Molecules

Research

Jump to: Review

10 pages, 274 KiB

Open AccessArticle

Antimicrobial Potential of Essential Oils from Cerrado Plants against Multidrug−Resistant Foodborne Microorganisms

by Genilson Silva de Jesus, Ana Camila Micheletti, Rafael Gonçalves Padilha, Jessica de Souza de Paula, Flavio Macedo Alves, Cassia Rejane Brito Leal, Fernanda Rodrigues Garcez, Walmir Silva Garcez and Nidia Cristiane Yoshida

Molecules 2020, 25(14), 3296; https://doi.org/10.3390/molecules25143296 - 21 Jul 2020

Cited by 16 | Viewed by 3580

Abstract

Foodborne pathogens are a real public health concern in an escalating antimicrobial resistance scenario. Natural products represent a promising source of bioactive molecules, and essential oils have attracted much attention due to their myriad of biological properties, including antibacterial activities. In this context, [...] Read more.

Foodborne pathogens are a real public health concern in an escalating antimicrobial resistance scenario. Natural products represent a promising source of bioactive molecules, and essential oils have attracted much attention due to their myriad of biological properties, including antibacterial activities. In this context, essential oils obtained from the leaves of Chromolaena squalida, Campomanesia sessiliflora, Myrsine guianensis, Matayba guianensis, Siparuna guianensis, Ocotea minarum and Endlicheria paniculata—species from the Cerrado biome of Midwest Brazil—were extracted and evaluated for their antibacterial activity against a panel of four standard and three clinical multidrug−resistant bacterial strains. All tested oils showed moderate to good activity against at least four bacterial strains, including Salmonella Typhi and oxacillin−resistant Staphylococcus. The essential oils from C. squalida, C. sessiliflora, My. guianensis and Ma. guianensis showed strong inhibition of clinical Staphylococcus strains, which cause bovine mastitis and are related to milk−borne diseases. Their chemical profiles were investigated by gas chromatography coupled to mass spectrometry (GC/MS), which revealed a predominance of mono− and sesquiterpene hydrocarbons, some of which with well−known antimicrobial properties. The essential oil from Cerrado plants proved active against resistant Gram−positive and Gram−negative bacteria, revealing their potentialities for the development of new alternative agents to prevent the spreading of resistant bacterial contamination. Full article

(This article belongs to the Special Issue Essential Oils in Weed Control and Food Preservation)

► Show Figures

Graphical abstract

31 pages, 5177 KiB

Open AccessArticle

Herbicidal Activity of Thymbra capitata (L.) Cav. Essential Oil

by Mercedes Verdeguer, Natalia Torres-Pagan, Marta Muñoz, Amira Jouini, Susana García-Plasencia, Pablo Chinchilla, Mónica Berbegal, Adele Salamone, Santo Agnello, Alessandra Carrubba, Luz Cabeiras-Freijanes, Lois Regueira-Marcos, Adela M. Sánchez-Moreiras and María Amparo Blázquez

Molecules 2020, 25(12), 2832; https://doi.org/10.3390/molecules25122832 - 19 Jun 2020

Cited by 18 | Viewed by 3841

Abstract

The bioherbicidal potential of Thymbra capitata (L.) Cav. essential oil (EO) and its main compound carvacrol was investigated. In in vitro assays, the EO blocked the germination and seedling growth of Erigeron canadensis L., Sonchus oleraceus (L.) L., and Chenopodium album L. at [...] Read more.

The bioherbicidal potential of Thymbra capitata (L.) Cav. essential oil (EO) and its main compound carvacrol was investigated. In in vitro assays, the EO blocked the germination and seedling growth of Erigeron canadensis L., Sonchus oleraceus (L.) L., and Chenopodium album L. at 0.125 µL/mL, of Setaria verticillata (L.) P.Beauv., Avena fatua L., and Solanum nigrum L. at 0.5 µL/mL, of Amaranthus retroflexus L. at 1 µL/mL and of Portulaca oleracea L., and Echinochloa crus-galli (L.) P.Beauv. at 2 µL/mL. Under greenhouse conditions, T. capitata EO was tested towards the emergent weeds from a soil seedbank in pre and post emergence, showing strong herbicidal potential in both assays at 4 µL/mL. In addition, T. capitata EO, applied by spraying, was tested against P. oleracea, A. fatua and E. crus-galli. The species showed different sensibility to the EO, being E. crus-galli the most resistant. Experiments were performed against A. fatua testing T. capitata EO and carvacrol applied by spraying or by irrigation. It was verified that the EO was more active at the same doses in monocotyledons applied by irrigation and in dicotyledons applied by spraying. Carvacrol effects on Arabidopsis root morphology were also studied. Full article

