Gas Chromatography Coupled To Mass Spectrometry Analysis Research Articles

Chemical Characterization of Crude Phenolic Leaf Extract of Acalypha wilkesiana

Acalypha wilkesiana is a widely eaten vegetable, reportedly used traditionally in the management of hypertension, diabetes and as an antimicrobial agent, probably because of its rich phenolic composition. The phytochemical and phenolic profiles of the crude leaf extract of the plant were assessed using standard methods, and gas chromatography coupled to mass spectrometry (GC-MS) and flame ionization detector (GC-FID). Qualitative phytochemical screening showed the presence of alkaloids, phenols, flavonoids, cardiac glycosides, tannin, steroids and saponins. GC-FID analysis revealed the presence of dihydrocytisine, ammodendrine, spartein, hydroxylupanine, ribalinidine, anthocyanin, flavone, flavonones, aphylidine, proanthocyanidin, isolupanine, narigenin, sapogenin, cardiac glycoside, tannin, and cyanogenic glycoside in varying proportions. GC-MS analysis identified 14 constituents with major ones being 2,6-Octadienal, 3,7-dimethyl-, (Z) Citral (14.88 %), citral 2,6-Octadienal, 3,7-dimethyl-, (E) (16.9 %), cis-3-Hexenyl cis-3-hexenoate (10.59 %), trans-2,7-Dimethyl-4,6-octadien-2-ol (20.56 %) and 3,8,11-Trioxatetracyclo[4.4.1.0(2,4).0(7,9)] undecane (11.69 %). This study has shown that crude phenolic leaf extract of A. wilkesiana contains pharmacologically active compounds which support its traditional use in the treatment of oxidative stress related diseases and hence a potential candidate for drug discovery. Keywords: Acalypha wilkesiana, phytochemicals, gas chromatography-mass spectrometry, Secondary metabolites.

Oral acute, sub-acute toxicity and phytochemical profile of Brassica carinata A. Braun microgreens ethanolic extract in Wistar rats

Ethnopharmacological relevanceCurrently, there is a remarkable increase in the consumption of microgreens, (young edible vegetables or herbs), as potential nutraceuticals for the management of diseases. Brassica carinata A. Braun is one of the traditional leafy vegetables cultivated in various parts of Sub- Saharan Africa. The plant is revered for its efficacy in the treatment of wounds and gastrointestinal disorders among other medicinal benefits. It is therefore crucial to characterize Brassica carinata microgreens for their phytoconstituents and ascertain their safety for use. Aim of the studyThe study evaluated the oral acute and subacute toxicity of Brassica carinata microgreens ethanol extract (BMEE) in Wistar rats and identification of its chemical composition and profile. Materials and methodsFor acute toxicity (14 days), rats were grouped into four and received a single oral dose, the control group received distilled water, while others received 500 mg/kg, 1000 mg/kg, and 2000 mg/kg of BMEE. For the subacute toxicity (28 days), rats in four groups received daily doses of 250 mg/kg, 500 mg/kg or 1000 mg/kg and distilled water. Daily clinical observations like lethargy and mortality were conducted. Hematological, biochemical, and histopathological evaluations were performed at the end of each experiment. Phytochemical profile was determined using a UV-VIS spectrophotometer and Gas Chromatography coupled to Mass Spectrometry (GC-MS) analysis determined the potential bioactive components in the microgreens extract. ResultsIn both acute and sub-acute toxicity studies, no mortalities, indications of abnormality, or any treatment related adverse effects were observed at doses of 2000 mg/kg, 1000 mg/kg, 500 mg/kg, and 250 mg/kg. The LD50 of BMEE was above 2000 mg/kg. No significant (p > 0.05) changes in the hematological and biochemical parameters of the treated groups compared to the control groups in both studies. Histopathological examination of the liver, kidney, lungs, and heart revealed a normal architecture of the tissues in all the treated animals. Phytochemical analyses revealed the presence of flavonoids (most abundant), phenols and alkaloids. Phytol, linoleic acid, and 9,12,15-octadecatrienoic acid, among other compounds, were identified by GC-MS analysis. ConclusionThe results showed that B. carinata microgreens ethanol extract is nontoxic and found to have several compounds with reported pharmacological significance suggesting safety for use.

