Gas Chromatography-flame Ionization Detector Research Articles

Molecular profiling of triacylglycerols in bovine and goat milk powders via ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry

Triacylglycerols (TAG) play several nutritional, technological, and functional roles in the dairy industry, representing approximately 98 % of milk fat. In the present study, the total fatty acid composition and the sn-2 fatty acid positional distribution of bovine and goat milk powders fat were analyzed by using the gas chromatography-flame ionization detector. Furthermore, the identification of TAG molecular species from milk powders was conducted using ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS). The separation of milk TAG was accomplished by using isopropanol/acetonitrile (90:10, v/v) as mobile phase A, and water/acetonitrile (60:40, v/v) as mobile phase B. Myristic, palmitic, stearic, and oleic acids were identified as the most abundant fatty acids making up 11.55 and 10.71 %, 33.23 and 30.64 %, 10.86 and 12.52 %, and 26.74 and 21.80 % in the bovine and goat milk powders, respectively. In bovine milk, 221 molecular species of TAG were identified, with the predominant molecular species (LaCyO, CaLaPa, CyPaM, OCaCa, CaGCy, GLaCo) detected at a retention time of 6.362 min, with a relative abundance of 8.28 %. In goat milk, 202 molecular species were identified, with the major molecular species (CaLaM, CaPCa, CaCyS, CaCoAra, CaBuBe, LaPCy, LaCoS, LaBuAra, MPCo, MCyM, MBuS, PBuP, CyCoBe) detected at a retention time of 6.106 min, making up 8.14 % of the total TAG detected. These results provide valuable insights into milk fat composition for the dairy sector, aiding in the development of specialized dairy products.

Effects of anthropogenic activities on the microbial community diversity of Ologe Lagoon sediment in Lagos State, Nigeria.

The impact of pollution on the Ologe Lagoon was assessed by comparing physicochemical properties, hydrocarbon concentrations and microbial community structures of the sediments obtained from distinct sites of the lagoon. The locations were the human activity site (OLHAS), industrial-contaminated sites (OLICS) and relatively undisturbed site (OLPS). The physicochemical properties, heavy metal concentrations and hydrocarbon profiles were determined using standard methods. The microbial community structures of the sediments were determined using shotgun next-generation sequencing (NGS), taxonomic profiling was performed using centrifuge and statistical analysis was done using statistical analysis for metagenomics profile (STAMP) and Microsoft Excel. The result showed acidic pH across all sampling points, while the nitrogen content at OLPS was low (7.44 ± 0.085mg/L) as compared with OLHAS (44.380 ± 0.962mg/L) and OLICS (59.485 ± 0.827mg/L). The levels of the cadmium, lead and nickel in the three sites were above the regulatory limits. The gas chromatography flame ionization detector (GC-FID) profile revealed hydrocarbon contaminations with nC14 tetradecane > alpha xylene > nC9 nonane > acenaphthylene more enriched at OLPS. Structurally, the sediments metagenomes consisted of 43 phyla,75 classes each, 165, 161, 166 orders, 986, 927 and 866 bacterial genera and 1476, 1129, 1327 species from OLHAS, OLICS and OLPS, respectively. The dominant phyla in the sediments were Proteobacteria, Firmicutes, Actinobacteria, and Chloroflexi. The principal component ordination (PCO) showed that OLPS microbial community had a total variance of 87.7% PCO1, setting it apart from OLHAS and OLICS. OLICS and OLHAS were separated by PCO2 accounting for 12.3% variation, and the most polluted site is the OLPS.

