Volatile Essential Oils Research Articles

Dopamine modulation of chemotactic behavior in response to natural aroma substances in Drosophila melanogaster larvae

BackgroundOrganisms perceive various sensory information from the outside world and use this information to initiate several actions. In particular, odors are strongly linked to emotion and often evoke different feelings and specific memories. Aromatic substances are volatile essential oils extracted from plants, each containing more than 200 types of organic compounds, and they are known as distinctive odors that interact with emotion. However, the mechanisms of how aromas cause emotion, for example, feelings of like or dislike that elicit attractive or aversive behavior, have not yet been elucidated. PurposeTo reveal the mechanisms, we studied aroma-induced behaviors using Drosophila melanogaster larvae. We focused on the involvement of dopamine in the chemotactic behavior in response to aromas. MethodsFirst, the larval chemotactic behavior was examined using 37 types of essential oils in three concentrations (100, 10−1, and 10−2dilutions). We then investigated the involvement of dopamine in chemotactic behavior since it is well known as a neuromodulator related to emotion. ResultsWe found that most of these substances elicited larval attractive behavior and identified the following essential oils as attractive odors: German chamomile, ylang-ylang, cajeput, pine, eucalyptus lemon, spikenard, ginger, cypress, pepper, clove, cinnamon cassia, citronella java, and Roman chamomile. However, some other substances induced neutral or aversive behavior, and Ho wood was determined to be an aversive odor in the screening experiment. Interestingly, the inhibition of dopamine transmission suppressed the attractive behavior in response to aromatic substances and to a larval food or yeast paste, but not to the odor of a single chemical compound. ConclusionThese results suggest that there is a distinct neural mechanism underlying the behavior that is induced by aromatic substances.

Exposure to Volatile Essential Oils of Myrtle (Myrtus communis L.) Leaves for Improving the Postharvest Storability of Fresh Loquat Fruits

Fresh loquat (Eriobotrya japonica Lindl.) fruits easily lose their marketability because of fungal spoilage, browning, and weight loss after harvest. The use of essential oils as postharvest treatment is a talented alternative to fungicides mainly because of their ability to reduce respiration and transpiration of the fresh fruits during storage. However, the postharvest studies with the volatiles of essential oils are limited. The present study was conducted to determine the effectiveness of volatile essential oils of myrtle (Myrtus communis L.) leaves for preserving the postharvest storability of loquat fruits. Test fruits of the present study were exposed to 5 different treatments, which are (i) water vapor (2 min), (ii) myrtle leaves (3% w/w), (iii) myrtle leaf vapor (2 min), (iv) myrtle leaf vapor (10 min), and (v) untreated control. A total of 30 compounds were isolated from the essential oil, and the three highest amounts of compounds were determined as eucalyptol (39.38%), α-pinene (24.98%), and linalool (8.18%). Exposure to myrtle leaves (3% w/w) and myrtle leaf vapor (2 min) was also noted to provide higher efficacy for reducing the weight loss, decay incidence, and browning index.

Pengaruh Lama EkstraksiI Terhadap Rendemen Oleoresin Kulit Mangga Kuweni (Mangifera Odorata Griff) Menggunakan Metode MAE

Mango peel is one of the by-products that is wasted when processing the fruit into certain products. One form of mango peel utilization is by extracting the oleoresin content in it. Oleoresin is a extractive substance that contains the main components of flavoring in the form of volatile (essential oil) and non-volatile (resin and gum) substances, these two main components play an important role in determining aroma and taste. The purpose of this study is to identify the best extraction treatment by MAE method of kuweni mango peel oleoresin, so that it can be an alternative form of storage for volatile compounds found in the skin of kuweni mango. This study used the microwave assisted extraction (MAE) method. Extraction was carried out using n-hexane solvent to extract the oleoresin component of the mango skin of the kuweni mango. The ratio of the amount of material with the solvent used is 1:10, with a raw material weight of 20 grams. The extracted solvent is evaporated using a rotary vacuum evaporator to produce a more concentrated result. MAE is done for 1 minute, 2 minutes, 3 minutes, 4 minutes and 5 minutes. Microwave used 50% power. The parameters measured in this study were the yield of oleoresin extracted. The results showed that the yield of oleoresin from extraction was 42,25% for 1 minute, 44,55% for 2 minutes, 44.10% for 3 minutes, 22,80% for 4 minutes, and 22.35% for 5 minutes. The conclusion of this research is that the extract of mango kuweni peel oleoresin which is produced from MAE process with n-hexane solvent produces the best yield in the 2-minute extraction time treatment which is 44.55%.