Strategies for Metabolomic Analysis of Damaged Skin from Cell and Tissue Samples Using Gas Chromatography-Mass Spectrometry

Metabolomics can provide a readout of the biochemical and physiological state of a biological system. Gas chromatography coupled to mass spectrometry (GC-MS) has been widely applied for metabolomic analysis due to its numerous advantages, such as good sensitivity, high resolution, reproducibility, extensive database, lower acquisition cost and greater coverage. In addition, combined with efficient methods of sampling and sample preparation, the metabolomic analysis of damaged skin based on GC-MS can provide an important step toward elucidating several skin diseases. Based on this, this review presents a comprehensive overview of sampling, sample preparation, data processing and GC-MS analysis of metabolomic studies of damaged skin. Also, part of the biological interpretation of metabolites such as cis- and trans-urocanic acid (UCA) altered in photoexposed skin and lauric acid (C12:0) and palmitic acid (C16:0) in melanoma is discussed. Finally, to improve decision-making, a part of the integration of skin metabolomics with other omics sciences for the advancement of diagnosis is presented.

Cylindropuntia cholla aqueous root rich in phytosterols enhanced immune response and antimicrobial activity in tilapia Oreochromis niloticus leukocytes

“Cacti” are rich sources of phytochemicals with antioxidant activity, and their use is mainly focused on infusions in traditional medicine in Mexico. This study characterizes the chemical compounds found in Cylindropuntia cholla root by gas chromatography coupled to mass spectrometry (GC-MS) and determines the total content of polyphenols and flavonoids, as well as their antioxidant capacity. The immunostimulatory effect of aqueous C. cholla root extract (ACcr) was evaluated at concentrations of 50, 250, 500, and 1000 μg/mL in Tilapia peripheral blood leukocytes. The results obtained by the GC-MS analysis revealed the presence of phenolic acids, flavonoid and phytosterol derivatives as β-sitosterol and campesterol. The determination of the total polyphenol and flavonoid contents indicated that ACcr is abundant in polyphenols, showing an anti-radical capacity of scavenging free radicals, such as those of hydroxyl and superoxide, as well as an increase in lipid peroxidation inhibition capacity. Stimulation of tilapia leukocytes resulted in the increase of its phagocytic activity, respiratory burst, nitric oxide production, and superoxide dismutase activity. Finally, the results obtained for the first time allowed establishing the chemical profile of ACcr and its antimicrobial activity against three important pathogenic bacteria. The potential of this root is indicated as an additive in formulating antioxidant and immunostimulant supplements for the aquaculture and pharmaceutical industry.

Fecal descriptor in honey: indole from a floral source as an explanation.

Animal odor, is one of the most common aroma defects described in the honey odor aroma wheel. It comprises two secondary descriptors: 'fecal' and 'cowshed'. However, the compounds responsible for these honey defects have not been fully identified. In this context, the aim of this work was to identify the compounds responsible for the aromatic defect 'fecal' in Uruguayan honeys by means of gas chromatography coupled to olfactometry (GC-O). Samples of honey described by beekeepers as having fecal aroma were analyzed by GC-O and gas chromatography coupled to mass spectrometry (GC-MS). Through GC-O, it was possible to establish the region of the chromatogram corresponding to the fecal descriptor, while the GC-MS analysis allowed to identify indole as the compound responsible for the fecal descriptor. The content of indole in the analyzed samples ranged between 132 and 414 μg kg-1 . The melissopalynological analysis indicated the presence of Scutia buxifolia ('quebracho' or 'coronilla') pollen in all samples studied. The volatile profile of Scutia buxifolia flowers was evaluated during the full day, enabling the identification of indole as one of its components. The detection threshold value for indole in honey was experimentally determined as 64 μg kg-1 of honey, a value lower than the concentration found in the evaluated samples. Results from the study allowed the identification of indole as the compound responsible for the 'fecal' aroma defect in Scutia buxifolia honeys. © 2022 Society of Chemical Industry.