(This article belongs to the Special Issue Essential Oils in Weed Control and Food Preservation)

► Show Figures

Graphical abstract

12 pages, 1854 KiB

Open AccessArticle

Drying Induced Impact on Composition and Oil Quality of Rosemary Herb, Rosmarinus Officinalis Linn

by Hamdoon A. Mohammed, Mohsen S. Al-Omar, Salman A. A. Mohammed, Mohamed S. A. Aly, Abdulmalik N. A. Alsuqub and Riaz A. Khan

Molecules 2020, 25(12), 2830; https://doi.org/10.3390/molecules25122830 - 19 Jun 2020

Cited by 31 | Viewed by 3256

Abstract

The natural drying of Rosmarinus officinalis Linn. herbs severely affects its volatile oil quality and yields, which is reported here for the first time. The oils obtained through hydrodistillation from fresh, one, two, and three-weeks dried herbs were analyzed by gas chromatography–mass spectroscopy [...] Read more.

The natural drying of Rosmarinus officinalis Linn. herbs severely affects its volatile oil quality and yields, which is reported here for the first time. The oils obtained through hydrodistillation from fresh, one, two, and three-weeks dried herbs were analyzed by gas chromatography–mass spectroscopy (GC–MS) and gas chromatography–flame ionization detector (GC-FID), and the yields were 198 ± 3.45, 168.7 ± 5.11, and 97.8 ± 1.27 mg, respectively, as compared to the internal referral standard of 327 ± 5.91 mg yield of the one-week dried herbs’ oil. Camphor, the major constituent, significantly depleted from 20.96% to 13.84%, while bornyl acetate yields increased from 1.42% to 12.46% (p values < 0.0001) in three-weeks drying, reflecting the redox processes undergoing within the oil during drying. Several constituents (25) were found in one-week dried herbs’ oil as compared to the fresh, two-, and three-weeks oils, which consisted of 23, 19, and 14 constituents, respectively, leading to the recommendation of the one-week drying of the herb for maximum oil yield. The DPPH (2, 2-diphenyl-1-picryl-hydrazyl) reactivity was highest for the two- and three-weeks dried herb-based oils, followed by the one-week dried- and fresh-herb-based oils (p < 0.0001), again indicating major chemical changes during herbs’ dryings, affecting the free-radical scavenging capacity of these batches of oils obtained after different drying times. Full article

(This article belongs to the Special Issue Essential Oils in Weed Control and Food Preservation)

► Show Figures

Graphical abstract

22 pages, 1671 KiB

Open AccessArticle

Control of Erigeron bonariensis with Thymbra capitata, Mentha piperita, Eucalyptus camaldulensis, and Santolina chamaecyparissus Essential Oils

by Mercedes Verdeguer, Luis Guillermo Castañeda, Natalia Torres-Pagan, Juan Antonio Llorens-Molina and Alessandra Carrubba

Molecules 2020, 25(3), 562; https://doi.org/10.3390/molecules25030562 - 28 Jan 2020

Cited by 20 | Viewed by 3565

Abstract

In the search of sustainable and environmentally friendly methods for weed control, there is increasing interest in essential oils (EOs) as an approach to reduce synthetic herbicide use. The phytotoxicity of Thymbra capitata, Mentha piperita, Eucalyptus camaldulensis, and Santolina chamaecyparissus EOs [...] Read more.

In the search of sustainable and environmentally friendly methods for weed control, there is increasing interest in essential oils (EOs) as an approach to reduce synthetic herbicide use. The phytotoxicity of Thymbra capitata, Mentha piperita, Eucalyptus camaldulensis, and Santolina chamaecyparissus EOs against the noxious weed Erigeron bonariensis were evaluated in pre- and post-emergence assays in greenhouse conditions. The EOs were applied at 2, 4, and 8 µL/mL, with Fitoil used as emulsifier. In post-emergence, two ways of application were tested, irrigation and spraying. Several germination parameters (germination %, mean germination time, and synchrony of the germination process) were evaluated in pre-emergence tests, and the phytotoxicity level was assessed in post-emergence. In pre-emergence, all EOs significantly reduced seed germination as compared to the controls, ranking: T. capitata > E. camaldulensis > S. chamaecyparissus > M. piperita. The effectiveness of all EOs varied with the tested dose, always following the rank 2 μL < 4 μL < 8 μL, with T. capitata EO showing full effectiveness even at the lowest dose. In post-emergence, T. capitata was the most effective EO, inducing a rather complete inhibition of plantlet growth at the highest two doses. These EOs demonstrated to have good potential for the formulation of natural herbicides. Full article

