Volatile Components Of Essential Oils Research Articles

Selenium content, chemical composition and volatile components of essential oil and hydrosol from flowers of Cardamine violifolia.

Cardamine violifolia is a unique selenium hyperaccumulating vegetable in China, but its flowers are commonly wasted in large-scale cultivation. To better utilize this resource, this study explored the selenium content, chemical composition, and volatile organic compounds (VOCs) of hydro-distilling essential oil (EO) and hydrosol from C. violifolia flowers. ICP-MS results indicated that the EO and hydrosol contained selenium reaching 13.66±2.82 mg/kg and 0.0084±0.0013 mg/kg, respectively. GC-MS analysis revealed that organic acids, hydrocarbons, and amines were the main components of EO. Additionally, benzyl nitrile, benzaldehyde, benzyl isothiocyanate, benzyl alcohol, megastigmatrienone, and 2-methoxy-4-vinylphenol also existed in considerable amounts. The hydrosol extract had fewer components, mainly amines. HS-SPME-GC-MS corresponded to the composition analysis and aromatic compounds were the prevalent VOCs, while HS-GC-IMS primarily identified C2-C10 molecular alcohols, aldehydes, ethers, and sulfur-containing compounds. This study first described the chemical composition and VOC profiles of EO and hydrosol from selenium hyperaccumulating plant.

Hydroponic cultivation enhances the morpho-physiological traits and quality flower production in three cultivars (marigold scarlet red, marigold orange, and marigold yellow) of French marigold (Tagetes patula L.)

In soil-less agriculture, hydroponic is considered a potential farming system for the production of uniform quality plant material in significantly less time. Therefore, for the first time, the current investigation corroborates the effect of different cultivation conditions (open-field, poly-house, and hydroponic) on morpho-physiological traits, phenolic content, and essential oil components analysis in three French marigold cultivars (marigold scarlet red, marigold orange, and marigold yellow) of Tagetes patula L. The results revealed that the maximum plant height, number of secondary branches, number of flowers, photosynthesis, stomatal conductance, and transpiration rate were observed under the hydroponic system as compared to other conditions. However, the maximum content of gallic acid (0.82 mg/g dry weight), syringic acid (3.98 mg/g dry weight), epicatechin (0.48 mg/g dry weight), p-coumaric acid (7.28 mg/g dry weight), protocatechuic acid (0.59 mg/g dry weight), ferulic acid (2.58 mg/g dry weight), and luteolin (8.24 mg/g dry weight) were quantified under open-field conditions. However, under hydroponic conditions, the higher content of vanillic acid (0.43 mg/g dry weight), caffeic acid (0.49 mg/g dry weight), and quercetin (0.92 mg/g dry weight) were observed. In addition, a total of nineteen volatile components were identified in the essential oil of different French marigold cultivars (marigold scarlet red, marigold orange, and marigold yellow) T. patula L. cultivated under different conditions. The major reported volatile components in essential oil were (-)-caryophyllene oxide, trans-β-caryophyllene, trans-geraniol, 3-methyl-benzyl alcohol, and 2,2′:5′,2″-terthiophene. It has also been observed that the volatile component percentage range in all cultivars was observed in open-field (70.85 % to 90.54 %), poly-house (59.03 % to 77.93 %), and hydroponic (68.78 % to 89.41 %). In conclusion, the research highlighted that maximum morpho-physiological performance with a higher number of flower production per plant was observed under hydroponic cultivation conditions. However, phenolic content and volatile components were maximally observed under open-field conditions. Though, significant results have been reported under hydroponic conditions in all studied parameters, so it could be a potential strategy for quality flower production in T. patula.