GC/MS Analysis, Antioxidant Activity, and Antimicrobial Effect of Pelargonium peltatum (Geraniaceae).

In recent years, the increase in antibiotic resistance demands searching for new compounds with antimicrobial activity. Phytochemicals found in plants offer an alternative to this problem. The genus Pelargonium contains several species; some have commercial use in traditional medicine such as P. sinoides, and others such as P. peltatum are little studied but have promising potential for various applications such as phytopharmaceuticals. In this work, we characterized the freeze-dried extracts (FDEs) of five tissues (root, stem, leaf, and two types of flowers) and the ethyl acetate fractions from leaf (Lf-EtOAc) and flower (Fwr-EtOAc) of P. peltatum through the analysis by thin-layer chromatography (T.L.C.), gas chromatography coupled to mass spectrometry (GC-MS), phytochemicals quantification, antioxidant capacity, and antimicrobial activity. After the first round of analysis, it was observed that the FDE-Leaf and FDE-Flower showed higher antioxidant and antimicrobial activities compared to the other FDEs, for which FDE-Leaf and FDE-Flower were fractionated and analyzed in a second round. The antioxidant activity determined by ABTS showed that Lf-EtOAc and Fwr-EtOAc had the lowest IC50 values with 27.15 ± 1.04 and 28.11 ± 1.3 µg/mL, respectively. The content of total polyphenols was 264.57 ± 7.73 for Lf-EtOAc and 105.39 ± 4.04 mg G.A./g FDE for Fwr-EtOAc. Regarding the content of flavonoid, Lf-EtOAc and Fw-EtOAc had the highest concentration with 34.4 ± 1.06 and 29.45 ± 1.09 mg Q.E./g FDE. In addition, the minimum inhibitory concentration (M.I.C.) of antimicrobial activity was evaluated: Lf-EtOAc and Fwr-EtOAc were effective at 31.2 µg/mL for Staphylococcus aureus and 62.5 µg/mL for Salmonella enterica, while for the Enterococcus feacalis strain, Fwr-EtOAc presented 31.2 µg/mL of M.I.C. According to the GC-MS analysis, the main compounds were 1,2,3-Benzenetriol (Pyrogallol), with 77.38% of relative abundance in the Lf-EtOAc and 71.24% in the Fwr-EtOAc, followed by ethyl gallate (13.10%) in the Fwr-EtOAc and (Z)-9-Octadecenamide (13.63% and 6.75%) in both Lf-EtOAc and Fwr-EtOAc, respectively.

Unravelling the Anti-Inflammatory and Antioxidant Potential of the Marine Sponge Cliona celata from the Portuguese Coastline.

Inflammation is a double-edged sword, as it can have both protective effects and harmful consequences, which, combined with oxidative stress (OS), can lead to the development of deathly chronic inflammatory conditions. Over the years, research has evidenced the potential of marine sponges as a source of effective anti-inflammatory therapeutic agents. Within this framework, the purpose of this study was to evaluate the antioxidant and the anti-inflammatory potential of the marine sponge Cliona celata. For this purpose, their organic extracts (C1–C5) and fractions were evaluated concerning their radical scavenging activity through 2,2-diphenyl-1-picrylhydrazyl radical (DPPH), ferric reducing antioxidant power (FRAP), oxygen radical absorbance capacity (ORAC), and anti-inflammatory activity through a (lipopolysaccharides (LPS)-induced inflammation on RAW 264.7 cells) model. Compounds present in the two most active fractions (F5 and F13) of C4 were tentatively identified by gas chromatography coupled to mass spectrometry (GC-MS). Even though samples displayed low antioxidant activity, they presented a high anti-inflammatory capacity in the studied cellular inflammatory model when compared to the anti-inflammatory standard, dexamethasone. GC-MS analysis led to the identification of n-hexadecanoic acid, cis-9-hexadecenal, and 13-octadecenal in fraction F5, while two major compounds, octadecanoic acid and cholesterol, were identified in fraction F13. The developed studies demonstrated the high anti-inflammatory activity of the marine sponge C. celata extracts and fractions, highlighting its potential for further therapeutic applications.

