Constituents Of Essential Oil Research Articles

Comparative study of volatile oil constituents, anti-microbial properties, and antibiofilm activities in Eucalyptus camaldulensis and Eucalyptus globulus: insights from central Saudi Arabia

Eucalyptus is a fragrant plant with a highly volatile oil content grown worldwide. This study investigated the phytochemical and biological features of two Eucalyptus species, E. camaldulensis and E. globulus, cultivated in Central Saudi Arabia. Phytochemical analysis revealed 17 compounds in E. camaldulensis and 13 in E. globulus, with α-pinene and 1,8-cineole being both plants’ most abundant volatile components. The antimicrobial activity revealed that Salmonella typhimurium ATCC 13311 and Candida albicans ATCC 10231 are the most susceptible to E. camaldulensis, with the zone of inhibition diameters (ZIDs) of 17.0 ± 0.2 mm and 22.0 ± 0.3 mm, respectively. In contrast, for E. globulus, methicillin-resistant Staphylococcus aureus and Candida albicans ATCC 10231 were the most susceptible, with ZIDs of 13.0 ± 0.2 mm and 20.0 ± 0.2 mm, respectively. E. camaldulensis had minimum inhibitory concentration (MIC) range from 1.56 to 12.5 μL/mL, minimum biocidal concentration (MBC) range from 3.125 to 25.0 μL/mL, minimum biofilm inhibitory concentration (MBIC) range from 3.125 to 25.0 μL/mL, and minimum biofilm eradication concentration (MBEC) from 6.25 to 50.0 μL/mL, while E. globulus had MIC range from 3.125 to 12.5 μL/mL, MBC range from 6.25 to 25.0 μL/mL, MBIC range from 6.25 to 25.0 μL/mL, and MBEC range from 12.5 to 50.0 μL/mL, for the tested organisms. E. camaldulensis demonstrated better antimicrobial activity than E. globulus against the tested organisms, making it a promising antimicrobial drug candidate. Further research is required to determine its effectiveness in treating different human infections.

Antimicrobial effects of catnip (Nepeta cataria L.) essential oil against canine skin infection pathogens

Background and Aim: Catnip essential oils have antimicrobial effects against bacteria, yeast, and fungi; however, there is limited information regarding their antimicrobial activity against pathogens that cause canine skin infections. This study aimed to identify the phytochemical constituents of catnip essential oil and assay its antimicrobial activity against Staphylococcus pseudintermedius, Malassezia pachydermatis, Microsporum canis, Microsporum gypseum, Microsporum gallinae, and Trichophyton mentagrophytes. Materials and Methods: Catnip essential oil was extracted by hydrodistillation, and its chemical constituents were analyzed by gas chromatography–mass spectrometry (GC–MS). In vitro antimicrobial activity was investigated using broth microdilution and time-kill tests. To evaluate the effect of catnip essential oil on microbial morphology and cell membrane integrity, scanning electron microscopy (SEM) and leakage studies were conducted. Results: GC–MS analysis revealed that the principal components of catnip essential oil were cis- and trans-nepetalactone (57.09% of peak area), trans-, cis-nepetalactone (39.69% of peak area), trans-caryophyllene (1.88% of peak area), and caryophyllene oxide (1.34% of peak area). The minimum inhibitory concentration, minimum bactericidal concentration, and minimum fungicidal concentration values determined by broth microdilution ranged from 0.0625 mg/mL to 4.0 mg/ mL. Time-kill testing showed that the germicidal effects of catnip essential oil were time and concentration-dependent, respectively. Environmental SEM and cell leakage analysis indicated that catnip essential oil disrupted the integrity of cell membranes in the tested microorganisms. Conclusion: Catnip essential oil has potential as an alternative antimicrobial against a wide range of canine skin infection pathogens, including S. pseudintermedius, M. pachydermatis, Mi. canis, Mi. gypseum, Mi. gallinae, and T. mentagrophytes. Keywords: antimicrobial activity, canine dermatitis, catnip, Nepeta cataria.

Chemical Constituents of Essential Oil from Garcinia gaudichaudii and Its Antimicrobial Activity

Chemical Constituents of Essential Oil from Garcinia gaudichaudii and Its Antimicrobial Activity

N-Containing Constituents of Essential Oil from Megacarpaea gigantea and its Antimicrobial Activity

N-Containing Constituents of Essential Oil from Megacarpaea gigantea and its Antimicrobial Activity

Wound healing effect of nutmeg (Myristica fragrans) cream on second-degree burn in animal model.