BTEX concentration and health risk assessment in automobile workshops

This study focused on the measurement of BTEX (benzene, toluene, ethylbenzene, and xylene) concentrations in the air of indoor and outdoor environments of automobile workshops in Damghan, Iran. Air samples from twenty-five workshops were actively collected and analyzed using Gas Chromatography-Flame Ionization Detection (GC-FID). The results showed that the concentrations of BTEX were higher in the indoor air compared to the outdoor air. The highest mean concentration of benzene (153.22 ± 34.21 μg m−3), toluene (94.41 ± 25.25 μg m−3), and xylenes (385.38 ± 34.21 μg m−3) was found in auto paint (AP) workshops, while the highest mean concentration of ethylbenzene (43.39 ± 12.57 μg m−3) was observed in auto body (AB) workshops. The significant negative correlations between benzene, ethylbenzene, xylene isomers, and relative humidity (RH) indicated that controlling humidity is an effective strategy. The mean inhalation lifetime cancer risk (LTCR) for benzene in both indoor and outdoor air of all automobile workshops exceeded the EPA (Environmental Protection Agency) recommended limits. The highest mean LTCR values for benzene and ethylbenzene were observed in the AP (3.24E10-4) and AB (2.95E10-5) workshops, respectively. The hazard quotient (HQ) of benzene and Xylene in the indoor air of the AP and AB workshops was >1, which indicates that the non-carcinogenic risks associated with exposure to these compounds are considerable. This study underscores the need for international attention to BTEX pollution in automobile workshops, highlighting the global health risks. The findings provide crucial data for developing strategies to mitigate these risks and protect workers’ health.

From Leaves to Reproductive Organs: Chemodiversity and Chemophenetics of Essential Oils as Important Tools to Evaluate Piper mollicomum Kunth Chemical Ecology Relevance in the Neotropics.

Piper mollicomum Kunth (Piperaceae) plays a vital role in the preservation of the Brazilian Atlantic Forest by contributing to the regeneration of deforested areas. Recent scientific investigations have analyzed the chemical constituents and seasonal dynamics of essential oils (EO) from various Piper L. species, highlighting the need to elucidate their chemical-ecological interactions. This study aims to expand the chemical-ecological knowledge of this important taxon in neotropical forests, using P. mollicomum as a model. The methodologies employed include the collection of plant material, EO extraction by hydrodistillation, analysis of EO by gas chromatography-mass spectrometry (GC-MS) and gas chromatography-flame ionization detector (GC-FID), recording the frequency of visits by potential pollinators and microclimatic variables, and by conducting calculations of chemodiversity and chemophenetic indices. Chemical analyses indicated that the diversity of EO and environmental factors are linked to the activities of potential pollinators. In the Tijuca Forest, P. mollicomum revealed significant interactions between its volatile constituents and microclimatic variables, showing that the chemodiversity of the leaves and reproductive organs correlates with pollinator visitation. Additionally, a notable difference in chemical evenness was observed between these vegetative structures. The chemophenetic indices by Ramos and Moreira also revealed correlations with chemical diversity.

Enhancement of ultrasonic-assisted and agitation-assisted flaxseed oil extractions: Kinetic modeling and optimization

The flaxseed oil extraction process has been investigated and enhanced by applying Ultrasonic-Assisted Extraction (UAE), and Mixer-Assisted Extraction (MAE) methods in this study. Response Surface Methodology (RSM) was also utilized to find the optimal values of the extraction parameters. The optimal conditions for UAE were determined to be 42.7 min extraction time, 0.283 mm particle size, and 2.48 W/mL power intensity, achieving the oil yield of 94.56 %. For MAE, the optimal conditions were 54.5 min extraction time, 0.274 mm particle size, 21.1 °C temperature, and 0.74 W/mL agitation intensity, resulting in the oil yield of 96.73 %. RSM showed high reliability with R2 values above 0.99 for both methods. Gas Chromatography Flame Ionization Detector (GC-FID) analysis revealed that UAE and MAE resulted in higher unsaturated fatty acids concentrations (85.8 % and 86 %, respectively) compared to CPE (78.2 %). Kinetic studies indicated that UAE and MAE are more efficient in extracting unsaturated fatty acids, with MAE showing the highest double bond content. The Kinetic models demonstrated that extraction kinetics were controlled primarily by solid-phase resistance, with the washing coefficients being significantly higher than the diffusion coefficients. The Perez model calculated diffusion coefficients of 8.03 × 10⁻12 m2/s for UAE and 1.41 × 10⁻11 m2/s for MAE, activation energies of 16.44 kJ/mol for UAE and 15.64 kJ/mol for MAE.

