PSVII-17 Use of a dimethyl carbonate extraction for rumen fluid volatile fatty acid quantification by gas chromatograph mass spectrometry

Analysis of rumen fluid volatile fatty acids (VFA) is typically conducted by injecting acidified aqueous rumen fluid into a gas chromatograph (GC) with a flame ignition detector (FID). Water in GC samples can lead to poor peak shape and to contamination of inlets, potentially causing sample carryover. Aqueous methods are not well suited for use in mass spectrometer (MS) detector systems. The objective of this project was to validate a dimethyl carbonate (DMC) extraction process and GCMS method for rumen VFA analysis. To perform the extraction, 100 µL of sample, KHSO4 (50 g/L), and 2-ethylbutyrate (internal standard; 0.86 mM) are added to a microcentrifuge tube (in order) followed by 1 mL of DMC. The mixture is thoroughly vortexed and centrifuged. The organic layer (top) is removed and placed in a GC vial. The DMC extract is injected (0.5 µL) into an Agilent 5977B GCMS (8:1 split injection) with a polar DB-FFAP column. The column was held at 105°C for 5 min, increased at 10°C/min to 150°C, then 65°C/min to 240°C, and held constant for 10 min. The assay is linear for acetate from approximately 2 mM to at least 130 mM and covers the expected values of rumen concentrations for the other VFA. Recovery of VFA from spiked rumen fluid was tested at three concentrations in rumen fluid from steers fed a finishing diet or grazing wheat pasture. Recovery was not affected by the diet of the animals (P > 0.19) or the amount of VFA spiked (P > 0.27) and averaged 99.9% for all VFA, with valerate being the lowest (95.9%). Including the 10 min hold at 240°C at the end of each run prevented carryover from sample to sample. This method appears to perform well in a GCMS system and accurately and precisely quantify rumen fluid VFA.

Potential insecticidal activity of four essential oils against the rice weevil, Sitophilus oryzae (L.) (Coleoptera: Curculionidae)

Oils extracted from Cymbopogon citratus, Lantana camara, Artemisia camphorata, and Imperata cylindrica plants were used as potential insecticides against the rice weevil, Sitophilus oryzae (L.) (Coleoptera: Curculionidae). The phytochemical composition of the isolated oils was identified by gas chromatograph-mass spectrometry (GC-MS). Oil contact toxicities were evaluated against the adults of S. oryzae. The activities of acetylcholinesterase (AChE), alkaline phosphatase (ALP), and transaminases enzymes (AST) were measured. L. camara oil (LC50 = 9.81 mg/cm2) demonstrated the highest effect, followed by C. citratus oil (LC50 = 10.89 mg/cm2), A. camphorata EO (LC50 = 16.12 mg/cm2), and I. cylindrica oil (LC50= 36.85 mg/cm2) against the adults of S. oryzae. The inhibition percentages of AChE were 38.8, 41.7, 35.0, and 27.2%; ALP were 42.4, 49.3, 28.1, and 18.7%; AST were 33.9, 38.7, 20.8, and 11.8%; and ALT were 22.7, 30.5, 14.6, and 9.6% after treated S. oryzae with oils from C. citratus, L. camara, A. camphorata and I. cylindrica, respectively. The highest abundant compounds in C. citratus were geranial (25.95%), nerylacetal (8.85%), and neral (8.45%), in L. camara were caryophyllene (12.2%), and 3-elemene (8.89%), in A. camphorata were germacrene D-4-ol (20.83%), and borneol (19.47%), and in I. cylindrica were 5-phenylundecane (10.68%), and 6-phenyldodecane (8.70%).

Electrochemical Oxidation of Perfluorooctanoic Acid (PFOA) from Aqueous Solution using Non-Active Ti/SnO2-Sb2O5/PbO2 Anodes

In this study, electrochemical oxidation of perfluorooctanoic acid (PFOA, C7H15CO2H) from aqueous solution was examined in terms of PFOA and total organic carbon (TOC) removal by using Ti/SnO2-Sb2O5/PbO2non-active electrodes. The effects of operating parameters: initial pH (pHo), current density (j), and electrolyte concentration (m) at different time intervals were examined. Specific energy consumption (SEC) was used to determine the process proficiency. The C-C bond between C7F15 was first cleaved and thendegraded into fluoride ions (F−) and short carbon-chain per-fluorinated carboxylic acids (PFCAs) ((∼C2−C7) such as perfluoroethanoic acid (PFEA: C2F5CO2H), perfluoropropanoic acid (PFPA: C3F7CO2H), perfluorobutanoic acid (PFBA: C4F9CO2H), perfluoropentanoic acid (PFPeA: C5F11CO2H), perfluorohexanoic acid (PFHxA: C6F13CO2H), perfluoheptanoic acid (PFHpA: C7F14CO2H). These intermediates by-products were determined using the gas chromatograph-mass spectrometry (GC/MS) analysis. The rate of PFOA decomposition was followed the pseudo-first-order kinetics. About 82%TOC and 94% PFOA removals were formed at the optimal condition of pHo = 3.58, j=168.34 Am-2, and m = 250 mgL-1 at 120 min of electrolysis with SEC = 593 kWh/kg TOC. A plausible degradation mechanism was also proposed at the optimal treatment condition.

