High Resolution GC-MS Research Articles

High-Resolution Mass Spectrometry Study of the Bio-Oil Samples Produced by Thermal Liquefaction of Microalgae in Different Solvents.

We have performed a comparative analysis of the bio-oil produced by thermal liquefaction of microalgae in different solvents using high-resolution Orbitrap mass spectrometry and GC-MS approach. Water, methanol, ethanol, butanol, isopropanol, acetonitrile, toluene, and hexane were used as solvents in which the liquefaction was performed. It was observed that all resulting oils demonstrate a considerable degree of similarity. For all samples, compounds containing 1 and 2 nitrogen atoms dominated in the positive ESI spectra, while a relative contribution of other compounds was small. In negative ESI mode, compounds having 2 to 7 oxygens were observed. Statistical analysis revealed that products can be combined in two groups depending on the solvent used for the liquefaction. To the first group, we can attribute the products obtained by using protic (alcohols) and to the second by using aprotic (acetonitrile, toluene) solvents. Nevertheless, based on our results, we concluded that solvent possesses a minor impact on molecular composition of bio-oil. We suggested that the driving force of the liquefaction reaction is the thermal dehydration of the carbohydrate in algae, resulting in water formation, which could be the trigger of the producing of bio-oil. To prove this hypothesis, we performed the reaction with the dry algae in the absence of the solvent and observed the formation of bio-oil. Graphical Abstract.

Automated Determination of Xenobiotics (Pesticides, PCBs, PAHs, and PBDEs) in Sediment Samples Applying HS-SPME-GC-HRMS.

Background: Automated methods are needed for the reliable determination of xenobiotics in environmental samples. Objective: Optimization and application of an automated method for the ultra-trace analysis of 34 organic contaminants including polycyclic aromatic hydrocarbons (PAHs), polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs), organochlorinated (OCPs), and organophosphorus pesticides (OPPs) in sediment samples have been performed. Methods: Automated method based on headspace solid-phase microextraction (SPME) coupled to GC-high-resolution MS (GC-HRMS) for the ultra-trace analysis of the targeted compounds has been developed. Conclusions: Suitable validation parameters in terms of linearity, trueness, selectivity, intraday and interday precision, LODs, and LOQs were obtained. Relative recovery values between 70 and 120% were achieved for all compounds (concentration levels assayed 1 and 10 μg/kg). RSD values were always lower than 25% for intra- and interday precision, and LODs and LOQs were 0.1 and 1.0 μg/kg, respectively, for all analytes. Highlights: The proposed method was applied to the analysis of sediments collected in Andalusia, Spain, and Poland, finding PCB 18 in one sample (15.9 μg/kg) and p,p'-DDE in several samples at concentrations ranging from 27.6 to 297.2 μg/kg.

Emission factors of volatile organic compounds (VOCs) based on the detailed vehicle classification in a tunnel study

In order to obtain VOCs emission characteristics and emission factors from vehicle, a tunnel experiment was conducted in the Fu Gui Mountain Tunnel in Nanjing, China. The tunnel is located in the middle of city, with total length of 480m and speed limit of 50km/h. The studied vehicle fleet was composed of 87% light duty vehicles and 13% heavy duty vehicles (liquefied natural gas bus, LNGB). The emerging radio frequency identification (RFID) technology was used to divide fine vehicles type including China I, China II, China III, China IV, China V and LNGB. Ambient air samples (4-h averages) were collected inside the tunnel using 3.2L stainless-steel canisters. Samples collected in the canisters were analyzed for 97 individual VOCs using high-resolution GC-MS in the laboratory. The average tunnel emission factor for the collective light-duty vehicles was 160.79±65.94mg/(km∗veh), and for the China I, China II, China III, China IV and China V vehicles, it was 632.07±259.44, 450.35±184.85, 205.42±84.32, 118.51±48.65, and 110.61±45.4mg/(km∗veh), respectively. The average emission factor for heavy-duty vehicles was 358.02±124.86mg/(km∗veh). Ethane, isopentane, propane, ethylene, toluene, propylene and 2,3-dimethylbutane were the most common VOC species in vehicle emissions. The total O3 formation potential was 373.88mg∗O3/(km∗veh) in the tunnel. Ethylene, propylene, m/p-xylene, toluene, and isopentane were the largest contributors to O3 production. Compared with previous studies, fuel quality increased from China II-FQ to China IV-FQ levels, while the BTEX emission levels exhibited a decreasing trend.