Second-degree burn, the most common among burn degrees, underscores the importance of timely and proper treatment in influencing prognosis. Nutmeg (Myristica fragrans), renowned for its potent antibacterial and antifungal properties, also serves as an effective antiseptic for open wounds. The aim of this study was to identify the phytochemical constituents of nutmeg essential oil and analyze the wound healing effect of nutmeg cream on second-degree burns in an animal model. An experimental study with a completed randomized design was conducted on Rattus norvegicus strain Wistar rats with second-degree burn. This study had four groups and each group consisting of four rats: B (burn-treated base cream), B+N (burn-treated 3% nutmeg cream), B+SSD (burn-treated silver sulfadiazine (BSS)), and B+N+SSD (burn-treated 3% nutmeg cream and SSD in a 1:1 ratio). The phytochemical analysis of nutmeg essential oil was conducted by gas chromatography and mass spectroscopy (GC-MS). The burn diameter and burn wound healing percentage were measured from day 0 to 18. One-way ANOVA followed by post hoc analysis using the least significant difference (LSD) was employed to analysis the effect. The phytochemical analysis of nutmeg essential oil found that myristicin, terpinene-4-ol, terpinene, safrole and terpinolene were the most abundant putative compounds in nutmeg essential oil. On day 0, the average burn wound diameters were 1.4 cm in all groups and increases were observed in all groups on day 3. The wound diameter decreased until day 18 with the smallest burn wound diameter was found in the B+N group (0.86±0.37 cm), followed by B+SSD (0.93±0.29 cm). The B+SSD group exhibited the highest percentage of burn wound healing (56.80±14.05%), which was significantly different from the base cream (p<0.05). The percentage of burn wound healing in rats given 3% nutmeg cream was 41.88±13.81%, suggesting that nutmeg cream could promote burn wound healing in rats induced by second-degree burns.

Adulticidal synergy of two plant essential oils and their major constituents against the housefly Musca domestica and bioassay on non-target species

Single and mixture formulations of lemongrass (Cymbopogon citratus (DC.) Stapf.) and star anise (Illicium verum (J. Presl.)) essential oils (EOs) and their major constituents were assayed for their adulticidal activities against housefly, Musca domestica L., and two non-target species, stingless bee (Tetragonula pegdeni Schwarz) and guppy (Poecilia reticulata Peters). The efficacies of the mixture formulations were compared against those of the single formulations and 1.0% α-cypermethrin, a common synthetic insecticide. GC-MS analysis found that the major constituent of lemongrass EO was geranial (45.23%), and that of star anise EO was trans-anethole (93.23%). Almost all mixture formulations were more effective in adulticidal activity against housefly adults than single formulations and 1.0% α-cypermethrin. A mixture of 1.0% lemongrass EO + 1.0% trans-anethole exhibited the strongest synergistic insecticidal activity with a 100% mortality rate (KT50 of 3.2 min and LT50 of 0.07 h). The relative percentage increase in mortality rate over single formulations was between 1.6 and 91.9%. In addition, it was three times more effective than 1.0% α-cypermethrin. To find the mechanism of adulticidal action, scanning electron microscopy (SEM) was done to find morphological aberrations, such as antennal and mouthpart aberrations, after the houseflies were treated with 1.0% lemongrass EO + 1.0% trans-anethole. The aberrations included deformed and abnormal shape of arista and flagellum, change in labellum pigmentation, and damage to pseudotracheae. Regarding toxicity against non-target species, all single and mixture formulations were not toxic to the two non-target species, while 1.0% α-cypermethrin was highly toxic. To conclude, a mixture of 1.0% lemongrass EO + 1.0% trans-anethole can be an excellent, natural, sustainable housefly adulticidal agent.

Exploring the Potential of Essential Oil from Plectranthus amboinicus Leaves against Breast Cancer: In vitro and In silico Analysis.