Influence of Nitrogen, Calcium and Nano-Fertilizer on Strawberry (Fragaria × ananassa Duch.) Fruit Inner and Outer Quality

The production system, especially fertilisation has an important effect on yield and quality of strawberries. In the present study, plants were fertilized with different doses of nitrogen (0–100% recommended doses), calcium chelate, as well as nano fertilizer Lithovit. Strawberry cultivar ‘Clery’ yield and quality parameters (fruit color and firmness) including nutritional indicators (total soluble solids, sugars, organic acids, phenolic and volatile compounds) were monitored. Volatiles were identified and monitored using headspace solid phase microextraction and analysed using gas chromatograph-mass spectrometry (SPME/GC-MS) and sugars, organic acids, and phenolic compounds with high performance liquid chromatography. Organic acids and phenolic compounds were detected with mass spectrometer (HPLC/MS). Both nitrogen and calcium fertilisation had altered sugars, organic acids, volatile and phenolic contents in strawberry fruits. Fertilisation with higher doses of nitrogen and calcium increased the content of unpleasant aromas aldehydes hexanal (up to 3.8-fold) and (E)-2-hexen-1- (up to 3.7-fold). The content of fruity esters was uppermost in fruits fertilised with nano-fertiliser Lithovit (up to 2.3-fold). Fertilisation with N and Ca decreased the strength of ketone and terpenoids fruity aroma. The highest content of total phenols, as well as all individual hydroxycinnamic and hydroxybenzoic acid derivatives were obtained in the nano-fertiliser Lithovit treatment. Fertilisation, especially with nitrogen, had mostly negative impact on strawberry flavour while nano-fertilization with Lithovit improved strawberry phenolic content and aroma.

Quantitative Reduction of Gut Microbiota-Derived Short-Chain Fatty Acids in Stool and Serum in Diabetic Kidney Disease

ObjectivesPrevious studies found the dysbiosis of intestinal microbiota in individuals with diabetic kidney disease (DKD),especially the decreased SCFA-producing bacteria. We aimed to investigate stool and serum short-chain fatty acids (SCFAs), gut microbiota-derived metabolites, in individuals with DKD and the correlations. MethodsA total of 30 participants with DKD, 30 participants with type 2 diabetes mellitus (DM) and 30 normal controls (NC) in HwaMei Hospital were recruited from 1/1/2018 to 12/31/2019. Participants with DKD were divided into low estimated glomerular filtration rate (eGFR) (eGFR<60ml/min, n=14) and high eGFR (eGFR≥60ml/min, n=16) subgroups. Stool and serum were measured for SCFAs with gas chromatograph-mass spectrometry.ResultsThe group with DKD showed markedly lower levels of fecal acetate, propionate and butyrate versus NC group (P<0.05), and the lowest fecal total SCFAs concentration among the the groups. The group with DKD also had a lower serum caproate concentration than that with diabetes (P<0.05). In the univariate regression analysis, fecal and serum acetate correlated with eGFR in the group with DKD (OR= 1.013, P=0.072; OR=1.017, P=0.032). The correlation between serum total SCFAs and eGFR showed statistical significance (OR= 0.019, P=0.024) unadjusted and a borderline significance (OR= 1.024, P =0.063) when adjusted for Hb and LDL. The decrease in serum acetate and total SCFAs were found of borderline significant correlation in both subgroups (P=0.055, P=0.050). ConclusionThis study provides evidence that in individuals with DKD, serum and fecal SCFAs levels (fecal level in particular) were lowered, and there was a correlation between lower SCFAs and a worsened renal function.

Bay Leaf (Laurus Nobilis L.) Incense Improved Scopolamine-Induced Amnesic Rats by Restoring Cholinergic Dysfunction and Brain Antioxidant Status

Bay leaf (Laurus nobilis L.) has been shown to possesses various biological activities such as wound healing activity, antioxidant activity, antibacterial activity, antiviral activity, immunostimulant activity, anticholinergic activity, antifungal activity, insect repellant activity, anticonvulsant activity, antimutagenic activity, and analgesic and anti-inflammatory activity. The present study aimed to investigate whether the bay leaf incense (BL) elicits the memory formation via the action on the cholinergic system using a scopolamine (Sco)-induced rat model. Rats were exposed to BL over 5 min in a smoking chamber apparatus once daily for 22 days, whereas memory impairment was induced by Sco (0.7 mg/kg), a muscarinic receptor antagonist, delivered 30 min before each behavioral test. The phytochemical composition of BL was achieved by gas chromatograph–mass spectrometry (GCMS). Behavioral effects in rats were assessed by Y-maze, radial arm maze (RAM), and novel object recognition (NOR) paradigms. Additionally, the acetylcholinesterase (AChE) activity and the oxidative stress markers in the rat hippocampus were also evaluated. Exposure to BL significantly ameliorated Sco-induced cognitive impairment and oxidative stress in the rat hippocampus. The obtained results suggested that BL-induced ameliorative cognitive effects are mediated by enhancement of the cholinergic system and antioxidant activities.

