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Nutritional Neuroscience 2006Citrus essential oils have been utilized widely in traditional medicine, and there are various reports of actions such as effects on behavior and effects on pain...
Citrus essential oils have been utilized widely in traditional medicine, and there are various reports of actions such as effects on behavior and effects on pain stimulation response due to exposure. However, there are no reports concerning effects on neurotransmitters after ingestion, and uptake within the brain. We used brain tissue slices to investigate the effect of compounds in lemon essential oil on monoamine release. We investigated R-limonene, gamma-terpinene and citral, major components of lemon essential oil; S-limonene, an isomer of R-limonene and metabolites of these compounds. The effect of each compound on monoamine release from brain tissue slices was found to be dose-dependent. R-Limonene and its S-isomer demonstrated differences with regard to monoamine release from brain tissue. S-Limonene and its metabolites were found to have a stronger effect than the R-isomer. Limonene metabolites taken up in vivo were also found to have a stronger effect on monoamine release than both the R-form and the S-form. In an investigation of dopamine release using stratum slices, terpinene and pinene demonstrated no clear differences in activity attributable to isomers. However, rho-cymene, a gamma-terpinene metabolite, was found to have a stronger effect than gamma-terpinene. These results suggest that the metabolites of these monoterpene compounds contained in citrus essential oils have a stronger effect on monoamine release from brain tissue than the monoterpene compounds themselves.
Topics: Acyclic Monoterpenes; Animals; Biogenic Monoamines; Brain; Cerebral Cortex; Citrus; Corpus Striatum; Cyclohexane Monoterpenes; Cyclohexenes; Cymenes; Dopamine; Isomerism; Limonene; Monoterpenes; Oils, Volatile; Rats; Rats, Wistar; Serotonin; Taste; Terpenes
PubMed: 16913049
DOI: 10.1080/10284150600573660 -
Archives of Biochemistry and Biophysics Feb 2024Rhodococcus globerulus (R. globerulus) was isolated from the soil beneath a Eucalypt tree. Metabolic growth studies revealed that R. globerulus was capable of living on...
Rhodococcus globerulus (R. globerulus) was isolated from the soil beneath a Eucalypt tree. Metabolic growth studies revealed that R. globerulus was capable of living on certain monoterpenes, including 1,8-cineole and p-cymene, as sole sources of carbon and energy. Multiple P450 genes were identified in the R. globerulus genome that shared homology to known bacterial, monoterpene hydroxylating P450s. To date, two of these P450s have been expressed and characterised as 1,8-cineole (CYP176A1) and p-cymene (CYP108N12) monooxygenases that are believed to initiate the biodegradation of these terpenes. In this work, another putative P450 gene (CYP108N14) was identified in R. globerulus genome. Given its amino acid sequence identity to other monoterpene hydroxylating P450s it was hypothesised to catalyse monoterpene hydroxylation. These include CYP108A1 from Pseudomonas sp. (47 % identity, 68 % similarity) which hydroxylates α-terpineol, and CYP108N12 also from R. globerulus (62 % identity, 77 % similarity). Also present in the operon containing CYP108N14 were putative ferredoxin and ferredoxin reductase genes, suggesting a typical Class I P450 system. CYP108N14 was successfully over-expressed heterologously and purified, resulting in a good yield of CYP108N14 holoprotein. However, neither the ferredoxin nor ferredoxin reductase could be produced heterologously. Binding studies with CYP108N14 revealed a preference for the monoterpenes p-cymene, (R)-limonene, (S)-limonene, (S)-α-terpineol and (S)-4-terpineol. An active catalytic system was reconstituted with the non-native redox partners cymredoxin (from the CYP108N12 system) and putidaredoxin reductase (from the CYP101A1 system). CYP108N14 when supported by these redox partners was able to catalyse the hydroxylation of the five aforementioned substrates selectively at the methyl benzylic/allylic positions.
Topics: Monoterpenes; Eucalyptol; Cytochrome P-450 Enzyme System; Ferredoxins; Limonene; Cyclohexane Monoterpenes; Cymenes; Rhodococcus
PubMed: 38072297
DOI: 10.1016/j.abb.2023.109852 -
Insect Science Feb 2017Monoterpenes, source of the distinctive odor of conifers, are generally considered plant defensive compounds. However, they are also known to act as long-range insect...
