Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Oils, Volatile”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 523 records · Page 29Linked to original sources

Phytochemical analysis and in vitro antimicrobial activity of two Satureja species essential oils.

The phytochemical GC[sol ]MS analysis and in vitro antimicrobial activity of the essential oils of the aerial parts of Satureja montana L. and Satureja cuneifolia Ten., collected in Croatia were performed. The major compound of S. montana oil was the phenolic monoterpene carvacrol (45.7%). Other important compounds were the monoterpenic hydrocarbons p-cymene (12.6%), gamma-terpinene (8.1%) and the oxygen-containing compounds carvacrol methyl ether, borneol, thymol and thymol methyl ether. The volatile oil of S. cuneifolia was characterized as beta-cubebene (8.7%), limonene (8.3%), alpha-pinene (6.9%), spathulenol and beta-caryophyllene. The antimicrobial effects of S. montana and S. cuneifolia oils were found to have a broad spectrum activity against multidrug-resistant pathogens by the broth microdilution method. These oils were active against all the test strains, with the exception of Pseudomonas aeruginosa. Compared with S. cuneifolia, savory oil exhibited greater antimicrobial activity. The maximum activity of savory oil was observed against Escherichia coli, methicillin-resistant Staphylococcus aureus and against the yeast (Candida albicans). The essential oil of S. cuneifolia was also found to inhibit the growth of medically important pathogens such as S. aureus and E. coli. Fungicidal activity for both oils against C. albicans and S. cerevisiae was also observed.

Anti-Infective Agents↗

The antioxidant activity of the essential oils of Artemisia afra, Artemisia abyssinica and Juniperus procera.

The essential oils of Artemisia afra Jacq., Artemisia abyssinica Schultz-Bip. and Juniperus procera Hoechst ex Endl. were examined for their potential radical scavenging activities. First a rapid evaluation of antioxidants was made using a TLC screening method. The abilities of the volatile oils to act as nonspecific donors for hydrogen atoms or electrons were checked in the diphenylpicrylhydrazyl assay. Oils from all three species showed positive results and were examined further. The oils of A. afra and J. procera were also effective hydroxyl radical scavenging agents when assessed in the deoxyribose degradation assay, whilst oils from A. abyssinica exhibited a paradoxical effect. In the in vitro assay for non-enzymatic lipid peroxidation in liposomes, the oils of A. afra and J. procera also displayed antioxidant potential. It was not possible to measure the effect of A. abyssinica oil in this system because certain components, e.g. alk-2-enals, interfered with the assay. The compounds that contribute to the radical scavenging activities of A. afra and J. procera were identified and then assessed for their effects in the various test systems. Finally, the qualitative and quantitative compositions of the essential oils were studied by GC-MS.

Antioxidants↗

Influence of carrot psyllid (Trioza apicalis) feeding or exogenous limonene or methyl jasmonate treatment on composition of carrot (Daucus carota) leaf essential oil and headspace volatiles.

The effect of carrot psyllid (Trioza apicalis Förster) feeding and limonene and methyl jasmonate (MeJA) treatments on the essential oil composition and headspace volatiles of carrot (Daucus carota ssp. sativus), cvs. Parano and Splendid, leaves was studied. Carrot psyllid feeding significantly increased the concentrations of sabinene, beta-pinene, and limonene, whereas limonene treatment increased the concentration of (Z)-beta-ocimene in the leaves of both cultivars. The limonene treatment significantly increased the concentration of total phenolics in the leaves of both cultivars, and MeJA treatment increased phenolic concentration in the leaves of Parano. Exogenous limonene spray did not decrease the number of carrot psyllid eggs laid either 2 or 24 h after treatment. The results suggest that carrot psyllid feeding induces changes in the endogenous monoterpene pool in the carrot leaves. Limonene and MeJA treatments affect some induced defenses of the carrot, but the exogenous limonene spray is not an effective oviposition deterrent against carrot psyllid.

