GC-MS System Research Articles

Essential Oil Composition Of Two Scutellaria species from Tokat, Turkey

The genus Scutellaria L. (Lamiaceae) is represented in Turkey by 16 species, 1 natural hybrid, 38 taxa, 16 being endemic in Turkey (1,2). Hydrodistilled essential oils of the aerial parts of Scutellaria altissima L. and Scutellaria orientalis L. subsp. pinnatifida Edmondson were analyzed by GC and GC-MS systems, simultaneously. The oil of S. altissima contained β-caryophyllene (34.7 %), caryophyll-5-en-12-al (14.4%), linalool (14.3%) and hexadecanoic acid (7.1%) as main constituents. The oil of S. orientalis L. subsp. pinnatifida was characterized by the occurrence of germacrene D (56.9%), β-caryophyllene (10.5%) and bicyclogermacrene (10.1%) as major components. To the best of our knowledge, this is the first report on the GC and GC/MS determination of the essential oil composition of the S. altissima and S. orientalis subsp. pinnatifida species studied.

Death related to transdermal nicotine patches: A case report

Transdermal nicotine patches (TNPs) are widely used in substitution therapy after cessation of smoking. Toxic concentrations of nicotine and cotinine, its main metabolite, are poorly reported in the literature, either in cases of misuse or in fatal contexts. We report here an exceptional fatal case due to a massive exposition of TNPs without any other apparent cause. A 41-years-old male was found dead by his cellmate with 7 TNPs (21 mg/24 h) on his body. In total, 14 TNPs and 5 empty blisters of 1.5 mg nicotine capsules were found in the bin. Autopsy findings did not reveal any pathology that could explain death. No evidence of violence was highlighted. No signs of trauma were noticeable and no arteriosclerosis was observed. In addition, histological investigation did not show any other element concluding on the death circumstances. Various biological samples were collected at autopsy for toxicological analysis. Toxicological screening was performed for ethanol (GC-FID), drugs and illicit drugs (LC-DAD, GC-MS, LC-MS/MS) on the biological samples. Nicotine and cotinine analyses were performed on an Agilent 5977B GC-MS system after liquid-liquid extraction in alkaline condition. Chromatographic separation was achieved using an Agilent capillary column VF-5ms. Any fatal case related to the nicotine substitution medication was explored using the French pharmacovigilance and the French poison control centers databases. Nicotine and cotinine concentrations are described in the Table 1 . A nicotine blood concentration above 1000 ng/mL is assumed to be lethal [1] . The analyses yielded therapeutic concentrations of cyamemazine, lormetazepam, nordiazepam, oxazepam, buprenorphine and its metabolite. THC and its metabolites were also detected reflecting a use of cannabis. The databases exploration did not reveal any other fatal case exclusively related to the nicotine substitution medication. According to the autopsy findings and the toxicological analyses, death was caused by a suicidal or accidental acute nicotine intoxication. This observation directs attention to the potential risk of nicotine poisoning from nicotine patches.

Alteration of gut microbiota induced by DPP-4i treatment improves glucose homeostasis.

BackgroundIncreasing evidence indicates that the gut microbiota contributes to the occurrence and development of metabolic diseases. However, little is known about the effects of commonly used antidiabetic agents on the gut microbiota. In this study, we investigated the roles of dipeptidyl peptidase-4 inhibitors (DPP-4i) and α-glucosidase inhibitor in modulating the gut microbiota.Methods16S-rDNA sequencing was performed to analyse the effects of DPP-4i and acarbose on the gut microbiota in mice fed a high-fat diet (HFD). Fecal microbiota transplantation (FMT) from type 2 diabetes patients to germ-free mice was performed to investigate the contribution of the altered microbiome to antidiabetic effects of the drugs. Fecal metabolomics was also analysed by untargeted and targeted GC–MS systems.FindingsAlthough DPP-4i and α-glucosidase inhibitor both altered the gut microbial composition, only the microbiome modulation of DPP-4i contributed to its hypoglycemic effect. Specifically, the changes of 68.6% genera induced by HFD were rescued by DPP-4i. FMT showed that the DPP-4i-altered microbiome improved glucose tolerance in colonized mice, while acarbose did not. Moreover, DPP-4i increased the abundance of Bacteroidetes, and also promoted a functional shift in the gut microbiome, especially increasing the production of succinate.InterpretationOur findings demonstrate an important effect of DPP-4i on the gut microbiota, revealing a new hypoglycemic mechanism and an additional benefit of it. Furthermore, modulating the microbial composition, and the functional shift arising from changes in the microbiome, might be a potential strategy for improving glucose homeostasis.FundThis work was supported by grants from the National Natural Science Foundation of China (No. 81700757, No. 81471039, No. 81700714 and No. 81770434), the National Key R&D Program of China (No. 2017YFC1309602, No. 2016YFC1101100, No. 2017YFD0500503 and No. 2017YFD0501001), and the Natural Science Foundation of Chongqing (No. cstc2014jcyjjq10006, No. cstc2016jcyjA0093 and No. cstc2016jcyjA0518).

