinal chemistry, microbiology, natural product chemistry, food preservation, plant protection, etc.

Prof. Dr. Ladislav Kokoska
Guest Editor

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Keywords

  • Antibacterial activity
  • Antifungal activity
  • Anti-infective agents
  • Antimicrobial activity
  • Biological effects
  • Essential oils
  • Food safety
  • Human health
  • Phenylpropanoids
  • Plant protection
  • Plant volatiles
  • Terpenoids
  • Toxicity
  • Vapor phase
  • Volatile compounds
  • Volatile oils

Published Papers (11 papers)

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Research

18 pages, 507 KiB  
Article
Validation of Broth Macrodilution Volatilization Method for Testing of Essential Oils in Liquid and Vapor Phase: Chemical Composition, Cytotoxicity, and Antibacterial Effect of Indian Medicinal Plants against Pneumonia-Causing Pathogens
by Aishwarya Chaure, Marketa Houdkova, Julien Antih, Klara Urbanova, Ivo Doskocil, Mukund Lal Naik, Khageshwar Singh Patel and Ladislav Kokoska
Molecules 2023, 28(12), 4625; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules28124625 - 07 Jun 2023
Cited by 3 | Viewed by 1450
Abstract
Essential oils (EOs) have great potential in inhalation therapy for the treatment of respiratory infections. However, innovative methods for evaluation of antimicrobial activity of their vapors are still needed. The current study reports validation of the broth macrodilution volatilization method for assessment of [...] Read more.
Essential oils (EOs) have great potential in inhalation therapy for the treatment of respiratory infections. However, innovative methods for evaluation of antimicrobial activity of their vapors are still needed. The current study reports validation of the broth macrodilution volatilization method for assessment of the antibacterial properties of EOs and shows the growth-inhibitory effect of Indian medicinal plants against pneumonia-causing bacteria in liquid and vapor phase. Among all samples tested, Trachyspermum ammi EO exhibits the strongest antibacterial effect against Haemophilus influenzae, with minimum inhibitory concentrations of 128 and 256 µg/mL in the liquid and vapor phases, respectively. Furthermore, Cyperus scariosus EO is found to be nontoxic to normal lung fibroblasts assessed by modified thiazolyl blue tetrazolium bromide assay. Chemical analysis performed using gas chromatography–mass spectrometry identified α-citral, cyperotundone, and thymol as the main constituents of Cymbopogon citratus, C. scariosus, and T. ammi EOs, respectively. In addition, β-cymene is identified as the major compound of T. ammi EO vapors when analyzed using solid-phase microextraction and gas-tight syringe sampling techniques. This study demonstrates the validity of the broth macrodilution volatilization method for antimicrobial screening of volatile compounds in the vapor phase and suggests the therapeutic potential of Indian medicinal plants in inhalation therapy. Full article
(This article belongs to the Special Issue Antimicrobial Activity of Plant Volatiles in Vapor Phase)
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17 pages, 4738 KiB  
Article
Enhancing the Antimicrobial Effect of Ozone with Mentha piperita Essential Oil
by Alin-Daniel Floare, Ramona Dumitrescu, Vlad Tiberiu Alexa, Octavia Balean, Camelia Szuhanek, Diana Obistioiu, Ileana Cocan, Alina-Georgeta Neacsu, Iuliana Popescu, Aurora Doris Fratila and Atena Galuscan
Molecules 2023, 28(5), 2032; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules28052032 - 21 Feb 2023
Viewed by 1429
Abstract
This study aimed to obtain and analyse Mentha piperita essential oil (MpEO) for the prospect of being used as an enhancement agent for the antimicrobial potential of ozone against gram-positive and gram-negative bacteria and fungi. The research was done for different exposure times, [...] Read more.