Animals↗

[Volatile phenolic compounds in white wines].

By gas-liquid chromatography the following volatile phenols were identified in extracts and distillates of white table wines prepared with the aid of husks and pulp used in fermentation: phenol, m-cresol, guaicol, ethyl-4-phenol, vinyl-4-phenol, eugenol, tyrosol; phenol, m-cresol, guaicol, ethyl-4-phenol, vinyl-4-phenol. The amount of volatile oils grew significantly with an increase in the number of husks in the fermenting liquid and fermentation temperature.

Chromatography, Gas↗

The scientific basis for the reputed activity of Valerian.

The underground organs of members of the genus Valeriana (Valerianaceae), as well as related genera such as Nardostachys, are used in the traditional medicine of many cultures as mild sedatives and tranquillizers and to aid the induction of sleep. V. officinalis is the species most commonly used in northern Europe and still retains its official pharmacopoeial status although it is most commonly encountered as an ingredient of herbal medicines. This plant is still the subject of considerable research aimed at establishing the chemical and pharmacological basis of the activity which has been clearly shown in a number of animal and clinical studies. The constituents of the volatile oil are very variable due to population differences in genetics and to environmental factors. The major constituents include the monoterpene bornyl acetate and the sesquiterpene valerenic acid, which is characteristic of the species, in addition to other types of sesquiterpene. Some of these have been shown to have a direct action on the amygdaloid body of the brain and valerenic acid has been shown to inhibit enzyme-induced breakdown of GABA in the brain resulting in sedation. The non-volatile monoterpenes known as valepotriates were first isolated in 1966 and contribute to the overall activity by possessing sedative activity based on the CNS although the mode of action is not clearly known. The valepotriates themselves act as prodrugs which are transformed into homobaldrinal which has been shown to reduce the spontaneous motility of mice. More recent studies have shown that aqueous extracts of the roots contain appreciable amounts of GABA which could directly cause sedation but there is some controversy surrounding the bioavailability of this compound. Another recent finding is the presence of a lignan, hydroxypinoresinol, and its ability to bind to benzodiazepine receptors. Valerian is a good example of both the negative and positive aspects of herbal drugs. The considerable variation in its composition and content as well as the instability of some of its constituents pose serious problems for standardization but the range of components which contribute to its overall activity suggest that it may correct a variety of underlying causes of conditions which necessitate a general sedative or tranquilizing effect.

Alkaloids↗

Influence of the addition of rosemary essential oil on the volatiles pattern of porcine frankfurters.

The effect of the addition of increasing levels of rosemary essential oil (150, 300, and 600 mg/kg) on the generation of volatile compounds in frankfurters from Iberian and white pigs was analyzed using solid-phase microextraction coupled to gas chromatography and mass spectrometry (SPME-GC-MS). Lipid-derived volatiles such as aldehydes (hexanal, octanal, nonanal) and alcohols (pentan-1-ol, hexan-1-ol, oct-1-en-3-ol) were the most abundant compounds in the headspace (HS) of porcine frankfurters. Frankfurters from different pig breeds presented different volatile profiles due to their different oxidation susceptibilities as a likely result of their fatty acid composition and vitamin E content. Rosemary essential oil showed a different effect on the generation of volatiles depending on the type of frankfurter in which they were added. In frankfurters from Iberian pigs, the antioxidant effect of the essential oil improved with increasing levels, showing the highest activity at 600 mg/kg. In contrast, 150 mg/kg of the essential oil improved the oxidative stability of frankfurters from white pigs, whereas higher levels led to no effect or a prooxidant effect. The activity of the essential oil could have been affected by the different fatty acid compositions and vitamin E contents between types of frankfurters. SPME successfully allowed the isolation and analysis of volatile terpenes from frankfurters with added rosemary essential oil including alpha-pinene, beta-myrcene, l-limonene, (E)-caryophyllene, linalool, camphor, and 1,8-cineole, which might contribute to the aroma characteristics of frankfurters.