Defensive functions of volatile organic compounds and essential oils from northern white-cedar in China

BackgroundPlants are known to emit diverse volatile organic compounds (VOCs), which may function as signaling substances in plant communication with other organisms. Thuja occidentalis, which is widely cultivated throughout China, releases aromatic VOCs into the air in winter and early spring. The relationship of this cultivated plant with its neighboring plants is necessary for the conservation of biodiversity.Results(−)-α-thujone (60.34 ± 5.58%) was found to be the major component in VOCs from the Shenyang population. The essential oils (EOs) from the Kunming and Shenyang populations included the major components (−)-α-thujone, fenchone, (+)-β-thujone, and (+)-hibaene, identified using GC-MS analyses. (−)-α-thujone and (+)-hibaene were purified and identified by NMR identification. EOs and (−)-α-thujone exhibited valuable phytotoxic activities against seed germination and seedling growth of the plants Taraxacum mongolicum and Arabidopsis thaliana. Moreover, the EOs displayed potent inhibitory activity against pathogenic fungi of maize, including Fusarium graminearum, Curvularia lunata, and Bipolaris maydis, as well as one human fungal pathogen, Candida albicans. Quantitative analyses revealed high concentrations of (−)-α-thujone in the leaves of T. occidentalis individuals from both the Shenyang and Kunming populations. However, (−)-α-thujone (0.18 ± 0.17 μg/g) was only detected in the rhizosphere soil to a distance of 0.5 m from the plant.ConclusionsTaken together, our results suggest that the phytotoxic effects and antifungal activities of the EOs and (−)-α-thujone in T. occidentalis certainly increased the adaptability of this plant to the environment. Nevertheless, low concentrations of released (−)-α-thujone indicated that reasonable distance of T. occidentalis with other plant species will impair the effects of allelochemical of T. occidentalis.

Use of cashew gum combined with galactomannan for encapsulation of Rosmarinus officinalis essential oil

Encapsulating matrices are important to maintain the properties, promote the low and controlled release, and avoid these bioactive compounds' undesirable reactions. This study's objective was to evaluate cashew gum (CG) use combined with galactomannan (GAL) in the rosemary essential oil encapsulation by atomization. During the emulsification, the polysaccharides were crosslinked with sodium trimetaphosphate. The particles obtained after encapsulation were evaluated for moisture, solubility, particle size, encapsulation efficiency, morphology, antimicrobial activity, and chemical composition of the essential oil volatiles. GAL/CG blend showed higher encapsulation efficiency and lower oil release than the cashew gum matrix. Undoubtedly, galactomannan combined with cashew gum improved the microparticles' characteristics due to the galactomannan's high emulsifying property even in low concentration. Essential oil maintained its antimicrobial and chemical properties practically after the encapsulation procedure.

Formulation and Nanotechnology-Based Approaches for Solubility and Bioavailability Enhancement of Zerumbone.

About 40–70% of drug molecules in the clinical development pipeline suffer from one of either low aqueous solubility, poor absorption, or extremely low bioavailability. Approximately 75% of the world population relies on traditional therapies and therefore there has been a growing interest in the utilization of natural compounds. Zerumbone is one such natural compound, classified as a sesquiterpenoid that is extracted from the essential volatile oils of rhizomes from Zingiber zerumbet. It possesses strong antitumor, antioxidant, antimicrobial, and anti-inflammatory activity. However, despite promising preclinical studies demonstrating the therapeutic utility of zerumbone, its clinical development has been limited due to its low aqueous solubility, poor absorption, or associated low bioavailability. Multiple reviews demonstrating the pharmacological effects of zerumbone for various diseases have been published. However, to our knowledge, no review demonstrates the various formulation strategies developed to overcome the biopharmaceutical challenges of zerumbone. The purpose of this review is to provide a comprehensive perspective on zerumbone as a molecule for formulation development. A section related to pharmacokinetics, toxicity, and patents of zerumbone is included. This review provides the importance of developing novel formulations of zerumbone to overcome its biopharmaceutical challenges thereby advance its potential in the treatment of various diseases.