GC-MS application in determination of volatile profiles emitted by infected and uninfected human tissue

Volatile organic compounds (VOCs) released into the headspace air over human tissues infected with different bacteria were investigated in this work. The above-mentioned VOCs result both from bacterial metabolic processes (pathogen-specific signals) and from the matrix (tissue samples themselves). The objective of this study was to investigate whether one could reliably identify various microorganism strains that exist inside infected tissue samples by direct monitoring of the headspace atmosphere above their cultures. Headspace samples were directly interrogated using a GC-MS system, which produced distinct profiles for samples contaminated with single bacterial strains or with multiple strains (mixed infections). Principal component analysis (PCA) and predictive analysis based on receiver operating characteristics curves (ROC) were the statistical procedures utilized for differentiating between infected and uninfected samples, while network analysis and heat-mapping were used to highlight the connections between emitted volatiles and infectious pathogens. By using ROC curves, obtained results demonstrated that the area under the ROC (95% probability interval) was 0.86 in case of infected samples and 0.48 for uninfected samples. On the other hand, PCA highlighted separation between components coming from infected and uninfected patients, where 67% of variance was described from the first 2 principal components. The biomarker chemicals documented from this work, as well as the developed methodology may ultimately be applied to identify bacterial infections by analyzing exhaled breath.

Assessment of GC–MS response of selected pesticides in apple matrices related to matrix concentration

A uniform analyte response is required for GC–MS analysis in order to obtain acceptable quantitative results. The response of pesticides in complex matrices is susceptible to variation due to the interactions of co-extractives, both with pesticides or with GC–MS system. This study was conducted to determine the magnitude of the interactions, called matrix effect, and their behavior with the matrix dilution. The response of pyrimethanil (4,6-dimethyl-N-phenylpyrimidin-2-amine), cyprodinil (4-cyclopropyl-6-methyl-N-phenylpyrimidin-2-amine), trifloxystrobin (methyl-(2Z)-2-methoxyimino-2-[2-[[(E)-1-[3(trifluoromethyl)phenyl]ethylidene amino]oxymethyl]phenyl]acetate) and bifenthrin(2-methyl-3-phenylphenyl)methyl-3-[(Z)-2-chloro-3,3,3-trifluoroprop-1-enyl]-2,2-dimethylcyclopropane-1-carboxylate), used in apple crops protection, was evaluated in different concentrations of peel and flesh extracts of Granny Smith, Golden Delicious and Demi Rouge, selected as representatives of different matrix types. The matrix effect ranged from −0.05 to 146.14%, depending on matrix type and pesticide. The highest response variation was observed in extracts of Granny Smith—an enhancement in flesh and suppression in peel extract. With the dilution, the matrix effect decreased with different magnitudes, but for Granny Smith peel extract an inverted effect was observed. The presence of the matrix effect in GC–MS pesticides analysis was obvious, requiring the application of matrix-matched calibration in quantification procedures for each variety, with calibration standards matched by the matrix concentration.