Phytochemical characterization and antibiotic potentiating effects of the essential oil of Aloysia gratissima (Gillies & Hook.) and beta-caryophyllene

The traditional knowledge associated with the use of medicinal plants has significantly contributed to drug development research. In this context, Aloysia gratissima, commonly known as bee-brush or white-brush, has been widely used in Brazilian folk medicine as an analgesic and antimicrobial species. Phytochemical analysis of A. gratissima essential oil has identified sesquiterpene β-caryophyllene (17.3%) as a major component with significant antibacterial activity. Thus, this study aimed to characterize the antibacterial effects of the essential oil obtained from A. gratissima (EOAG) and its major compound β-caryophyllene, as well as to evaluate their potential to act as efflux pumps inhibitors in association with conventional antibiotics. The phytochemical characterization of EOAG was performed by gas chromatography coupled to mass spectrometry (GC-MS), while the antibacterial activity against the strains Pseudomonas aeruginosa 24, Staphylococcus aureus 10, and Escherichia coli 06 was assessed using the broth microdilution method. The antibiotic potentiating activity was investigated by analyzing the ability of the natural products to decrease the minimum inhibitory concentration (MIC) of norfloxacin and ciprofloxacin against S. aureus strains 1199B and K2068. A reduction in the MIC of ethidium bromide in the presence of essential oil components was interpreted as efflux pump inhibition. The GC-MS analysis identified 30 compounds, including β-caryophyllene as the major component. The antibacterial activity analysis demonstrated that both EOAG and β-caryophyllene both EOAG and β-caryophyllene presented antibacterial effects against S. aureus 10 (MIC = 32 μg/mL), in addition to potentiating the activity of norfloxacin against [S. aureus 10], [P. aeruginosa 24], and [E. coli 06]. The isolated compound also reversed the degree of antibiotic resistance observed in strains carrying efflux pumps. In conclusion, the essential oil of A. gratissima and β-caryophyllene have the potential to increase the effectiveness of antibiotics and as such can be used in the development of new therapies against bacterial resistance.

Enhanced antibacterial effect of antibiotics by the essential oil of Aloysia gratissima (Gillies & Hook.) Tronc. and its major constituent beta-caryophyllene

BackgroundAloysia gratissima (Verbenaceae), popularly known as bee-brush or whitebrush, has been widely used in Brazilian folk medicine as analgesic, expectorant and antimicrobial. Phytochemical studies have identified β-caryophyllene as one of the major components of the essential oil of this plant. This bioactive sesquiterpene has been shown to have anti-inflammatory and antibacterial activities. PurposeThe present study aimed to characterize the chemical profile and evaluate the antibacterial and antibiotic-enhancing activities of the essential oil obtained from Aloysia gratíssima (EOAG) and β-caryophyllene. MethodsThe phytochemical analysis was performed by gas chromatography coupled to mass spectrometry (GC-MS). The antibacterial activity against Pseudomonas aeruginosa 24, Staphylococcus aureus 10, and Escherichia coli 06 was assessed by determining the minimum inhibitory concentration (MIC) using the broth microdilution method. The potentiation of the antibiotic activity by the EOAG and the β-caryophyllene was performed using the MIC evaluation of the antibiotic alone or in association with the essential oil and its main compound. To evaluate the minimum reduction of the drug concentration necessary, the Dose Reduction Index (DRI) was calculated. ResultsA reduction in the MIC of the antibiotics against strains treated simultaneously with the essential oil or β-caryophyllene was observed. The GC-MS analysis of the EOAG identified 30 compounds, including β-caryophyllene as the major component. Both OEAG and β-caryophyllene presented antibacterial activity against S. aureus, in addition to potentiating the action of norfloxacin against S. aureus, P. aeruginosa, and E. coli. ConclusionsThese substances also reversed the antibiotic resistance to gentamicin and erythromycin against of S. aureus and P. aeruginosa, respectively.