Overview of Trachyspermum ammi and its Medicinal applications

Trachyspermum ammi (1) Sprague or commonly Ajwain is a herbaceous herb belongs to the family Apiaceae and vastly grown in Egypt iran, Pakistan, Afghanistan, and India as well as European region. In India, it is mostly cultivated in Gujarat and Rajastan. Morphological features the fruit are consisting of two mericarps with bifid slyopod and have five light-coloured ridges. It is avoid in shape and has pungent taste, aromatic odour and is greyish brown in colour. It is 2mm long and 1mm wide in size. The temprature of fruit according to unani literature is hot and dry. The most useful element of ajwain is the little fruit like caraway, which always especially admired in Indian delectable recipes, flavorful baked goods, and snacks. In Ayurvedic meds, it is utilized as a restorative plant for its stimulant, carminative, antispasmodic, and tonic properties. The volatile components of essential oils mainly consist of monoterpenes, sesquiterpenes and their oxygenated derivatives such as alcohols, aldehyde, ketones, acids and esters (Suntar et al. 2014). Terpenes having a diverse variety of structures with specific functions constituted the largest amount (71.10%) of essential oils (Zule et al. 2003) Ajwain seeds revealed to possess antiseptic, stimulant, carminative, diuretic, anesthetic,antimicrobial, antiviral, nematicidal, antiulcer, antihypertensive, antitussive, bronchodilatory, antiplatelet and hepatoprotective as well as antihyperlipidemic effects, many of those were remarked by early Persian physicians.Ajwain methanolic extract revealed to exhibit in vivo hepatoprotective activity with 80% defense against an in general deadly dose of paracetamol in pests. The bronchodilatory impact of the decocted concentrate of Ajwain on the asthmatic patients' airways was inspected in an ensuing examination ponders. According to the outcomes, the concentrate has a reasonably bronchodilatory impact on asthmatic airways assessed to the impact of Theophylline at fixations utilized.

Chemical Compositions of Essential Oil of Agarwood <i>(Aquilaria crassna)</i> Harvested in Phu Quoc Island, Vietnam

The importance of natural products derived from Agarwood species is increasingly emphasized in the production of perfumery or cosmetic products made on Agarwood species. On the other hand, due to the predominant amount of aromatic compounds in essential oils, frankincense essential oil is increasingly popular with high economic value. Therefore, in this study, we focused on the extraction process of essential oils and evaluated the chemical composition present in the essential oils by the GC-MS method. Differences in the composition of essential oils between natural and artificial agarwood may be due to species, habitat conditions, climate, geographical conditions, and extraction methods in different regions. Specifically, volatile components in essential oils were identified as Neopetasone (14.43%); Dihydroagarofuran-15-al (9.20%); Jinko-cramol (5.02%); Valeriano (4.94%); Agarofuran <b-> (8.02%); Dihydrokaranone (3.25%), Valenca-1 (10), 8-dien-11-ol (5.95%) and Selina-4,11-dien-14-al (2.73%), contribute to determining the main aroma in Agarwood essential oil.

Protective Effect of Celeriac (Apium graveolens) Leaf Essential Oil on Temperature and Oxygen-Induced Fish Oil Oxidation

The purpose of this work was to identify the volatile components of essential oil extracted from Celeriac (Apium graveolens) leaves (CEO) and assess its antioxidant performance during thermal oxidation of fish oil. Steam distillation method and Clavenger apparatus was used to extrat of CEO from fresh leafs. The volatile component analysis revealed that 98.81% of the volatile components in the resulting product could be recognized. Following examination, the principal components of the product were discovered to be Phthalide (3-isobutylidene) and Fenipentol with a concentration of 49.42% and 28.45% respectively. The product's antioxidant activity was tested using a 2,2-diphenyl-1-picrylhydrazyl (DPPH) study. The 50% inhibitory concentration value (IC50) for CEO was discovered to be 30.52 ppm by the study. To test the product's ability to protect fish oil from oxidation, CEO ratios of 0% (CEO0), 0.1% (CEO0.1), 0.5% (CEO0.5), 1% (CEO1), and 3% (CEO3) were added to fish oil, and the experimental groups were subjected to 24 hours of oxidation at 70 °C with continuous ventilation. According to the oxidation investigation, the addition of CEO suppressed fish oil oxidation and significantly reduced the product's oxidation radicals (p

Volatile Components of Essential Oils from Spices and It’s Inhibitory Effects against Biofilm Formed by Food Poisoning Bacteria

Volatile Components of Essential Oils from Spices and It’s Inhibitory Effects against Biofilm Formed by Food Poisoning Bacteria

Study on the Composition and Physiological Activity of the Essential Oils and Extracts of Cinnamomum camphora Fruit.

