SciCombinator

Discover the most talked about and latest scientific content & concepts.

Concept: Oil

221

Postoperative nausea (PON) is a common complication of anesthesia and surgery. Antiemetic medication for higher-risk patients may reduce but does not reliably prevent PON. We examined aromatherapy as a treatment for patients experiencing PON after ambulatory surgery. Our primary hypothesis was that in comparison with inhaling a placebo, PON will be reduced significantly by aromatherapy with (1) essential oil of ginger, (2) a blend of essential oils of ginger, spearmint, peppermint, and cardamom, or (3) isopropyl alcohol. Our secondary hypothesis was that the effectiveness of aromatherapy will depend upon the agent used.

Concepts: Carbon, Anesthesia, Alcohol, Chemotherapy, Ethanol, Oil, Ginger, Essential oil

188

The primary defence against mosquitoes and other disease vectors is often the application of a repellent. Despite their common use, the mechanism(s) underlying the activity of repellents is not fully understood, with even the mode of action of DEET having been reported to be via different mechanisms; e.g. interference with olfactory receptor neurones or actively detected by olfactory receptor neurones on the antennae or maxillary palps. In this study, we discuss a novel mechanism for repellence, one of P450 inhibition. Thirteen essential oil extracts from Colombian plants were assayed for potency as P450 inhibitors, using a kinetic fluorometric assay, and for repellency using a modified World Health Organisation Pesticide Evaluations Scheme (WHOPES) arm-in cage assay with Stegomyia (Aedes) aegypti mosquitoes. Bootstrap analysis on the inhibition analysis revealed a significant correlation between P450-inhibition and repellent activity of the oils.

Concepts: Xanthine oxidase inhibitor, Oil, Inhibitor, Enzyme inhibitor, Aedes aegypti, Mosquito, Aedes, Insect repellent

168

BACKGROUND: Pelargonium graveolens (P. graveolens) L. is an aromatic and medicinal plant belonging to the geraniacea family. RESULTS: The chemical compositions of the essential oil as well as the in vitro antimicrobial activities were investigated. The GC-MS analysis of the essential oil revealed 42 compounds. Linallol L, Citronellol, Geraniol, 6-Octen-1-ol, 3,7-dimethyl, formate and Selinene were identified as the major components. The tested oil and organic extracts exhibited a promising antimicrobial effect against a panel of microorganisms with diameter inhibition zones ranging from 12 to 34 mm and MICs values from 0.039 to10 mg/ml. The investigation of the phenolic content showed that EtOAc, MeOH and water extracts had the highest phenolic contents. CONCLUSION: Overall, results presented here suggest that the essential oil and organic extracts of P. graveolens possesses antimicrobial and properties, and is therefore a potential source of active ingredients for food and pharmaceutical industry.

Concepts: Rose, Rose oil, Oils, Water, Pharmacology, Pelargonium graveolens, Essential oil, Oil

152

Ranunculus nipponicus var. submersus is an aquatic macrophyte; it is known as a wild edible plant in Japan for a long time. In this study, the essential oils from the fresh and dried aerial parts of R. nipponicus var. submersus were extracted by hydrodistillation and analyzed by gas chromatography (GC) and GC-mass spectrometry (GC-MS). Moreover, important aroma-active compounds were also detected in the oil using GC-olfactometry (GC-O) and aroma extract dilution analysis (AEDA). Thus, 98 compounds (accounting for 93.86%) of the oil were identified. The major compounds in fresh plant oil were phytol (41.94%), heptadecane (5.92%), and geranyl propionate (5.76%), while those of. Dried plant oil were β-ionone (23.54%), 2-hexenal (8.75%), and dihydrobovolide (4.81%). The fresh and dried oils had the green-floral and citrus-floral odor, respectively. The GC-O and AEDA results show that phenylacetaldehyde (green, floral odor, FD-factor = 8) and β-ionone (violet-floral odor, FD-factor = 8) were the most characteristic odor compounds of the fresh oils. β-Cyclocitral (citrus odor, FD-factor = 64) and β-ionone (violet-floral odor, FD-factor = 64) were the most characteristic odor compounds of the dried oil. These compounds are thought to contribute to the flavor of R. nipponicus var. submersus.