Structure Assignment of Seized Products Containing Cathinone Derivatives Using High Resolution Analytical Techniques.

The innovation of the new psychoactive substances (NPS) market requires the rapid identification of new substances that can be a risk to public health, in order to reduce the damage from their use. Twelve seized products suspected to contain illicit substances were analyzed by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), gas chromatography coupled to mass spectrometry (GC-MS), and nuclear magnetic resonance spectroscopy (NMR). Synthetic cathinones (SCat) were found in all products, either as a single component or in mixtures. Infrared spectra of all products were consistent with the molecular structure of SCat, showing an intense absorption band at 1700–1674 cm−1, corresponding to the carbonyl stretching, a medium/strong peak at 1605–1580 cm−1, indicating stretching vibrations in the aromatic ring (C=C) and bands with relative low intensity at frequencies near 2700–2400 cm−1, corresponding to an amine salt. It was possible to identify a total of eight cathinone derivatives by GC-MS and NMR analysis: 4′-methyl-α-pyrrolidinohexanophenone (MPHP), α-pyrrolidinohexanophenone (α-PHP), 3-fluoromethcathinone (3-FMC), methedrone, methylone, buphedrone, N-ethylcathinone, and pentedrone. Among the adulterants found in these samples, caffeine was the most frequently detected substance, followed by ethylphenidate. These results highlight the prevalence of SCat in seized materials of the Portuguese market. Reference standards are usually required for confirmation, but when reference materials are not available, the combination of complementary techniques is fundamental for a rapid and an unequivocal identification of such substances.

Identification of antimicrobial compounds in different hydrophilic larch bark extracts

Larch bark is an undervalued material, but it has unique and valuable characteristics and compounds. The objective of this study was to extract and characterize molecular compounds of bark materials from different larch trees and to test these for their antimicrobial properties. The extractions were performed using methanol or water. The obtained extracts were analysed by gas chromatography coupled to mass spectrometry (GC-MS). Antimicrobial properties also were determined using different microbial strains, for example, Staphylococcus aureus. The GC-MS analysis showed that long chain alcohols, fatty acids, and polyphenols were present in the extracts. According to the results of the agar diffusion tests, only the methanol extract of larch bark had an inhibitory effect on the growth of Staphylococcus aureus. Two compounds of flavonoids and stilbenoids were shown to affect the microbial activity of the larch bark. Therefore, larch bark can be used for the extraction of compounds with specific anti-microbial properties.

Chemical constituents and antimicrobial activity of the leaf essential oil of Ixora coccinea L (Rubiaceae) collected from North Central Nigeria

Essential oils have found vast applications in many fields including aromatherapy, flavor and fragrance industries. Ixora coccinea Linn. is a reputable medicinal plant with long history of use in Nigeria. This study aimed to investigate the chemical constituents and antimicrobial activity of the leaf Essential Oil (EO) of Ixora coccinea grown in Nigeria. EO was obtained by hydrodistillation with yield of 0.16% (w/w). Chemical constituents of EO were determined using Gas Chromatography coupled to Mass Spectrometry (GC-MS). The GC-MS analysis identified 43 compounds, representing 94.67% of the oil constituents. The analysis revealed eight classes of compounds including hydrocarbons, alcohols, carboxylic acids, esters, aldehydes, ketones, sesquiterpenoids and triterpenoids. Hydrocarbons accounted for 33.77% with decane (11.12%) as the highest; alcohols comprised 28.86% of the oil with the highest being linalool (10.54%). Esters made up 14.15% of the oil. Carboxylic acid (10.91%) was dominated by malonic acid (10.26%); sesquiterpenoids made up 6.84% of the oil dominated by 3,7,11-trimethyl-1,6,10-dodecatrien-3-ol (3.07%). Aldehydes made up 3.36% of EO dominated by heptadecanal (2.30%). Ketones accounted for 1.38% of the oil. The inhibitory effect of EO was evaluated against Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Candida albicans and Mycobacterium tuberculosis (BCG) using broth microdilution method. The essential oil showed significant antimicrobial effects against the test organisms, with Minimum Inhibitory Concentration (MIC) ranging from 50 to 200 I¼g/mL. This result showed that EO could serve as adjunct therapy in the treatment of community acquired infections.

