MS Screening Research Articles

Comprehensive UHPLC–MS screening methods for the analysis of triazolopyrazine precursor and its genotoxic nitroso-derivative in sitagliptin pharmaceutical formulation

A case study on Sitagliptin drug products and Sitagliptin/Metformin drug products concerning contamination with N-nitrosamines was performed using two newly developed analytical methods for determination of N-nitroso-triazolopyrazine (NTTP; 7-nitroso-3-(trifluoromethyl)–5,6,7,8-tetrahydro-[1,2,4]triazolo[4,3-a]pyrazine) and its precursor triazolopyrazine (3-(trifluoromethyl)–5,6,7,8-tetrahydro-[1,2,4]triazolo[4,3-a]pyrazine). The method for determination of triazolopyrazine was previously unpublished, the method for determination of NTTP was published only for analysis of active pharmaceutical ingredient Sitagliptin and not the drug forms. Solving the N-nitrosamine contamination is requested by regulatory authorities all over the world and thus is vital for all pharmaceutical companies. The solution always requires a sensitive analytical method. Both newly developed methods use liquid chromatography coupled with mass spectrometry (single quadrupole analyzer in case of triazolopyrazine and triple quadrupole analyzer in case of NTTP). Separation of triazolopyrazine was achieved on a column Acquity CSH C18 using a mobile phase consisting of aqueous ammonium formate buffered at pH 4.2 and acetonitrile. Detection was performed using positive electrospray and selected ion monitoring at m/z 193. Separation of NTTP was achieved on a column Acquity HSS T3 using a mobile phase consisting of 0.1 % formic acid in water and methanol. Detection was performed using positive electrospray and multiple reaction monitoring at transitions m/z 222.15→42.05 (collision energy 17 eV) and m/z 222.15→192.15 (collision energy 11 eV). Two issues specific to NTTP and triazolopyrazine previously not described in scientific literature were successfully troubleshooted. Spontaneous degradation of Sitagliptin to triazolopyrazine and methyl (R)–3-amino-4-(2,4,5-trifluorophenyl)butanoate was solved by using N,N-dimethylformamide as sample solvent during development of the method for quantitation of triazolopyrazine. A bad peak shape of NTTP due to the presence of rotamers of NTTP was successfully troubleshooted by increasing column temperature. Both methods were used during an optimization study of manufacturing of Sitagliptin and Sitagliptin/Metformin drug products. The goal of the study was to decrease NTTP content in the final drug product under the strict legislative limit set by Federal Drug Agency. The efficacy of several solutions was proven, but could not be fully disclosed due to Intellectual Property Protection policy of Zentiva. Instead, a brief review of recently published strategies to cope with N-nitrosamine contamination is presented.

Generation and physiological characterization of genome-edited Nicotiana benthamiana plants containing zeaxanthin as the only leaf xanthophyll

Main conclusionSimultaneous genome editing of the two homeologousLCYeandZEPgenes ofNicotiana benthamianaresults in plants in which all xanthophylls are replaced by zeaxanthin.Plant carotenoids act both as photoreceptors and photoprotectants in photosynthesis and as precursors of apocarotenoids, which include signaling molecules such as abscisic acid (ABA). As dietary components, the xanthophylls lutein and zeaxanthin have photoprotective functions in the human macula. We developed transient and stable combinatorial genome editing methods, followed by direct LC–MS screening for zeaxanthin accumulation, for the simultaneous genome editing of the two homeologous Lycopene Epsilon Cyclase (LCYe) and the two Zeaxanthin Epoxidase (ZEP) genes present in the allopolyploid Nicotiana benthamiana genome. Editing of the four genes resulted in plants in which all leaf xanthophylls were substituted by zeaxanthin, but with different ABA levels and growth habits, depending on the severity of the ZEP1 mutation. In high-zeaxanthin lines, the abundance of the major photosystem II antenna LHCII was reduced with respect to wild-type plants and the LHCII trimeric state became unstable upon thylakoid solubilization. Consistent with the depletion in LHCII, edited plants underwent a compensatory increase in PSII/PSI ratios and a loss of the large-size PSII supercomplexes, while the level of PSI-LHCI supercomplex was unaffected. Reduced activity of the photoprotective mechanism NPQ was shown in high-zeaxanthin plants, while PSII photoinhibition was similar for all genotypes upon exposure to excess light, consistent with the antioxidant and photoprotective role of zeaxanthin in vivo.

Rapid determination of colistin resistance in Klebsiella pneumoniae by MALDI-TOF peak based machine learning algorithm with MATLAB

IntroductionTo date, limited data exist on demonstrating the usefulness of machine learning (ML) algorithms applied to MALDI-TOF in determining colistin resistance among Klebsiella pneumoniae. We aimed to detect colistin resistance in K. pneumoniae using MATLAB on MALDI-TOF database. Materials and methodsA total of 260 K. pneumoniae isolates were collected. Three ML models, namely, linear discriminant analysis (LDA), support vector machine, and Ensemble were used as ML algorithms and applied to training data set. ResultsThe accuracies for the training phase with 200 isolates were found to be 99.3%, 93.1%, and 88.3% for LDA, support vector machine, and Ensemble models, respectively. Accuracy, sensitivity, specificity, and precision values for LDA in the application test set with 60 K. pneumoniae isolates were 81.6%, 66.7%, 91.7%, and 84.2%, respectively. ConclusionThis study provides a rapid and accurate MALDI-TOF MS screening assay for clinical practice in identifying colistin resistance in K. pneumoniae.