Thermo-treatment affects Quercus cerris L. wood properties and the antioxidant activity and chemical composition of its by-product extracts

Nowadays, there is an increasing interest on thermo-treatment and its effects on wood structure and extraction processes, connected to the wood use for industrial application and for its use as biorefinery. The present investigation aimed to provide the main changes on wood properties (mass loss, color variation and modulus of elasticity) and a comparative analysis of the antioxidant properties and GC–MS profile of the extracts from Turkey oak (Quercus cerris L.) wood. Untreated and thermo-treated wood (170 °C x 3 h) samples were compared. Thermo-treatment induced a mass loss (5.1%) in wood, a darkening of color surface (ΔE = 7.6) and a decrease of MOE (4.1%). Moreover samples were extracted using different techniques: maceration (ME), ultrasound assisted extraction (UAE) and accelerated solvent extraction (ASE). Extracts were tested to evaluate the content of polyphenols and flavonoids along with the in vitro antioxidant activity. Results showed that extracts obtained from thermo-treated wood reported the highest Relative Antioxidant Capacity Index and extraction techniques affected the value in the following rating: UAE > ME > ASE. Qualitative and quantitative measurements of chemical compounds were carried out by GC–MS system. Taking into account the thermo-treatment and extraction techniques, principal component analysis (PCA) was performed also in order to evaluate the relationships among principal chemical compounds. According to results obtained, thermo-treatment and extraction technique had a determinant role in the antioxidant efficiency and, consequently, on the potential application of extracts.

Potential of Fish Wastes as Feedstock for Biodiesel

Fish wastes are the discarded parts include the internal organs, viscera, bones, trimmings, tails, fins and skin of fishes. These discarded portions while disposing of cause major environmental damage. Usually, the discarded parts of fishes are ground into fishmeal for livestock and aquaculture feed. This study was undertaken to explore biodiesel production based on the fatty acids composition. The fish waste sample was collected from Kota Kinabalu, Sabah fish market. The sample was drained for excess water and oven-dried at 55°C - 60°C for complete dryness. Crude oils were extracted in petroleum ether in Soxhlet extraction method. Methylation of the extracted crude fish oil was carried out to yield fatty acid methyl esters (FAME). The FAME was analyzed by GCMS system and the reference to NIST library was used to identify the fatty acids present in the FAME. A total of 21 fatty acids were identified that composed of 53.53% saturated fatty acids (SFA), 22.1% monounsaturated fatty acid (MUFA) and 24.37% polyunsaturated fatty acids (PUFA). The important fatty acids [myristic acid (C14:0), palmitic acid (C16:0), palmitoleic acid (C16:1), oleic acid (C18:1), linoleic acid (C18:2), linolenic acid (C18:3), docosapentaenoic acid (C22:5) and docosahexaenoic acid (C22:6)] found in fish oil indicated the potentiality of biodiesel production if fish waste was stocked. The highest percentage of SFA causes higher viscosity, cetane number and density and hence these properties of biodiesel produced from the fish waste are expected to be high. Therefore, the fish waste has high potential of fatty acid in FAME to produce biodiesel through transesterification process.

Morphine Concentrations in Human Urine Following Poppy Seed Paste Consumption

Papaver somniferum (opium poppy) is one of the world’s oldest medicinal plants which are widely used for medicinal, nutritive and scientific purposes. Turkey is one of the major legal opium poppy producer countries in the world and the seed paste of the poppies is consumed in great deal, even more than 100g per meal. The main objective of this study is to investigate the influence of poppy seed paste ingestion on urine tests for opiates whether or not could lead to opiate positive urine test results. For this purpose, a variety of poppies were used and the morphine content of white, yellow and blue-black poppies were determined as 1.9, 4.0 and 2.6mg/kg, respectively. 100g of these seed pastes were consumed in the breakfast by ten healthy adults enrolled in the study over three days and urine samples were collected before and after the breakfast. Opiate screening analysis was carried out by enzyme immunoassay method and the results were evaluated by two different cut-off values (300 and 2000ng/mL). Morphine confirmation analysis was made by GC–MS system and the chromatographic method was validated in terms of selectivity, extraction efficiency, linearity (25–2000ng/ml), intra-assay precision, accuracy, limit of detection (LOD) and limit of quantitation (LOQ) (3 and 10ng/ml), carryover, matrix effect, dilution integrity and stability. According to cut-off value 300ng/ml, opiate concentrations were found positive up to 48h. For cut-off value 2000ng/mL; this time was up to 12h in collected urine samples after consumption of three different colored poppy seed pastes. In all urine samples, thebaine was detected while the heroin abuse metabolite 6-acetyl morphine (6-AM) was not. Urine drug testing legislation was revised on 2016 in Turkey and opiate screening cut-off values increased from 300 to 2000ng/mL. Overall results have shown that poppy seed paste as food consumption could lead to opiate positive urine test result even if increased cut off levels are used. It can also be deduced that thebaine can be taken as supportive biomarker for poppy seed paste consumption. Awareness of interpretation of urine test results and defining the procedures especially for forensic drug testing must be done in legal aspect to ensure justice for each individual (workplace, traffic, court etc.).