Alcohols↗

Analysis of menthol in three traditional Chinese medicinal herbs and their compound formulation by GC-MS.

A GC-MS method was developed for identification and determination of menthol in three traditional Chinese medicinal herbs and their compound formulation, a granule for treating colds. Volatile oil was simultaneously distilled and extracted into ethyl ether in a unique glass extractor. The separation was performed on an HP-5 MS column. The standard addition method was used for quantitative determination of menthol content in herbal materials and in the granule. A component in the samples was chosen as the internal standard. The contents were calculated with the ratio of peak area percentage. Menthol was identified as the main component in Mentha haplocalyx Briq., and also existed in spikes of Schizonepeta tenuifolia Briq., Folium perilla frutescens (L.) Britt. and granules. The quantitative calibration range was 0.21-10.5 mg/mL. Good precision was demonstrated by an RSD < 4.0%. The mean content of menthol in Mentha haplocalyx Briq., spikes of Schizonepeta tenuifolia Briq., Folium perilla frutescens (L.) Britt. and granules was 121, 0.234, 1.03 and 1.84 mg/kg respectively.

Calibration↗

Degradation of the natural mutagenic compound safrole in spices by cooking and irradiation.

Safrole was determined using gas-liquid chromatography in some common spices as star anise, cumin, black pepper and ginger. Safrole concentration in these spices was 9,325, 3,432, 955 and 500 mg.kg-1, respectively. Black pepper was chosen to use in the following experiments. Using Ames-test with Salmonella TA 98 and TA 100 proved high cytotoxic effects due to pure safrole and black pepper volatile oil in both of them. The degradation of safrole was obvious after drying of the washed seeds of black pepper especially at 70 degrees C for 30 min or with sun-drying. Also, high irradiation doses (20 and 30 kGy) caused high degradation of more than 90% of the initial toxic concentration in black pepper. Whereas, microwave caused same effects at 75 s, but unfortunately, the powder was burned due to moisture absence. Boiling whole seeds or powder of black pepper during cooking for few minutes (1-5 min) were more efficient in decreasing safrole content. Finally, these results proved that the mutagenicity of some spices due to presence of safrole can be destructed during drying of the washed seeds or during cooking either with or without any additional treatment as irradiation. But irradiation of these species became more necessary for using in some food industries as milk products to get more safe for human consumption.

Chromatography, Gas↗

Immunosuppressive and cytotoxic properties of Nigella sativa.

In this study the volatile oil of Nigella sativa seeds (NSVO) was investigated for its immunomodulating and cytotoxic properties. A rat model was designed to examine the effect of NSVO on selected immune components. Long-Evans rats were challenged with a specific antigen (typhoid TH) and treated with NSVO; and the changes produced in their serum antibody titre along with the splenocytes and peripheral immune cells were analysed. Antibody titre for the experimental animal was found to be 1280 as compared to the 2560 in the control rats. There was a significant (p < 0.05) decrease in splenocytes and neutrophils counts, but a rise in peripheral lymphocytes and monocytes in the experimental animals. To test the cytotoxicity of NSVO, a panel of five human cancer cell lines and a fibroblast line was used. The MTT assay was employed to estimate the cell mortality. Vinblastine sulphate and mitomycin C were used as the positive control. LC(50) values for NSVO were 155.02 +/- 10.4, 185.77 +/- 2.9, 120.40 +/- 20.5, 384.53 +/- 12.1 and 286.83 +/- 23.3 micro g/ml respectively against the SCL, SCL-6, SCL-37'6, NUGC-4 cancer lines and 3T6 fibroblast line. Results indicate that the NSVO could be considered as a potential immunosuppressive cytotoxic agent.

Animals↗

Identification of volatile compounds in hybrids between raspberry (Rubus idaeus, L.) and arctic bramble (Rubus arciticus, L.).

