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PubMed2000

Differential signalling and plant-volatile biosynthesis.

At least two different signalling pathways have been identified that result in clearly distinguishable volatile profiles in response to pathogens and herbivores in the lima bean Phaseolus lunatus. Alamethicin, a voltage-gated ion-channel-forming peptide from Trichoderma viride, is a potent inducer of volatile biosynthesis in the lima bean. Unlike elicitation with cellulysin or herbivore damage, which act through the jasmonic acid pathway and result in a complex pattern of volatile compounds, the emitted blend comprises only the two homoterpens, 4,11-dimethylnona-1,3,7-triene and 4,8,12-trimethyltrideca-1,3,7,11-tetraene, and methyl salicylate. Both pathways, represented by jasmonic acid and alamethicin, depend on lipid-derived signalling compounds, set off by the activation of a phospholipase A and further processing by lipoxygenase activity. The alamethicin-induced signal-transduction pathway interferes with the octadecanoid cascade, probably due to increased salicylic acid levels, resulting in an inhibition of the typical jasmonic acid-induced volatile profile.

Alamethicin↗
PubMed2003

Analytical aspects of volatile substance abuse (VSA).

Through a case report, the authors illustrate the volatile substance abuse (VSA) toxicological investigation difficulties mainly due to evaporation of the compounds from postmortem samples and to the lack of reference data for interpretation. A 17-year-old man, student in a chemistry institute, was found dead with a plastic bag placed over his head. Several chemical substances were found in his belongings. Autopsy findings included serious pulmonary lesions and hemorrhagic digestive ulcerations. A large screening of drugs and toxic compounds and selective analyses for several classes of drugs of abuse were carried out in the autopsy samples. In particular, a headspace (HS), -gas chromatography/-mass spectrometry (GC/MS) technique was used to screen for volatile substances and metabolites in the biological samples and for residues of volatile substances on the surface of the plastic bag and in the chemicals found on the scene. The main analytical finding was the presence of alkanes (heptane, methyl-2-pentane, methyl-3-hexane, methylcyclohexane) in the gastric content. The literature data, VSA practices, long time-delay between death and autopsy, preservation conditions of the biological samples before analysis, and in-lab experiments on evaporation of volatile substances were considered to interpret this result. The present fatality was attributed to VSA with a gasoline-based stain remover like "eau écarlate," associated with a hypoxic recreation practice using a plastic bag.

Adolescent↗
PubMed2004

[Component and content changes of volatiles from Chinese cabbage damaged by Plutella xylostella].

The study showed that Chinese cabbage, Brassica campestris could release a variety of volatiles, especially when infested by Plutella xylostella larvae. Among these volatiles, saturated hydrocarbon was dominant, aromatic hydrocarbon was the second, and unsaturated hydrocarbon, aldehyde, alcohol, ketone, acid and heteroaromatic compounds were existed with a small amount. Chinese cabbage damaged by Plutella xylostella larvae produced 3 times of volatiles in amount with more species than the control. The volatiles from control plants were mostly of small molecular weight, and those from Chinese cabbage damaged by Plutella xylostella were mostly of high molecular weight.

Animals↗
PubMed2005

[Neuroadaptive mechanisms form development of psychological dependence on volatile organic solvents].

Abuse of volatile organic solvents among youth remains a major social problem. Organic solvents are cheap and relatively easy to obtain, so they carry the risk of becoming a so-called "gateway drug" for users. Most research regarding organic solvents has until now focused on their neurotoxicity, specifically examining the mechanism of neuron death in terms of the involvement of substances such as nerve growth factor. However, systems to assess psychological dependence on volatile organic solvents that take into account the mechanism involved in the development of this dependence have not been established due to the difficulty of creating animal models. The conditioned place preference procedure, which can easily assess whether psychological dependence has been formed, has been phased in in recent years, and dependence assessment systems have been established for drug inhalation. There have also been new research developments regarding dependence on volatile organic solvents. The importance of mesolimbic dopamine neurons has been indicated in the expression of CNS stimulant action and the development of psychological dependence on drugs such as stimulants, cocaine, and heroin, which are typical abused drugs. It has recently become apparent that the increase in dopamine release in the nucleus accumbens accompanying activation of mesolimbic dopamine neurons, as has conventionally been proposed, is important to the expression of CNS stimulant action and the formation of psychological dependence in response to inhalation of toluene, a volatile organic solvent. Furthermore, research with regard to organic solvents' site of action is also proceeding based on studies using molecular biological techniques. Research regarding toluene is progressing, and the importance of receptors that gate ion channels such as N-methyl-D-aspartate (NMDA) and y-aminobutyric acid (GABA)A receptors as candidates for toluene's site of action has been indicated. Clarification of organic solvents' mechanism for the development of psychological dependence is expected to progress, thanks to analysis focusing on such new sites of action.