This study aimed to obtain and analyse Mentha piperita essential oil (MpEO) for the prospect of being used as an enhancement agent for the antimicrobial potential of ozone against gram-positive and gram-negative bacteria and fungi. The research was done for different exposure times, and it gained time–dose relationships and time–effect correlations. Mentha piperita (Mp) essential oil (MpEO) was obtained via hydrodistillation and further analysed by using GC-MS. The broth microdilution assay was used to determine the strain inhibition/strain mass growth by using spectrophotometric optical density reading (OD). The bacterial/mycelium growth rates (BGR/MGR) and the bacterial/mycelium inhibition rates (BIR/MIR) after ozone treatment in the presence and absence of MpEO on the ATTC strains were calculated; the minimum inhibition concentration (MIC) and statistical interpretations of the time–dose relationship and specific t-test correlations were determined. The effect of ozone on the following tested strains at maximum efficiency was observed after 55 s of single ozone exposure, in order of effect strength: S. aureus > P. aeruginosa > E. coli > C. albicans > S. mutans. For ozone with the addition of 2% MpEO (MIC), maximum efficacy was recorded at 5 s for these strains, in order of effect strength: C. albicans > E. coli > P. aeruginosa > S. aureus > S. mutans. The results suggest a new development and affinity regarding the cell membrane of the different microorganisms tested. In conclusion, the use of ozone, combined with MpEO, is sustained as an alternative therapy in plaque biofilm and suggested as helpful in controlling oral disease-causing microorganisms in medicine. Full article
(This article belongs to the Special Issue Antimicrobial Activity of Plant Volatiles in Vapor Phase)
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22 pages, 2592 KiB  
Article
Chemical Composition and Antibacterial Activity of Liquid and Volatile Phase of Essential Oils against Planktonic and Biofilm-Forming Cells of Pseudomonas aeruginosa
by Malwina Brożyna, Justyna Paleczny, Weronika Kozłowska, Daria Ciecholewska-Juśko, Adam Parfieńczyk, Grzegorz Chodaczek and Adam Junka
Molecules 2022, 27(13), 4096; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules27134096 - 25 Jun 2022
Cited by 4 | Viewed by 2214
Abstract
Pseudomonas aeruginosa is an opportunistic pathogen causing life-threatening, hard-to-heal infections associated with the presence of a biofilm. Essential oils (EOs) are promising agents to combat pseudomonal infections because of the alleged antimicrobial activity of their volatile fractions and liquid forms. Therefore, the purpose [...] Read more.
Pseudomonas aeruginosa is an opportunistic pathogen causing life-threatening, hard-to-heal infections associated with the presence of a biofilm. Essential oils (EOs) are promising agents to combat pseudomonal infections because of the alleged antimicrobial activity of their volatile fractions and liquid forms. Therefore, the purpose of this paper was to evaluate the antibacterial efficacy of both volatile and liquid phases of seven EOs (thyme, tea tree, basil, rosemary, eucalyptus, menthol mint, lavender) against P. aeruginosa biofilm and planktonic cells with the use of a broad spectrum of analytical in vitro methods. According to the study results, the antibacterial activity of EOs in their liquid forms varied from that of the volatile fractions. Overall, liquid and volatile forms of rosemary EO and tea tree EO displayed significant antibiofilm effectiveness. The outcomes indicate that these particular EOs possess the potential to be used in the therapy of P. aeruginosa infections. Full article
(This article belongs to the Special Issue Antimicrobial Activity of Plant Volatiles in Vapor Phase)
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16 pages, 3947 KiB  
Article
Antifungal Volatilomes Mediated Defense Mechanism against Fusarium oxysporum f. sp. lycopersici, the Incitant of Tomato Wilt
by Praveen Thangaraj, Akshaya Subbaih Balamurali, Krishnamoorthy Akkanna Subbiah, Nakkeeran Sevugapperumal, Thiribhuvanamala Gurudevan, Sivakumar Uthandi and Haripriya Shanmugam
Molecules 2022, 27(11), 3631; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules27113631 - 06 Jun 2022
Cited by 2 | Viewed by 1684
Abstract
In this study, the volatilomes of naturally growing plant leaves were immobilized in a suitable substrate to enhance vapors’ diffusion in the soil to eradicate the Fusarium wilt pathogens in Tomato. Volatilomes produced by Mentha spicata leaves immobilized in vermiculite ball was found [...] Read more.