Fungistatic Activity of Floral Volatile Compounds of Alstonia scholaris

Aims: The fragrant flowers of Alstonia scholaris are rich in volatile compounds or essential oils, which comprise terpenes such as 1,8-cineole and linalool. The effects of the oils on the growth of Aspergillus niger were assessed for the first time in the present study.
 Study Design: Fungal growth assay.
 Place and Duration of Study: Sample: Department of Botany, St. Xavier’s College, Mumbai, between September 2006 and December 2006.
 Methodology: The volatile compounds of A. scholaris were extracted through steam distillation and hydrodistillation by using a Clevenger apparatus. The effect of the steam distillate (10% v/v) on the number of spores of A. niger was observed over 5 days. Furthermore, three fractions with distinct fragrances and boiling points were collected through hydrodistillation. The effects of each fraction on mycelial growth and sporulation in A. niger were examined. Accordingly, each hydrodistilled fraction was incorporated in growth medium (10% v/v) inoculated with fungal spores. The growth of the fungus was observed over 5 days. Distilled water was used as the control. All experiments were conducted in triplicate.
 Results: The fungal samples treated with steam distillates showed a significantly lower number of spores than the control after 5 days (165 ± 36 vs. 35 ± 7 spores/mL) at P ≤ .05. Furthermore, the fungal samples treated with the hydrodistilled fractions exhibited a delayed mycelial growth and sporulation compared with the control over 5 days. Fraction 1 was most effective in delaying mycelial growth (Day 4 vs. Day 1). Notably, on Day 4 none of the treated samples but the control sample exhibited sporulation.
 Conclusion: The volatile compounds of A. scholaris flowers clearly suppressed and delayed both mycelial growth and sporulation in A. niger but did not inhibit growth entirely. Hence, the floral volatile compounds exhibit fungistatic activity against A. niger.

Rosmarinus officinalis L. (Rosemary): An Ancient Plant with Uses in Personal Healthcare and Cosmetics

This work is a bibliographical review of rosemary (Rosmarinus officinalis) that focuses on the application of derivatives of this plant for cosmetic products, an application which has been recognized and valued since Ancient Egyptian times. Rosemary is a plant of Mediterranean origin that has been distributed throughout different areas of the world. It has many medicinal properties, and its extracts have been used (mainly orally) in folk medicine. It belongs to the Labiatae family, which contains several genera—such as Salvia, Lavandula, and Thymus—that are commonly used in cosmetics, due to their high prevalence of antioxidant molecules. Rosemary is a perennial shrub that grows in the wild or is cultivated. It has glandular hairs that emit fragrant volatile essential oils (mainly monoterpenes) in response to drought conditions in the Mediterranean climate. It also contains diterpenes such as carnosic acid and other polyphenolic molecules. Herein, the botanical and ecological characteristics of the plant are discussed, as well as the main bioactive compounds found in its volatile essential oil and in leaf extracts. Afterward, we review the applications of rosemary in cosmetics, considering its preservative power, the kinds of products in which it is used, and its toxicological safety, as well as its current uses or future applications in topical preparations, according to recent and ongoing studies.