Simultaneous determination of multiresidue and multiclass emerging contaminants in waters by rotating-disk sorptive extraction–derivatization-gas chromatography/mass spectrometry

An efficient method has been developed for the multiresidue and multiclass determination of 16 emerging contaminants (parabens, hormones, anti-inflammatory drugs, triclosan and bisphenol A) in water samples using rotating-disk sorptive extraction (RDSE) and gas chromatography coupled to mass spectrometry (GC-MS). Silylation of the compounds prior to GC-MS analysis was optimized using a factorial experimental design; the optimal derivatization conditions to maximize the response of the set of analytes included 70 μL of N-methyl-N-(trimethylsilyl)trifluoroacetamide at 80 °C for 35 min. RDSE was implemented using Oasis® HLB as a sorptive phase and an extraction time of 60 min.The method was applied to Chilean environmental samples. In tap water, none of the analytes under study were detected. In the river and well waters, the concentrations of the four detected contaminants were below 0.38 μg L−1. In the effluent and influent of the wastewater treatment plant, the maximum concentrations of contaminants were 3.1 and 4.2 μg L−1, respectively.The proposed analytical strategy suggests clear improvements with respect to other methods reported in the literature, considering not only the different steps involved in the analytical process (extraction, derivatization and chromatography) but also taking into account that this method involves the determination of different families of analytes with different physicochemical and structural properties.

Antibiofilm activity of the essential oil of Campomanesia aurea O. Berg against microorganisms causing food borne diseases

Campomanesia aurea O. Berg is a native plant of the biome Pampa, which belongs to the family Myrtaceae. The present study aimed to evaluate the antimicrobial and antibiofilme activity of the essential oil of Campomanesia aurea (EOCA) against Listeria monocytogenes ATCC 19114, Staphylococcus aureus ATCC 25923, Salmonella enteritidis ATCC 13076 and Pseudomonas aeruginosa ATCC 27853. An analysis of the chemical composition of the EOCA was realized through gas chromatography coupled to mass spectrometry (GC-MS). The analysis for in vitro evaluation of the antimicrobial and antibiofilm activity was realized by determination of the minimal inhibitory concentration (MIC) and that of the antibiofilm through utilization of 96-well plates with crystal violet, respectively. The action of standard (E)–nerolidol (major compound of the EOCA) was also tested. GC-MS analysis revealed the presence of the sesquiterpene (E)-nerolidol (56.04%) as the main compound in the EOCA. Antimicrobial activity of the EOCA against L. monocytogenes (MIC 5.0 mg mL−1) and S. aureus (MIC 0.7 mg mL−1) was observed. Inhibition of biofilm formation against L. monocytogenes, S. aureus and S. enteritidis could be observed for EOCA and (E)-nerolidol. The results demonstrate that the EOCA was efficient against inhibition of biofilm formation for most of the tested pathogens.

Extraction, characterization and antioxidant activity of fenugreek (Trigonella-Foenum Graecum) seed oil