(This article belongs to the Special Issue Essential Oils in Weed Control and Food Preservation)

► Show Figures

Graphical abstract

15 pages, 1435 KiB

Open AccessArticle

Cytisus scoparius and Ulex europaeus Produce Volatile Organic Compounds with Powerful Synergistic Herbicidal Effects

by María Pardo-Muras, Carolina G. Puig and Nuria Pedrol

Molecules 2019, 24(24), 4539; https://doi.org/10.3390/molecules24244539 - 11 Dec 2019

Cited by 19 | Viewed by 3578

Abstract

New herbicides based on natural products are claimed to address weed resistance and environmental concerns related to synthetic herbicides. In our previous studies, certain volatile organic compounds (VOCs) produced by Ulex europaeus and Cytisus scoparius were argued to be responsible for the phytotoxicity [...] Read more.

New herbicides based on natural products are claimed to address weed resistance and environmental concerns related to synthetic herbicides. In our previous studies, certain volatile organic compounds (VOCs) produced by Ulex europaeus and Cytisus scoparius were argued to be responsible for the phytotoxicity of both shrub species. Interactions among VOCs were hypothesized to explain the inconsistency between the effects of the identified pure compounds and those naturally emitted from fresh plant material. In this work, eugenol, verbenone, terpinen-4-ol, α-terpineol, and linalool were assayed as binary mixtures of Amaranthus retroflexus and Digitaria sanguinalis. Powerful synergistic inhibitory effects were revealed for germination and early growth. Only 3.1 ppm of verbenone was enough to inhibit A. retroflexus germination when paired to other VOCs. Eugenol was capable of exacerbating the effects of terpinen-4-ol on A. retroflexus, even though it was innocuous when acting alone at 12.5 ppm. The verbenone and linalool pair produced very significant synergistic effects in terms of D. sanguinalis germination. The synergistic effects were predominantly irreversible for D. sanguinalis, since seeds exposed to paired VOCs were unable to recover their germination capacity after removing the phytotoxins or produced damaged seedlings. Both shrub species have been revealed as sources of natural herbicide molecules, with promising synergistic modes of action that deserve to be studied in depth. Full article

(This article belongs to the Special Issue Essential Oils in Weed Control and Food Preservation)

► Show Figures

Graphical abstract

15 pages, 1035 KiB

Open AccessArticle

Menthol Increases Bendiocarb Efficacy Through Activation of Octopamine Receptors and Protein Kinase A

by Milena Jankowska, Justyna Wiśniewska, Łukasz Fałtynowicz, Bruno Lapied and Maria Stankiewicz

Molecules 2019, 24(20), 3775; https://doi.org/10.3390/molecules24203775 - 20 Oct 2019

Cited by 13 | Viewed by 3437

Abstract

Great effort is put into seeking a new and effective strategies to control insect pests. One of them is to combine natural products with chemical insecticides to increase their effectiveness. In the study presented, menthol which is an essential oil component was evaluated [...] Read more.

Great effort is put into seeking a new and effective strategies to control insect pests. One of them is to combine natural products with chemical insecticides to increase their effectiveness. In the study presented, menthol which is an essential oil component was evaluated on its ability to increase the efficiency of bendiocarb, carbamate insecticide. A multi-approach study was conducted using biochemical method (to measure acetylcholinesterase enzyme activity), electrophysiological technique (microelectrode recordings in DUM neurons in situ), and confocal microscopy (for calcium imaging). In the electrophysiological experiments, menthol caused hyperpolarization, which was blocked by an octopamine receptor antagonist (phentolamine) and an inhibitor of protein kinase A (H-89). It also raised the intracellular calcium level. The effect of bendiocarb was potentiated by menthol and this phenomenon was abolished by phentolamine and H-89 but not by protein kinase C inhibitor (bisindolylmaleimide IX). The results indicate that menthol increases carbamate insecticide efficiency by acting on octopamine receptors and triggering protein kinase A phosphorylation pathway. Full article

(This article belongs to the Special Issue Essential Oils in Weed Control and Food Preservation)

► Show Figures

Graphical abstract

15 pages, 1021 KiB

Open AccessArticle

Phytotoxic Effects of Commercial Eucalyptus citriodora, Lavandula angustifolia, and Pinus sylvestris Essential Oils on Weeds, Crops, and Invasive Species

by María Dolores Ibáñez and María Amparo Blázquez

Molecules 2019, 24(15), 2847; https://doi.org/10.3390/molecules24152847 - 05 Aug 2019

Cited by 28 | Viewed by 5242

Abstract

Background: essential oils are well known for their pharmacological effectiveness as well as their repellent, insecticide, and herbicide activities. The emergence of resistant weeds, due to the overuse of synthetic herbicides, makes it necessary to find natural alternatives for weed control. The aim [...] Read more.

