SciCombinator

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Concept: Essential oil

226

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

176

New agents that are effective against common pathogens are needed particularly for those resistant to conventional antimicrobial agents. Essential oils (EOs) are known for their antimicrobial activity. Using the broth microdilution method, we showed that (1) two unique blends of Cinnamomum zeylanicum, Daucus carota, Eucalyptus globulus and Rosmarinus officinalis EOs (AB1 and AB2; cinnamon EOs from two different suppliers) were active against the fourteen Gram-positive and -negative bacteria strains tested, including some antibiotic-resistant strains. Minimal inhibitory concentrations (MICs) ranged from 0.01% to 3% v/v with minimal bactericidal concentrations from <0.01% to 6.00% v/v; (2) a blend of Cinnamomum zeylanicum, Daucus carota, Syzygium aromaticum, Origanum vulgare EOs was antifungal to the six Candida strains tested, with MICs ranging from 0.01% to 0.05% v/v with minimal fungicidal concentrations from 0.02% to 0.05% v/v. Blend AB1 was also effective against H1N1 and HSV1 viruses. With this dual activity, against H1N1 and against S. aureus and S. pneumoniae notably, AB1 may be interesting to treat influenza and postinfluenza bacterial pneumonia infections. These blends could be very useful in clinical practice to combat common infections including those caused by microorganisms resistant to antimicrobial drugs.

Concepts: Bacteria, Microbiology, Virus, Cinnamon, Medicinal plants, Antimicrobial, Essential oil, Cinnamomum aromaticum

168

Lavender essential oils are predominantly constituted of regular monoterpenes, for example linalool, 1, 8 cineole and camphor. However, they also contain irregular monoterpenes including lavandulol and lavandulyl acetate. Although the majority of genes responsible for the production of regular monoterpenes in lavenders are now known, enzymes (including LPPS) catalyzing the biosynthesis of irregular monoterpenes in these plants have not been described. Here, we report the isolation and functional characterization of a novel cis prenyl diphosphate synthase cDNA, termed L. x intermedia lavandulyl diphosphate synthase (LiLPPS), through a homology based cloning strategy. The LiLPPS ORF, encoding for a 305 amino acids long protein, was expressed in E. coli and the recombinant protein was purified by NiNTA affinity chromatography. The ca. 34.5 kDa bacterially produced protein specifically catalyzed the head to middle condensation of two DMAPP units to LPP in vitro with apparent Km and kcat values of 208 microM and 0.1, respectively. LiLPPS is a homodimeric enzyme with a sigmoidal saturation curve and hill coefficient of 2.7, suggesting a positive cooperative interaction among its catalytic sites. LiLPPS could be used to modulate the production of lavandulol and its derivatives in plants through metabolic engineering.

Concepts: DNA, Protein, Amino acid, Metabolism, Enzyme, Escherichia coli, Essential oil, Lavender

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

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

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

145

The Asian citrus psyllid, Diaphorina citri Kuwayama, is the insect vector of the pathogen causing huanglongbing. We selected three botanical oils to evaluate behavioral activity against D. citri. In laboratory olfactometer assays, fir oil was repellent to D. citri females, while litsea and citronella oils elicited no response from D. citri females. In choice settling experiments, D. citri settled almost completely on control plants rather than on plants treated with fir oil at a 9.5 mg/day release rate. Therefore, we conducted field trials to determine if fir oil reduced D. citri densities in citrus groves. We found no repellency of D. citri from sweet orange resets that were treated with fir oil dispensers releasing 10.4 g/day/tree as compared with control plots. However, we found a two-week decrease in populations of D. citri as compared with controls when the deployment rate of these dispensers was doubled. Our results suggest that treatment of citrus with fir oil may have limited activity as a stand-alone management tool for D. citri and would require integration with other management practices.

Concepts: Water, Citrus, Liquid, Fruit, Orange, Hemiptera, Essential oil, Insect repellent

140

Patchouli is used as an incense material and essential oil. The characteristic odor of patchouli leaves results from the drying process used in their production; however, there have to date been no reports on the changes in the odor of patchouli leaves during the drying process. We investigated the aroma profile of dried patchouli leaves using the hexane extracts of fresh and dried patchouli leaves. We focused on the presence or absence of the constituents of the fresh and dried extracts, and the differences in the content of the common constituents. Fourteen constituents were identified as characteristic of dried patchouli extract odor by gas chromatography-olfactometry analysis. The structures of seven of the 14 constituents were determined by gas chromatography-mass spectrometry (α-patchoulene, seychellene, humulene, α-bulnesene, isoaromadendrene epoxide, caryophyllene oxide, and patchouli alcohol). The aroma profile of the essential oil obtained from the dried patchouli leaves was clearly different from that of dried patchouli. The aroma profile of the essential oil was investigated by a similar method. We identified 12 compounds as important odor constituents. The structures of nine of the 12 constituents were determined by gas chromatographymass spectrometry (cis-thujopsene, caryophyllene, α-guaiene, α-patchoulene, seychellene, α-bulnesene, isoaromadendrene epoxide, patchouli alcohol, and corymbolone). Comparing the odors and constituents demonstrated that the aroma profile of patchouli depends on the manufacturing process.

Concepts: Olfaction, Drying, Perfume, Odor, Essential oil, Aroma compound, Aromatherapy, Patchouli

110

Olfactory stimulation is an often overlooked method of environmental enrichment for cats in captivity. The best known example of olfactory enrichment is the use of catnip, a plant that can cause an apparently euphoric reaction in domestic cats and most of the Pantherinae. It has long been known that some domestic cats and most tigers do not respond to catnip. Although many anecdotes exist of other plants with similar effects, data are lacking about the number of cats that respond to these plants, and if cats that do not respond to catnip respond to any of them. Furthermore, much is still unknown about which chemicals in these plants cause this response.

Concepts: Felidae, Essential oil, Valerian, Nepeta, Dipsacales, Nepetalactone

41

The accurate identification of bay leaf in natural products commerce may often be confusing as the name is applied to several different species of aromatic plants. The true “bay leaf”, also known as “bay laurel” or “sweet bay”, is sourced from the tree Laurus nobilis, a native of the Mediterranean region. Nevertheless, the leaves of several other species including Cinnamomum tamala, Litsea glaucescens, Pimenta racemosa, Syzygium polyanthum, and Umbellularia californica are commonly substituted or mistaken for true bay leaves due to their similarity in the leaf morphology, aroma, and flavor. Substitute species are, however, often sold as “bay leaves”. As such, the name “bay leaf” in literature and herbal commerce may refer to any of these botanicals. The odor and flavor of these leaves are, however, not the same as the true bay leaf, and for that reason they should not be used in cooking as a substitute for L. nobilis. Some of the bay leaf substitutes can also cause potential health problems. Therefore, the correct identification of the true bay leaf is important. The present work provides a detailed comparative study of the leaf morphological and anatomical features of L. nobilis and its common surrogates to allow for correct identification.

Concepts: Plant morphology, Essential oil, Herbs, Lauraceae, Laurus, Malabathrum, Bay Laurel, Laurales genera