Animals↗
PubMed2005

[Effects of volatile anesthetics on cortical somatosensory evoked potential and Bispectral index].

OBJECTIVE: To improve the anesthetic environment in monitoring short-latency somatosensory evoked potentials (SSEP) during operation, we compared the effects of different anesthetics on SSEP and Bispectral index (BIS), which aim to select suitable anesthetics and their doses used intraoperatively. METHODS: 60 ASA I-II patients undergoing elective neurosurgery were randomly allocated into three groups: enflurane, isoflurane and desflurane group. The concentration of each volatile anesthetic was increased step by step from 0 to end-tidal 0.3, 0.5, 0.75, 1.0 and 1.5 MAC. The changes of cortical SSEP component N20 were recorded as well as Bispectral index (BIS) monitoring. The effects of three volatile anesthetics in various concentrations on short-latency SSEP and BIS were investigated. RESULTS: All three volatile anesthetics significantly decreased N20 amplitude and prolonged N20 latency. The N20 waveform disappeared in some patients when the end-tidal concentration of enflurane reached 1.0 MAC, it occurred when that of isoflurane or desflurane was at 1.5 MAC. BIS monitoring showed BIS values were all under 60 when at 1.0 MAC in three group. For some patients in enflurane group and desflurane group, BIS values were above 60 (45-64, 44-61, respectively) when at 0.75 MAC, while those in isoflurane group were still less than 60 (39-58). And the amplitude or latency of cortical SSEP correlated poorly with BIS. CONCLUSION: The effects of three volatile anesthetics on SSEP and BIS are significant in dose-dependent manner. Anesthetic regimen of 0.75 MAC isoflurane for intraoperative cortical SSEP monitoring may be optimal. It seemed that the correlation between BIS and short-latency SSEP was poor, although both are associated with the effects of anesthetics on cerebral cortex.

Adult↗
PubMed1987

[Volatile anesthetics and n-alcohols inhibit the uptake of noradrenaline in pheochromocytoma cells].

UNLABELLED: Studies with perfused animal organs did not show a significant inhibition of the norepinephrine uptake by volatile anesthetics However, the uptake of norepinephrine into isolated chromaffin granules proved to be halothane-sensitive , and there is indirect evidence for an inhibition of norepinephrine uptake by halothane in the dog saphenous vein. So far no literature is available on norepinephrine uptake into cultured cells in the presence of volatile anesthetics. The rat pheochromocytoma cell line PC 12, which shares many properties with adrenal medulla cells and also with sympathetic neurons, has been used as a model to study norepinephrine uptake and release. One of its properties in common with sympathetic neurons is the high-affinity uptake system for norepinephrine. Therefore, we have used PC 12 cells as a pharmacologically well-established model system to study the effect of general anesthetics on the uptake of norepinephrine. METHODS: The experiments were performed with monolayers of PC 12 cells on 3 cm petri dishes. The cells were allowed to take up tritiated norepinephrine (0.25 microCI/ml) for 20 min at 36 degrees C in the presence and absence of general anesthetics. RESULTS AND DISCUSSION: The volatile anesthetics halothane, enflurane, isoflurane, and methoxyflurane in clinical relevant concentrations inhibited the high-affinity uptake of tritiated norepinephrine into the PC 12 cells (Fig. 1). We could further show an inhibition of norepinephrine uptake by n-alkanols at concentrations that cause anesthesia in tadpoles. Fig. 2 illustrates that a good correlation (r = 0.997 for the n-alkanols, r = 0.934 for the volatile anesthetics) exists between anesthetic potency and the IC50 for norepinephrine uptake inhibition.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenal Gland Neoplasms↗
PubMedDate not supplied

Volatile N-nitrosamines in infant pacifiers sold in the United States as determined by gas chromatography/thermal energy analysis.