Fenugreek (Trigonella-Foenum Graecum) is known as one of the traditional and most promising medicinal herbs belongs to the leguminous family. The seeds of fenugreek have been extensively studied for the treatment of inflammation, cancer and diabetes. In this study, fenugreek seed oil was extracted and evaluated for its chemical compositions and bonding through gas chromatography coupled to mass spectrometry (GC-MS) and Fourier transform infrared spectroscopy (FT-IR) analysis, respectively. The antioxidant activity against 2,2-diphenyl-picrylhydrazyl (DPPH) and 2,2′-Azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS+•) radicals, total phenolic content (TPC) and total flavonoid content (TFC) of the oil were also studied. The capacity of antioxidants detected by ABTS was stronger than that by DPPH. A total number of 23 chemical compounds were detected and identified in fenugreek seed oil comprising of 99% of the total oil through GC-MS analysis. The major compounds of the extracted oil were linoleic acid (54.13%), palmitic acid (16.21%), pinene (4.56%), 4-Pentyl-1-(4-propylcyclohexyl)-1-cyclohexene (3.87%) and linoleic acid methyl ester (3.19%). FTIR analysis confirmed the presence of carboxyl group in the oil which were more dominated by unsaturated essential fatty acids. Moreover, the oil of fenugreek seed indicated a strong antioxidant radical scavenging activity against both DPPH and ABTS assays with an IC50 of 172.6 ± 3.1 and 161.3 ± 2.21, respectively. The TPC and TFC of the oil were 38.97 ± 0.34 mg GAE/g. oil and 14.417 ± 0.23 mg QE/g.oil. Thus, this study suggests that the fenugreek seed oil could be used for pharmaceutical purposes.

Use of fatty acids in the chemotaxonomy of the family Selenastraceae (Sphaeropleales, Chlorophyceae)

The family Selenastraceae includes many species of freshwater green microalgae with morphological characteristics that are so subtly different that it is difficult to discriminate species within it. Therefore, the use of the diacritical characteristics of traditional morphological taxonomy may be ineffective at differentiating among many species of the family. Chemotaxonomy based on fatty acid methyl ester (FAME) can help resolve uncertainties not completely addressed by other approaches, such as molecular studies of some species within the Selenastraceae. Here, we first tested three techniques for the analysis of microalgal FAME to choose the one that would provide the best profiles for chemotaxonomy: 1) direct transesterification (DT) of the biomass followed by gas chromatography coupled to mass spectrometry analysis (GC-MS); 2) extraction using chloroform and methanol, followed by transesterification (T) and then analysis by gas chromatography/flame ionization detector (GC-FID); and 3) extraction with chloroform and methanol and then separation into lipid classes using thin-layer chromatography (TLC) using the Iatroscan-Chromarod system. The tests were conducted on 12 strains (11 species) of Selenastraceae and one outgroup strain. The fatty acid profiles produced by the DT-GC-MS technique yielded the best results for the chemotaxonomy of the Selenastraceae species using 12 FAME. The proportion of the variance in the fatty acid profiles obtained with DT-GC-MS analysis explained by species was 85%, whereas the differences explained by strains was 92%. Therefore, DT-GC-MS was used to analyze other microalgae strains, totaling 15 species of 8 genera of green coccoid microalgae, including the recently described Curvastrum. The results with all strains showed that fatty acid profiles obtained by DT-GC-MS were significantly different (p < 0.001) among strains and among species. The variance in fatty acids profiles explained by separation into strains was 97%, whereas the separation into species explained 93% of the variance. Statistical analyses showed that, for our dataset, the C18 fatty acids 18:3ω3 and 18:4ω6 were indicative of the Selenastraceae. Therefore, fatty acid profiles are a useful auxiliary chemotaxonomic tool for species identification in Selenastraceae.

Identification of Fusarium oxysporum Fungus in Wheat Based on Chemical Markers and Qualitative GC-MS Test

Fusarium oxysporum is usually found in foods such as corn, wheat, soybeans and barley, and can cause economic losses and risks to health in humans and animals due to the production of mycotoxins. The conventional microbiological test for fungal identification is based on morphological characteristics, requires specialists, and it is very time-consuming as it is necessary to carry out a culture of the fungus for two weeks before microorganism identification. Nowadays, researchers have made efforts to develop alternative analytical methods with advantages such as shorter time of analysis and better accuracy and reproducibility when compared to microbiological methods. In this way, in the present work, a qualitative analytical method to detect the secondary metabolites of Fusarium oxysporum in culture media by gas chromatography coupled to mass spectrometry (GC-MS) was developed with the intention of relating the presence of these chemical compounds to contamination by the fungus. The method comprised liquid-liquid or liquid-solid extractions with ethyl acetate from liquid and solid culture media, respectively, followed by GC-MS analysis, which was able to identify the presence of fusaric acid, 13-socosenamide, 5-(4-hydroxybutyl)-2-pyridinecarboxylic acid and toxin HT-2. The presence of these compounds was confirmed by high-performance liquid chromatography coupled to mass spectrometry quadrupole time of flight (HPLC-MS/QTOF).