Process-Oriented Diagnosis of Tropical Cyclones in High-Resolution GCMs

This study proposes a set of process-oriented diagnostics with the aim of understanding how model physics and numerics control the representation of tropical cyclones (TCs), especially their intensity distribution, in GCMs. Three simulations are made using two 50-km GCMs developed at NOAA’s Geophysical Fluid Dynamics Laboratory. The two models are forced with the observed sea surface temperature [Atmospheric Model version 2.5 (AM2.5) and High Resolution Atmospheric Model (HiRAM)], and in the third simulation, the AM2.5 model is coupled to an ocean GCM [Forecast-Oriented Low Ocean Resolution (FLOR)]. The frequency distributions of maximum near-surface wind near TC centers show that HiRAM tends to develop stronger TCs than the other models do. Large-scale environmental parameters, such as potential intensity, do not explain the differences between HiRAM and the other models. It is found that HiRAM produces a greater amount of precipitation near the TC center, suggesting that associated greater diabatic heating enables TCs to become stronger in HiRAM. HiRAM also shows a greater contrast in relative humidity and surface latent heat flux between the inner and outer regions of TCs. Various fields are composited on precipitation percentiles to reveal the essential character of the interaction among convection, moisture, and surface heat flux. Results show that the moisture sensitivity of convection is higher in HiRAM than in the other model simulations. HiRAM also exhibits a stronger feedback from surface latent heat flux to convection via near-surface wind speed in heavy rain-rate regimes. The results emphasize that the moisture–convection coupling and the surface heat flux feedback are critical processes that affect the intensity of TCs in GCMs.

Chemical Analysis of Counterfeit Hepatitis C Drug Found in Japan.

In January 2017, counterfeits of the hepatitis C drug 'HARVONI® Combination Tablets' (HARVONI®) were found at a pharmacy chain through unlicensed suppliers in Japan. A total of five lots of counterfeit HARVONI® (samples 1-5) bottles were found, and the ingredients of the bottles were all in tablet form. Among them, two differently shaped tablets were present in two of the bottles (categorized as samples 2A, 2B, 4A, and 4B). We analyzed the total of seven samples by high-resolution LC-MS, GC-MS and NMR. In samples 2A, 3 and 4B, sofosbuvir, the active component of another hepatitis C drug, SOVALDI® Tablets 400 mg (SOVALDI®), was detected. In sample 4A, sofosbuvir and ledipasvir, the active components of HARVONI®, were found. A direct comparison of the four samples and genuine products showed that three samples (2A, 3, 4B) are apparently SOVALDI® and that sample 2A is HARVONI®. In samples 1 and 5, several vitamins but none of the active compounds usually found in HARVONI® (i.e., sofosbuvir and ledipasvir) were detected. Our additional investigation indicates that these two samples are likely to be a commercial vitamin supplement distributed in Japan. Sample 2B, looked entirely different from HARVONI® and contained several herbal constitutents (such as ephedrine and glycyrrhizin) that are used in Japanese Kampo formulations. A further analysis indicated that sample 2B is likely to be a Kampo extract tablet of Shoseiryuto which is distributed in Japan. Considering this case, it is important to be vigilant to prevent a recurrence of distribution of counterfeit drugs.