Background: essential oils are well known for their pharmacological effectiveness as well as their repellent, insecticide, and herbicide activities. The emergence of resistant weeds, due to the overuse of synthetic herbicides, makes it necessary to find natural alternatives for weed control. The aim of this study was to evaluate the phytotoxic effects of Eucalyptus citriodora, Lavandula angustifolia, and Pinus sylvestris, three common commercial essential oils, on weeds (Portulaca oleracea, Lolium multiflorum, and Echinochloa crus-galli), food crops (tomato and cucumber), and the invasive species Nicotiana glauca. Methods: to determine herbicidal effects, essential oils were tested at different concentrations (0.125–1 µL/mL). The index of germination and seedling length data were recorded over 14 days. Results: the in vitro assays showed that L. angustifolia with linalool (38.7 ± 0.1%), 1,8-cineole (26.5 ± 0.1%), and camphor (14.2 ± 0.1%) as the main compounds showed the most phytotoxic effects affecting seed germination in weeds and tomato, and the aforementioned invasive species. L. multiflorum was the most sensitive weed, particularly to lavender essential oil, which decreased the growth of its hypocotyl and radicle by 87.8% and 76.7%, respectively, at a dose of 1 µL/mL. Cucumber was the most resistant food crop, with no significant reduction observed in seed germination and hypocotyl growth with E. citriodora and L. angustifolia essential oils. Conclusions: lavender essential oil represents a promising candidate for the development of effective and safe herbicides in the management of L. multiflorum affecting cucumber crops. Full article

(This article belongs to the Special Issue Essential Oils in Weed Control and Food Preservation)

► Show Figures

Graphical abstract

14 pages, 2773 KiB

Open AccessArticle

Evaluation of Biological Response of Lettuce (Lactuca sativa L.) and Weeds to Safranal Allelochemical of Saffron (Crocus sativus) by Using Static Exposure Method

by Hossein Mardani, John Maninang, Kwame Sarpong Appiah, Yosei Oikawa, Majid Azizi and Yoshiharu Fujii

Molecules 2019, 24(9), 1788; https://doi.org/10.3390/molecules24091788 - 08 May 2019

Cited by 16 | Viewed by 4811

Abstract

Safranal, the main volatile chemical of Saffron (Crocus sativus) was studied to estimate its allelopathic effects on the photosynthetic pigment chlorophyll, leaf electrolyte leakage, fresh weight, catalase (CAT), and peroxidase (POX) activity of the test plant Lettuce (Lactuca sativa). [...] Read more.

Safranal, the main volatile chemical of Saffron (Crocus sativus) was studied to estimate its allelopathic effects on the photosynthetic pigment chlorophyll, leaf electrolyte leakage, fresh weight, catalase (CAT), and peroxidase (POX) activity of the test plant Lettuce (Lactuca sativa). In this study, the effective concentration (EC₅₀) of safranal on CAT was estimated to be 6.12 µg/cm³. CAT activity was inhibited in a dose-dependent manner by the increase in the safranal concentration while POX activity was increased. Moreover, Safranal caused significant physiological changes in chlorophyll content, leaf electrolyte leakage, and fresh weight of several weed species with Lolium multiflorum being the most sensitive. Furthermore, 5 µM Safranal showed significant inhibitory activity against dicotyledonous in comparison to the monocotyledons under greenhouse conditions. The inhibition of the CAT by safranal was similar to those of uncompetitive inhibitors, and therefore the decline in carbon fixation by plants might be the mechanism behind the inhibitory activity of safranal. Full article

(This article belongs to the Special Issue Essential Oils in Weed Control and Food Preservation)

► Show Figures

Graphical abstract

Review

Jump to: Research

20 pages, 553 KiB

Open AccessFeature PaperReview

Encapsulated Limonene: A Pleasant Lemon-Like Aroma with Promising Application in the Agri-Food Industry. A Review

by María Dolores Ibáñez, Noelia M. Sanchez-Ballester and María Amparo Blázquez

Molecules 2020, 25(11), 2598; https://doi.org/10.3390/molecules25112598 - 03 Jun 2020

Cited by 60 | Viewed by 7568

Abstract

Limonene, mainly found as a major component in Citrus spp., has been proven to possess a valuable potential as sustainable replacement to synthetic pesticides and food preservatives. This review intends to give a clear overview of the principal emerging applications of limonene in [...] Read more.