Volatile N-nitrosamines in infant latex rubber pacifiers were determined using a modification of a previously described dichloromethane extraction procedure, followed by gas chromatography/thermal energy analysis. Under an interagency agreement between the National Center for Toxicological Research and the Consumer Product Safety Commission (CPSC), data were obtained on the baseline and compliance concentrations of volatile N-nitrosamines in infant pacifiers sold in the United States. Pacifiers made by 18 different manufacturers before and after the January 1, 1984 action level of 60 ppb was set by the CPSC were analyzed for volatile N-nitrosamines. N-Nitrosodibutylamine was the principal N-nitrosamine found, along with trace amounts of N-nitrosodimethylamine, N-nitrosodiethylamine, and N-nitrosopiperidine. Mean total volatile N-nitrosamine levels for baseline and compliance samples were 63.9 and 21.2 ppb, respectively. The pacifier lots sampled after January 1, 1984 showed a significant decrease in contamination levels, indicating that at least 98% of the market share is in compliance with the CPSC enforcement policy for N-nitrosamines in infant pacifiers sold in the United States.

Chromatography, Gas↗
PubMed1981

Metabolic abnormalities associated with diabetes mellitus, as investigated by gas chromatography and pattern-recognition analysis of profiles of volatile metabolites.

Patterns of volatile metabolites in urine, as obtained by glass-capillary gas chromatography, were investigated by use of a nonparametric pattern-recognition method, in an effort to detect abnormalities associated with diabetes. We used threshold logic unit analysis on a data set consisting of normal subjects and those with diabetes mellitus, and could predict patterns for volatile metabolites as belonging to the proper class in 94.83% of the cases examined. In addition, a feature-extraction algorithm isolated those volatile constituents that are most useful in making the normal/diabetic classification. We used gas chromatography/mass spectrometry to identify important profile constituents. Finally, these same pattern-recognition methods indicated strong sex-related patterns in these volatiles.

Chromatography, Gas↗
PubMedDate not supplied

Determination of volatile chemicals released from microwave-heat-susceptor food packaging.

Microwave heat susceptors that convert electromagnetic energy to heat attain high temperatures that make it possible to cook some foods to golden crispness in a microwave oven. Susceptors are typically packaged with foods intended for microwave use, e.g., waffles, pizzas, and french fries. The high temperatures > 302 degrees F used to cook some foods release trace levels of volatile chemicals from metalized polyester film, adhesive, and paper packaging materials; these volatile chemicals may be absorbed by the food. We simulated microwave susceptor cooking conditions and developed protocols by using headspace concentration capillary gas chromatography and mass spectrometry to identify volatile chemicals released from heated susceptors. We purchased a limited, cross-sectional sample of local retail microwave food products packaged with susceptors and used our protocol to analyze 10 different susceptor products. Although more than 140 unique chromatographic peaks were tabulated, only 44 volatile chemicals were identified, including 1,1,1-trichloroethane, benzene, and 2-(2-butoxyethoxy)ethanol, which were derived primarily from the paper and adhesive susceptor components. No one susceptor contained all the identified substances. The standard additions technique was the preferred method for quantitation. Trichloroethane and 2-(2-butoxyethoxy)ethanol were present in several products at 75-122 micrograms/in.2 of susceptor surface area. Benzene was found in 3 susceptors at < or = 0.22 microgram/in.2 levels. Examination indicates that adhesives used in more recent susceptor products were reformulated to remove even this trace level of benzene.

Benzene↗
PubMed1996

[A case of volatile solvent psychosis accompanied with multiple neurological and psychological symptoms].