Concepts: Aroma compound, Gas chromatography, Fat, Chemical compound, Water, Oil, Oils, Essential oil

145

This article describes the various chemical components as obtained from the oils in the leaves of Cymbopogon citratus using hydrodistillation and solvent-free microwave extraction methods. Furthermore, extractions of the oils were also carried out with a slight in pH variation and compared, “GC-MS evaluation of C. citratus (DC) Stapf oil obtained using modified hydrodistillation and microwave extraction methods” (Ajayi et al., 2016 [1]). The current article contains one table exhibiting a list of compounds in the four different methods of extraction. Comparative studies amongst the various methods of extraction are highlighted in the table.

Concepts: Oils, Essential oil, Chemical compound, Cymbopogon citratus, Oil, Cymbopogon

48

The widespread prevalence of commercial products made from microgels illustrates the immense practical value of harnessing the jamming transition; there are countless ways to use soft, solid materials that fluidize and become solid again with small variations in applied stress. The traditional routes of microgel synthesis produce materials that predominantly swell in aqueous solvents or, less often, in aggressive organic solvents, constraining ways that these exceptionally useful materials can be used. For example, aqueous microgels have been used as the foundation of three-dimensional (3D) bioprinting applications, yet the incompatibility of available microgels with nonpolar liquids, such as oils, limits their use in 3D printing with oil-based materials, such as silicone. We present a method to make micro-organogels swollen in mineral oil, using block copolymer self-assembly. The rheological properties of this micro-organogel material can be tuned, leveraging the jamming transition to facilitate its use in 3D printing of silicone structures. We find that the minimum printed feature size can be controlled by the yield stress of the micro-organogel medium, enabling the fabrication of numerous complex silicone structures, including branched perfusable networks and functional fluid pumps.

Concepts: Glass transition, Lubricant, Oil, Linear elasticity, Elasticity, Polymer chemistry, Liquid, Polymer

32

Quantitative information regarding the endmember composition of the gas and oil that flowed from the Macondo well during the Deepwater Horizon oil spill is essential for determining the oil flow rate, total oil volume released, and trajectories and fates of hydrocarbon components in the marine environment. Using isobaric gas-tight samplers, we collected discrete samples directly above the Macondo well on June 21, 2010, and analyzed the gas and oil. We found that the fluids flowing from the Macondo well had a gas-to-oil ratio of 1,600 standard cubic feet per petroleum barrel. Based on the measured endmember gas-to-oil ratio and the Federally estimated net liquid oil release of 4.1 million barrels, the total amount of C(1)-C(5) hydrocarbons released to the water column was 1.7 10(11) g. The endmember gas and oil compositions then enabled us to study the fractionation of petroleum hydrocarbons in discrete water samples collected in June 2010 within a southwest trending hydrocarbon-enriched plume of neutrally buoyant water at a water depth of 1,100 m. The most abundant petroleum hydrocarbons larger than C(1)-C(5) were benzene, toluene, ethylbenzene, and total xylenes at concentrations up to 78 μg L(-1). Comparison of the endmember gas and oil composition with the composition of water column samples showed that the plume was preferentially enriched with water-soluble components, indicating that aqueous dissolution played a major role in plume formation, whereas the fates of relatively insoluble petroleum components were initially controlled by other processes.