Plectranthus amboinicus leaves were subjected to hydrodistillation to obtain essential oil (EO). Phytochemical analysis using gas chromatography-mass spectrometry revealed a diverse range of compounds in the EO, with p-cymen-4-ol (18.57%) emerging as the most predominant, followed by isocaryophyllene (12.18%). The in vitro antiproliferative activity of EO against breast cancer was assessed in MCF-7 and MDA-MB-231 cell lines. The MTT assay results revealed that EO showed IC50 values of 42.25μg/mL and 13.44μg/mL in MCF-7 cells and 63.67μg/mL and 26.58μg/mL in MDA-MB-231 cells after 24 and 48h, respectively. The in silico physicochemical and pharmacokinetic profiles of the EO constituents were within acceptable limits. Molecular docking was conducted to investigate the interactions between the constituents of the EO and protein Aromatase (PDB ID:3S79). Among the EO constituents, 4-tert-butyl-2-(5-tert-butyl-2-hydroxyphenyl)phenol (4BHP) exhibited the highest dock score of -6.580kcal/mol when compared to the reference drug, Letrozole (-5.694kcal/mol), but was slightly lesser than Anastrozole (-7.08kcal/mol). Molecular dynamics simulation studies (100 ns) of the 4BHP complex were performed to study its stability patterns. The RMSD and RMSF values of the 4BHP protein complex were found to be 2.03 Å and 4.46 Å, respectively. The binding free energy calculations revealed that 4BHP displayed the highest negative binding energy of -43kcal/mol with aromatase protein, compared to Anastrozole (-40.59kcal/mol) and Letrozole (-44.54kcal/mol). However, further research is required to determine the safety, efficacy, and mechanism of action of the volatile oil. Taking into consideration the key findings of the present work, the development of a formulation of essential oil remains a challenging task and novel drug delivery systems may lead to site-specific and targeted delivery for the effective treatment of breast cancer.

Phytochemistry and antimicrobial activity of the essential oil of Ferula latisecta Rech. f. & Aellen. oleo-gum resin

Ferula latisecta belongs to the Ferula genus and is endemic to Iran. The present study aims to extract the essential oil of F. latisecta oleo-gum-resin for the first time and evaluate its phytochemistry and antimicrobial activity. The essential oil was extracted using a Clevenger-type hydrodistillation apparatus. The essential oil constituents were identified and quantified using GC and GC/MS methods. The antimicrobial activity of the essential oil was assayed against two Gram-negative bacteria, Acinetobacter baumannii and Pseudomonas aeruginosa, a Gram-positive bacterium, Staphylococcus aureus, and a fungal strain, Candida krusei using the broth microdilution method to determine MIC and MBC values. The results showed that the essential oil was rich in β- and α-pinene with 30.72% and 25.07% content, respectively. Additionally, the essential oil contained a significant amount of sulfur-containing compounds (7.49%) such as (E)-sec-butyl propenyl disulfide (4.21%), (Z)-sec-butyl propenyl disulfide (2.34%), and hexamethylene sulfide (0.94%). According to the results, the essential oil exhibited high inhibitory activity against C. krusei fungi, with MIC and MBC values of 2 μg/mL, which were more potent than amphotericin B (MIC: 8 and MBC: 32 μg/mL), as a standard antifungal agent. Additionally, the essential oil showed significant antibacterial activity against A. baumannii, with MIC and MBC values of 32 μg/mL, which were more potent than cefixime. Furthermore, the essential oil exhibited moderate activity against S. aureus with MIC and MBC values of 16 μg/mL. This study introduces a new oleo-gum resin from F. latisecta, with a high content of terpenoids and strong antimicrobial potency.

Valorization of Citrus peels: GC/MS-based metabolites profiling, multivariate analysis, and antiaging potential.

Aging and agro-waste are major challenges. Natural ingredients are preferred in skincare. This study intended to isolate the essential oils (EO) from the leftover peels obtained from three commonly edible Citrus species fruit peels, namely Citrus paradisi (grapefruit), Citrus sinensis (sweet orange), and Citrus deliciosa (mandarin). Gas chromatography/mass spectrometry analysis identified volatile constituents in EO and headspace aroma. Multivariate analysis distinguished between the three species. The antiaging effects of Citrus EO were assessed in vitro and in silico, studying volatile interactions with target enzymes. C. sinensis peels had the highest oil yield, rich in monoterpenes. C. paradisi and C. deliciosa contained sesquiterpenes. Limonene dominated the hydrodistilled EO: 94.50% in C. paradisi, 96.80% in C. sinensis, and 80.66% in C. deliciosa. Unsupervised multivariate analysis of Citrus species revealed that d-limonene, γ-terpinene, and β-pinene are the key phytochemical markers contributing to their diverse chemical composition. C. paradisi exhibited the highest enzyme inhibitory activity, with IC50 values of 12.82, 27.58, and 18.16 µg/mL for tyrosinase, elastase, and collagenase, respectively. In silico studies showed that the volatiles can inhibit the tested antiaging enzymes. According to these findings, the investigated agro-waste might slow aging in skin care.