A case of psychosis accompanied with variable symptoms induced by chronic volatile solvent inhalation is reported in this study. The patient was a 27-year-old male who had abused volatile solvents for 15 years, and was sent to the hospital because of a tonic-clonic seizure. Severe psychomotor excitement was observed on the first day and the 7th day after admission. After 10 days of admission, we observed visual transformation and hyperthermia, which suggested acute toxic symptoms due to a volatile solvent. Furthermore, symptoms such as incoherence, delusions of persecution, and catalepsy were also observed in this case. There have been few reports of multiple neurological and mental symptoms appearing in cases of volatile solvent psychosis. Although we sometimes experience cases of solvent abuse with acute mental symptoms and recurrent excitement after sedation, such symptoms are not always observed because of flashback in the strict sense. Therefore, careful early treatment should be employed to prevent 'secondary excitement'.

Adult↗
PubMed2005

Short-term and long-term effects of increasing temperatures on the stability and the production of volatile sulfur compounds in full-scale thermophilic anaerobic digesters.

This study compares the effect of a rapid increase of the digester temperature (from 54 degrees C to 58 degrees C in 2 weeks) with a slow increase (from 53.9 degrees C to 57.2 degrees C at a rate of 0.55 degrees C per month) on full-scale thermophilic anaerobic digestion at Hyperion Treatment Plant. The short-term test demonstrated that rapidly increasing the digester temperature caused elevated production of volatile sulfur compounds, most notably methyl mercaptan, but volatile solids destruction and methane production were not significantly affected. The increase of the volatile fatty acid to alkalinity ratio from 0.1 to over 0.3 indicated a transient change in digester biochemistry, which was reversed by lowering the temperature. In the long term-test, a slow increase of digester temperature, the production of hydrogen sulfide increased above temperatures of 56.1 degrees C, but was controlled by increased injection of ferrous chloride. Methyl mercaptan was detected in trace amounts at the highest temperature tested (57.2 degrees C). This test showed insignificant effects on other digestion parameters, although some temperature-independent changes were observed that could have been seasonal effects over the year that the long-term test lasted. Thus a slow temperature increase was preferable. This observation contrasts with previous results showing the desirability of a rapid temperature rise to first establish a thermophilic culture when converting from mesophilic operation. Further research is warranted on temperature limits and process changes to optimize thermophilic anaerobic digestion.

Adaptation, Physiological↗
PubMed2026

From bioactive compounds to volatile profiles: a multidimensional characterization of Indonesian stingless bee honeys.

BACKGROUND: Stingless bee honeys are drawing increasing attention as ingredients for functional foods and health-oriented products because of their distinctive sensory characteristics and bioactive potential. In this study, honeys collected from nine stingless bee species reared in West Sumatra, Indonesia, were comprehensively characterized using physicochemical indices, antioxidant assays [DPPH (i.e. 2,2-diphenyl-1-picrylhydrazyl) and ferric reducing antioxidant power], microbiological screening, volatile profiling [gas chromatography-mass spectrometry (GC-MS)] and Fourier transform infrared (FTIR) fingerprinting. RESULTS: Marked between-sample variability was observed across key quality attributes, including pH (2.80-3.68), Brix (49.83-61.25), viscosity (23.36-175.22&#x2009;cP) and color parameters. FTIR spectra were consistent with carbohydrate-rich matrices and exhibited carbonyl-related bands. GC-MS profiling identified linalool oxide isomers and junenol among the predominant volatiles. To the best of our knowledge, junenol has not previously been reported in stingless bee honey and may represent a potential regional chemical marker for Indonesian stingless bee honeys. Lactic acid bacteria were detected in selected samples, whereas yeast and mold were not detected. Antioxidant activities were comparatively low, which may reflect local environmental and ecosystem-related factors. CONCLUSION: The results provide a multi-parameter baseline for stingless bee honeys produced within a shared ecosystem in West Sumatra and demonstrate the value of integrating conventional chemical indices with FTIR and volatile fingerprints for quality assessment. This combined approach may also support future authentication and origin-tracing frameworks for Indonesian stingless bee honeys. &#xa9; 2026 Society of Chemical Industry.