Supercritical carbon dioxide (SC-CO2 ), hydrodistillation (HDO), ethanol extraction (EE), and petroleum ether extraction (PE) were used to extract the essential oil and extracts of Cinnamomum camphora fruit in this study. Gas chromatography-mass spectrometry was used to identify the volatile components of essential oils and extracts, and 63 compounds were identified. 2,2-Diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging assay and Ferric reducing ability of plasma (FRAP) assays and the inhibition experiment of bacteria and fungi (Staphylococcus aureus (S. aureus), Hay bacillus (H. bacillus), Escherichia coli (E. coli), Aspergillus niger (A. niger), Candida albicans (C. albicans)) showed these essential oils and extracts indicated antioxidant and antibacterial activities. S. aureus was the most sensitive to the essential oil (MIC=0.08 mg/ml). Combined with the Brine Shrimp Lethality Test (BSLT) experiment, HDO (LD50 =68.21 μg/ml) was considered to have the most potential natural preservative. Subsequently, the inhibitory mechanism of HDO on bacteria and fungi was explored through extracellular conductivity and SEM, and the possibility of HDO to preserve the freshness of bananas was verified through banana shelf-life experiments. The results suggested these essential oils and extracts of Cinnamomum camphora fruit indicated effectively inhibit the growth of microorganisms on the surface of bananas, extend the shelf-life, and have the potential to become a natural antiseptic ingredient.

Lemongrass and Perilla Essential Oils Synergistically Increased Antimicrobial Activity.

We postulated that disinfection of viable Trichophyton species in shoes would help reduce the number of patients with tinea pedis in Japan and that this might be accomplished safely using volatile components of essential oils. As vapor of lemongrass (Cymbopogon citratus) oil and citral have strong antimicrobial activities against Trichophyton, we examined the conditions under which lemongrass oil or citral show optimal antimicrobial activity in shoes. First, we investigated whether or not a strong antimicrobial effect could be obtained by combining with terpene aldehydes or aromatic aldehydes. When combined with citral, perillaldehyde showed superior antimicrobial activity to citronellal, cinnamaldehyde, cuminaldehyde, hydroxycitronellal, and vanillin. The combined effects of citral and perillaldehyde against Trichophyton mentagrophytes, Bacillus subtilis, and Candida albicans as volatile components dotted on filter paper placed away from the petri dish inoculated with fungi or bacteria were examined. Citral (2.5 mg/mL) and perillaldehyde (2.5 mg/mL) showed a greater inhibitory effect on growth of C. albicans than either solution alone in the aromatogram (disc diffusion) descent method (fractional inhibitory concentration [FIC] index of 0.58). Citral (2.5 mg/mL) and perillaldehyde (1.25 mg/mL) vapors in a closed box synergistically inhibited growth of B. subtilis and T. mentagrophytes (FIC indexes of 0.5 and 0.38, respectively). These results suggested that this combination would be safe and useful for disinfection of shoes.