In this study, the volatilomes of naturally growing plant leaves were immobilized in a suitable substrate to enhance vapors’ diffusion in the soil to eradicate the Fusarium wilt pathogens in Tomato. Volatilomes produced by Mentha spicata leaves immobilized in vermiculite ball was found to be effective and exhibit 92.35 percent inhibition on the mycelial growth of Fusarium oxysporum f. sp. lycopersici (FOL). Moreover, the volatilomes of M. spicata immobilized vermiculite balls were tested based on the distance traveled by the diffused volatilomes from the ball and revealed that the volatilomes of M. spicata traveled up to 20 cm distance from the center of PVC (Polyvinly chloride) chamber showed maximum reduction in colony growth of FOL at 12th day after inoculation. Tomato plants inoculated with FOL revealed increased expressions of defense gene, pathogenesis related protein (PR1) with 2.63-fold after 72 h and the gene, transcription factor (WRKY) increased with 2.5-fold after 48 h on exposure to the volatilomes of M. spicata vermiculite balls. To the best of our knowledge, this is the first report on development of volatilomes based vermiculite ball formulations. This result indicated that the volatilomes of M. spicata are promising phyto-fumigants for management of Tomato Fusarial wilt. Full article
(This article belongs to the Special Issue Antimicrobial Activity of Plant Volatiles in Vapor Phase)
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15 pages, 334 KiB  
Article
Assessment of Chemical Composition and Anti-Penicillium Activity of Vapours of Essential Oils from Abies Alba and Two Melaleuca Species in Food Model Systems
by Veronika Valková, Hana Ďúranová, Nenad L. Vukovic, Milena Vukic, Maciej Kluz and Miroslava Kačániová
Molecules 2022, 27(10), 3101; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules27103101 - 12 May 2022
Cited by 7 | Viewed by 1750
Abstract
The possibilities of the practical utilization of essential oils (EOs) from various plant species in the food industry have attracted the attention of the scientific community. Following our previous studies, the antifungal activities of three further commercial EOs, Melaleuca armillaris subsp. armillaris (rosalina; [...] Read more.
The possibilities of the practical utilization of essential oils (EOs) from various plant species in the food industry have attracted the attention of the scientific community. Following our previous studies, the antifungal activities of three further commercial EOs, Melaleuca armillaris subsp. armillaris (rosalina; REO), Melaleuca quinquenervia (niaouli; NEO), and Abies alba (fir; FEO), were evaluated in the present research in respect to their chemical profiles, over four different concentrations, 62.5 μL/L, 125 μL/L, 250 μL/L, and 500 μL/L. The findings revealed that the major compounds of REO, NEO, and FEO were linalool (47.5%), 1,8-cineole (40.8%), and α-pinene (25.2%), respectively. In vitro antifungal determinations showed that the inhibition zones of a Penicillium spp. mycelial growth ranged from no inhibitory effectiveness (00.00 ± 00.00 mm) to 16.00 ± 1.00 mm, indicating a very strong antifungal activity which was detected against P. citrinum after the highest REO concentration exposure. Furthermore, the in situ antifungal efficacy of all EOs investigated was shown to be dose-dependent. In this sense, we have found that the highest concentration (500 µL/L) of REO, NEO, and FEO significantly reduced (p < 0.05) the growth of all Penicillium strains inoculated on the bread, carrot, and potato models. These results indicate that the investigated EOs may be promising innovative agents in order to extend the shelf life of different types of food products, such as bread, carrot and potato. Full article
(This article belongs to the Special Issue Antimicrobial Activity of Plant Volatiles in Vapor Phase)
24 pages, 1129 KiB  
Article
Antibacterial Activity of Thymus vulgaris L. Essential Oil Vapours and Their GC/MS Analysis Using Solid-Phase Microextraction and Syringe Headspace Sampling Techniques
by Julien Antih, Marketa Houdkova, Klara Urbanova and Ladislav Kokoska
Molecules 2021, 26(21), 6553; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules26216553 - 29 Oct 2021
Cited by 18 | Viewed by 2873
Abstract
While the inhalation of Thymus vulgaris L. essential oil (EO) is commonly approved for the treatment of mild respiratory infections, there is still a lack of data regarding the antimicrobial activity and chemical composition of its vapours. The antibacterial activity of the three [...] Read more.