Facile Mechanical-Induced Functionalization of Hexagonal Boron Nitride and Its Application as Vehicles for Antibacterial Essential Oil

Herein, we report a novel type of functionalized hexagonal boron nitride (h-BN) materials as vehicles for the delivery of volatile tea tree oil (TTO) to address the challenges in bacterial infection by killing germs without using antibiotics. For the sake of improving aqueous dispersity, biocompatibility, and effective utilization, h-BN was simultaneously exfoliated and functionalized via mixed ball milling with polysaccharide (carboxymethyl cellulose, CMC) and soy protein isolate (SPI). The CMC-SPI-assisted mechanical-induced method endowed the resultant good and stable aqueous dispersity. The mechanical force-induced exfoliation and noncovalent bonding between CMC and SPI incorporated into boron nitride nanosheets (BNNS) promoted the curling and peeling of BNNS surfaces and formed orderly layered nanochannels, which provided the nanoconfinement effect as vehicles for TTO retention and transportation. Such vehicles achieved a high loading capacity for TTO with a value of 359 mg g–¹ and exhibited a long-term sustained-release behavior fitting with the Korsmeyer–Peppas release kinetics model indicative of the Fick diffusion mechanism, owing to the hydrogen bond, π–π stacking, and hydrophobic interactions as well as the strong interfacial interaction between vehicles and essential oils. Furthermore, we also demonstrated the proof of concept for the antibacterial activity of TTO-loaded CMC-SPI-BNNS vehicles through larger inhibition zones and a higher minimal inhibitory concentration (MIC) value against Escherichia coli (E. coli) compared to pure TTO, indicating that CMC-SPI-BNNS protects the active ingredient and exhibits a more excellent effect. Overall, this study provides a facile method for simultaneous exfoliation and functionalization of boron nitride materials with intriguing properties that can be an effective and promising approach for the delivery of volatile essential oils for antibacterial infection.

Volatile Essential Oils Can Be Used to Improve the Efficacy of Heat Treatments Targeting the Western Drywood Termite: Evidence from Simulated Whole House Heat Treatment Trials.

Colonies of western drywood termites, Incisitermes minor (Hagen) (Blattodea: Kalotermitidae), are difficult to detect and treat due to their cryptic nature. The use of heated air to create lethal temperatures within infested wood serves as a nonchemical treatment option targeting whole structure or large portions of the structure. However, the presence of hard-to-heat areas and potential risk of damage for heat-sensitive items are recognized as important challenges. Here, we tested if a localized injection of volatile essential oil could be utilized to address the heat sink issue, potentially increasing the overall efficiency of heat treatments against drywood termites. Artificially infested wooden blocks were placed in several locations of the test building, and heat treatments were conducted. For the treatment group, a small amount of essential oil (methyl salicylate) was added in the blocks prior to the heat treatment. All blocks placed in uninsulated wall voids had 92-100% termite mortality by day 7. However, the presence of a large concrete wall in the subarea hindered heating of blocks therein, resulting 36-44% mortality by day 7 when there was no essential oil treatment. Incorporation of the essential oil substantially increased the control efficacy for the subarea, resulting in more than 90% mortality. This approach might also be helpful in reducing the risk of potential heat damage during heat treatment without compromising its control efficacy.

Effects of Sublethal Doses of Methyl Benzoate on the Life History Traits and Acetylcholinesterase (AChE) Activity of Aphis gossypii

Safer alternatives to synthetic pesticides are essential for sustainable agriculture. Methyl benzoate (MB) is a volatile essential oil found in several plants. Recent reports of the toxicity of MB to arthropod pests suggest that MB may be a useful alternative insecticide. The present study assessed the effects of a sublethal concentration of MB (LC30, 0.22%) on the life history and reproductive characteristics of the cotton aphid, Aphis gossypii Glover, in both a treated parental generation (F0) and untreated progeny (F1). MB treatment significantly decreased longevity and fecundity in both the F0 and F1 generations, and prolonged the developmental duration of each immature instar of the F1 generations, compared with controls. The intrinsic rate of increase (r), finite rate of increase (λ), and net reproductive rate (R0) of the F1 generation were significantly reduced, compared to controls. The mode of action of MB is not known, but in aphids treated with LC30 MB, the activity of the enzyme acetylcholinesterase (AChE) decreased by more than 65%, compared with untreated controls. AChE activity was rapidly inhibited within 1 h, and remained inhibited for 6 h after in vivo exposure to MB. Moreover, molecular docking analysis revealed that MB had a strong affinity with the catalytic site of AChE, with a binding energy value of −6.2 kcal/mole. Our results suggest that MB targets AChE, and that a sublethal dose of MB can have adverse transgenerational effects on cotton aphids.