Development of Free Fatty Acid (FFA) monitoring device for evaluation of oil samples used for biodiesel production

Diversion of oil sources for biodiesel production has been gaining importance to meet the environmental concerns and energy demand. The free fatty acid (FFA) content of the feedstock is a significant factor in biodiesel production. The FFA values determine the complexity of the biodiesel production. Until date, an experimental procedure has been used to determine the FFA concentration of an oil source; this method is dependent on titration, which is a laborious process involving significant volumes of chemicals. Hence, in the present study, an attempt was made to develop a device for the identification of FFA of the oils. Waste cooking oil samples subjected to wide range of cooking conditions like cooking time, temperature, type of food are collected from different food outlets. Subsequently, the composition of oil samples and the variation in their quality were analysed using gas chromatography flame ionization detector (GC – FID). Biodiesel is prepared from the oil samples through transesterification and the impact of FFA and their respective methyl esters in the quality and properties have been investigated. The properties of biodiesel were determined as per ASTM standards. The study was further extended to correlate the properties of biodiesel with the composition of the oil from which it was derived. The analysis evidently proved the dependence of biodiesel properties on the FFA percentage and the composition of the oil. The results have been further substantiated with the performance and emission characteristics of internal combustion engine fuelled with the prepared biodiesel samples.

Evaluation of volatile and bioactive compounds of ethanol leaf extracts of Justicia secunda using GC-MS and GC-FID analysis.

The study evaluated the volatile and bioactive constituents of ethanol extracts of Justicia secunda using gas chromatography-mass spectrometry (GC-MS) for volatile composition while bioactive compound were assessed using gas chromatography flame ionization detector (GC-FID). The leaf extracts were prepared by being collected, air-dried, macerated in 96% ethanol, filtered and concentrated at 450C. The result obtained revealed the presences of bioactive compound such as flavonoid that include: Spartein (28.10 µg/ml), Ruti (15.6 µg/ml), Oxalate (12.70 µg/ml), Naringin (12.4 µg/ml), Steroids (11.7 µg/ml), Epinedrine (11.10 µg/ml), Cardiac glycoside (10.10 µg/ml), Flavonone (10.10 µg/ml), Ribalinidine (9.30 µg/ml), Anthocyanin (7.70%), Flavone (7.30 µg/ml), Sapogenin (7.30µg/ml), Proanthocyanin (6.90 µg/ml),Resveratol (6.70µg/ml), Epicatechin (5.70 µg/ml), Phytate (5.70µg/ml), Kaempferol (3.90 µg/ml),Catechin (2.00 µg/ml), Tannin (2.00 µg/ml). The GC-MS Screening of the plant’s extract identified eighty-two (82) bioactive compounds, which include Ethyl palmitate (5.54%), 2,4-Di-tert-butylphenol (4.04%),9,17-Octadecadienal, (4.05%), Linoleic acid ethyl ester (4.05%), 9,12-Octadecadienoic acid, ethyl ester (4.00%), Decane, 2-methyl (3.82%), Hexadecane (3.82%), Heptadecane, 2,6-dimethyl (3.26%), N-(3-methylButyl) acetamide (3.02%), Sulfurous acid, butyl octyl ester (3.25%), Hexane,1-(hexyloxy)-5-(3.06%) as the major bioactive compounds. The result of the GC-MS analysis showed that the ethanol extract of Justicia secunda contains many pharmacologically important bioactive compounds such as antioxidant, anti-inflammatory, anti-microbial, anti-diabetic anti-cancer effects. Traditionally, Justicia species are used in the treatment of inflammation, rheumatism, arthritis gastrointestinal diseases, anaemia and respiratory tract infection. The proximate analysis of the ethanol extract of the leaves revealed notable levels of various components, where carbohydrates were found to be the highest, followed by moisture content, protein, fats, fiber, and ash content, respectively.