Chemical Composition, Antioxidant, and Anticancer Effect ofRuta chalepensis’s Extracts against Human Leukemic Cells

Ruta chalepensisis a native herb of the Mediterranean region used in the traditional medicine of many countries. Phytochemical screening has shown the presence of bioactive molecules that are responsible for its pharmacological properties. The present study aimed at investigating the in vitro antioxidant and cytotoxic effect of volatile, ethanol and aqueous extracts ofR. chalepensiscollected from Bejaia, a region in Algeria. The phenolic compounds composition of the extracts was analyzed by HPLC-UV (High Performance Liquid Chromatography with UV detector) and the essential oil composition was analyzed by GC–MS (Hewlett Packard 5973-6890 GC-MS system) analysis. The antioxidant activity was assessed by the scavenging activity of DPPH (1,1-diphenyl-2-picrylhydrazyl) and the cytotoxic effect of MTT assay against cancerous cells (T-leukemic cells and B lymphoblasts) and normal blood cells (PBLs: stimuled peripheral blood cells by PHA/IL2). Ethanol extract ofR. chalepensispresented the highest amount of total phenolics (72 08 ± 1.94 mg GAE/g DW (Milligrammes of Galic Acid per Grammes of Dry Weight), flavonoids (31.90 ± 2.12 mg QE/g DW (Milligrammes of Quercetin Equivalent per Grammes of DryWeight), and flavonols (13.22 ± 0.86 mg QE/g DW) compared to the aqueous extract, which presented a total phenolics of 39.71 ± 0.22 mg GAE/g DW, flavonoids of 1.96 ± 0.12 mg QE/g DW, and flavonols of 3.00 ± 0.2586 mg QE/g DW. Ethanol extract also showed a potent antioxidant activity (IC50= 51.18 ± 1, 14 μg/ml) and a high reducing power (IC50 = 660 ± 8, 3 μg/ml). Moreover, we establish herein that ethanol extract exerts a strong cytotoxicity against T-leukemic cells (CEM, H9, Jurkat, and CEM-IRCs) and B lymphoblast cells (SKW 6.4) without affecting normal blood cells (PBL and PBLs).This study showed thatRuta chalepensiscan be used as promising source of natural antioxidant and anticancer agents. The encouraging results obtained on anticancer activity suggest further investigations can be undertaken to isolate the bioactive phenolic compounds and to understand their mechanism of cytotoxicity.

Alteration of Gut Microbiota Induced by DPP-4i Treatment Improves Glucose Homeostasis