Comparative Antibacterial Activity and Quality Assessment of Essential Oils from Different Producers Against Oral Pathogens

Abstract The aim of the study is to evaluate antibacterial properties of commercial essential oils (Oregano, Black pepper, Coriander, Cinnamon) against oral pathogens (Streptococcus mutans, Enterococcus faecalis). Nevertheless, we want to asses if the price of the essential oils (EO) which were purchased from 2 different retailers, can influence the quality of essential oil and the antimicrobial effect. Materials and methods: Essential oils from two different Producers (A-high price range, respectively B-low price range) with two opposite price ranges were purchased from local retailers. The inhibitory effect was assessed by disk diffusion. Bacterial inoculums of 0.5 McFarland units (~1.5 x 108 CFU/ml) were prepared from Streptococcus mutans Enterococcus faecalis. Muller-Hinton agar plates were inoculated with bacterial inoculums. Sterile paper disks with the diameter of 6 mm (Bioanalyse Ltd, Turkey) were dispensed on the medium surface. Five μl of essential oils were pipetted on corresponding disks. After 10 minutes (time needed for a proper diffusion of active components), the plates were incubated in normal atmosphere at 37°C. After 24 hours of incubation, the inhibition zone diameters (in millimeters) were read and noted in spreadsheet software, aside the average price in €/ml of essential oil. A cost-efficiency antibacterial activity index was also calculated.Results:With regard to EO from Producer A, the inhibition zone against Enteroccocus ranged from the weakest 14mm(Black pepper), 28mm(Coriander) to the strongest over 40 mm(Oregano and Cinnamon). With regard to volatile essential oils from Producer B, against the Enteroccocus, the smallest inhibition zone was observed for Coriander (10 mm), followed by Black pepper(11 mm); on the opposite side, the strongest inhibition zone presented both Oregano EO and Cinnamon EO (34 mm). Against S. mutans, the weakest inhibition zone showed Black pepper(6 mm), followed by Coriander EO(12 mm) and the strongest inhibition zone had Oregano EO(38 mm) and Cinnamon EO (40 mm). All the EO from the Producer A managed to successfully inhibit S. mutans growth. In both producers, Origanum vulgare EO was the most cost-efficient against E. faecalis (index=0.06 for Producer A and 0.03 for Producer B). In the case of Producer A, against S.mutans the best index was seen at Coriandrum sativum EO (0,05) and the weakest at Cinnamonum zeylanicum (0,14). In the case of Producer B, against E. faecalis, the lowest index was seen at Piper nigrum(0,13). The same pattern was seen against S. mutans, the highest index had Origanum vulgare(0,03) and the lowest Piper nigrum (0,23) Conclusions:Most of essential oils studied from both Producers, had better antibacterial effect against S. mutans compared to E. faecalis.All the EO from the Producer A managed to successfully inhibit S. mutans growth.The high price EO had a better antimicrobial effect compared to the low price EO.The strongest antimicrobial effect against E.faecalis had the high-price Oregano and Cinnamon EO and the weakest antimicrobial effect had low-price Coriander EO. Against S. mutans, the greatest efficacy had all high-price EO, and the lowest had the low-price Black pepper EO.The high price of some EO (Piper nigrum) does not make any difference regarding the antibacterial effect. Lower price EO may be still suitable in regards of antibacterial effect if considering the associated costs, even if the effect does not reach the potency of the higher-price alternatives.