Chemical composition of essential and fixed oils of Tagetes erecta fruits (Iran) and their implications in inhibition of cancer signaling

The current research was conducted to explore, for the first time, Tagetes erecta L. (family Asteraceae) fruits from northwest Iran in terms of the chemical composition of essential and fixed oils, their cytotoxic activities, and the inhibitory effect of essential oil on the PI3K/AKT/mTOR signaling pathway. The volatile oil was obtained through hydrodistillation (Clevenger apparatus). According to gas chromatography–mass spectrometry analysis, the essential oil was rich in cyclic monoterpenoids, 2-isopropyl-5-methyl-3-cyclohexen-1-one (19.99%), d-limonene (12.75%), terpinolene (11.64%) and also the saturated fatty acid palmitic acid (19.09%). Furthermore, the seeds of T. erecta were extracted using hexane by the maceration method. The analysis of fatty acid profile of the fixed oil by gas chromatography-flame ionization detector (GC-FID) demonstrated that the most predominant fatty acids in fixed oil were linoleic acid (59.53%), palmitic acid (13.70%), stearic acid (10.20%), and oleic acid (9.20%). The cytotoxic activity of essential oil, crude oil, and fraction A (obtained from fixed oil) were evaluated by using the MTT assay on MCF7 (human breast cancer cell line), PC3 (human prostate cancer cell line), and U87MG (human glioblastoma cell line). Finally, the effect of essential oil on inhibiting the PI3K/Akt/mTOR signaling pathway was evaluated using real-time PCR. The essential oil exhibited vigorous cytotoxic activity on the U87MG cell line, with an IC50 value of 32.65 μg/mL. Interestingly, the essential oil significantly inhibited the PI3K/AKT/mTOR cascade compared to the non-treated group. Our results suggest that the essential oil holds promise as an anticancer agent for glioblastoma cell lines. To the best of our knowledge, this study is the first to report on the profile of the essential oil of T. erecta fruits and its implications for targeting the PI3K/AKT/mTOR signaling pathway.

Aruncus dioicus var. kamtschaticu: A Newly Identified Source of Lactucaxanthin (ε,ε-Carotene-3,3′-diol)

Green leafy vegetables are rich in lipophilic metabolites such as carotenoids, phytosterols, tocopherols, and fatty acids, known for their significant health benefits. Goat’s beard (Aruncus dioicus var. kamtschaticus), a wild leafy vegetable native to Ulleungdo Island, South Korea, is reported to possess various biological activities and bioactive compounds. However, the content and profiles of lipophilic metabolites, especially carotenoids, have not been reported. This study investigated the composition of lipophilic metabolites in the foliage of goat’s beard using liquid chromatography–diode-array detection–mass spectrometry, gas chromatography–mass spectrometry, and gas chromatography–flame ionization detection. Five carotenoids (violaxanthin, neoxanthin, lactucaxanthin, lutein, β-carotene) and α-tocopherol were identified and quantified using liquid chromatography–diode-array detection–mass spectrometry. Lactucaxanthin, previously discovered in lettuce, was identified for the first time in goat’s beard foliage, with a higher concentration (45.42 ± 0.80 µg/g FW) compared to red lettuce (19.05 ± 0.67 µg/g FW). Furthermore, total carotenoids and α-tocopherol contents were higher in goat’s beard than in red lettuce. Gas chromatography–mass spectrometry analysis showed the presence of three phytosterols, namely, campesterol (3.53 ± 0.20 µg/g FW), stigmasterol (65.30 ± 4.87 µg/g FW), and β-sitosterol (89.54 ± 2.46 µg/g FW). Gas chromatography–flame ionization detection analysis revealed the presence of five essential fatty acids, with α-linolenic acid (57.03 ± 0.47%) being the most abundant, contributing to a favorable polyunsaturated FA/saturated FA ratio. These findings underscore the nutritional potential of a goat’s beard, suggesting its promising use in dietary supplements and the commercial extraction of valuable lipophilic antioxidants, particularly lactucaxanthin, for nutraceuticals and functional foods.

Synthetic V(V)-peroxido-zwitterionic species catalyze benzene oxidation under mild reaction conditions