Bayesian approach to peak deconvolution and library search for high resolution gas chromatography – Mass spectrometry

A novel probabilistic Bayesian strategy is proposed to resolve highly coeluting peaks in high-resolution GC-MS (Orbitrap) data. Opposed to a deterministic approach, we propose to solve the problem probabilistically, using a complete pipeline. First, the retention time(s) for a (probabilistic) number of compounds for each mass channel are estimated. The statistical dependency between m/z channels was implied by including penalties in the model objective function. Second, Bayesian Information Criterion (BIC) is used as Occam's razor for the probabilistic assessment of the number of components. Third, a probabilistic set of resolved spectra, and their associated retention times are estimated. Finally, a probabilistic library search is proposed, computing the spectral match with a high resolution library. More specifically, a correlative measure was used that included the uncertainties in the least square fitting, as well as the probability for different proposals for the number of compounds in the mixture. The method was tested on simulated high resolution data, as well as on a set of pesticides injected in a GC-Orbitrap with high coelution. The proposed pipeline was able to detect accurately the retention times and the spectra of the peaks. For our case, with extremely high coelution situation, 5 out of the 7 existing compounds under the selected region of interest, were correctly assessed. Finally, the comparison with the classical methods of deconvolution (i.e., MCR and AMDIS) indicates a better performance of the proposed algorithm in terms of the number of correctly resolved compounds.

Monitoring of organic pollutants in marine environment by semipermeable membrane devices and mussels: accumulation and biochemical responses.

This study involves the monitoring of organic pollutants using transplanted mussels (Mytilus galloprovincialis) as bioindicator organisms and semipermeable membrane devices (SPMDs) as passive samplers. Mussels and SPMDs were deployed to marinas, shipyards and shipbreaking yards on the coastal area of Turkey and retrieved after 60days. Polycyclic aromatic hydrocarbons (PAH), polychlorinated biphenyls (PCB) and organochlorine pesticide (OCP) compounds were analysed with high-resolution GC-MS. Total PAH concentrations in SPMDs and mussels ranged from 200 to 4740ngg sampler-1 and from 7.0 to 1130ngg-1 in wet weight (ww). PCB and OCP concentrations in SPMDs changed between 0.04-200 and 4.0-26ngg sampler-1, respectively. The highest PCB (190ngg-1ww) and OCP (200ngg-1 ww) concentrations in mussels were measured at shipyard stations. A strong correlation was observed between the PAH and PCB concentrations in SPMDs and mussels. Enzyme assays (acetylcholinesterase, ethoxyresorufin-O-deethylase, glutathione S-transferase, glutathion reductase and carboxylesterase activities) were performed as biomarkers to reveal the effects of pollution on the mussels. There was no clear relationship found between the enzyme levels and the pollutant concentrations in mussels. Integrated biomarker responses were calculated to interpret the overall effect of pollutants.

Bactericidal and antioxidant properties of essential oils from the fruits Dennettia tripetala G. Baker

BackgroundThe antibacterial and antioxidant properties of the essential oils (EOs) of unripe and ripe fruits of Dennettia tripetala and their potential for the management of infectious and oxidative-stress diseases were investigated in-vitro in this study.MethodEssential oil obtained from the fruit in Clevenger modified apparatus, was characterized by high resolution GC-MS, while antioxidant and antibacterial properties were tested by spectrophotometric and agar diffusion methods respectively.ResultsThe EO demonstrated strong antibacterial properties when subjected to multi –drug resistant bacterial strains: Enterococcus faecium (ATCC19434), Escherichia coli (ATCC 700728), Staphylococcus aureus (NCINB 50080), Listeria ivanovii (ATCC 19119), Enterobacter cloacae (ATCC13047) and four previously confirmed multi resistant bacterial isolates from our laboratory stock culture. The unripe fruit oil (UFO) demonstrated greater activity than the ripe fruit oil (RFO) against most of the tested bacteria with minimum inhibition concentrations (MIC) ranging between 0.05–0.20 mg/mL while that of the ripe fruit oil (RFO) ranged from 0.10–0.20 mg/mL. The IC50 for RFO (0.62 ± 0.12 mg/mL) showed that it has higher antioxidant strength than UFO and vitamin C (0.87 ± 0.23 and 3.39 ± 0.12 mg/mL) but a lower activity compared to β-carotene (0.32 ± 0.22 mg/mL) in scavenging 2, 2-diphenyl-1-picrylhydrazyl radicals (DPPH•). The EOs also demonstrated strong ability in scavenging three other different radicals (ABTS, lipid peroxide and nitric oxide radicals) in concentration dependant -manner.ConclusionFindings from this study suggest that apart from the local uses of the plant extracts, the EO has strong bioactive compounds, noteworthy antibacterial, antiradical properties and may be good candidates in the search for lead constituents for the synthesis of novel potent antibiotics.