Monoterpenes, source of the distinctive odor of conifers, are generally considered plant defensive compounds. However, they are also known to act as long-range insect attractants, as they are volatile and permeate forest airspaces. Moreover, they are lipid soluble and can be absorbed into plant epicuticular waxes. We test their role in short-range host plant choice by both adult females and larvae of a folivorous forest pest (Choristoneura fumiferana). We conducted laboratory assays testing the responses of Eastern spruce budworm to an artificial monoterpene mix (α-pinene, β-pinene, limonene, myrcene) and to white spruce (Picea glauca) epicuticular waxes in closed arenas. Ovipositing females preferred filter paper discs treated with P. glauca waxes to controls, and preferred the waxes + monoterpenes treatment to waxes alone. However, females showed no preference between the monoterpene-treated disc and the control when presented without waxes. Feeding larvae prefered wax discs to control discs. They also consumed discs treated with realistic monoterpene concentrations and wax preferentially over wax-only discs, but showed no preference between extremely high monoterpene concentrations and wax-only controls. In an insect-free assay, P. glauca epicuticular wax decreased monoterpene volatilization. These results suggest that P. glauca waxes and realistic concentrations of monoterpenes are stimulatory to both egg-laying females and feeding larvae, and that their effects are synergistic.
Topics: Animals; Female; Larva; Monoterpenes; Moths; Oviposition; Picea; Plant Leaves; Waxes
PubMed: 26463122
DOI: 10.1111/1744-7917.12279 -
Se Pu = Chinese Journal of... Aug 2019One of the most abundant biological volatile organic compounds (BVOCs) in the atmosphere, monoterpene, is characterized by its short lifetime, low concentration, fast...
One of the most abundant biological volatile organic compounds (BVOCs) in the atmosphere, monoterpene, is characterized by its short lifetime, low concentration, fast temporal and spatial variations, and wide variety of isomers. In this study, a multi-capillary column (MCC) was combined with high-pressure photoionization time-of-flight mass spectrometry (HPPI-TOF MS) and employed to develop an MCC-HPPI-TOF MS combination instrument as an online two-dimensional gas chromatography-mass spectrometry (GC-MS) method for the rapid qualitative and quantitative analysis of monoterpene isomers. As a result, six monoterpene isomers, -pinene, -pinene, -terpinene, -terpinene, 3-carene, and limonene, were successfully isolated in 180 s with limits of detection (LODs) as low as 6 μg/m without sample pre-enrichment. This method was successfully applied to the rapid online analysis of monoterpenes released from the branches and leaves of and , which shows the capability and potential application of the method for the online detection of complex sample mixtures in environmental monitoring, process analysis, and other fields.
Topics: Gas Chromatography-Mass Spectrometry; Mass Spectrometry; Monoterpenes; Volatile Organic Compounds
PubMed: 31642262
DOI: 10.3724/SP.J.1123.2019.04037 -
Archives of Toxicology Nov 1981A patient attempting suicide ingested 400-500 ml pine oil and was admitted to the clinic. Since more than the lethal dose had been ingested hemoperfusions with activated...
A patient attempting suicide ingested 400-500 ml pine oil and was admitted to the clinic. Since more than the lethal dose had been ingested hemoperfusions with activated charcoal and amberlite and a hemodialysis were performed. The composition of the ingested pine oil was determined by gaschromatography/mass spectrometry. Four monoterpenes were identified: 57% alpha-pinene, 8% beta-pinene, 26% carene, 6% limonene and 3% other hydrocarbons. The blood and urine monoterpene concentrations were continuously monitored. The data suggest that monoterpenes are poorly resorbed in the gastrointestinal tract. The resorbed portion of the hydrocarbons cumulates in the lipophilic body compartments and is slowly metabolized and then excreted by the kidneys. The main metabolic pathways are hydratation, hydroxylation, rearrangement, and acetylation. Five metabolites were identified.