Essential oils of Lauraceae: antimicrobial activity and constituents of essential oil from two Machilus species from Vietnam

The chemical constituents and antimicrobial activity of the essential oils isolated from the leaves of Machilus cicatricosa S.K. Lee and Machilus bonii Lecomte from Vietnam were studied and reported. The techniques of gas chromatography (GC) and gas chromatography coupled with mass spectrometry (GC-MS) were used to characterize the chemical constituents of the essential oil while the microdilution assay was used to evaluate the antimicrobial activity. The main constituents of the leaf oil of M. cicatricosa were α-pinene (20.6%), bicyclogermacrene (15.2%), linalool (14.9%), and β-pinene (8.4%). On the other hand (E)-β-ocimene (26.3%), bicyclogermacrene (23.6%) and (E)-nerolidol (9.1%) were the major constituents of M. bonii leaf essential oil. The studied essential oils displayed antimicrobial activity against Enterococcus faecalis ATCC 29212, and Staphylococcus aureus ATCC 25923, with minimum inhibitory concentration (MIC) value of 64.0 μg/mL. In addition, essential oil from the leaf of M. bonii was the most active towards Bacillus cereus ATCC14579 with MIC value of 64.0 μg/mL, while M. cicatricosa showed stronger anti-candidal activity against Candida albicans ATCC 10231 with MIC value of 32.0 μg/mL. This is the first report on the chemical constituents and antimicrobial activity of the essential oils of M. cicatricosa and M. bonii.

Spatial variation in constituents of essential oils from fruit pericarp of Zanthoxylum armatum DC of Nepali origin and their antibacterial activity

The fruit pericarp of Zanthoxylum armatum DC is used in spices and to manage different diseases like toothaches, inflamed gums, arthritis, swollen joints, insect bites, diarrhea, common flu, and respiratory difficulties by local people. In this study, the essential oil was extracted from the fruit pericarp of Z. armatum DC collected from different commercial sites in Nepal using the hydro-distillation method. The chiral gas chromatography-mass spectrometry (GC/MS) was used to identify the chemical compounds present in the essential oil with their stereochemistry. Major constituents identified in all samples included linalool, limonene, and methyl trans-cinnamate. Linalool, a monoterpene alcohol, exhibited the highest percentages in all three samples, recording 58.31%, 58.45%, and 80.37% in Salyan, Surkhet, and Myagdi respectively. Notably, twenty-five enantiomeric components were identified using chiral GC/MS among its sixty constituents. The enantiomeric component distribution of linalool and limonene was in their (+) dextrorotatory form, while others were dominant in the levorotatory form. This research underscores that Z. armatum from the Myagdi district of Nepal, is a prominent source of the medicinally and industrially important compound linalool, along with exhibiting higher antimicrobial activity. To the best of our knowledge, this represents the first report of a chiral GC/MS study conducted on this plant.

GC-MS Analysis and Study of the Antimicrobial Activity of Citrus paradisi, Citrus aurantifolia, and Citrus sinensis Peel Essential Oils as Hand Sanitizer.