Anti- Candida albicans Activity and Safety of Cinnamomum camphora Essential Oil and Its Components

To explore the anti-Candida albicans activity and safety of Cinnamomum camphora essential oil and its components,the anti-Candida albicans activity of Cinnamomum camphora essential oil that compared with grapefruit,lemon and lavender was determined by disk diffusion method and dilution method. Meanwhile,the GC-MS was used to detect the volatile components of essential oil. Moreover,the significant difference analysis among the chemical components and its correlation with anti-Candida acbicans activity were conducted. Finally,the Cinnamomum camphora essential oil and its components to stimulate the skin of guinea pigs and vascular permeability were observed. The results showed that the anti-Candida albicans activity of Cinnamomum camphora essential oil was stronger than that of grapefruit,lemon and lavender essential oil and it was mainly derived from α-Terpineol,Terpinolene,α-Terpinene,Terpinen-4-ol,Sabinene,1,8-Eucalyptol. The skin of guinea pigs showed slight erythema after 5 days of continuous application of 4% Cinnamomum camphora essential oil,while 4% terpinen-4-ol showed slight erythema after 2 days of application. In addition,4% terpinene-4-ol could significantly increase the vascular permeability of mice. The results would provide a theoretical basis for the development and utilization of Cinnamomum camphora essential oil and the treatment of Candida albicans-related diseases.

Nanoemulsion of Minthostachys verticillata essential oil. In-vitro evaluation of its antibacterial activity

Infectious diseases constitute a problem of great importance for animal and human health, as well as the increasing bacterial resistance to antibiotics. In this context, medicinal plants emerge as an effective alternative to replace the use antibiotics. The essential oil (EO) of Minthostachys verticillata (Griseb.) Epling (Lamiaceae) has demonstrated a strong antimicrobial activity. However, its instability and hydrophobicity under normal storage conditions are limitations to its use. Nanoemulsion technology is an excellent way to solubilize, microencapsulate, and protect this compound. This study aimed to obtain a nanoemulsion based on M. verticillata EO and evaluate its antibacterial activity against Staphylococcus aureus. The EO was obtained by steam distillation. Identification and quantification of their components were determined by GC-MS revealing that the dominated chemical group was oxygenated monoterpenes. Nanoemulsions (NE) were characterized by measuring pH, transmittance, separation percentage, release profile, and morphology. The effect of NE on the growth of S. aureus and cyto-compatibility was also evaluated. The results showed that NE containing a higher percentage of tween 20 exhibited higher stability with an approximated droplet size of 10 nm. The effect of encapsulation process was evaluated by GC-MS revealing that the volatile components in EO were no affected. After 24 h, 74.24 ± 0.75% of EO was released from NE and the antibacterial activity of EO was enhanced considerably by its encapsulation. The incubation of S. aureus with the NE and pure EO, show a bacterial growth inhibition of 58.87% ± 0.99 and 46.72% ± 3.32 (p < 0.05), respectively. In addition, nanoemulsión did not cause toxicity to porcine and equine red blood cells. The results obtained showed that NE could be a potential vehicle for M. verticillata EO with promissory properties to emerge as a tool for developing advanced therapies to control and combat infections.

Chemical composition, antimicrobial, and lipase enzyme activity of essential oil and solvent extracts from Serapias orientalis subsp. orientalis.

The volatile components of essential oil (EO), SPME, and SPME of solvent extracts ( n -hexane, methanol, and water) obtained from fresh Serapias orientalis subsp. orientalis ( Soo ) were analyzed by GC-FID/MS. EO of Soo gave 11 compounds in the percentage of 99.97%; capronaldehyde (37.01%), 2-( E )-hexenal (23.19%), and n -nonanal (19.05%) were found to be major constituents. SPME GC-FID/MS analyses of fresh plant and solvent extracts of Soo revealed 7, 12, 7, and 4 compounds within the range of 99.7% to 99.9%. Limonene (76.5%, 41.7%, and 61.3%) was the major compound in SPMEs of the n -hexane and methanol extracts. α -Methoxy- p -cresol (52.9%) was the main component in its water extract. The antimicrobial activity of EO and the solvent extracts of Soo were screened against 9microorganisms. EO showed the best activity against Mycobacterium smegmatis , with 79.5 µg/mL MIC value. The n -hexane, methanol, and water extracts were the most active against the Staphylococcus aureus within the range of 81.25–125.0 µg/mL (MIC). IC 50 values for the lipase enzyme inhibitory activity of EO and solvent extracts ( n -hexane, methanol, and water) were determined to be 59.87 µg/mL, 64.03 µg/mL, 101.91 µg/mL, and 121.24 µg/mL, respectively.