A series of dinuclear complexes were synthesized, involving vanadium with N-methylglycine (sarcosine)/N,N’-dimethylglycine in aqueous media and H2O2, capable of exerting catalytic activity. Specifically, the ternary V(V) tetraperoxido dinuclear species (NH4)2[V2O2(O2)4(CH3NH2CH2COO)] (symmetric conformer) (1), (NH4)2[V2O2(O2)4(CH3NH2CH2COO)] (asymmetric conformer) (2), K2(Η2Ο)[V2O2(O2)4(CH3NH2CH2COO)] . H2O (3) (asymmetric conformer), and K2(Η2Ο)2[V2O2(O2)4{(CH3)2NHCH2COO)}] (4) (asymmetric conformer) were synthetically isolated in crystalline form. Compounds 1 and 2 are the same, whilst with profound conformational differences exemplified through pH-specific chemistries. The new materials 1–4 were characterized by elemental analysis, FT-IR, Raman, NMR, and UV–Visible spectroscopy, cyclic voltammetry, thermogravimetric analysis (TGA-DTG), and X-ray crystallography. Further support of the spectroscopic and structural profile was achieved through Bond Valence Sum (BVS) and Hirshfeld molecular mapping calculations. In all of the studied compounds, pH appears to be a crucial factor in the synthesis and isolation. The physicochemical characterization of the hybrid materials justified further use of compound 3 as a potential hydroxylation catalyst of benzene under a variable set of mild reaction conditions. The products of the catalytic reaction systems investigated were identified and quantified by gas chromatography–mass spectrometry (GC-MS) and gas chromatography–flame ionization detection (GC-FID), respectively. The results a) exemplify the involvement of the hybrid dinuclear vanadium compounds in the pursued benzene transformations, and b) distinctly demonstrate the structural and chemical characteristics justifying the emergence of catalytic action of vanadium under mild conditions (40 °C) in reactions toward organic substrates (e.g. benzene) as the basis for the pursuit of selective industrial applications, affording readily available useful compounds.

Solvent-Focused Gas Chromatographic Determination of Thymol and Carvacrol Using Ultrasound-Assisted Dispersive Liquid-Liquid Microextraction through Solidifying Floating Organic Droplets (USA-DLLME-SFO).

An ultrasound-assisted dispersive liquid-liquid microextraction by solidifying floating organic droplets, coupled to a form of temperature-programmed gas chromatography flame ionization detection, has been developed for the extraction and determination of thymol and carvacrol. This method utilizes undecanol as the extraction solvent, offering advantages such as facilitating phase transfer through solidification and enhancing solvent-focusing efficiency. The optimal gas chromatography conditions include a sample injection volume of 0.2 µL, a split ratio of 1:10, and a flow rate of 0.7 mL min-1. The extraction conditions entail an extraction solvent volume of 20 µL, a disperser solvent (acetone) volume of 500 µL, pH 7.0, 7.0% NaCl (3.5 M), a sample volume of 5.0 mL, an ultrasound duration of 10 min, and a centrifuge time of 7.5 min (800 rpm). These conditions enable the achievement of a high and reasonable linear range of 3.5 to 70. 0 μg mL-1 for both thymol and carvacrol. The detection limits are found to be 0.95 and 0.89 μg mL-1, respectively, for thymol and carvacrol. The obtained relative standard deviations, 2.7% for thymol and 2.6% for carvacrol, demonstrate acceptable precision for the purpose of quantitative analysis.

Cymbopogon distans: A source of essential oil with potential antibacterial, antifungal, and mosquito-repelling properties

The essential oils have become increasingly popular in recent years due to their potential as natural antimicrobial agents and a means of controlling mosquitoes. This study explored the chemical composition and antibacterial, antifungal, and mosquito-repellent properties of Cymbopogon distans (Nees ex Steud.) Wats (Poaceae) is a less explored aromatic plant distributed in the Himalayas. The fresh biomasses of C. distans and two commercially grown Cymbopogon species, namely C. flexuous and C. martini were submitted to hydrodistillation to extract their essential oils. Gas chromatography-flame ionisation detector (GC-FID) and gas chromatography-mass spectrometry (GC-MS) analyses revealed the presence of citral, geraniol, and geranyl acetate as major constituents of C. distans. The essential oils of C. flexuous and C. martini were dominated by citral and geraniol, respectively. Antibacterial and antifungal activities of C. distans essential oil were evaluated using disc diffusion and micro-dilution methods and compared with the essential oils of C. flexuous and C. martini. C. distans essential oil showed a broader spectrum of potent antibacterial and antifungal activities (minimum inhibitory concentration: 0.41 mg/ml and minimum bactericidal concentration/minimum fungicidal concentration: 0.82 mg/ml) against the test strains. C. distans essential oil, in combination with norfloxacin and penicillin G showed synergistic interactions (fractional inhibitory concentration ≤0.5) against Staphylococcus aureus and Staphylococcus epidermidis. C. distans essential oil showed a repellent effect against Aedes aegypti (73.3 %) that was comparable to C. winterianus essential oil (75.6 %). This study suggests that C. distans essential oil may be a promising natural candidate for developing new herbal therapies for combating microbial infections and mosquito-borne diseases.