The present work is concerned with the aroma of hybrids between raspberry (Rubus idaeus, L.) and arctic bramble (Rubus arcticus, L.). Analyses of the volatiles were performed in three stages. The carbonyl compounds were determined as 2,4-dinitrophenylhydrazones, the volatile acids and the neutral components separately in a combined gas chromatography-mass spectrometer components separately in a combined gas chromatograph-mass spectrometer using glass capillary columns. Over 70 compounds were identified in the aroma concentrates of the hybrids. The major components included acetic and hexanoic acids, trans 3-penten-1-ol, 2-heptanol, 3-methyl-2-buten-1-ol, benzyl alcohol and linalool. 2,5-Dimethyl-4-methoxy-2,3-dihydro-3-furanone together with alpha and beta-ionones, characteristic compounds of arctic bramble and raspberry, respectively, were found in the hybrids in much lower concentrations than in the parent berries. Percentage concentrations of the main components in the volatile oils, together with their approximate concentrations in the press juices, were determined. The contents of the corresponding compounds in arctic bramble and in raspberry are also given.

Acids↗

Effect of irradiation on the microbiological status and flavouring materials of selected spices.

Spices from Egyptian local markets were irradiated with different recommended doses (0, 5, 10, 20 and 30 kGy). The spices tested included dried leaves of marjoram (Majorana hortensis Moench), rhizomes of ginger (Zingiber officinale Roscoe) and powdered hot pepper (Capsicum annum L.). The study included the isolation and identification of micro-organisms in spices following their irradiation, as well as gas chromatographic (GLC) chemical analysis for the presence and structure of volatile oils, pungent and pigment materials. The results showed that hot pepper was contaminated more (9.2 x 10(5)/g) than marjoram (4.2 x 10(3)/g) and ginger (14.3 x 10(3)/g) with respect to total aerobic bacterial content. The total contents of moulds were 4.8 x 10(3)/g, 5.7 x 10(3)/g and 19 x 10(3)/g in the same spices, respectively, but the pathogenic moulds and bacterial strains differed according to the type of spice. Irradiation at 10, 20 and 30 kGy caused complete elimination of micro-organisms, whereas 5 kGy was less effective. With the GLC method chosen 18 and 50 compounds could be detected in the extracts of marjoram and ginger, respectively; gamma-terpinen and zingiberen being the major compounds in marjoram and ginger, respectively. A noticeable reduction was observed in the amount of terpenes present in irradiated marjoram; they were converted to monoterpenesalcohols. Ginger was more sensitive to irradiation, especially at high doses, but moderate changes were detected at low doses (5 and 10 kGy). A slight, but significant effect on the capsaicin (pungent compound) in hot-pepper was observed following irradiation, whereas no changes in total pigments resulted at any dose. These results prove that 10 kGy is a sufficiently high dose to eliminate the micro-organisms in spices, causing only slight changes in the flavouring materials.

Capsicum↗

Methods for detection of irradiation of spices.

Three types of methods for the identification of irradiation of spices were tested as potential control methods. The methods were microbiological, combining a direct epifluorescent filter technique (DEFT) with a total aerobic plate count (APC), a chemiluminescence method and chemical gas-chromatographic (GC) and GC mass-spectrometric (MS) methods for analysis of volatile oils of spices isolated by steam distillation. Twelve samples of spices, mainly peppers, were analysed before and after gamma-irradiation with doses of 10 and 50 kGy. The chemiluminescence measurements were performed before the irradiation and 10 and 100 days after the irradiation. The best methods for control purposes were the microbiological (DEFT + APC) methods combined with chemiluminescence measurements. No differences were detected between the irradiated and non-irradiated samples with the chemical methods.

Chromatography, Gas↗

Demonstration that limonene is the first cyclic intermediate in the biosynthesis of oxygenated p-menthane monoterpenes in Mentha piperita and other Mentha species.