EASI-IMS an expedite and secure technique to screen for 25I-NBOH in blotter papers.

The increasing number of new psychoactive substances (NPS) and their quick worldwide spreading, often only slightly modified in the form of new derivatives and analogues, have brought the need for fast, wide-ranging, and unequivocal identification methods in clinical and forensic investigations. Because it usually provides secure results, gas chromatography coupled to mass spectrometry (GC-MS) has been routinely employed as the standard technique for the detection of NPS in blotter papers. For 25I-NBOH (N-(2-hydroxybenzyl)-2-(4-iodo-2,5-dimethoxyphenyl)ethan-1-aminium), however, GC-MS analysis of an blotter paper extract leads to incorrect results. In this work, we investigated whether easy ambient sonic-spray mass spectrometry imaging (EASI-IMS), and ambient ionization MS method can be applied directly to the surface of the sample requiring therefore no extraction or sample preparations, would serve as an efficient, sensitive, and secure alternative for 25I-NBOH screening.

Rapid Quantification of Major Volatile Metabolites in Fermented Food and Beverages Using Gas Chromatography-Mass Spectrometry.

Here we present a method for the accurate quantification of major volatile metabolites found in different food and beverages, including ethanol, acetic acid and other aroma compounds, using gas chromatography coupled to mass spectrometry (GC-MS). The method is combined with a simple sample preparation procedure using sodium chloride and anhydrous ethyl acetate. The GC-MS analysis was accomplished within 4.75 min, and over 80 features were detected, of which 40 were positively identified using an in-house and a commercial mass spectrometry (MS) library. We determined different analytical parameters of these metabolites including the limit of detection (LOD), limit of quantitation (LOQ) and range of quantification. In order to validate the method, we also determined detailed analytical characteristics of five major fermentation end products including ethanol, acetic acid, isoamyl alcohol, ethyl-L-lactate and, acetoin. The method showed very low technical variability for the measurements of these metabolites in different matrices (<3%) with an excellent accuracy (100 ± 5%), recovery (100 ± 10%), reproducibility and repeatability [Coefficient of variation (CV) 1–10%)]. To demonstrate the applicability of the method, we analysed different fermented products including balsamic vinegars, sourdough, distilled (whisky) and non-distilled beverages (wine and beer).

Chemical composition and antibacterial activity of essential oil and leaf extracts of Zanthoxylum caribaeum Lam. against serotypes of Salmonella

SUMMARY The present study aimed to identify and quantify the components of the essential oil of Zanthoxylum caribaeum and to evaluate the antimicrobial potential of different plant extracts and the essential oil of this plant against different serotypes of Salmonella enterica, which is of greater occurrence and isolated in the western region of Paraná, Brazil. The extraction of the essential oil was performed using Clevenger apparatus and the chemical composition was determined by Gas Chromatography coupled to Mass Spectrometry (GC-MS). The extracts were obtained through different solvents (ethanol, methanol, hexane, acetone, dichloromethane, ethyl acetate and distilled water). The antibacterial activity was carried out according to the broth microdilution technique. The GC-MS analysis resulted in the identification of 15 main components, all terpenes, representing 63.88% of the total essential oil. The major compounds identified were Germacrene-D (20.77%), a-Panasinsene (14.40 %) and b-Selinene (11.68 %). The essential oil presented antibacterial activity against 5 serotypes of Salmonella enterica, with MIC and MBC ranging from 7000 to 437 μg.mL-1. While MIC and MBC from the range from 200 to 25 mg.mL-1, being effective to most serotypes of S. enterica, with the exception of the aqueous extract. The results suggest that the essential oil and leaf extracts of Z. caribaeum represent an alternative for the control of S. enterica in the poultry sector, in this way reflecting a new perspective for studies with natural products.