Characterization of the Volatile Components of Essential Oils of Selected Plants in Kenya.

Essential oils are secondary metabolites that plants produce for protection from pests and predators, attraction of pollinators, and seed dispersal. The oils are made up of a mixture of compounds that give a characteristic flavour and odour. Currently, essential oils are receiving great attention in research for their phytochemical and antimicrobial activities. However, there is scanty information on the chemical composition of many plants. This study provides a detailed analysis of the chemical composition of essential oils of ginger, garlic, tick berry, and Mexican marigold in Kenya. The essential oils were extracted by steam distillation and analysed by gas chromatography–mass spectrometry. The study identified a total of 52 different chemical classes from the essential oils of the four different plants that were analysed. Their percentage composition was also found to vary between the test plants. The essential oils of Mexican marigold constituted the highest composition of the identified chemical classes at 71.2%, followed by ginger at 55.8%, while both tick berry and garlic oils constituted 53.8% of the total classes identified. Terpenes constituted the highest composition in the essential oils of all the four test plants. Other major chemical classes included esters, ketones, organosulfurs, alkanes, cycloalkanes, steroids, aromatic hydrocarbons, and alkanols. Some of these chemical compounds have been shown to have a huge utility potential in biopesticides, pharmaceutical, and food industries, and hence, their industrial extraction and purification from the essential oils of these plants are recommended.

Microwave-assisted hydrodistillation and determines volatile components of essential oils from Calamondin (Citrus microcarpa) shells

Since the industrial economic development, natural compounds have received much attention and study in recent years. Essential oils (EOs) that contain many volatile constituents and aromatic compounds have been around for a long time but are still considered today due to their natural characteristics and unique application. In this study, the leaves of Calamondin (Citrus microcarpa) shells were used to investigate the yield of essential oil extracted by the Microwave-assisted hydrodistillation (MAHD). Calamondin essential oil is determined by the microwave assisted hydrodistillation method and analyzed by GC-MS. Extraction essential oil Calamondin with MAHD in optimal conditions for 45 min, 300W capacity and 1:3 shells/water ratio. The main components of volatile compounds in Calamondin essential oils include limonene (96.039%), β-myrcene (0.953%), 1R-α-pinene (0.266%), sabinene (0.55%), 1,6-cyclodecadiene (1.611%), ϒ-eudesmol (0.207%), β-eudesmol (0.232%), α-eudesmol (0.185%). The oil produced by microwaves assisted hydrodistillation (MAHD) method was found to have higher levels of compounds and significant economic values.

Antimicrobial activity of the volatile phase of essential oils and their constituents on Legionella pneumophila

Abstract Pathogenic bacteria of the genus Legionella cause atypical pneumonia known as Legionnaires’ disease and flu – like disease known as Pontiac fever. As pathogens of the respiratory system, these bacteria represent a public health problem and there is a need for examine new alternative ways to inactivate them. These bacteria live naturally in water and are transmitted by infectious aerosols. To purify the air, essential oils that show antimicrobial properties are widely used. The anti-Legionella activity of five exotic essential oils and five Mediterranean essential oils characteristic for coastal Croatia was examined. Model organism used in experiments was L. pneumophila (strain 130b). This experiment was conducting with modified version of sealed plate method using a BCYE medium. The exotic essential oil with highest anti-Legionella activity was Niaouli essential oil, and the best anti-Legionella activity among Mediterranean essential oils showed Immortelle essential oil. Anti- Legionella activity of four main chemical compounds was examined and compound that show significant highest anti-Legionella activity was α – pinene. Volatile components of essential oils have a great potential as anti-Legionella agents and further research are needed.