Animals↗
PubMedDate not supplied

Monitoring seasonal variation in apple fruit volatile emissions in situ using solid-phase microextraction.

Emissions of volatiles from apple fruits (Malus domestica Borkh.) were monitored in situ over the course of a growing season (from early June to mid September) for two apple varieties, Golden Delicious and Maigold. Results indicate a characteristic time-course of volatile emissions as the sampling date was a statistically significant factor for nine of the 13 compounds considered. The amounts of volatiles collected were greatest early and late in the season. The temporal effect on emissions was generally much larger than the effect of variety, which was significant for only four of the 13 compounds considered. The possible sources of variation which are not explained by the statistical models are discussed, and it is considered that they are most likely related to differences in the emissions from individual fruits.

Acetates↗
PubMed1982

Diagnosis of anaerobic infection by gas chromatographic estimation of volatile fatty acids.

Nine hundred and eighty-one fluid specimens were analysed by culture and by gas chromatography. The presence of obligate anaerobes was best predicted if one or more of the volatile acids isobutyric, butyric, isovaleric, valeric, isocaproic or caproic acid were detected in the specimen. Propionic acid was not a good indicator of the presence of obligate anaerobes. The agreement between gas chromatography and culture for obligate anaerobes in the main study (841 specimens, 232 culture positive) was: co-positivity 82%; co-negativity 92%. Falsely negative specimens contained anaerobes which had probably not produced sufficient of their characteristic volatile fatty acids to be detected. When it was the sole infecting anaerobe, Bacteroides fragilis seemed especially likely to be missed by gas chromatography. Forty-five of the 51 falsely positive specimens probably represented failure to culture anaerobes rather than spurious volatile fatty acid detection.

Anaerobiosis↗
PubMed2006

Comprehensive two-dimensional gas chromatography in the analysis of volatile samples of natural origin: a multidisciplinary approach to evaluate the influence of second dimension column coated with mixed stationary phases on system orthogonality.

The study evaluates the influence of selectivity tuning of the stationary phase of the second dimension on the orthogonality of a comprehensive two-dimensional gas chromatography (GC x GC) system. Two different sets of columns, providing independent and semi-independent separation mechanisms were used. The first consisted of a first dimension separating analytes on a volatility basis (i.e. a non-polar polydimethylsiloxane (OV1) column) combined with a second dimension separating by polarity, using columns coated with 100% polyethylene glycol (CW20M), CW20M/OV1 mixtures in ratios of 25-75%, and polydimethylsiloxane, 7% phenyl, 7% cyanopropyl (OV1701). The second set consisted of a first dimension separating analytes on a polarity basis (100% CW20M column) combined with a second dimension separating by volatility, consisting of columns coated with 100% OV1, OV1/CW20M mixtures in ratios of 25-75%, and 100% OV1701. Medium-complexity mixtures of natural origin (i.e. peppermint essential oil and a standard mixture of suspected allergens) consisting of components in a relatively limited range of molecular weights (MW) and volatilities, but belonging to different classes of compounds in a wide range of polarity (mono- and sesquiterpenoids, hydrocarbons and oxygenated compounds) were analysed with the above sets of columns. Different approaches were used to evaluate peak spreading on the GC x GC separation plane and degree of orthogonality of the column sets, namely: (1) a Factor Analysis (FA) approach, estimating the correlation coefficients and spreading angles of the sample components in the two-dimensional chromatographic plane; (2) an Informational Theory (IT) approach, based on determining a group of parameters including: informational entropy, % synentropy and similarity (H); and (3) an approach based on estimating the amount of separation space used, i.e. a practical parameter that directly refers to the experimental separation plane of the GC x GC chromatogram. Results showed that peak spreading in the chromatographic plane, when CW20M and OV1 are combined in different ratios, can be predicted from retention mechanisms, and that the degree of orthogonality measured with different approaches, is consistent with the divergent nature, in terms of polarity of the stationary phases combined in the GC x GC system.