Photomineralization of aqueous salicylic acids. Photoproducts characterization and formation of light induced secondary OH precursors (LIS-OH)

The photolysis of aqueous 5-chlorosalicylic acid (ClSA) and dihydroxybenzoic acid (DHBA), its main photoproduct, was studied to determine the extent of degradation caused by simulated solar light. Photoproducts identification was achieved using high resolution LC-MS and GC-MS. About 40 photoproducts from C19 to C1 were characterized, including a dihydroxycyclopentadienic acid, a ring contraction photoproduct, and numerous carbonyls and carboxylic acid derivatives that were detected thanks to derivatization. UV–visible spectral monitoring of the reactions revealed that ClSA and DHBA underwent photobleaching after developing a temporarily featureless absorbance between 300 and 500 nm. Measurement of OH radicals using terephtalic acid as a probe showed that OH radicals were generated with an average rate of 7 × 10−9 M s−1 and a total cumulated concentration of 10−3 M, corresponding to ∼ 5-fold the initial concentration of DHBA. Furthermore, TOC analysis indicated that significant mineralization (51–90%) occurred. These findings are consistent with the formation of light induced secondary OH (LIS-OH) precursors such as featureless long wavelength absorbing compounds as well as non-absorbing hydroperoxides. The formation of LIS-OH illustrated here may also take place in the aqueous photodegradation of other substituted phenols likely present in dissolved organic matter and humic substructures, it deserves to be studied in more details.

Abstract 4271: Beta-glucan activates macrophages in human NSCLC demonstrated by Stable Isotope Resolved Metabolomics (SIRM)

Abstract Introduction: We use SIRM to evaluate metabolic reprogramming of lung cancer cells in monoculture, in mouse xenograft/explant models, and in NSCLC patients in situ (1,2). We have now extended the range of models to fresh human tissue slices, which retain the original tissue architecture and heterogeneity with a paired benign versus cancer tissue design under defined cell culture conditions. β-glucan is a polysaccharide that repolarizes tumor-associated macrophages (TAMs) from the M2 to the M1 phenotype in mice (3). Here we report the activation of TAMs in human NSCLC tissue slices. Experimental: Freshly resected paired tissue slices from individual patients (approx. 1 mm or less thick and 5-40 mg wet weight) were incubated ± particulate β-glucan in standard cell culture conditions, with gentle rocking to enable efficient gas, nutrient, and waste product exchange. Tissue slices could be maintained metabolically viable for at least 48 h of incubation. The metabolic activity was determined by measuring the uptake and transformation of 13C and/or 15N-enriched common nutrient tracers such as glucose and glutamine, using high resolution mass spectrometry, GC-MS, and NMR after a period of incubation (2). Findings: Time-course analysis of the slices by NMR, MS, and histology revealed that NSCLC tissue slices, both benign and tumorous, retained their architecture and a broad spectrum of metabolic activities. Glucose and glutamine metabolism was reprogrammed in the tumor relative to the paired benign tissues ex vivo, as the in vivo case. The paired tissues from different patients showed significantly different metabolic responses to β-glucan, as expected Conclusions: This platform offers a human tissue model for preclinical studies on metabolic reprogramming of human cancer and stromal cells in their tissue context, and response to drug treatment (4). As the microenvironment of the target human tissue is maintained, including the resident immune cells, individualized response to immune-active agents can be determined in a clinically relevant setting. Supported by NCI P01CA163223-01 and NIEHS 1R01ES022191-01 1. Lane, A.N., Fan, T.W.-M., Bousamra II, M., et al. (2011) Clinical Applications of Stable Isotope-Resolved Metabolomics (SIRM) in Non-Small Cell Lung Cancer. Omics, 15, 173-182. 2. Sellers, K., Fox, M.P., Bousamra, M., II, et al. (2015) Pyruvate carboxylase is critical for non-small-cell lung cancer proliferation. Journal of Clinical Investigation, 125, 687-698. 3. Liu, M., Luo, F., Ding, C., et al. (2015) Particulate β-Glucan Converts Immunosuppressive Macrophages into M1 Phenotype Through Dectin-1-induced Syk-Card9-Erk Pathway and Raf-1-c-Maf Pathway. J. Immunol., 195, 5055-5065. 4. Xie, H., Hanai, J., Ren, et al. (2014) Targeting lactate dehydrogenase-A (LDH-A) inhibits tumorigenesis and tumor progression in mouse models of lung cancer and impacts tumor initiating cells. Cell Metabolism 19, 795-809 Citation Format: Teresa W-M Fan, Andrew N. Lane, Jun Yan, Richard M. Higashi, Jeremiah T. Martin, Michael Bousamra. Beta-glucan activates macrophages in human NSCLC demonstrated by Stable Isotope Resolved Metabolomics (SIRM). [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 4271.