Changes in the chemical composition of essential oils during storage

During the storage of essential oils, physical and chemical changes occur, leading to changes in the component composition, as a result of which the organoleptic and pharmacological properties of the oils change. The composition of the essential oils of Tagetes minuta L. and Cymbopogon flexuosus (Nees ex Steud.) W. Watson was studied by chromatography-mass spectrometry fresh and after storage. It was found that in T. minuta essential oil after storage for 6 months, the mass fraction of the main component, tagetenone, decreases due to the appearance of products of its oligomerization. Such changes lead to an improvement in the organoleptic properties of the oil. After storing the oil for 24 months, polymer forms of tagetones are formed in it and its viscosity is significantly increased, which makes its further use impossible. When storing C. flexyosus essential oil for 6 months, no changes were found in its chemical composition. After 24 months of storage, the mass fractions of cis and trans citral are reduced and undesirable components appear: isomeric forms of citrals, photocitral and caryophyllene oxide. Unpleasant notes appear in the aroma of the oil, and its quality decreases. Studies show that the chemical transformations of volatile components in essential oils do not always lead to a deterioration in their properties and depend on the species of the plant material and the duration of storage.

Volatile components of essential oils extracted from Pu-erh ripe tea by different extraction methods

ABSTRACTPu-erh ripe tea is one of the main tea products in China, which has a unique woody, chestnut fragrance flavour, distinct from other teas. Because of the largely excessive production capacity, it is now possible and necessary to utilise it to produce tea essential oil. In this study, the extraction efficiency of Soxhlet extraction (Soxhlet), ultrasonic-assisted extraction (UAE), simultaneous distillation extraction (SDE), and steam distillation extraction (SD) for extraction oil of Pu-erh ripe tea was investigated. GC-MS and HS-SPME/GC-MS were then applied to identify the volatile compounds in the essential oils and tea samples. The results showed that the extraction ratios of the essential oil were 0.81±0.01 g/kg (Soxhlet), 0.36±0.01 g/kg (UAE), 0.11±0.01 g/kg (SDE), and 0.59±0.01 g/kg (SD). GC-MS identified 40, 38, 35, and 47 volatile compounds in the essential oils extracted by the different methods, whereas 55 compounds were identified by HS-SPME/GC-MS. Therefore, when both the essential oil extraction rate and oil flavour are considered, the best method is SD.

Drug-in-cyclodextrin-in-liposomes as a carrier system for volatile essential oil components: Application to anethole.

A combined approach based on cyclodextrin/drug inclusion complex formation and loading into liposomes was applied to improve the effectiveness of liposome loading with essential oils. Hydroxypropyl-β-cyclodextrin/ANE (HP-β-CD/ANE) inclusion complexes were prepared and encapsulated into liposomes (ACL). ANE-double-loaded liposomes (ACL2) were obtained with the HP-β-CD/ANE complex in the aqueous phase and ANE in the organic phase. Liposomes were prepared from saturated (Phospholipon 90H) or unsaturated (Lipoid S100) phospholipids and characterized for size, polydispersity index, zeta potential, morphology, loading rate (LR) and photo- and storage stabilities. All liposome batches were nanometric oligolamellar-type vesicles. Compared to ANE-loaded liposomes, ACL-90H, ACL2-90H and ACL2-S100 displayed significantly increased ANE LR, with ACL2-S100 exhibiting the highest LR. All formulations provided ANE photoprotection, were physically stable after 15months of storage at 4°C (with the exception of ACL2-S100), and retained more than 25% of the ANE initially present in the liposome suspensions.