Background: Increasing evidence indicates that the gut microbiota contributes to the occurrence and development of metabolic diseases. However, little is known about the effects of commonly used antidiabetic agents on the gut microbiota. In this study, we investigated the roles of dipeptidyl peptidase-4 inhibitors (DPP-4i) and α-glucosidase inhibitor in modulating the gut microbiota. Methods: 16S rRNA sequencing was performed to analyze the effects of DPP-4i and acarbose on the gut microbiota in mice fed a high fat diet (HFD). Fecal microbiota transplantation (FMT) from type 2 diabetic patients to germ-free mice was conducted to investigate the contribution of the altered microbiome to antidiabetic effects of the drugs. Fecal metabolomics were also analyzed by untargeted and targeted GC-MS systems. Findings: Although DPP-4i and α-glucosidase inhibitor both altered the gut microbial composition, only the microbiome modulation of DPP-4i contributed to its hypoglycemic effect. Specifically, the changes of 68.6% genera induced by HFD were rescued by DPP-4i. FMT showed that the DPP-4i-altered microbiome improved glucose tolerance in conventionalized mice, while acarbose did not. Moreover, DPP-4i reduced the ratio of Firmicutes to Bacteroidetes, predominantly by increasing the abundance of Bacteroidetes. It also promoted the functional shift in the gut microbiome, especially the increased production of succinate. Interpretation: Our findings demonstrate a novel effect of DPP-4i on the gut microbiota, revealing a new hypoglycemic mechanism and additional benefit for it. Furthermore, modulating the ratio of Firmicutes to Bacteroidetes, and the functional shift arising from changes in the microbiome, might be a potential strategy for improving glucose homeostasis. Clinical Trial Number: Complete clinical trial registration is deposited in the Chinese Clinical Trials Registry (http://www.chictr.org.cn/index.aspx), and the registration number is ChiCTR-OPC-17010757. Funding Statement: This work was supported by grants from the National Natural Science Foundation of China (No.81700757, No.81471039, No.81700714 and No.81770434), the National Key R&D Program of China (No.2017YFC1309602, No.2016YFC1101100, No.2017YFD0500503 and No.2017YFD0501001), and the Natural Science Foundation Project of Chongqing (No. cstc2014jcyjjq10006, No. cstc2016jcyjA0093 and No. cstc2016jcyjA0518). Declaration of Interests: The authors disclose no conflicts interest. Ethics Approval Statement: Informed written consent was obtained from all participants. The experiment was approved by the Ethics Committee of Xinqiao Hospital of the Third Military Medical University.

Exposures to Volatile Organic Compounds (VOCs) among Rural and Urban Households in Southern India in Relation to Primary Cooking Fuels

Background: Emissions from cooking fuels that include many health damaging pollutants such as fine particulate matter and a range of polycyclic aromatic hydrocarbons and volatile organic compounds (VOCs) are a major public health concern in low and middle income countries (LMICs). Despite the ubiquity of exposures in India, VOC profiles in rural and urban households are poorly understood. Methods: We report results from cooking period measurements conducted in 112 (56 biomass, 23 kerosene and 34 gas using ) rural and urban households that were part of the larger Tamil Nadu Air Pollution and Health Effects (TAPHE) cohort study in Southern India. Samples were collected on a mixed-bed sorbent (Tenax and Carbopack) tubes. Active air sampling was performed using pre-calibrated constant flow pumps (SKC Inc., PA, USA) set to a flow rate of 0.1 L/min for 100 min. An automated thermal desorption unit connected to GC-MS system was used to quantify 59 VOCs. Pentafluorobenzene, 1,4-difluorobenzene and chlorobenzene-d5 were used as internal standards and percent recovery ranged from 81.7% to 119.9%.Results: Total VOC (TVOC) concentrations in rural homes (4426.8 µg/m3) were significantly higher when compared to urban homes (2010.9 µg/m3). Toluene, styrene, m,p-xylene and benzene were dominant in rural kitchens whereas toluene, m,p-xylene, benzene and isopropyltoluene were dominant in urban kitchens during cooking. Mean TVOC concentrations were the highest in biomass using homes (4617 µg/m3) followed by LPG (2839.7 µg/m3) and kerosene (1639.8 µg/m3) respectively. Benzene levels consistently exceeded the National Ambient Air Quality Guideline value of 5µg/m3 in all rural and urban homes. Winter season, open field burning and industry nearby were associated with significantly higher VOC concentrations.Conclusions: Additional large scale assessments of population exposure to VOCs are needed in LMICs to better characterize health risks associated with solid fuel use.

Effect of spray drying on bioactive and volatile compounds in soursop (Annona muricata) fruit pulp.