Antibacterial and Antioxidant Properties of the Leaves and Stem Essential Oils ofJatropha gossypifoliaL.

Antibacterial and antioxidant properties of the leaves and stem essential oils (EOs) of Jatropha gossypifolia and their efficacies against infectious and oxidative stress diseases were studied in vitro. The EOs obtained using Clevenger modified apparatus were characterized by high resolution GC-MS, while their antioxidant and antibacterial properties were examined by spectrophotometric and agar diffusion techniques, respectively. The EOs exhibited strong antibacterial activity against Escherichia coli, Enterococcus faecium, and Staphylococcus aureus. The stem essential oil (SEO) was more active than the leaf essential oil (LEO) against test bacteria with minimum inhibition concentration (MIC) ranging from 0.025 to 0.05 mg/mL and the LEO from 0.05 to 0.10 mg/mL. The SEO was bactericidal at 0.025 and 0.05 mg/mL against S. aureus and E. faecium, respectively, and the LEO was bacteriostatic against the three bacteria at 0.05 and 0.10 mg/mL. The SEO IC50 (0.07 mg/mL) showed that the antiradical strength was superior to LEO (0.32 mg/mL) and β-carotene (1.62 mg/mL) in scavenging 2, 2-diphenyl-1-picrylhydrazyl radicals (DPPH•). The oils effectively reduced three other oxidants to neutral molecules in concentration dependent manner. Findings from this study suggest that, apart from the traditional uses of the plant extracts, the EOs have strong bioactive compounds with noteworthy antibacterial and antiradical properties and may be good candidates in the search for lead compounds for the synthesis of novel potent antibiotics.

Abstract 3199: Stable isotope resolved metabolomics (SIRM) on fresh human tissues as a preclinical drug testing platform