Mouse brain concentrations of α‐pinene, limonene, linalool, and 1,8‐cineole following inhalation

AbstractThe main volatile components of essential oils are monoterpenes. It is known that olfactory receptors recognize monoterpenes as a fragrance, and that they can affect emotions. On the other hand, the components of essential oils may act directly on the central nervous system as well as the olfactory nerve. However, the transport of monoterpenes to the brain following inhalation, which is the main method of administration in aromatherapy, is unclear. In this study, we investigated major monoterpenes of essential oils, such as (+)‐α‐pinene, (+)‐limonene, (‐)‐linalool, and 1,8‐cineole. After the inhalation of each compound, the mice brains were dissected, and brain extracts prepared with n‐hexane. The extracts were then subjected to gas chromatography‐mass spectrometry analysis. The results revealed that α‐pinene was transported to the brain maximally with 30 min inhalation, which may be due to its high volatility. Limonene and linalool showed maximal transport to the brain with 90 min inhalation. Brain concentrations of 1,8‐cineole showed minimal level after 30 min inhalation. Moreover, 1,8‐cineole was easily transported to the brain following intraperitoneal administration. These results could be applied as one of the indices for the effective use of essential oils in aromatherapy. Copyright © 2016 John Wiley &amp; Sons, Ltd.

Larvicidal efficacy of monoterpenes against the larvae of Anopheles gambiae

ObjectiveTo evaluate the larvicidal efficacy of eight volatile components of essential oils against 3rd instar larvae of Anopheles gambiae s.s. MethodsLarvicidal effects of each compound were evaluated in both laboratory and semi-field trials. Stock solution was prepared and serial dilutions were made in six concentrations for each compound. A total of 20 larvae were exposed to larvicides for each replicate and monitored at intervals of 12, 24, 48 and 72 h. Larvae monitoring was done on basis of dead and live larvae in all intervals. ResultsAll assayed compounds were larvicides and presented varying degrees of larval toxicity, with LC50 values ranging from 1.28 to 1938.92 mg/L depending on the treatment time (12, 24, 48 or 72 h). (−)-Perillyl alcohol presented the strongest larvicidal activity towards Anopheles gambiae larvae, with LC50 values of 73.60, 18.36, 1.72 and 1.28 mg/L after 12, 24, 48 and 72 h of exposure, respectively. The next strongest were (−)-isopulegol (LC50 = 135.10, 49.39, 34.39 and 20.22 mg/L) and (−)-carvone epoxide (LC50 = 168.86, 124.74, 80.84 and 23.46 mg/L). After 12, 24 and 48 h of treatment, hydroxydihydrocarvone was the least toxic compound, with LC50 values of 1938.92, 1172.18 and 401.03 mg/L, respectively. ConclusionsThe data obtained in this study suggest that all evaluated monoterpenes, especially (−)-perillyl alcohol, have remarkable larvicidal effects and may be considered as potential sources for the development of suitable natural larvicides for mosquito management programs. Further small-scale field trials should be conducted.

Antioxidative and neuroprotective effects of volatile components in essential oils from Chrysanthemum indicum Linné flowers

Chrysanthemum indicum Linne, belonging to the family Compositae, is a perennial herb that is widespread in Korea. C. indicum Linne flowers have been traditionally used as an oriental medicine for treatment of infectious diseases. The chemical compositions, antioxidant capacity, and neuroprotective effects of volatile components in essential oils from C. indicum Linne flowers were investigated. GC-MS analysis of essential oils revealed the 15 major components of 1,8-cineole, o-cymene, camphor, pinocarvone, chrysanthenyl acetate, bornyl acetate, trans-caryophyllene, terpinen-4-ol, umbellulone, trans-pinocarveol, cis-verbenol, borneol, α-terpineol, caryophyllene oxide, and thymol. Thymol had the highest antioxidant capacity. Essential oils and thymol dose-dependently decreased intracellular oxidative stress, exhibited anticholinesterase activities, and increased the cell viability of neuronal PC-12 cells. Essential oils and thymol from C. indicum Linne flowers can be sources of natural antioxidants and functional foods.