Isolation and characterization of Thymus serpyllum L. essential oil and mass fragmentation analysis of major constituents

ABSTRACT The essential oils were isolated from Thymus serpyllum L. leaves, stem, flowers and whole plant using hydrodistillation technique and % yield was determined. The chemical constituents were studied using Gas Chromatography-Mass Spectrometry and Gas Chromatography-Flame Ionisation Detection. The analysis revealed the presence of 38 compounds in the essential oils obtained from different plant parts. Identification of compounds was achieved by detailed analysis of mass spectrum and retention indices. The major constituents of essential oil from the whole plant were thymol (35.25%), p-cymene (27.57%), thymol acetate (8.03%) and γ-terpinene (6.92%). In leaves they were thymol (45.59%), p-cymene (24.26%), thymol acetate (6.41%), and β-bisabolene (5.91%); whereas in flowers these were thymol (68.74%) and thymol acetate (7.40%) and in the stem, these were thymol (55.15%) and thymol acetate (8.01%). Specifically, it is the first report wherein essential oil constituents of T. serpyllum L. whole plant, leaves, flowers, and stems have been analyzed separately. Further, fundamental analysis of complex mass fragmentation patterns of terpenes and terpenoids using EI-MS has been achieved and the logical reason for the fragmentation pattern has been elaborated. Detailed elaboration of the mass fragmentation pattern may strengthen the EI-MS-based compound identification of terpenes and terpenoids from essential oils.

Relationship between types and levels of free fatty acids, peripheral insulin resistance, and oxidative stress in T2DM: A case-control study.

Free Fatty Acids (FFAs) are vital for energy homeostasis and the pathogenesis of a variety of diseases, including diabetes. For the first time, we presumed and investigated the types and levels of FFAs and their links to Insulin Resistance (IR) and Oxidative Stress (OS) in T2DM. A case-control study was conducted on 60 individuals with diabetes, 60 prediabetics with IFG, and 60 control groups. A Gas Chromatography Flame Ionization Detector (GC-FID) was used to estimate FFAs, which were then classified based on length and saturation. Indeed, antioxidant parameters such as TAC, MDA levels, PON-1, SOD-3, and CAT activity were assessed. Higher levels of LCFFA, SFFA, USFFA, and total FFA were found in people with diabetes and prediabetes. These levels were also linked to higher levels of HOMA-IR, BMI, FBS, HbA1C, and MDA, but lower levels of antioxidants. Furthermore, adjusting the above FFAs with age, sex, and antihypertensive medication increased T2DM development. SCFFA and ω3/6 fatty acids had a negative relationship with HOMA-IR, FBS, and insulin and a positive relationship with TAC. Adjusted SCFFA reduces T2DM risk. According to our models, total FFA is utilized to diagnose diabetes (AUC = 83.98, cut-off > 919 μM) and SCFFA for prediabetes (AUC = 82.32, cut-off < 39.56 μM). Total FFA (≥ 776 μM), LCFFA (≥ 613 μM), SFFA (≥ 471 μM), and USFFA (≥ 398 μM) all increase the risk of T2DM by increasing OS, BMI, and HOMA-IR. On the other hand, SCFFAs (≥ 38.7 μM) reduce the risk of T2DM by reducing BMI, HOMA-IR, and OS. SCFFAs and total FFAs can be used for the diagnosis of prediabetes and diabetes, respectively.