Topics: Bicyclic Monoterpenes; Bridged Bicyclo Compounds; Cyclohexenes; Electroencephalography; Gas Chromatography-Mass Spectrometry; Hemoperfusion; Humans; Limonene; Male; Middle Aged; Monoterpenes; Oils; Terpenes
PubMed: 7325802
DOI: 10.1007/BF00352074 -
Biomedicine & Pharmacotherapy =... Oct 2020Australian tea tree (Melaleuca alternifolia) oil (TTO) and its monoterpene constituents such as terpinen-4-ol (T4O), 1,8-cineole, limonene, p-cymene, and α-terpinene... (Review)
Review
Australian tea tree (Melaleuca alternifolia) oil (TTO) and its monoterpene constituents such as terpinen-4-ol (T4O), 1,8-cineole, limonene, p-cymene, and α-terpinene have been shown to be effective in controlling a wide range of parasitic infections. The anti-parasitic effects of these compounds are mainly due to their anti-histamine and anti-acetylcholinesterase activities as well as their ability to modulate host inflammatory responses. This review attempts to summarize recent advances in the uses of TTO and its 15 major monoterpene constituents in treating parasitic infections in both humans and animals. Activities against parasitic protozoans (Plasmodium falciparum, Leishmania spp., Trypanosoma spp., Acanthamoeba castellanii, Trichomonas vaginalis, Eimeria, and Ichthyophthirius multifiliis), nematodes (Haemonchus contortus and Anisakis simplex), cestode (Echinococcus ortleppi), and monogeneans (Gasterosteus spp. and Dactylogyrus minutus) have been reported, showing good potentials in treating parasitic infections. Further studies are necessary for developing anti-parasite therapies using TTO or its monoterpenes constituents.
Topics: Animals; Anti-Infective Agents, Local; Antiprotozoal Agents; Helminthiasis; Humans; Melaleuca; Monoterpenes; Protozoan Infections; Tea Tree Oil
PubMed: 33503761
DOI: 10.1016/j.biopha.2020.110624 -
Current Pharmaceutical Design 2008Oregano essential oils obtained from the genera Origanum, Thymus, Coridothymus, Thymbra, Satureja and Lippia are rich in carvacrol, a monoterpenic phenol isomeric with... (Review)
Review
Oregano essential oils obtained from the genera Origanum, Thymus, Coridothymus, Thymbra, Satureja and Lippia are rich in carvacrol, a monoterpenic phenol isomeric with thymol. Turkey is the biggest exporter of oregano herb and oil to the world markets. Oregano is mainly used in food, spice and pharmaceutical industries. Carvacrol is responsible for the biological activities of oregano. Many diverse activities of carvacrol such as antimicrobial, antitumor, antimutagenic, antigenotoxic, analgesic, antispasmodic, antiinflammatory, angiogenic, antiparasitic, antiplatelet, AChe inhibitory, antielastase, insecticidal, antihepatotoxic and hepatoprotective activities and uses such as feed additive, in honeybee breeding and in gastrointestinal ailments have been shown. This paper highlights these activities and attempts to explain the possible in vivo mechanism of action of carvacrol.
Topics: Animals; Classification; Cymenes; Humans; Molecular Structure; Monoterpenes; Oils, Volatile; Origanum; Plant Oils; Turkey
PubMed: 19075694
DOI: 10.2174/138161208786404227 -
Journal of Chemical Ecology May 2002We conducted defoliation experiments with 7- to 8-year-old clones of Douglas fir [Pseudotsuga menziesii (Mirb.) Franco var. glauca] to assess the role of monoterpenes as...
We conducted defoliation experiments with 7- to 8-year-old clones of Douglas fir [Pseudotsuga menziesii (Mirb.) Franco var. glauca] to assess the role of monoterpenes as a resistance mechanism to western spruce budworm (Choristoneura occidentalis Freeman) defoliation. The grafted clones were derived from mature trees that showed resistance or susceptibility to budworm defoliation in the forest. All clones were exposed to either budworm defoliation or nondefoliation treatments in 1998 and 1999 under greenhouse conditions. We found that the total concentration of monoterpenes in current-year foliage varied greatly between two consecutive years in clones in the greenhouse and in their corresponding mature trees in the forest. Fractional composition of different monoterpenes was similar between different years and between clones and mature trees, indicating genetic control of this trait. Two different defoliation experiments were conducted to assess the importance of budburst phenology as a factor determining host plant resistance. In the 1998 experiment, budworm feeding was matched to the budburst of each individual plant. Monoterpene concentration was high in 1998, and budworm potential fitness was greater on clones from the resistant mature trees that had lower concentrations of total monoterpenes. In the 1999 experiment, budworm feeding was matched to budburst of the whole population of plants in order to mimic conditions similar to insects feeding on trees in the field. The concentration of monoterpenes was low in 1999, and budworm fitness was not related to monoterpenes. Total monoterpene concentration was negatively related to foliar nitrogen concentration, suggesting that C/N balance may affect monoterpene synthesis in needles. However, tree growth was not related to total monoterpene concentration. We concluded that expression of differences in budworm resistance among Douglas fir genotypes might be caused by interactions among multiple resistance mechanisms such as needle monoterpenes and tree budburst phenology.