Electrohydrodynamic encapsulation of eugenol-cyclodextrin complexes in pullulan nanofibers

In this report, the inclusion complexes of eugenol-gamma cyclodextrin (γCD) were incorporated in pullulan nanofibers using electrospinning technique. As a control sample, the pristine eugenol contained pullulan nanofibers were electrospun, as well. The nanofibrous webs were prepared with the initial eugenol content of 12% (w/w) and pullulan/eugenol-γCD nanofibers could preserve ~93% of this volatile essential oil compound due to inclusion complexation. On the other hand, only ~23% of eugenol was preserved in case of pullulan/eugenol nanofibers. The inclusion complexation also provided an enhanced thermal stability for eugenol and its volatilization shifted from ~50-190 °C to ~125–300 °C in case of pullulan/eugenol-γCD nanofibers. The antioxidant performance of eugenol was not affected by the inclusion complexation and the nanofibers of pullulan/eugenol-γCD and pullulan/eugenol indicated ~100% and ~58% radical scavenging activity for the same nanofiber concentration (250 μm/mL). Moreover, pullulan/eugenol-γCD nanofibers maintained the antioxidant activity even after 3-months storage at room temperature (~98%) and heat-treatment performed at 175 °C for 1 h (~93%). The time dependent release test indicated that pullulan/eugenol-γCD nanofibers has a release profile in a relatively controlled manner compared to pullulan/eugenol nanofibers under the same experimental conditions. Here, the functional nanofibrous web encapsulated an essential oil compound was developed using the edible pullulan and non-toxic and natural cyclodextrin molecules. Therefore, pullulan/eugenol-γCD nanofibers can be quite a promising encapsulation and carrying matrix for the essential oils which are widely used in both food and pharmaceutical areas.

Development of Clove Oil <i>In Situ</i> Gels for Buccal Mucoadhesive

Clove oil is the volatile essential oil obtained from Syzygium aromaticum. Eugenol, which is the main component, has antimicrobial, antifungal activity and antioxidant. From antiseptic activity, clove oil can be used in treatment of oral cavity infection. The aims of this research are to formulate and evaluate clove oil mucoadhesive gel for oral applications. Gel bases were prepared from Poloxamer 407 (P407). The effect of clove oil, P407 and xanthan gum on formulations were studied. Clove oil preparations were evaluated for their physicochemical properties (physical appearance, pH, viscosity, gelling capacity and gel dissolving time at 37 °C in artificial saliva). Mucoadhesive property was studied using porcine buccal mucosa. The amount of eugenol in clove oil was analyzed by gas chromatography (GC). Stability study of clove oil gel was performed under stress and room temperature conditions (1 month). The results showed that preparations containing 0% and 1% clove oil were in situ gel while those containing 3% and 5% clove oil were gel. All formulations showed good and clear physical appearance with the pH value of 5.2. The gelling capacity and gel dissolving time of more than 15 minutes in artificial saliva at 37°C was found in all preparations. They also showed mucoadhesive property. The GC results showed that the amount of eugenol in clove oil were 99.52 ± 0.51 %V/V. The preparations containing 1% clove oil showed good physical and chemical stability after storage at room temperature for 1 month. There was no significant difference in the amount of eugenol after storage (p>0.05). In conclusion, the preparations containing 20% P407 and 1% clove oil are the most appropriate formulation.

Antifungal activity of selected volatile essential oils against Penicillium sp.

Phytopathogenic fungi have been responsible for considerable economic losses in vineyards, and therefore, more attention should be paid to the development and implementation of preventative treatment that is environmentally friendly. The aim of this study was to evaluate the antifungal activity of ten essential oils (EOs) (viz. Lavandula angustifolia Mill., Carum carvi L., Pinus mugo var. pumilio, Mentha piperita L., Foeniculum vulgare L., Pinus sylvestris L., Satureja hortensis L., Origanum vulgare L., Pimpinella anisum L. and Rosmarinus officinalis L.). For the antifungal activity evaluation against Penicillium brevicompactum, P. citrinum, P. crustosum, P. expansum, P. funiculosum, P. glabrum, P. chrysogenum, P. oxalicum, P. polonicum and Talaromyces purpurogenus a disc diffusion method was used. The ten EOs exhibited different antifungal properties. Three tested EOs (Carum carvi L., Satureja hortensis L. and Pimpinella anisum L.) at concentrations of 0.75, 0.50, 0.25 and 0.125 µL/mL showed antifungal activity, inhibiting the mycelial growth. The Origanum vulgare L. EOs exhibited a lower level of inhibition. Overall, Lavandula angustifolia Mill., Pinus mugo var. pumilio, Mentha piperita L., Foeniculum vulgare L., Pinus sylvestris L., Satureja hortensis L., Pimpinella anisum L. and Rosmarinus officinalis L. were effective as fungicidal agents but their efficiency varied between the strains of fungi. Carum carvi L. showed strong antifungal activity against all tested strains at both full strength and reduced concentrations. These EOs could be considered as potential sources of antifungal compounds for treating plant fungal diseases.