Antitumor properties of traditional lactic acid bacteria: Short-chain fatty acid production and interleukin 12 induction

This paper presents an in vitro evaluation of antitumor properties through producing short-chain fatty acids and inducing interleukin 12. In addition, it offers the most important and functional probiotic properties of 24 Lactobacillus gasseri, Lactiplantibacillus plantarum, Lactobacillus acidophilus, and Limosilactobacillus fermentum strains isolated from humans, foods, and fermented foods. To this end, survival in an acidic environment (pH = 2.5), tolerance in bile salt, viability in the presence of pepsin-pancreatin, adhesion percentage, antibiotic resistance, auto-aggregation, and potential percentage of co-aggregation are studied in contact with three human intestinal pathogens. These pathogens are Escherichia coli O157: H7 NCTC 12900, Salmonella enterica subsp. enterica ATCC 13076, and Listeria monocytogenes ATTC 7644. Also, in vitro induction amount of IL-12 in mouse splenocytes is investigated to evaluate antitumor properties by 19 strains of L. gasseri and L. plantarum along with the development of short-chain fatty acids (SCFA) by 5 strains of L. fermentum and L. acidophilus. Gas Chromatography Flame Ionization Detector (GC-FID) and enzyme-linked immunosorbent assay (ELISA) were used to measure short-chain fatty acids and IL-12, respectively. All strains had high viability under acidic conditions. The highest levels of pancreatin and pepsin resistance were found in strains LF56, LF57, LF55, OF, and F and strains LF56, LF57, and A7, respectively. All strains except LF56 had high resistance to bile salts. L. gasseri 54C had the highest average adhesion score (hydrophobicity) of 62.9 % among 19 strains. Despite the susceptibility of different strains of L. plantarum to the tested antibiotics, M8 and M11, S2G, A7, LF55, LF57, and 5G were resistant to kanamycin and chloramphenicol, respectively. Also, 21G was resistant to ampicillin, LF56 to tetracycline and M8, and M11, LF56, and 21G to Erythromycin. In addition, L. gasseri showed moderate resistance to ampicillin, erythromycin, and tetracycline, while L. fermentum ATCC 9338 showed good resistance to ampicillin, erythromycin, and chloramphenicol. In this respect, L. plantarum LF56 and gasseri 54C had the highest average auto-aggregation and co-aggregation against three pathogenic bacteria, respectively. The highest and lowest levels of acetic acid as short-chain fatty acids were produced by L. fermentum 19SH isolated from Horre 41.62 and L. fermentum 21SH from fermented seeds 27.047, respectively. Moreover, L. fermentum, with the OF code of traditional-fermented food origin, produced the most isobutyric acid, butyric acid, and valeric acid, with values of 0.6828, 0.74165, and 0.49915 mmol, respectively. L. fermentum isolated from the human origin with code F produced the most isovaleric acid of 1.1874 mmol. All the tested strains produced good propionic acid except L. fermentum 21SH from fermented seeds. Among strains, L. plantarum M11 isolated from milk and L. gasseri 52B from humans had the highest in vitro induction of IL-12, which is probably related to their cell wall compositions and structure.

Statistical analysis for chemical compound based on several species of aquilaria essential oil

The paper examines the characterization of Aquilaria essential oils from different species, namely Aquilaria malaccensis, Aquilaria beccariana, Aquilaria crassna, and Aquilaria subintegra, renowned for agarwood production in Malaysia. Gas chromatography-mass spectrometry (GC-MS) and gas chromatography-flame ionization detector (GC-FID) were employed for extracting essential oil data, facilitating compound identification. Subsequently, a preliminary analysis focused on classifying significant chemical compounds in the samples. The study then utilized boxplot pre-processing for visualizing and interpreting data distribution. The statistical analyses were performed using MATLAB software version R2021b, considering two key parameters which are the peak area (%) of significant chemical compounds and the classification of Aquilaria species (A. beccariana, A. malaccensis, A. crassna, and A. subintegra) based on their chemical composition. The results, presented through boxplot analyses, demonstrated a clear representation of the parameters and their distribution in the data. This method not only confirmed the potential of boxplot analysis in statistical evaluation of significant compounds in Aquilaria essential oil but also suggested its applicability for further classification work.

Measuring Dissolved Methane in Aquatic Ecosystems Using An Optical Spectroscopy Gas Analyzer.