In the setting of healthcare, the use of hand sanitizers and antiseptics for hand hygiene is of paramount importance to avoid transfer of pathogenic microorganism through hand and skin contact. There is an increasing interest in the incorporation of essential oils in hand sanitizer's formula to avoid the adverse effect of conventional hand sanitizers on health. This study aimed to detect the chemical constituents of citrus peel essential oils and study their antimicrobial activity compared with commercial hand sanitizers. The qualitative and quantitative analysis of the hydrodistillated essential oils of peels of grapefruit (Citrus paradisi), lime (Citrus aurantifolia), and orange (Citrus sinensis) were carried out using gas chromatography mass spectroscopy. The disc diffusion method was used to screen the antibacterial activity of the essential oils against Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis, Staphylococcus aureus, and Candida albicans compared with a 78% alcohol-based commercial hand sanitizer. The antimicrobial testing results were statistically analyzed. The highest yield percentage of the obtained essential oils was 1.09% obtained by orange oil. The GC-MS analysis indicated that monoterpene and sesquiterpene hydrocarbons occupied the largest portion of the chemical composition of the three essential oils with D-limonene as the most predominant component. All essential oils showed activity against all tested organisms. Lime essential oil showed comparable antimicrobial activity relative to the commercial 78% alcohol hand sanitizer. In conclusion, essential oils obtained from citrus fruit peel represent a rich source of compounds possessing antimicrobial properties and could be an alternative to synthetic antimicrobial agents.

Antifungal efficacy and phytochemical characterization of citronella (Cymbopogon winterianus Jowitt ex Bor) essential oil against fungal pathogens causing severe diseases in Mentha arvensis L.

Mentha arvensis L. (family Lamiaceae) is one of the important medicinal plants and India is the largest producer of Mentha oil in the world, contributing about 80% of the total global production followed by China (9%), Brazil (7%) and the USA (4%). However, this crop suffers quantitative and qualitative losses due to the wilt and leaf spot diseases caused by the fungi Fusarium oxysporum and Alternaria alternata, respectively; therefore, an attempt has been made for the management of these fungal pathogens. The citronella essential oil was extracted by hydro-distillation method (Clevenger, 1928). The oil thus extracted was used for in vitro antifungal efficacy against the both fungi F. oxysporum and A. alternata, using poison food technique. The results showed that the minimum inhibitory concentration (MIC) of the citronella oil against F. oxysporum and A. alternata was 1.0 μL/mL; however, it was cidal in nature at 1.2 μL /mL and 1.5 μL/mL against both fungi, respectively. Further, phytochemical characterization of citronella oil was done using GC/GC-MS. Gas chromatographic analysis of the citronella oil revealed 18 phytoconstituents which were identified by retention indices aided with NIST-MS database. The major constituents of essential oil were citronellal (28.78%), geraniol (26.31%), citronellol (12.90%), geranial (9.85%), and neral (7.9%). The findings of the current study show that citronella oil could be an alternative to synthetic fungicides, after detailed investigations.

Antioxidant, α-glucosidase, antimicrobial activities chemical composition and &lt;i&gt;in silico&lt;/i&gt; analysis of &lt;i&gt;eucalyptus camaldulensis&lt;/i&gt; dehnh

&lt;p&gt;Throughout history, medicinal plants have been the primary source for preventing and treating infectious diseases and other health issues. The flowering plant &lt;italic&gt;Eucalyptus camaldulensis&lt;/italic&gt;, also called river red gum, is a member of the Myrtaceae family and has numerous traditional uses. The objectives of the present study were to identify the essential oil components of &lt;italic&gt;Eucalyptus camaldulensis&lt;/italic&gt; using Gas Chromatography Mass Spectrometry (GCMS), and to determine the antioxidant, antidiabetic, and antibacterial activities of ethanol, aqueous, and essential oil extracts from &lt;italic&gt;E. camaldulensis&lt;/italic&gt; leaves. Addtionally, the essential oil constituents that were identified underwent an &lt;italic&gt;in silico&lt;/italic&gt; analysis. The efficacy of various extracts in combat pathogens and free radicals was assessed through the utilization of the 1,1-Diphenyl-2-Picryl Hydrazyl (DPPH), ferric reducing antioxidant power (FRAP), α-glucosidase inhibition, and disk diffusion methods. In terms of radical scavenging, reducing power, and α-glucosidase inhibitory activity, the essential oil showed strong antioxidant activity at 84.01 %, 20.1 mmol/g, and 78.2 %, respectively. The essential oil showed a potent antimicrobial action against &lt;italic&gt;Staphylococcus aureus&lt;/italic&gt; and &lt;italic&gt;Pseudomonas aeruginosa&lt;/italic&gt;, with 12 and 14 mm inhibitions, respectively, which were higher than ampicillin's 9 and 6 mm inhibitions, respectively. The GCMS analysis showed that the following chemicals were the most common: cis-11-hexadecenal (10.2%), trans-13-octadecenoic acid (9.5%), and 6-Octadecenoic acid, methyl ester, (Z)-(8.8%). The α-glucosidase enzyme was targeted in a docking study to investigate the antidiabetic properties of the 42 phytochemicals found in the essential oil extract. The compound, namely 5.alpha.-Androstan-16-one, showed the highest binding affinities of −8.6 Kcal/mol during the docking screening of the 42 identified phytochemicals against α-glucosidase. These two compounds show potential as competitive α-glucosidase inhibitors. &lt;italic&gt;E. camaldulensis&lt;/italic&gt; will be a particularly useful source to improve health and fight communicable and non-communicable diseases. Nonetheless, human evaluations of &lt;italic&gt;E. camaldulensis&lt;/italic&gt; safety and effectiveness are necessary, and more well-planned clinical trials are needed to confirm our &lt;italic&gt;in vitro&lt;/italic&gt; and &lt;italic&gt;in silico&lt;/italic&gt; findings.&lt;/p&gt;