While the inhalation of Thymus vulgaris L. essential oil (EO) is commonly approved for the treatment of mild respiratory infections, there is still a lack of data regarding the antimicrobial activity and chemical composition of its vapours. The antibacterial activity of the three T. vulgaris EOs against respiratory pathogens, including Haemophilus influenzae, Staphylococcus aureus, and Streptococcus pyogenes, was assessed in both liquid and vapour phases using the broth microdilution volatilisation (BMV) method. With the aim of optimising a protocol for the characterisation of EO vapours, their chemical profiles were determined using two headspace sampling techniques coupled with GC/MS: solid-phase microextraction (HS-SPME) and syringe headspace sampling technique (HS-GTS). All EO sample vapours exhibited antibacterial activity with minimum inhibitory concentrations (MIC) ranging from 512 to 1024 μg/mL. According to the sampling technique used, results showed a different distribution of volatile compounds. Notably, thymol was found in lower amounts in the headspace—peak percentage areas below 5.27% (HS-SPME) and 0.60% (HS-GTS)—than in EOs (max. 48.65%), suggesting that its antimicrobial effect is higher in vapour. Furthermore, both headspace sampling techniques were proved to be complementary for the analysis of EO vapours, whereas HS-SPME yielded more accurate qualitative results and HS-GTS proved a better technique for quantitative analysis. Full article
(This article belongs to the Special Issue Antimicrobial Activity of Plant Volatiles in Vapor Phase)
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13 pages, 1464 KiB  
Article
New Broth Macrodilution Volatilization Method for Antibacterial Susceptibility Testing of Volatile Agents and Evaluation of Their Toxicity Using Modified MTT Assay In Vitro
by Marketa Houdkova, Aishwarya Chaure, Ivo Doskocil, Jaroslav Havlik and Ladislav Kokoska
Molecules 2021, 26(14), 4179; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules26144179 - 09 Jul 2021
Cited by 8 | Viewed by 3522
Abstract
In this study, a new broth macrodilution volatilization method for the simple and rapid determination of the antibacterial effect of volatile agents simultaneously in the liquid and vapor phase was designed with the aim to assess their therapeutic potential for the development of [...] Read more.
In this study, a new broth macrodilution volatilization method for the simple and rapid determination of the antibacterial effect of volatile agents simultaneously in the liquid and vapor phase was designed with the aim to assess their therapeutic potential for the development of new inhalation preparations. The antibacterial activity of plant volatiles (β-thujaplicin, thymohydroquinone, thymoquinone) was evaluated against bacteria associated with respiratory infections (Haemophilus influenzae, Staphylococcus aureus, Streptococcus pneumoniae, Streptococcus pyogenes) and their cytotoxicity was determined using a modified thiazolyl blue tetrazolium bromide assay against normal lung fibroblasts. Thymohydroquinone and thymoquinone possessed the highest antibacterial activity against H. influenzae, with minimum inhibitory concentrations of 4 and 8 µg/mL in the liquid and vapor phases, respectively. Although all compounds exhibited cytotoxic effects on lung cells, therapeutic indices (TIs) suggested their potential use in the treatment of respiratory infections, which was especially evident for thymohydroquinone (TI > 34.13). The results demonstrate the applicability of the broth macrodilution volatilization assay, which combines the principles of broth microdilution volatilization and standard broth macrodilution methods. This assay enables rapid, simple, cost- and labor-effective screening of volatile compounds and overcomes the limitations of assays currently used for screening of antimicrobial activity in the vapor phase. Full article
(This article belongs to the Special Issue Antimicrobial Activity of Plant Volatiles in Vapor Phase)
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15 pages, 710 KiB  
Article
In Vitro Antimicrobial Activity of Lavender, Mint, and Rosemary Essential Oils and the Effect of Their Vapours on Growth of Penicillium spp. in a Bread Model System
by Veronika Valková, Hana Ďúranová, Lucia Galovičová, Nenad L. Vukovic, Milena Vukic and Miroslava Kačániová
Molecules 2021, 26(13), 3859; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules26133859 - 24 Jun 2021
Cited by 28 | Viewed by 3478
Abstract
The chemical composition, antioxidant activity, and antimicrobial properties of three commercially available essential oils: rosemary (REO), lavender (LEO), and mint (MEO), were determined in the current study. Our data revealed that the major components of REO, MEO, and LEO were 1,8-cineole (40.4%), menthol [...] Read more.