Soursop is seasonal and highly perishable fruit, which limits its commercialization. Thus it is necessary to conserve its pulp so that it is available throughout the year. One of the most common forms of fruit preservation is by dehydration. This work had an objective to dehydrate soursop pulp by spray drying at optimum conditions and to analyze the retention of bioactive and volatile compounds in soursop powder, besides analyzing its antioxidant capacity. The total phenolics, carotenoids and flavonoids contents were determined, while volatile compounds were analyzed by Stir Bar Sorptive Extraction (SBSE) coupled with GC-MS system. The total content of the phenolic compounds and flavonoids in the fresh pulp were 160.28 mg of GAE/100 g and 87.17 mg of quercetin/100 g, respectively while for rehydrated dried powder their values were 158.95 mg of GAE/100 g and 85.17 mg of quercetin/100 g, respectively. The total phenolic compounds, flavonoids and antioxidant capacity did not show any significant difference (p < .05) between the fresh fruit pulp and dehydrated powder. A total of 85 volatile compounds were identified, of which 33 were esters, representing the major class of organic compounds, 15 were terpenes, 10 aldehydes, 7 acids, 5 alcohols, 5 lactones, 3 ketones, and 6 other compounds. Of the total 85 compounds, identified in soursop pulp, 58 compounds were identified in the rehydrated dried powder. The principal compounds for both samples were methyl (E)-2-hexenoate, methyl hexanoate and methyl (E)-2-butanoate, which contribute to soursop aroma according to their Odor Active Values (OAV). Considering that there was no significant difference (p < .05) between fresh pulp and the rehydrated dried powder in concentrations of bioactive compounds and even with the reduction in the concentration of the main volatile compounds while the OAVs of these compounds were relatively high, it is concluded that spray dried powder of soursop pulp retains its nutritional and aroma quality, besides maintaining the antioxidant capacity.

Essential Oil Composition of Some Sage (Salvia spp.) Species Cultivated in İzmir (Turkey) Ecological Conditions

Abstract: Background: Salvia L., the largest genus of Lamiaceae, includes about 1000 species, widespread throughout the world. This genus is represented, in Turkish flora, by 99 species and 113 taxa, 58 of which are endemic. Some members of this genus are of economic importance since they have been used as herbal tea, flavouring agents in perfumery and cosmetics. Some sage (Salvia L. ) species has been credited with a long list of medicinal uses: e.g. spasmolytic, antiseptic, astringent. Objective: In present study, essential oil composition of some sage (Salvia L.) species cultivated in Izmir (Turkey) was investigated. Sage species have recently become more common in Turkey and sage cultivation is increasing especially in the Aegean Region. Material and Methods: The species of Salvia fruticosa Mill., Salvia officinalis L., Salvia sclarea L., hybrid (Salvia fruticosa Mill. x Salvia officinalis L.) and Salvia dichroantha L. were used in the study. Essential oils were extracted according to hydro distillation method with clevenger type apparatus and analyzed using GC-FID and GC-MS system. Results: Essential oil contents of Salvia fruticosa Mill. was 3.86%, Salvia officinalis L. 2.42%, Salvia sclarea L. 0.5%, Salvia fruticosa Mill. x Salvia officinalis L. 2.84% and Salvia dichroantha L. 0.19%. The number of components in essential oils were detected 22, 16, 14, 20 and 16 respectively. The chemical composition of the essential oils in Salvia fruticosa Mill. 1,8-cineole (57.18%), Salvia officinalis L. β-thujone (34.59%), Salvia sclarea L. linalyl acetate (46.77%), Salvia fruticosa Mill. x Salvia officinalis L. 1,8-cineole (21.42%) and β-thujone (18.37%) and Salvia dichroantha L. β- caryophyllene (23.11%) and sabinyl acetate (21.87%). Key words: Salvia spp., Sage, Cultivation, Essential oil, Chemcial composition.

Effect of Thymus vulgaris L. (Lamiales: Lamiaceae) Essential Oil on Energy Reserves and Biomarkers in Culex pipiens L. (Diptera: Culicidae) from Tebessa (Algeria)