Allergens↗
PubMed2002

Volatile signaling in plant-plant-herbivore interactions: what is real?

Plants release volatiles after herbivore attack in a highly regulated fashion. These compounds attract natural enemies and function as indirect defenses. Whether neighboring plants 'eavesdrop' on these volatile signals and tailor their defenses accordingly remains controversial. Recent laboratory studies have identified transcriptional changes that occur in plants in response to certain volatiles. These changes occur under conditions that enhance the probability of signal perception and response. Field studies have demonstrated repeatable increases in the herbivore resistance of plants growing downwind of damaged plants.

Animals↗
PubMed2005

Analysis of volatile compounds and triglycerides of seed oils extracted from different poppy varieties (Papaver somniferum L.).

Poppy seed oil (Oleum Papaveris Seminis) is used for culinary and pharmaceutical purposes, as well as for making soaps, paints, and varnishes. Astonishingly, hardly anything was yet known about the volatile compounds of this promising comestible. Likewise, there are no current published data about the triglyceride (TAG) composition of poppy seed oils available. In this investigation solid-phase microextraction (SPME) with DVB/Carboxen/PDMS Stable-Flex fiber was applied to the study of volatile compounds of several seed oil samples from Papaver somniferum L. (Papaveraceae). 1-Pentanol (3.3-4.9%), 1-hexanal (10.9-30.9%), 1-hexanol (5.3-33.7%), 2-pentylfuran (7.2-10.0%), and caproic acid (2.9-11.5%) could be identified as the main volatile compounds in all examined poppy seed oil samples. Furthermore, the TAG composition of these oils was analyzed by MALDI-ReTOF- and ESI-IT-MS/MS. The predominant TAG components were found to be composed of linoleic, oleic, and palmitic acid, comprising approximately 70% of the oils. TAG patterns of the different poppy varieties were found to be very homogeneous, showing also no significant differences in terms of the applied pressing method of the plant seeds.

Chromatography, Gas↗
PubMed2004

Behavioral response of Lygus hesperus to conspecifics and headspace volatiles of alfalfa in a Y-tube olfactometer.

The western tarnished plant bug, Lygus hesperus Knight, feeds and develops on a variety of weeds in the spring, with later generations moving to alfalfa and cotton where severe damage to reproductive structures can occur. A synthetic attractant for monitoring or mass-trapping L. hesperus, or the identification of potential attractants for natural enemies, would be useful tools for integrated pest management programs. Studies investigated the response of naive and experienced fifth-instar and adult L. hesperus to odors associated with conspecifics and alfalfa, Medicago sativa L. Fifth-instar L. hesperus responded to all plant/insect combinations, whereas female L. hesperus only responded preferentially to vegetative and flowering alfalfa where conspecifics had fed for 24-72 hr, and to vegetative alfalfa where conspecifics were added approximately 30 min before the test began. Males were not attracted to headspace volatiles from any of the alfalfa treatments. Analysis of headspace volatiles showed that (E)-2-hexanal, (Z)-3-hexen-l-ol, alpha-pinene, (Z)-3-hexenyl acetate, (E)-2-hexenyl acetate, limonene, (Z)-ocimene, (E)-beta-ocimene, linalool, (3E)-4,8-dimethyl-1,3,7-nonatriene, and (E, E)-alpha-farnesene are emitted from both vegetative and flowering alfalfa. Indole and (3E, 7E)-4,8,12-trimethyl-1,3,7,11-tridecatetraene were only detected in flowering alfalfa. Damage to alfalfa by L. hesperus increased emissions of (Z)-ocimene, (E)-beta-ocimene, (E)-beta-caryophyllene, and (E, E)-alpha-farnesene, while beta-pinene, myrcene, methyl salicylate, and (3E, 7E)-4,8,12-trimethyl-1,3,7,11-tridecatetraene were only detected from damaged plants. Thus, individual or mixtures of these alfalfa volatiles may be useful as attractants for capturing nymphs and adult females of L. hesperus in the field.

Animals↗