The chemical composition, antioxidant activity, and antimicrobial properties of three commercially available essential oils: rosemary (REO), lavender (LEO), and mint (MEO), were determined in the current study. Our data revealed that the major components of REO, MEO, and LEO were 1,8-cineole (40.4%), menthol (40.1%), and linalool acetate (35.0%), respectively. The highest DPPH radical-scavenging activity was identified in MEO (36.85 ± 0.49%) among the investigated EOs. Regarding antimicrobial activities, we found that LEO had the strongest inhibitory efficiencies against the growth of Pseudomonas aeruginosa and Candida (C.) tropicalis, MEO against Salmonella (S.) enterica, and REO against Staphylococcus (S.) aureus. The strongest antifungal activity was displayed by mint EO, which totally inhibited the growth of Penicillium (P.) expansum and P. crustosum in all concentrations; the growth of P. citrinum was completely suppressed only by the lowest MEO concentration. The lowest minimal inhibitory concentrations (MICs) against S. enterica, S. aureus, and C. krusei were assessed for MEO. In situ analysis on the bread model showed that 125 µL/L of REO exhibited the lowest mycelial growth inhibition (MGI) of P. citrinum, and 500 µL/L of MEO caused the highest MGI of P. crustosum. Our results allow us to make conclusion that the analysed EOs have promising potential for use as innovative agents in the storage of bakery products in order to extend their shelf-life. Full article
(This article belongs to the Special Issue Antimicrobial Activity of Plant Volatiles in Vapor Phase)
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10 pages, 1236 KiB  
Article
Inhibition of Fungal Strains Isolated from Cereal Grains via Vapor Phase of Essential Oils
by Tereza Střelková, Bence Nemes, Anett Kovács, David Novotný, Matěj Božik and Pavel Klouček
Molecules 2021, 26(5), 1313; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules26051313 - 01 Mar 2021
Cited by 14 | Viewed by 2889
Abstract
Fungal contamination in stored food grains is a global concern and affects food economics and human and animal health. It is clear that there is a need to develop new technologies with improved performances that are also eco-friendly in nature. Due to the [...] Read more.
Fungal contamination in stored food grains is a global concern and affects food economics and human and animal health. It is clear that there is a need to develop new technologies with improved performances that are also eco-friendly in nature. Due to the bioactivity of essential oils (EOs) in the vapor phase, their low toxicity for humans, and their biodegradability and antifungal properties, EOs could be a suitable solution. In this study, we explored the potential of thyme, oregano, lemongrass, clove, and cajeput EOs in the vapor phase. For 17 days, inhibitory activity was assessed against five strains of postharvest pathogens—Aspergillus spp., Fusarium s. l. spp., and Penicilliumochrochloron—isolated from cereal grains. A modified disc volatilization method was used, which is more effective in comparison to traditional screening methods. Three concentrations were tested (250, 125, and 62.5 μL/L). The two highest concentrations resulted in complete inhibition of fungal growth; however, even 62.5 μL/L showed a significant antifungal effect. The efficiency of EOs followed this order: thyme > oregano > lemongrass > clove > cajeput. From our findings, it appears that the use of EOs vapors is a better option not only for laboratory experiments, but for subsequent practice. Full article
(This article belongs to the Special Issue Antimicrobial Activity of Plant Volatiles in Vapor Phase)
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11 pages, 293 KiB  
Article
Chemical Composition and Determination of the Antibacterial Activity of Essential Oils in Liquid and Vapor Phases Extracted from Two Different Southeast Asian Herbs—Houttuynia cordata (Saururaceae) and Persicaria odorata (Polygonaceae)
by Kristýna Řebíčková, Tomáš Bajer, David Šilha, Markéta Houdková, Karel Ventura and Petra Bajerová
Molecules 2020, 25(10), 2432; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules25102432 - 22 May 2020
Cited by 21 | Viewed by 4375
Abstract
Essential oils obtained via the hydrodistillation of two Asian herbs (Houttuynia cordata and Persicaria odorata) were analyzed by gas chromatography coupled to mass spectrometry (GC–MS) and gas chromatography with flame ionization detector (GC–FID). Additionally, both the liquid and vapor phase of essential [...] Read more.