Discriminating the leaves of Ocimum sanctum Linn. conferring to their age by gas chromatographic fingerprint analysis assisted with multivariate analysis

Ocimum species is having massive variations in their chemical composition that includes day time, terrestrial and cyclical variation according to the season etc. In this study, variation in overall essential oil constituents among matured, intermediate and young leaf samples of O. sanctum was studied. The leaf samples according to their age- matured, intermediate and young leaves were collected from three different plants at 11 a.m. each. Extract of collected leaf samples were then scrutinized using gas chromatographic technique having flame ionization detector (GC-FID). Result reveals that the noteworthy variance was observed in overall essential oil constituents of the leaf samples according to their age. The Average chromatographic fingerprint data of triplicate run for different leaf samples were then treated to multivariate methods such as hierarchical cluster analysis and principal component analysis. In this study, instead of considering one or two biomarkers, we have exasperated to obtain as many constituents in chloroform extracts of chosen leaf samples. Scree plot reveals that nine components were responsible for the whole variation. Score plot and dendogram efficiently discriminated all the three leaf types according to their age in different clusters. The outcome as an inference was, O. sanctum leaves according to their age exhibit variation in its chemical composition and developed tool can be used for routine quality control.

In silico molecular docking analysis of various essential oil constituents against key target proteins in non-alcoholic fatty liver disease

In silico molecular docking analysis of various essential oil constituents against key target proteins in non-alcoholic fatty liver disease

Comprehensive analyses of inhibition of the Chinese traditional food-packaging materials, Indocalamus latifolius leaves (Zongye) on Aspergillus flavus

Abstract Objectives The contamination of Aspergillus flavus and aflatoxins (AFs) is one of the most serious safety problems in food and feed. The discovery and application of plant-sourced antifungal agents are hot topics in mycotoxin control. In this study, we aim to develop efficient strategies to control A. flavus and subsequent contamination by AFs. Materials and Methods We focused on Zongye essential oil, which was extracted from Indocalamus latifolius leaves (Zongye, the traditional food-packaging materials). Its antifungal and antitoxin activities were observed by volatile test, and the significant morphological and ultrastructural variations were observed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analyses. The main components of Zongye essential oil were analyzed by gas chromatography-mass spectrometry (GC-MS). RNA sequencing (RNA-Seq) and real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) analyses were used to reveal the inhibitory mechanism. Results Among them, No. 2 Zongye essential oil completely inhibited the growth and toxin production of A. flavus after 10 µL treatment. Under Zongye essential oil treatment, evidently morphological and ultrastructural variations were observed, such as hyphae shrinkage, partial distortion, and a decrease in conidia number. Longifolene and linalool were the major constituents of Zongye essential oil, accounting for 9.55% and 7.95%, respectively, and linalool had stronger inhibitory effects on fungal growth and mycotoxin biosynthesis than longifolene. Based on the experimental results, the antifungal mechanism was proposed: down-regulations of membrane proteins (AFLA_005560, AFLA_019420, and AFLA_084310, etc.) and conidial genes (fblC, steA, and abaA, etc.) inhibited fungal development, and anti-aflatoxigenic activity might be due to significant down-regulation of AF cluster genes and global regulators (AtfA and AtfB). Conclusion A novel antifungal agent, Zongye essential oil, was identified, and its inhibitory mechanism was comprehensively clarified, which is helpful to control AF contamination in an environmentally friendly way.