The aim of this study was to assess the chemical composition of the leaf essential oil of Thymus vulgaris cultivated in Tebessa (Northeast Algeria) and to evaluate its potential larvicidal activity against fourth instar larvae of Culex pipiens L., 1758. A total of 20 fourth instar larvae of C. pipiens were exposed to a variety of concentrations (25-200 ppm) in laboratory according to the standard procedure portrayed by World Health Organization. The effects were examined on the mortality, the activities of acetylcholinesterase (AChE), glutathione S-transferase (GST), gluhatione (GSH) rate and the biochemical composition (proteins, lipids, carbohydrates) of larvae body, respectively. The EO yield calculated from the dry matter of the aerial part of the plant was 1.58 %. Its chemical composition has been analyzed by the GC and GC-MS systems. A chemical constituent of 18 compounds was identified in the oils of T. vulgaris compounds representing to 99.94 %. Bioassay test revealed that this essential oil exhibited larvicidal properties as they could induce 100 % mortality in the larvae of C. pipiens at the concentrations of 200 ppm. Biomarker measurments in treated larvae (LC25 and LC50) revealed no effect on AChE activity, activation of detoxification system as showed by an increase in GST activity and a decrease in GSH rate. The biochemical compositions show that the essential oil affected the energy reserves with a marked effect on proteins and lipids. Lastly, our results proved the potential use of this natural material as an alternative to synthetic insecticides for controlling mosquitoes.

Alteration of Gut Microbiota Induced by DPP-4i Treatment Improves Glucose Homeostasis

Background and Aims: Emerging evidence indicates that the gut microbiota contributes to the occurrence and development of metabolic diseases. While, little is known about the effect of antidiabetic agents on the gut microbiota. In the current study, we investigated the role of DPP-4i and acarbose in modulating the gut microbial community. Methods: 16S rRNA sequencing was performed to analysis the effect of DPP-4i and acarbose on the gut microbiota in HFD mice. Fecal microbiota transplantation (FMT) from DPP-4i, acarbose, or placebo- treated T2D patients to germ-free (GF) mice was performed to investigate the contribution of the altered microbiota to the antidiabetic effect. Fecal metabolomics were analyzed by untargeted and targeted GC-MS system. Results: DPP-4i and acarbose changed the gut microbial composition, and the DPP-4i- altered microbiome improved the glucose tolerance, while acarbose- altered microbiome did not. Moreover, DPP-4i primarily reduced the ratio of Firmicutes to Bacteroidetes, and changed the pattern of metabolites in HFD mice, especially the increase of succinate. Conclusions: Our findings demonstrated that the alterations of the gut microbial composition and metabolites might be a previously unsuspected hypoglycemic mechanism of DPP-4i. It might provide a potential strategy for modulating glucose homeostasis in the future. Disclosure X. Liao: None. H. Zheng: None.

Ultrasound-assisted emulsification microextraction for rapid determination of unmetabolized synthetic polycyclic and nitro-aromatic musks in human urine

An effective method to rapidly determine the presence of seven unmetabolized synthetic musks in human urine samples is developed. The target musks are five synthetic polycyclic musks (i.e., celestolide (ADBI), phantolide (AHMI), traseolide (ATII), galaxolide (HHCB), tonalide (AHTN)), and two nitro-aromatic musks (i.e., musk xylene (MX) and musk ketone (MK)). The method involved an ultrasound-assisted emulsification microextraction (USAEME) coupled with gas chromatography–mass spectrometry (GC–MS). The factors that affect USAEME efficiency were optimized in detail, and the optimized procedure involved the rapid injection of 50 μL of carbon tetrachloride into 1.0 mL of urine sample (contained 0.1-g of sodium chloride) in a conical bottom glass tube. After 1.0 min ultrasonication and 3 min centrifugation (at 7000 rpm), the sedimented extract 10 μL was directly injected into the GC–MS system. The limits of quantitation (LOQs) varied from 0.1 to 0.5 ng/mL. The precisions for both repeatability and reproducibility were <8%. The trueness varied from 79 to 96% with the RSD ranging from 2 to 8%. The total concentrations of the seven unmetabolized target musks in collected human urine samples were in the range from 0.93 to 3.74 ng/mL. HHCB and AHTN were detected in all the collected samples, and the daily excretion doses were evaluated.

Biocontrol of stem rust disease of wheat using arbuscular mycorrhizal fungi and Trichoderma spp.