Abstract Introduction: All preclinical drug testing models have advantages and drawbacks. We have been using SIRM to evaluate metabolic reprogramming of lung cancer cells in monoculture, in mouse xenograft/explant models, and in NSCLC patients in situ (1), and to determine the influence of the tumor microenvironment using these models. We have now extended the range of models to fresh human tissue slices, similar to those originally described by Warburg (2), which retain the original tissue architecture and heterogeneity with a paired benign versus cancer design under controlled cell culture conditions. Experimental: Freshly resected tissue slices from individuals (ca. 1 mm or less thick and 5-40 mg wet weight) were incubated in standard cell culture conditions with gentle rocking for efficient gas, nutrient and waste product exchange. The metabolic activity was determined by measuring the uptake and transformation of 13C and/or 15N-enriched nutrient tracers such as glucose and glutamine, using high-resolution MS, GC-MS, and NMR after a period of incubation. Acute metabolic and histologic response to inhibitors or drugs was readily detected in treated tissue slices. Findings: Analysis at different time points by NMR, MS and histology shows that the NSCLC tissue slices, both benign and tumorous, retained their architecture and remained metabolically viable for at least 48 h of incubation. Glucose and glutamine metabolism was reprogrammed in the tumor relative to the paired benign tissues. The paired tissue also showed very different responses to Se-containing compounds when incubated at the IC50 established for cell lines. After 24 h of incubation, large scale necrosis was evident in the tumor, but not in the benign slices, which was accompanied by large changes in metabolic activities observed by SIRM analysis. Conclusions: This platform offers a human tissue model for preclinical studies on metabolic reprogramming of human cancer cells in their tissue context, and response to drug treatment (3). As the microenvironment of the target human tissue is retained and individualized response to drugs is obtained, this platform promises to transcend current limitations of drug selection for clinical trials or treatments. Supported by NCI P01CA163223-01A1 and NIEHS 1R01ES022191-01 1. Lane, A.N., Fan, T.W.-M., Bousamra II, M., Higashi, R.M., Yan, J. and Miller, D.M. (2011) Clinical Applications of Stable Isotope-Resolved Metabolomics (SIRM) in Non-Small Cell Lung Cancer. Omics, 15, 173-182. 2. Warburg, O. (1923) Versuche an überlebendem Carcinomgewebe (Methoden). Biochem. Zeitschr., 142, 317-333. 3. Xie, H., Hanai, J., Ren, J.-G., Kats, L., Burgess, K., Bhargava, P., Signoretti, S., Billiard, J., Duffy, K.J., Grant, A. et al. (2014) Targeting lactate dehydrogenase-A (LDH-A) inhibits tumorigenesis and tumor progression in mouse models of lung cancer and impacts tumor initiating cells. Cell Metabolism 19, 795-809. Citation Format: Andrew N. Lane, Teresa W-M Fan, Alexander C. Belshoff, Richard M. Higashi, Jeremiah Martin, Michael Bousamra. Stable isotope resolved metabolomics (SIRM) on fresh human tissues as a preclinical drug testing platform. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3199. doi:10.1158/1538-7445.AM2015-3199

Formation of a Novel Macrocyclic Alkaloid from the Unnatural Farnesyl Diphosphate Analogue Anilinogeranyl Diphosphate by 5-Epi-Aristolochene Synthase.

As part of an effort to identify substrate analogs suitable for helping to resolve structural features important for terpene synthases, the inhibition of 5-epi-aristolochene biosynthesis from farnesyl diphosphate (FPP) by the tobacco 5-epi-aristolochene synthase incubated with anilinogeranyl diphosphate (AGPP) was examined. The apparent noncompetitive nature of the inhibition supported further assessment of how AGPP might be bound to crystallographic forms of the enzyme. Surprisingly, the bound form of the inhibitor appeared to have undergone a cyclization event consistent with the native mechanism associated with FPP catalysis. Biocatalytic formation of a novel 13-membered macrocyclic paracyclophane alkaloid was confirmed by high-resolution GC-MS and NMR analysis. This work provides insights into new biosynthetic means for generating novel, functionally diversified, medium-sized terpene alkaloids.

Levels, compositions and distributions of organochlorine pesticide residues in soil 5–14 years after clean-up of former storage sites in Tanzania

The levels, compositions and distributions of organochlorine pesticides and metabolites were determined in soil samples collected 5–14years after clean-up was carried out at seven contaminated sites in Tanzania. Samples were collected from various depths (5–10cm, 30cm, and 50cm for most sites and up to 300cm for one site. Determination of the analytes was performed using a high resolution GC–MS and isotope dilution technology. DDT, DDD, DDE, HCH isomers, aldrin, dieldrin, endrin, endosulfans, chlordanes and heptachlor were the major compounds detected. The concentrations of total DDT and total HCH were up to 250000 and 164000mgkg−1, respectively, while the highest concentrations for other compounds ranged from 29 to 3300mgkg−1. The results indicated that there were no significant degradations/transformations of the pesticides for most of the sites. The highest concentrations of the compounds were mostly found in surface soil samples and there were variations in distribution among the sampling depths. The results indicate risks and concerns for public health and the environment.