Concepts: Natural gas, Fluid dynamics, Liquid, Oil, Gasoline, Benzene, Hydrocarbon, Petroleum

30

Abstract Objectives: The objective of this pilot study was to determine the effectiveness of a mixture of essential oils (peppermint, basil, and helichrysum) on mental exhaustion, or moderate burnout (ME/MB) using a personal inhaler. Design: This was a randomized, controlled, double-blind pilot study. Data were collected 3 times a day for 3 weeks (Monday-Friday). The first week was baseline for both groups, the second week was intervention (aromatherapy or placebo), and the third week was washout. Settings/location: Participants used a personal inhaler at home or at work. Subjects: The subjects comprised a convenience sample of 13 women and 1 man who each had self-assessed ME/MB. Interventions: Participants were randomized to receive a personal inhaler containing either a mixture of essential oils or rose water (as used in Indian cooking). Outcome measures: The outcome measures were a 0-10 scale with 10=worst feeling of burnout, 0=no feeling of burnout. There was a qualitative questionnaire rating aroma and a questionnaire listing perceived stressors. Results: While both groups had a reduction in perception of ME/MB, the aromatherapy group had a much greater reduction. Conclusions: The results suggest that inhaling essential oils may reduce the perceived level of mental fatigue/burnout. Further research is warranted.

Concepts: Oil, Effectiveness, Perception, Aromatherapy, Mind, Rose, Psychology, Essential oil

29

ETHNOPHARMACOLOGICAL SIGNIFICANCE: Although no known medicinal use for Pittosporum undulatum Vent. (Pittosporaceae) has been recorded, anecdotal evidence suggests that Australian Aboriginal people used P. angustifolium Lodd., G.Lodd. & W.Lodd. topically for eczema, pruritis or to induce lactation in mothers following child-birth and internally for coughs, colds or cramps. AIMS OF THE STUDY: Essential oil composition and bioactivity as well as differential solvent extract antimicrobial activity from P. angustifolium is investigated here firstly, to partially describe the composition of volatiles released in traditional applications of P. angustifolium for colds or as a lactagogue, and secondly to investigate antibacterial activity related to topical applications. Essential oils were also investigated from P. undulatum Vent., firstly to enhance essential oil data produced in previous studies, and secondly as a comparison to P. angustifolium. MATERIALS AND METHODS: Essential oils were hydrodistilled from fruit and leaves of both species using a modified approach to lessen the negative (frothing) effect of saponins. This was achieved by floating pumice or pearlite obsidian over the mixture to crush the suds formed while boiling. Essential oil extracts were analysed using GC-MS, quantified using GC-FID then screened for antimicrobial activity using a micro-titre plate broth dilution assay (MIC). Using dichloromethane, methanol, hexane and H(2)O as solvents, extracts were produced from leaves and fruit of P. angustifolium and screened for antimicrobial activity and qualitative phytochemical character. RESULTS: Although the essential oil from leaves and fruit of P. undulatum demonstrated some component variation, the essential oil from fruits of P. angustifolium had major constituents that strongly varied according to the geographical location of collection, suggesting the existence of at least two chemotypes; one with high abundance of acetic acid decyl ester. This chemotype had high antimicrobial activity whilst the other chemotype had only moderate antimicrobial activity against the three microbial species investigated here. This result may support the occurrence of geographical specificity with regard to ethnopharmacological use. Antimicrobial activity screening of the solvent extracts from P. angustifolium revealed the leaves to be superior to fruit, with water being the most suitable extraction solvent. CONCLUSION: To the best of our knowledge, this study constitutes the first time essential oils, and solvent extracts from the fruits of P. angustifolium, have been examined employing comprehensive chemical and biological analysis. The essential oil composition presented in this paper, includes components with structural similarity as chemosemiotic compounds involved in mother-infant identification, which may have significance with regard to traditional applications as a lactagogue.

Concepts: Petroleum, Water, Acetic acid, Oil, Essential oil, Indigenous Australians, Solvent, Ethanol

28

Volatile compounds play a key role in determining the sensory appreciation of vegetable oils. In this study a systematic evaluation of odorants responsible for the characteristic flavour of roasted tigernut oil was carried out.

Concepts: Oil, Oils, Essential oil, Cyperus rotundus, Fat, Cyperus, Cyperus esculentus