Topics: Animals; Feeding Behavior; Female; Male; Monoterpenes; Moths; Pseudotsuga
PubMed: 12049230
DOI: 10.1023/a:1015297315104 -
Journal of Economic Entomology Jun 2009The medical and veterinary pest Musca domestica L. has developed resistance to most insecticides used against it. For this reason, there is a constant search for new...
The medical and veterinary pest Musca domestica L. has developed resistance to most insecticides used against it. For this reason, there is a constant search for new alternative control tools. The aims of this study were (1) to evaluate the toxicological effects caused by the fumigant activity and the topical application of five essential oils and five monoterpenes in M. domestica adult males and (2) to study the variation of the fumigant activity of the essential oils and monoterpenes according to the solvent used (acetone or a silicone base). Houses flies were exposed to vapors delivered by filter paper treated with 200 microl of essential oil or monoterpene (10%) in acetone or a silicone base. The knockdown time 50% (KT50) values obtained for essential oils (expressed in minutes) were 3.3 (eucalyptus); 10.1 (orange); 10.4 (mint); 10.9 (lavender); and 17.7 (geranium). The KT50 values obtained for monoterpenes (expressed in minutes) were 2.3 (eucalyptol); 7.5 (limonene); 7.6 (linalool); 19.0 (menthone); and 22.6 (menthyl acetate). In all cases, a delay in the onset of poisoning symptoms was observed when a silicone base vehicle was used. When topically applied, the lethal dose 50% (LD50) values for essential oils (expressed in micrograms of oil/insect) were 0.07 (geranium); 0.09 (mint); 0.13 (lavender); 0.14 (eucalyptus); and 0.16 (orange). The LD50 values for monoterpenes (expressed in micrograms of monoterpene/insect) were 0.04 (linalool); 0.09 (menthyl acetate); 0.10 (limonene); 0.11 (menthone); and 0.13 (eucalyptol). These results suggest that the studied essential oils and monoterpenes are potential tools for controlling M. domestica.
Topics: Animals; Houseflies; Insect Control; Lethal Dose 50; Monoterpenes; Oils, Volatile; Time Factors; Volatilization
PubMed: 19610461
DOI: 10.1603/029.102.0367 -
Tree Physiology Apr 2004Quercus ilex (L.) leaves emit monoterpenes, particularly alpha-pinene, beta-pinene and sabinene. Apart from the monoterpene pools that are stored in specialized...
Quercus ilex (L.) leaves emit monoterpenes, particularly alpha-pinene, beta-pinene and sabinene. Apart from the monoterpene pools that are stored in specialized structures and have a clear defensive or attractive role, the function of monoterpenes in Q. ilex leaves is unknown. We tested whether monoterpenes have an antioxidant role, as has previously been found for isoprene in isoprene-emitting leaves. We exposed Q. ilex leaves to either mild and repeated ozone exposure (Experiment I) or to a single acute ozone exposure (Experiment II) at temperatures ranging between 20 and 32 degrees C. Both ozone treatments rapidly stimulated monoterpene synthesis, but had no effect on photosynthesis and caused no visible damage to leaves maintained at 25, 30 or 32 degrees C. Ozone inhibited both photosynthesis and monoterpene synthesis in leaves maintained at 20 degrees C. To characterize the relationship between monoterpenes and ozone-induced damage, we fed detached leaves fosmidomycin, a selective inhibitor of isoprene synthesis. Fosmidomycin caused rapid and complete inhibition of monoterpene emissions in leaves maintained at 30 degrees C, confirming that monoterpenes are synthesized by the same biochemical pathway as isoprene. However, over the experimental period, fosmidomycin did not affect concentrations of compounds that are formed from chloroplastic isoprenoids and that might have conferred antioxidant protection, either directly (carotenoids) or indirectly (chlorophylls, xanthophylls). In leaves whose monoterpene synthesis had been inhibited by fosmidomycin, ozone rapidly and significantly inhibited photosynthesis and increased the production of hydrogen peroxide and malonyldialdehyde. We conclude that monoterpenes produced by Q. ilex leaves share the same biosynthetic pathway and function as isoprene. Furthermore, all volatile isoprenoids may have similar antioxidant properties and may be stimulated by the same stress-inducing conditions.
Topics: Antioxidants; Bicyclic Monoterpenes; Bridged Bicyclo Compounds; Fosfomycin; Monoterpenes; Ozone; Photosynthesis; Plant Leaves; Quercus; Terpenes; Trees
PubMed: 14757575
DOI: 10.1093/treephys/24.4.361