Volatile emission and essential oil composition of Sambucus nigra L. organs during different developmental stages

Volatile organic compounds (VOC) and essential oils (EO) extracted from different organs of Sambucus nigra (leaves, flower buds, flowers, unripe and ripe fruits), were evaluated in this work. VOC analyses highlighted that oxygenated monoterpenes were the major class for both flowers and ripe fruits with percentages of 71.1% and 35.1%, respectively. The ripe fruit showed a considerable amount of linalyl acetate (26.3%) while cis-linalool oxide (pyranoide) (38.6%) was the main constituent of the flowers. This latter compound was also one of the major constituents of the leaf extracts (10.3% of the total identified fractions). The leaves evidenced a high percentage of esters (31.6%) with (Z)-3-hexenol acetate (15.1%) as the major constituent. Alcohols were exclusively represented by 1-hexanol (42.5%) and (E)-3-hexen-1-ol (31.1%) in the unripe fruits, while β-caryophyllene (42.0%) was the characteristic component of the buds. All the studied EOs showed non-terpene derivatives as the main class of volatiles even though its percentage varied in an organ-dependent manner. Alkanes were predominant and especially represented by heneicosane (the highest percentage of 32.9% in the fresh flowers) and nonadecane (the highest percentage of 17.2% in the buds,). Benzaldehyde was the main aldehyde in the leaves (17.8%) while acids, chiefly n-hexadecanoic acid, were also found in quite high amounts in the ripe fruits (14.3%).

Antimicrobial Activity of Essential Oils Against Plant Pathogenic Fungi: A Review

Essential oils are obtained from non-woody parts of the plants, particularly foliage, stem or hydrodistillation. They are complex mixture of terpenoids and variety of aromatic phenols, oxides, ethers, alcohols, esters, aldehydes and ketones that determine the characteristics aroma and odour of the donor plants. Presence of volatile monoterpenes or essential oils in the plants provides an important defense strategy to the plants, particularly against herbivorous insect pest and plant pathogenic fungi. Fungi cause huge amount of yield losses due to their ability to cause serious devastating diseases to the crops. Minimizing their effect on the crops need to get a promising way of controlling them. Therefore, the use of essential oils could be a good option to tackle the challenge of fungal diseases. Essential oils are natural products that are extracted from plants by different methods. They have been used for a long history of time for different purposes. Fungicides used in disease management are expensive for resource-poor farmers andnegatively correlation with ecosystems. Nowadays there is a huge interest to use them as plant protection product to be alternative for new agro-chemicals with large antimicrobial spectrum properties. As we observed from the antifungal trials in different literature, the essential oils have a great antifungal effect on many plant pathogens and inhibited most of the tested plant pathogens in the laboratory. Thus, essential oils could be a control agent for plant fungal diseases and further investigation is required to use in the field. This review summarized that the importance, antimicrobial activity and management of fungi.