Airborne Antituberculosis Activity of Eucalyptus citriodora Essential Oil

The rapid emergence of multi- and extensively drug-resistant tuberculosis (MDR/XDR-TB) has created a pressing public health problem, which mostly affects regions with HIV/AIDS prevalence and represents a new constraint in the already challenging disease management of tuberculosis (TB). The present work responds to the need to reduce the number of contagious MDR/XRD-TB patients, protect their immediate environment, and interrupt the rapid spread by laying the groundwork for an inhalation therapy based on anti-TB-active constituents of the essential oil (EO) of Eucalyptus citriodora. In order to address the metabolomic complexity of EO constituents and active principles in botanicals, this study applied biochemometrics, a 3-D analytical approach that involves high-resolution CCC fractionation, GC-MS analysis, bioactivity measurements, and chemometric analysis. Thus, 32 airborne anti-TB-active compounds were identified in E. citriodora EO: the monoterpenes citronellol (1), linalool (3), isopulegol (5), and α-terpineol (7) and the sesquiterpenoids spathulenol (11), β-eudesmol (23), and τ-cadinol (25). The impact of the interaction of multiple components in EOs was studied using various artificial mixtures (AMxs) of the active monoterpenes 1, 2, and 5 and the inactive eucalyptol (33). Both neat 1 and the AMx containing 1, 2, and 33 showed airborne TB inhibition of >90%, while the major E. citriodora EO component, 2, was only weakly active, at 18% inhibition.

Leishmanicidal Activity ofBrosimum glaziovii(Moraceae) and Chemical Composition of the Bioactive Fractions by Using High-Resolution Gas Chromatography and GC-MS

As part of our ongoing SisBiota CNPq/FAPESP and Biota-FAPESP bioprospecting programs, this paper deals with the leishmanicidal properties of Brosimum glaziovii (Moraceae), and used gas chromatography analysis to determine the chemical composition of these fractions. The extracts and fractions from the leaves and branches of B. glaziovii were screened against Leishmania amazonensis. The hexane fractions from the leaves and branches displayed the highest leishmanicidal activities, with IC50 = 3.6 and 39.1 µg mL -1 . Using gas chromatography analysis it was possible to identify the sterols campesterol, stigmasterol, and b-sitosterol, as well as the triterpenes α-amyrin, b-amyrin, b-amyrin acetate, and lupenone, and other nonpolar components, mainly fatty acids and their derivatives. This is the first report on the leishmanicidal activity and the chemical composition of B. glaziovii.

A New Formulation of the Spectral Energy Budget of the Atmosphere, with Application to Two High-Resolution General Circulation Models

Abstract A new formulation of the spectral energy budget of kinetic and available potential energies of the atmosphere is derived, with spherical harmonics as base functions. Compared to previous formulations, there are three main improvements: (i) the topography is taken into account, (ii) the exact three-dimensional advection terms are considered, and (iii) the vertical flux is separated from the energy transfer between different spherical harmonics. Using this formulation, results from two different high-resolution GCMs are analyzed: the Atmospheric GCM for the Earth Simulator (AFES) T639L24 and the European Centre for Medium-Range Weather Forecasts (ECMWF) Integrated Forecast System (IFS) T1279L91. The spectral fluxes show that the AFES, which reproduces quite realistic horizontal spectra with a k−5/3 inertial range at the mesoscales, simulates a strong downscale energy cascade. In contrast, neither the k−5/3 vertically integrated spectra nor the downscale energy cascade are produced by the ECMWF IFS.

Volatile Organic Compound Emissions from Light-Duty Vehicles in Monterrey, Mexico: a Tunnel Study