Measuring greenhouse gas (GHG) fluxes and pools in ecosystems are becoming increasingly common in ecological studies due to their relevance to climate change. With it, the need for analytical platforms adaptable to measuring different pools and fluxes within research groups also grows. This study aims to develop a procedure to use portable optical spectroscopy-based gas analyzers, originally designed and marketed for gas flux measurements, to measure GHG concentrations in aqueous samples. The protocol involves the traditional headspace equilibration technique followed by the injection of a headspace gas subsample into a chamber connected through a closed loop to the inlet and outlet ports of the gas analyzer. The chamber is fabricated from a generic mason jar and simple laboratory supplies, and it is an ideal solution for samples that may require pre-injection dilution. Methane concentrations measured with the chamber are tightly correlated (r2 > 0.98) with concentrations determined separately through gas chromatography-flame ionization detection (GC-FID) on subsamples from the same vials. The procedure is particularly relevant for field studies in remote areas where chromatography equipment and supplies are not readily available, offering a practical, cheaper, and more efficient solution for measuring methane and other dissolved greenhouse gas concentrations in aquatic systems.

Determination of Free Fatty Acids in Foodstuff by Solid Phase Extraction and Gas Chromatography-Flame Ionization Detection Using H2SO4-MeOH Derivatization

Determination of Free Fatty Acids in Foodstuff by Solid Phase Extraction and Gas Chromatography-Flame Ionization Detection Using H2SO4-MeOH Derivatization

Chemical Characterization and Enantioselective Analysis of Tagetes filifolia Lag. Essential Oil and Crude Extract.

The essential oil (EO) of Tagetes filifolia Lag. was obtained from dried plant material through Clevenger-type steam distillation and analyzed using gas chromatography-mass spectrometry (GC/MS), a gas chromatography-flame ionization detector (GC/FID) and enantioselective gas chromatography. The results showed 50 compounds (93.33%) with a predominance of oxygenated monoterpenes. The main components were trans-anethole (55.57 ± 9.83%), tridecene <1-> (8.66 ± 0.01), methyl chavicol (5.81 ± 0.85%) and Neophytadiene (3.45 ± 0.88) Enantioselective analysis revealed linalool and <methyl-γ-> ionone as enantiomers. The identification of secondary metabolites from the ethyl acetate extract obtained by maceration was performed by GC-MS, NMR and by a literature comparison, determining the presence of mostly trans-anethole and a mixture of two triterpenes, fernenol and lupeol.

Bioactive molecules isolated from Cymbopogon flexuosus and Monarda citriodora essential oils: Chemical profiling, antimycotic potential, and molecular docking studies against green and blue molds of Kinnow

Among the most alarming postharvest fungal pathogens affecting the shelf life of citrus fruits are green (Penicillium digitatum) and blue (Penicillium italicum) molds. This in vitro study was aimed to evaluate the essential oils (EOs) of Cymbopogon flexuosus (CF) and Monarda citriodora (MC) and their principal components against these fungal pathogens. The composition of selected EOs was analyzed using Gas Chromatography- Mass Spectrometry (GC-MS) and Gas Chromatography-Flame Ionization Detector (GC-FID). Citral (83.81%) and thymol (62.51%) were identified as major components and were isolated by column chromatography from CF and MC EO respectively followed by characterization using spectral techniques such as Fourier Transform Infrared Spectroscopy (FTIR), Proton Nuclear Magnetic Resonance Spectroscopy (1H-NMR) and Carbon Nuclear Magnetic Resonance Spectroscopy (13C-NMR). Among EOs and their major components, thymol displayed promising potential against both Penicillium species with MIC values of 50 and 80 mg L-1 respectively. Molecular docking studies also confirmed the stable binding interaction of both components, particularly thymol with the active sites of target proteins i.e. 14-α-demethylase and chitin synthase of P. digitatum and P. italicum with the docking scores of -5.07, -5.41 kcal/mol and -5.78, -5.23 kcal/mol respectively. Optical microscopy studies revealed hyphal thinning and fragmentation at frequent sites with contraction of cytoplasmic content indicating incipient plasmolysis. The tested principal components, citral and thymol were predicted to exhibit similar mechanism of action to that of synthetic recommended molecules as revealed by molecular docking. Therefore, these findings provide empirical support to explore thymol as a promising eco-friendly antifungal agent for postharvest application in Kinnow.