Potential effects of essential oil from Zanthoxylum limonella seeds against Tribolium castaneum (Coleoptera: Tenebrionidae)

Essential oils of plants with insecticidal properties have been considered as replacements for synthetic chemical pesticides to combat and control insect pests. The chemical composition of the essential oil from dried seeds of Zanthoxylum limonella Alston was determined by the Gas Chromatograph-Mass Spectrometry technique. Insecticidal activity was investigated on Tribolium castaneum Herbst using impregnated filter paper with six concentrations of essential oil at 0, 1, 2, 3, 4, and 5% for adults and larvae mortality tests, and 0, 2, 4, 6, 8 and 10% for egg mortality. All experiments were performed under completely randomized design (CRD) with four replications at 30±5°C and 70±5% relative humidity in 16:8 hours light/dark cycle. A total of 83 components were identified. The principal compounds in the essential oil of Z. limonella were beta-pinene (19.65%), 9-octadecanone (18.80%), D-limonene (9.76%), alpha-fenchene (8.48%), p-mentha-1,5,8-triene (7.16%), 1,8-cineole (6.88%), gamma-terpinene (5.46%), terpinen-4-ol (3.81%), linalool (2.73%), alpha-thujene (1.34%), decanal (1.32%), alpha-phellandrene (1.20%) and linalyl propionate (1.13%). Insecticidal activity presented that 5% of essential oil had the highest effect against T. castaneum at 120 h for adults and 48 h for larvae, while 10% of essential oil at 14 days obtained 100% mortality against eggs of T. castaneum. Results indicated that the essential oil of Z. limonella from dried seeds showed potential for use in the control of T. castaneum

Plasma Metabolomic Profiling of Individuals Susceptible to High Altitude through Gas Chromatograph- mass Spectrometry

Objective We aimed to characterize metabolic alterations of people ascending to high altitude and susceptible to acute mountain sickness (AMS). Methods Peripheral blood samples were collected from 36 healthy volunteers on the 3rd day ascending to high altitude (4300m). AMS status was assessed using the Lake Louise Questionnaire. Plasma samples were characterized by gas chromatography-mass spectrometry (GC-MS) and principal component analysis (PCA) was used to discriminate the metabolite changes between sea level and high altitude status and between AMS group and non-AMS group. Results High altitude hypobaric hypoxia caused significant and comprehensive metabolic changes in plasma, including 18 metabolites between sea level and high altitude, 6 metabolites between AMS group and non-AMS group. By using MetaboAnalyst 3.0, several key metabolic pathways were found to be involved, including cysteine and methionine metabolism, alanine, aspartate and glutamate metabolism. Conclusion The GC-MS profiling was a useful approach to analyze metabolites variances and provides potential targets for further investigation to understand the pathophysiological mechanism of hypobaric hypoxia and susceptibility to high altitude.

Thymus vulgaris Essential Oil Protects Zebrafish against Cognitive Dysfunction by Regulating Cholinergic and Antioxidants Systems

Thymus vulgaris L. is an aromatic herb used for medicinal purposes such as antimicrobial, spasmolytic, antioxidant, anti-inflammatory, antinociceptive, antitumor, and may have beneficial effects in the treatment of Alzheimer’s disease. The present study aimed to investigate whether Thymus vulgaris L. essential oil enhances cognitive function via the action on cholinergic neurons using scopolamine (Sco)-induced zebrafish (Danio rerio) model of memory impairments. Thymus vulgaris L. essential oil (TEO, 25, 150, and 300 µL/L) was administered by immersion to zebrafish once daily for 13 days, whereas memory impairment was induced by Sco (100 μM), a muscarinic receptor antagonist, delivered 30 min before behavioral tests. Spatial memory was assessed using the Y-maze test and novel object recognition test (NOR). Anxiety and depression were measured in the novel tank diving test (NTT). Gas Chromatograph-Mass Spectrometry (GC-MS) analysis was used to study the phytochemical composition of TEO. Acetylcholinesterase (AChE) activity and oxidative stress response in the brain of zebrafish were determined. TEO ameliorated Sco-induced increasing of AChE activity, amnesia, anxiety, and reduced the brain antioxidant capacity. These results suggest that TEO may have preventive and/or therapeutic potentials in the management of memory deficits and brain oxidative stress in zebrafish with amnesia.