A two-week tunnel study was conducted in Monterrey, Mexico during June 2009 to characterizevolatile organic compound (VOC) emissions from the local vehicle fleet and estimate the correspondingemission factors (EFs). The Loma Larga Tunnel (LLT), a 532 meter-long structure that is mainly used by lightduty gasoline-powered vehicles was used as the experimental set-up. Ambient air samples (2-hour averages) were taken inside the LLT using 6 L SUMMA®-polished canisters. Samples collected in the canisters were analyzed for Total Non-Methane Hydrocarbons (TNMHC) and 53 individual VOCs using high-resolution GC-MS. Identified individual VOCs accounted for ~80% of the TNMHCs. The most abundant VOCs, on a molar basis, were ethene (13.8%), acetylene (9.0%), isopentane (7.1%), toluene (5.6%), and n-butane (5.5%). High correlations were obtained for known markers of vehicular emissions. Particularly, for the ethene/ acetylene ratio values between 1.1 and 2.4 were obtained (R2 = 0.95), indicating the presence of vehicles with a working catalytic converter. Estimated EFs were compared to values reported in similar studies elsewhere, including one in Mexico City. Results indicate that the vehicles in the LLT tend to emit lower molecular weight VOCs (in the C2 to C6 range). Reactivity of the emissions, expressed propylene-equivalent concentrations, was estimated resulting in an important contribution of the olefins (including isoprene) to the ozone-forming potential of the emitted mixtures.

Methoxylated polybrominated diphenyl ethers (MeO-PBDEs) are major contributors to the persistent organobromine load in sub-Arctic and Arctic marine mammals, 1986–2009

A selection of MeO-BDE and BDE congeners were analyzed in pooled blubber samples of pilot whale (Globicephala melas), ringed seal (Phoca hispida), minke whale (Balaenoptera acutorostrata), fin whale (Balaenoptera physalus), harbor porpoise (Phocoena phocoena), hooded seal (Cystophora cristata), and Atlantic white-sided dolphin (Lagenorhynchus acutus), covering a time period of more than 20years (1986–2009). The analytes were extracted and cleaned-up using open column extraction and multi-layer silica gel column chromatography. The analysis was performed using both low resolution and high resolution GC-MS. MeO-PBDE concentrations relative to total PBDE concentrations varied greatly between sampling periods and species. The highest MeO-PBDE levels were found in the toothed whale species pilot whale and white-sided dolphin, often exceeding the concentration of the most abundant PBDE, BDE-47. The lowest MeO-PBDE levels were found in fin whales and ringed seals. The main MeO-BDE congeners were 6-MeO-BDE47 and 2′-MeO-BDE68. A weak correlation only between BDE47 and its methoxylated analog 6-MeO-BDE47 was found and is indicative of a natural source for MeO-PBDEs.

Urinary Excretion Kinetics of 3,4-Methylenedioxymethamphetamine (MDMA, Ecstasy) and Its Phase I and Phase II Metabolites in Humans following Controlled MDMA Administration

3,4-Methylendioxymethamphetamine (MDMA) is excreted inhuman urine as unchanged drug and phase I and II metabolites. Previous urinary excretion studies after controlled oral MDMA administration have been performed only after conjugate cleavage. Therefore, we investigated intact MDMA glucuronide and sulfate metabolite excretion. We used LC-high-resolution MS and GC-MS to reanalyze blind urine samples from 10 participants receiving 1.0 or 1.6 mg/kg MDMA orally. We determined median C(max),t(max), first and last detection times, and total urinary recovery; calculated ratios of sulfates and glucuronides; and performed in vitro-in vivo correlations. Phase II metabolites of 3,4-dihydroxymethamphetamine (DHMA),4-hydroxy-3-methoxymethamphetamine (HMMA),3,4-dihydroxyamphetamine (DHA), and 4-hydroxy-3-methoxyamphetamine were identified, although only DHMA sulfates, HMMA sulfate, and HMMA glucuronide had substantial abundance. Good correlation was observed for HMMA measured after acid hydrolysis and the sum of unconjugated HMMA, HMMA glucuronide, and HMMA sulfate (R(2) = 0.87). More than 90% of total DHMA and HMMA were excreted as conjugates. The analyte with the longest detection time was HMMA sulfate. Median HMMA sulfate/glucuronide and DHMA 3-sulfate/4-sulfate ratios for the first 24 h were 2.0 and 5.3, respectively, in accordance with previous in vitro calculations from human liver microsomes and cytosol experiments. Human MDMA urinary metabolites are primarily sulfates and glucuronides,with sulfates present in higher concentrations than glucuronides. This new knowledge may lead to improvements in urine MDMA and metabolite analysis in clinical and forensic toxicology, particularly for the performance of direct urine analysis.