Control of stem rust disease of wheat was investigated using different combinations of Trichoderma spp. and arbuscular mycorrhizal (AM) fungi. Impact of the application of T. harzianum HL1 and T. viride HL5, singly or in combination, on the uredospores germination of Puccinia graminis Pers. f. sp. tritici was assessed in vitro. The combined spore suspension of both isolates showed the superiority over the others in this regard. Observations of the scanning electron microscopy confirmed this result. Using a GC-MS system, the chemical constitution of the culture filtrates of T. harzianum HL1 and T. viride HL5 was identified. Under the greenhouse conditions, application of AM fungi and Trichoderma spp. significantly reduced the disease measures, induced the peroxidase and polyphenol oxidase enzymes, increased the total phenol content and improved the tested growth and yield parameters. Based on their efficiency and eco-safety, we can recommend the use of this combination in controlling stem rust disease of wheat.

A new extraction phase based on a polymer inclusion membrane for the detection of chlorpyrifos, diazinon and cyprodinil in natural water samples

A simple and effective method for the detection of three pesticides (chlorpyrifos, diazinon and cyprodinil) is developed using a polymer inclusion membrane (PIM) prior to gas chromatography and mass spectrometry detection (GC-MS). Analytes are extracted from natural water samples using a 3 cm2 PIM made of the polymer, cellulose triacetate (CTA), and the plasticizer, nitrophenyl octyl ether (NPOE). Addition of the plasticizer to the CTA matrix is found to be necessary for the extraction of pesticides. After extraction, analytes are recovered from the membrane with 1 mL of acetonitrile and injected into the GC-MS system. The main factors affecting the extraction efficiency are evaluated, including membrane composition, stirring mode, extraction and elution time. Ultrasonic assisted elution of the extracted pesticides is accomplished after 15 min of contact. The PIM-assisted extraction method makes it possible for pesticides to be determined in the range of 50–1000 ng L−1 with good linearity (coefficient of determination ≥0.995) and suitable recoveries (85–119%) and precision (<21%, n = 3) using 100 mL of a water sample. This methodology is shown to be suitable for the detection of chlorpyrifos in local river waters.

A rapid low-consuming solvent extraction procedure for simultaneous determination of 34 multiclass pesticides associated to respirable atmospheric particulate matter (PM2.5) by GC–MS

A miniaturized and low-consuming solvent extraction procedure has been developed for the simultaneous determination of 34 multiclass pesticides in PM2.5 samples, using sample masses as low as 321μg. A central composite design was applied in order to establish the optimal extraction conditions: the solid-liquid extraction was done under sonication using 500μL of a solvent mix 70/30 acetonitrile/ethyl acetate and an extraction time of 17min at 39°C. It was followed by injection in a GC–MS system. Recoveries ranged from 72.1% (endrin aldehyde) to 120% (sulfotep) with RSD≤20% for most of pesticides. The method accuracy was assessed by determinations of organochlorine pesticides such as 4,4′-DDT, 4,4′-DDE and 4,4′-DDD in NIST SRM 1649b. PM2.5 samples were collected in Salvador city, State of Bahia-Brazil. 25 pesticides were successfully identified and quantified, among them organophosphates prohibited by European Union and some banned organochlorine. The average concentrations ranged from 0.88pgm−3 (aldrin) to 255pgm−3 (endrin aldehyde). Malathion, chlorpyrifos, 4,4′-DDE, endrin aldehyde, lambda-cyhalothrin and permethrin were detected with frequencies above 50%. This procedure was found to be comprehensive, precise, accurate and suitable to be employed for determination of pesticides associated to respirable atmospheric particulate matter.

Chemical Composition of Essential Oil of Pinus nigra subsp. pallasiana (Pinaceae) Twigs, From Different Regions of Turkey

We used GC and GC-MS systems to analyze the chemical composition of essential oils extracted from twigs of Pinus nigra arn. subsp. pallasiana (Lamb.) Holmboe (Black pine) naturally grown in Turkey. Twig samples were collected from four regions of Turkey (Adana, Adiyaman, Antalya and Elazig) and the twigs were hydrodistilled by clevenger apparatus. Forty three (Adana), 40 (Adiyaman), 29 (Antalya) and 44 (Elazig) components were identified representing 90.7%, 97.8%, 98.4% and 87.7%, respectively of all extracted oils. The main compounds of oil samples were germacrene D, α-pinene, δ-3-carene, β-pinene, limonene and β-caryophyllene. Here we discuss chemical differences with reference to forestry products and renewable resources, and we also assess intrapopulational means.