Qualitative Analysis of the Phytochemical Contents of Different Anatomical Parts of Ripe Solanum aethiopicum Linneaus Fruits

Aims: To determine qualitatively the amount of alkaloids, saponin, tannin, volatile oil, phenol and flavonoids in the different anatomical parts of ripe Solanum aethiopicum Linn fruits.
 Methodology: Solanum aethiopicum Linn fruits were purchased from Sabo market, Ogbomoso, Nigeria. The fruits were separated with a razor into four (4) anatomical parts (the epicarp, mesocarp, endocarp, and seed) after washing with distilled water. 1gram of each anatomical parts of the fruit were soaked in 20mls of distilled water,1% volume per volume (v/v), 2% v/v, 3%v/v, 4%v/v and 5%v/v of ethanol, ethylacetate and methanol separately. The mixtures were left for 24 hours after which they were sieved to obtain the extracts. The presence of alkaloid, tannin, saponin, volatile oil, phenol and flavonoid were determined qualitatively in the extracts at selected concentrations.
 Results: The results obtained showed that alkaloids are more concentrated in the mesocarp of Solanum aethiopicum Linn; volatile (essential) oil is more pronounced in the mesocarp and endocarp of Solanum aethiopicum Linn; saponin is confirmed in all anatomical parts of the fruit at reasonable quality except in the seed; tannin is found to be moderately present only in the aqueous extract of mesocarp of Solanum aethiopicum Linn fruit while the presence of phenol and flavonoids were confirmed in trace amount at few tested concentrations of the extracts.
 Conclusion: Taken together, the presence of a variety of phytochemicals in the different anatomical parts of Solanum aethiopicum Linn fruit indicate that the fruit might be pharmacologically active against a number of diseases. However, this should be subjected to subsequent researches.

Spicing up gastrointestinal health with dietary essential oils

Recent complex changes in social, dietary, and behavior routines led to a significant increase in functional and immune disorders of the human gastrointestinal tract. Volatile essential oils from major food commodities such as culinary and medicinal plants (spices) hold the potential to protect the digestive system from abusive agents and immune hypersensitivity by modulating inflammation and gut microbiome. Here we identify 8 botanical interventions including fennel (Foeniculum vulgare Mill.), rosemary (Rosmarinus officinalis L.), ginger (Zingiber officinale Ros.), garlic (Allium sativum L.), peppermint (Mentha × piperita L.), bitter orange (Citrus aurantium L.), cardamom (Elettaria cardamomum (L.) Maton), and dill (Anethum graveolens L.) essential oils that prevented gastric ulcer formation, reduced production of gastric acids, or promoted upper gastrointestinal healing in preclinical or early phase human studies. These oils were further evaluated for their biochemical constituents, antibacterial, anti-inflammatory, and antioxidant activities to provide insight into potential mechanisms of action in vivo. With a few current human studies in support of these findings, there is a critical opportunity to further examine clinical effects, efficacy, and acceptability of botanical essential oils to manage upper gastrointestinal health and wellbeing.

Volatile Essential Oils Can Be Used to Improve the Efficacy of Heat Treatments Targeting the Western Drywood Termite: Evidence from a Laboratory Study.

Use of heated air to create lethal temperatures within infested wood serves as a nonchemical treatment option against western drywood termites, Incisitermes minor (Hagen). When treating a whole or large portion of the structure, however, the presence of hard-to-heat areas (structural heat sinks) and potential risk of damaging heat-sensitive items are recognized as important challenges. To address these challenges, we tested if the incorporation of a volatile essential oil would increase the overall efficacy of heat treatments against the drywood termites. To choose an essential oil for use, we tested the volatile action of several candidate compounds against individual termites using a fumigant toxicity assay. As a proof-of-concept experiment, field-collected termites were housed in small wooden arenas and subsequently subjected to 2-h heat treatment at various air temperatures within a gas chromatography oven. A simulated heat sink and essential oil treatment was also included in the experimental design. Analyses of lethal temperatures (LTemp50 and LTemp99 values), probabilities of mortality, and survivorship data over time suggested that 1) the presence of a heat sink significantly increased the minimum air temperature needed for complete kill of the termites and 2) the volatile essential oil added at the site of a heat sink effectively counteracted the impact of the heat sink. The use of volatile essential oils makes it possible to effectively kill drywood termites even in areas which might not reach lethal temperatures (~50°C), potentially improving the overall efficacy of heat treatments while reducing the risk of heat damage.