Chemical Composition, Anti-bacterial Activity and Molecular Docking Studies of Essential Oil Isolated from Sa Sam Nam (Launaea sarmentosa).

Launaea sarmentosa, also known as Sa Sam Nam, is a widely used remedy in Vietnamese traditional medicine and cuisine. However, the chemical composition and bioactivity of its essential oil have not been elucidated yet. In this study, we identified 40 compounds (98.6% of total peak area) in the essential oil via GC-MS analysis at the first time. Among them, five main compounds including Thymohydroquinone dimethyl ether (52.4%), (E)-α-Atlantone (9.0%), Neryl isovalerate (6.6%), Davanol D2 (isomer 2) (3.9%), and trans-Sesquisabinene hydrate (3.9%) have accounted for 75.8% of total peak area. The anti-bacterial activity of the essential oil against 4 microorganisms including Staphylococcus aureus, Bacillus subtilis, Escherichia coli, and Pseudomonas aeruginosa has also investigated via agar well diffusion assay. The results showed that the essential oil exhibited a strong antibacterial activity against Bacillus subtilis with the inhibition zones ranging from 8.2 to 18.7 mm. To elucidate the anti-bacterial effect mechanism of the essential oil, docking study of five main compounds of the essential oil (Thymohydroquinone dimethyl ether, (E)-α-Atlantone, Neryl isovalerate, Davanol D2 (isomer 2), and trans-Sesquisabinene hydrate) against some key proteins for bacterial growth such as DNA gyrase B, penicillin binding protein 2A, tyrosyl-tRNA synthetase, and dihydrofolate reductase were performed. The results showed that the main constituents of essential oil were highly bound with penicillin binding protein 2A with the free energies ranging -27.7 to -44.8 kcal/mol, which suggests the relationship between the antibacterial effect of essential oil and the affinity of main compounds with penicillin binding protein. In addition, the free energies of main compounds of the essential oil with human cyclooxygenase 1, cyclooxygenase 2, and phospholipase A2, the crucial proteins related with inflammatory response were less than diclofenac, a non-steroidal antiinflammatory drug. These findings propose the essential oil as a novel and promising anti-bacterial and anti-inflammatory medicine or cosmetic products.

Investigation of the Essential Oil Constituents of Pimenta racemosa Aerial Parts and Evaluation of Its Antiviral Activity against Hsv 1 and 2

Investigation of the Essential Oil Constituents of Pimenta racemosa Aerial Parts and Evaluation of Its Antiviral Activity against Hsv 1 and 2

Lethal Toxicity of Thymus mastichina and Helichrysum italicum Essential Oils to Non-Target Aquatic Organisms: Tools to Screen Environmental Effects?

Essential oils (EOs) from Thymus mastichina (EO-thyme) and Helichrysum italicum (EO-curry) have wide commercial applications, but little is known about their ecotoxicity to aquatic life. We evaluated the lethal toxicity of both EOs toward standard freshwater (Daphnia. magna and Thamnocephalus platyurus) and saltwater (Artemia sp.) species. Dimethylsulfoxide was used as a solvent after establishing a maximum safe but effective concentration of 1% (v/v). EO-curry was significantly more toxic than EO-thyme (24–48 h LC50 values of 15.93–55.80 and of 84.78–153.0 mg L−1, respectively) for all species; sensitivity ratios ranged from threefold for D. magna (48 h) and Artemia sp. (24 h) to fivefold for T. platyurus (24 h). Artemia sp. was the least sensitive, and T. platyurus was the most sensitive species, although significantly more so than D. magna only to EO-curry. The second major compound in EO-thyme, β-pinene (5%), is more toxic to aquatic life than major compound 1,8-cineole (62%), although 1,8-cineole facilitates penetration of other EO constituents into crustaceans’ epidermis. Among the main compounds of EO-curry, only α-pinene (13%) is known to be toxic to aquatic organisms. However, minor compounds present in both EOs, like p-cymene (0.3–1.1%), also cause synergistic effects by enhancing the penetration of other EO constituents. Before any of these standard tests can be recommended for the ecotoxicity characterization and environmental management of EOs, their sensitivity to a wider range of EOs, at least from closely related families, needs to be assessed.