Limonene, mainly found as a major component in Citrus spp., has been proven to possess a valuable potential as sustainable replacement to synthetic pesticides and food preservatives. This review intends to give a clear overview of the principal emerging applications of limonene in the agri-food industry as antimicrobial, herbicidal and antioxidant agent. To successfully use limonene in a greener agri-food industry, its preservation had become a top concern for manufacturers. In order to elucidate the most efficient and sustainable manner to encapsulate limonene, the different techniques and materials tested up to the present are also reviewed. In general, encapsulation conserves and protects limonene from outside aggressions, but also allows its controlled release as well as enhances its low water solubility, which can be critical for the discussed applications. Other parameters such as scalability, low cost and availability of equipment will need to be taken into account. Further efforts would likely be oriented to the elucidation of encapsulating sustainable systems obtained by cost-efficient elaboration processes, which can deliver effective concentrations of limonene without affecting crops and food products. Full article

(This article belongs to the Special Issue Essential Oils in Weed Control and Food Preservation)

► Show Figures

Graphical abstract

33 pages, 640 KiB

Open AccessReview

Agrobiological Interactions of Essential Oils of Two Menthol Mints: Mentha piperita and Mentha arvensis

by Danuta Kalemba and Agnieszka Synowiec

Molecules 2020, 25(1), 59; https://doi.org/10.3390/molecules25010059 - 23 Dec 2019

Cited by 36 | Viewed by 10399

Abstract

This review article discusses the active constituents and potential of two menthol mint oils, Mentha piperita (MPEO) and Mentha arvensis (MAEO), as natural sources for botanical pesticides. The biological activities of these menthol mint oils, which can be useful in agriculture, have been [...] Read more.

This review article discusses the active constituents and potential of two menthol mint oils, Mentha piperita (MPEO) and Mentha arvensis (MAEO), as natural sources for botanical pesticides. The biological activities of these menthol mint oils, which can be useful in agriculture, have been broadly researched, especially toward phytotoxic microorganisms. To a lesser extent, the insecticidal and herbicidal activities of mint EOs have also been studied. It is apparent that the prospect of using menthol mint oils in agriculture is increasing in popularity. A number of investigations showed that the in vitro efficacy of MPEO and MAEO, as well as that of their main constituent, menthol, is pronounced. The results of in vitro research are useful for choosing EOs for further investigations. However, it is clear that in situ experiments are crucial and should be more extensively developed. At the same time, known techniques are to be applied to this area and new methods should be worked out, aiming at the improvement of EOs’ pesticidal efficacy and cost-effectiveness, for future implementation in agricultural pest control. Full article

(This article belongs to the Special Issue Essential Oils in Weed Control and Food Preservation)

► Show Figures

Figure 1

15 pages, 1066 KiB

Open AccessReview

Encapsulation of Essential Oils for the Development of Biosourced Pesticides with Controlled Release: A Review

by Chloë Maes, Sandrine Bouquillon and Marie-Laure Fauconnier

Molecules 2019, 24(14), 2539; https://doi.org/10.3390/molecules24142539 - 11 Jul 2019

Cited by 127 | Viewed by 9947

Abstract

Essential oil (EO) encapsulation can be carried out via a multitude of techniques, depending on applications. Because of EOs’ biological activities, the development of biosourced pesticides with EO encapsulation is of great interest. A lot of methods have been developed; they are presented [...] Read more.

Essential oil (EO) encapsulation can be carried out via a multitude of techniques, depending on applications. Because of EOs’ biological activities, the development of biosourced pesticides with EO encapsulation is of great interest. A lot of methods have been developed; they are presented in this review, together with the properties of the final products. Encapsulation conserves and protects EOs from outside aggression, but also allows for controlled release, which is useful for applications in agronomy. The focus is on the matrices that are of interest for the controlled release of their content, namely: alginate, chitosan, and cyclodextrin. Those three matrices are used with several methods in order to create EO encapsulation with different structures, capacities, and release profiles. Full article

(This article belongs to the Special Issue Essential Oils in Weed Control and Food Preservation)

► Show Figures

Figure 1

Journal Menu

Journal Browser

Essential Oils in Weed Control and Food Preservation

Share This Special Issue

Special Issue Editor

Special Issue Information

Keywords

Published Papers (11 papers)

Research

Review

Further Information

Guidelines

MDPI Initiatives

Follow MDPI