Essential oils obtained via the hydrodistillation of two Asian herbs (Houttuynia cordata and Persicaria odorata) were analyzed by gas chromatography coupled to mass spectrometry (GC–MS) and gas chromatography with flame ionization detector (GC–FID). Additionally, both the liquid and vapor phase of essential oil were tested on antimicrobial activity using the broth microdilution volatilization method. Antimicrobial activity was tested on Gram-negative and Gram-positive bacteria—Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Enterococcus faecalis, Streptococcus pyogenes, Klebsiella pneumoniae, Seratia marcescense and Bacillus subtilis. Hydrodistillation produced a yield of 0.34% (Houttuynia cordata) and 0.40% (Persicaria odorata). 41 compounds were identified in both essential oils. Essential oils contained monoterpenes and their oxidized forms, sesquiterpenes and their oxidized forms, oxidized diterpenes, derivates of phenylpropene and other groups, such as, for example, aldehydes, alcohols or fatty acids. Both essential oils were antimicrobial active in both vapor and liquid phases at least in case of one bacterium. They expressed various antimicrobial activity in the range of 128–1024 μg∙mL−1, 512–1024 μg∙mL−1 in broth and 1024 μg∙mL−1, 512–1024 μg∙mL−1 in agar, respectively. Research showed new interesting information about P. odorata and H. cordata essential oils and demonstrated that both essential oils could be possibly used in the field of natural medicine or natural food preservation. Full article
(This article belongs to the Special Issue Antimicrobial Activity of Plant Volatiles in Vapor Phase)
14 pages, 1073 KiB  
Article
Assessment of Mint, Basil, and Lavender Essential Oil Vapor-Phase in Antifungal Protection and Lemon Fruit Quality
by Renata M. Sumalan, Raufdzhon Kuganov, Diana Obistioiu, Iuliana Popescu, Isidora Radulov, Ersilia Alexa, Monica Negrea, Amonullo F. Salimzoda, Radu L. Sumalan and Ileana Cocan
Molecules 2020, 25(8), 1831; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules25081831 - 16 Apr 2020
Cited by 21 | Viewed by 3333
Abstract
There is an increasing interest in developing natural methods to replace the current chemicals used for maintaining postharvest quality of citrus fruits. The essential oil antifungal activity of mint (MEO), basil (BEO), and lavender (LEO) acting as the vapor-phases was tested against Penicillium [...] Read more.
There is an increasing interest in developing natural methods to replace the current chemicals used for maintaining postharvest quality of citrus fruits. The essential oil antifungal activity of mint (MEO), basil (BEO), and lavender (LEO) acting as the vapor-phases was tested against Penicillium digitatum. The minimum doses with fungistatic and fungicidal effect, in vitro, acting as the vapor-phases, were set up. The minimum fungicidal dose was 300 μL for BEO and 350 μL LEO, while for MEO only minimal dose with fungistatic effect was reached. The IC50 values were calculated and used (v/v) for testing preservation of lemon fruits, in close space enriched in vapor oil. For this purpose, the following two independent in vivo experiments were carried out: experiment 1, inoculated lemons with P. digitatum stored without chemical treatments 7 days, at 22 ± 2 °C, at two concentrations (C1—IC50 equivalent; C2—half of C1); and experiment 2, the non-inoculated lemons kept under the same conditions and concentrations of EO vapor served to evaluate the lemon quality properties. The results showed that antifungal protective effect was provided in the order of LEO-C1 > BEO-C1 > MEO-C1 > BEO-C2 > MEO-C2 > LEO-C2. The quality indicators like weight loss, pH, and firmness were not negatively influenced. Full article
(This article belongs to the Special Issue Antimicrobial Activity of Plant Volatiles in Vapor Phase)
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