The volatile oil of mature Mentha piperita (peppermint) leaves contains as major components the oxygenated p-menthane monoterpenes l-menthol (47%) and l-menthone (24%) as well as very low levels of the monoterpene olefins limonene (1%) and terpinolene (0.1%), which are considered to be probable precursors of the oxygenated derivatives. Immature leaves, which are actively synthesizing monoterpenes, produce an oil with comparatively higher levels of limonene (approximately 3%), and isolation of the pure olefin showed this compound to consist of approximately 80% of the l-(4S)-enantiomer and approximately 20% of the d-(4R)-enantiomer. The time course of incorporation of [U-14C]sucrose into the monoterpenes of M. piperita shoot tips was consistent with the initial formation of limonene and its subsequent conversion to menthone via pulegone. d,l-[9-3H]Limonene and [9,10-3H]terpinolene were prepared and tested directly as precursors of oxygenated p-menthane monoterpenes in M. piperita shoot tips. Limonene was readily incorporated into pulegone, menthone, and other oxygenated derivatives, whereas terpinolene was not appreciably incorporated into these compounds. Similarly, d,l-[9-3H]limonene was specifically incorporated into pulegone in Mentha pulegium and into the C-2-oxygenated derivative carvone in Mentha spicata, confirming the role of this olefin as the essential precursor of oxygenated p-menthane monoterpenes. Soluble enzyme preparations from the epidermis of immature M. piperita leaves converted the acyclic terpenoid precursor [1-3H]geranyl pyrophosphate to limonene as the major cyclic product, providing a further indication that this olefin plays a central role in the formation of oxygenated monoterpenes in Mentha. No free intermediates were detected in the cyclization of geranyl pyrophosphate to limonene, suggesting that the olefin is the first cyclic intermediate to arise in the pathway, and resolution of the biosynthetic limonene, by crystallization of the derived d- and l-carvoximes, indicated an enantiomer mixture nearly identical to that isolated from the leaf oil.

Cell-Free System↗

Biosynthesis of ascaridole: iodide peroxidase-catalyzed synthesis of a monoterpene endoperoxide in soluble extracts of Chenopodium ambrosioides fruit.

Ascaridole, an asymmetric monoterpene endoperoxide with anthelmintic properties, occurs as a major constituent (60-80%) in the volatile oil of American wormseed fruit (Chenopodium ambrosioides: Chenopodiaceae), and as a lesser component in the leaf pocket oil of the boldo tree (Peumus boldus: Monimiaceae). Determination of optical activity and chromatographic resolution of naturally occurring ascaridole, and several synthetic derivatives, showed that both wormseed and boldo produce ascaridole in racemic form. The biosynthesis of ascaridole from the conjugated, symmetrical diene alpha-terpinene (a major component of the oil from wormseed) was shown to be catalyzed by a soluble iodide peroxidase isolated from homogenates of C. ambrosioides fruit and leaves. The enzymatic synthesis of ascaridole was confirmed by capillary gas-liquid chromatography and mass spectrometry of the product, which was also shown to be racemic. Optimal enzymatic activity occurred at pH 4.0 in the presence of 2.5 mM H2O2 and 1 mM NaI. Soluble enzyme extracts were fractionated by gel filtration on both Sephacryl S-300 and Sephadex G-100, and were shown to consist of a high-molecular-weight peroxidase component (Mr greater than 1,000,000, 30% of total activity) and two other peroxidase species having apparent molecular weights of 62,000 and 45,000 (major component). Peroxidase activity was susceptible to proteolytic destruction only after periodate treatment, suggesting an association of the enzyme(s) with polysaccharide material. Ascaridole biosynthesis from alpha-terpinene was inhibited by cyanide, catalase, and reducing agents, but not by compounds that trap superoxide or quench singlet oxygen. A peroxide transfer reaction initiated by peroxidase-generated I+ is proposed for the conversion of alpha-terpinene to ascaridole.

Chromatography, Gel↗