Intact mass spectrometry screening to optimize hydroxyl radical dose for protein footprinting

Hydroxyl radical protein footprinting (HRPF) using synchrotron radiation is a well-validated method to assess protein structure in the native solution state. In this method, X-ray radiolysis of water generates hydroxyl radicals that can react with solvent accessible side chains of proteins, with mass spectrometry used to detect the resulting labeled products. An ideal footprinting dose provides sufficient labeling to measure the structure but not so much as to influence the results. The optimization of hydroxyl radical dose is typically performed using an indirect Alexa488 fluorescence assay sensitive to hydroxyl radical concentration, but full evaluation of the experiment's outcome relies upon bottom-up liquid chromatography mass spectrometry (LC-MS) measurements to directly determine sites and extent of oxidative labeling at the peptide and protein level. A direct evaluation of the extent of labeling to provide direct and absolute measurements of dose and “safe” dose ranges in terms of, for example, average numbers of labels per protein, would provide immediate feedback on experimental outcomes prior to embarking on detailed LC-MS analyses. To this end, we describe an approach to integrate intact MS screening of labeled samples immediately following exposure, along with metrics to quantify the extent of observed labeling from the intact mass spectra. Intact MS results on the model protein lysozyme were evaluated in the context of Alexa488 assay results and a bottom-up LC-MS analysis of the same samples. This approach provides a basis for placing delivered hydroxyl radical dose metrics on firmer technical grounds for synchrotron X-ray footprinting of proteins, with explicit parameters to increase the likelihood of a productive experimental outcome. Further, the method directs approaches to provide absolute and direct dosimetry for all types of labeling for protein footprinting.

Computational, chemical profile, in vitro antioxidant, hypoglycaemic, and anti-inflammatory activity of hexane extract of some selected dark green vegetables

This study investigated the phytochemical composition and in vitro antioxidant, hypoglycaemic and anti-inflammatory potential of n-hexane extracts of Vernonia amygdalina (VA), Telfairia occidentalis (TO), Gongronema latifolium (GL) and Ocimum gratissimum (OG). The extracts demonstrated a concentration-dependent increase in antioxidant activity. The antioxidant activity of TO was significantly (p < 0.05) higher than the other extracts; the total phenolic content of GL was significantly (p < 0.05) higher than OG, TO and VA; and the total flavonoid content (TFC) of OG was significantly (p < 0.05) higher than the other extracts. There was no significant (p > 0.05) difference in the TFC of GL and VA, while the TFC of TO was the least. The extracts produced a concentration-dependent increase in the percentage inhibition of haemolysis in both heat- and hypotonic solution-induced haemolysis. In the heat-induced haemolysis model, the percentage inhibition of haemolysis produced by TO, GL, OG, VA and diclofenac at 200 µg/mL concentration were 41.85, 18.26, 32.06, 15.56 and 25.49%, respectively. The extracts reduced starch digestibility and increased glucose adsorption, diffusion and uptake by yeast cells in a concentration-dependent manner. GC–MS screening of plant extracts showed the presence of five compounds in all the extracts: 2,6,6-trimethyl-bicyclo (3.1.1) heptane-2,3-diol; 9,12,15-octadecatrien-1-ol, (Z,Z,Z)-; 1-ethynyl-cyclohexanol; n-hexadecanoic acid; and phytol. Docking analysis of the major compounds common to all extracts showed a high affinity for target proteins compared to standard drugs. In conclusion, the extracts showed antioxidant, anti-inflammatory and hypoglycaemic activity, which can be linked to the identified phytocompounds.

GC–MS screening of the phytochemical composition of Ziziphus honey: ADME properties and in vitro/in silico study of its antimicrobial activity

A revival interest has been given to natural products as sources of phytocompounds to be used as alternative treatment against infectious diseases. In this context, we aimed to investigate the antimicrobial potential of Ziziphus honey (ZH) against twelve clinical bacterial strains and several yeasts and molds using in vitro and computational approaches. The well-diffusion assay revealed that ZH was able to induce growth inhibition of most Gram-positive and Gram-negative bacteria. The high mean growth inhibition zone (mGIZ) was recorded in E. coli (Clinical strain, 217), S. aureus followed by E. coli ATCC 10536 (mGIZ values: 41.00 ± 1 mm, 40.67 ± 0.57 mm, and 34.67 ± 0.57 mm, respectively). The minimal bactericidal concentrations (MBCs) and minimal fungicidal concentration values (MFCs) from approximately 266.33 mg/mL to over 532.65 mg/mL. Molecular docking results revealed that the identified compounds maltose, 2-furoic acid, isopropyl ester, 2,4-imidazolidinedione, 5-(2-methylpropyl)-(S)- and 3,4,5-trihydroxytoluene, S-Methyl-L-Cysteine, 2-Furancarboxylic acid, L-Valine-N-ethoxycarbonyl, Hexanoic acid, 3,5,5-trimethyl-, Methyl-beta-D-thiogalactoside, gamma-Sitosterol, d-Mannose, 4-O-Methylmannose, 2,4-Imidazolidinedione, 5-(2-methylpropyl)- (S) were found to have good affinity for targeted receptor, respectively. Through a 100-ns dynamic simulation research, binding interactions and stability between promising phytochemicals and the active residues of the studied enzymes were confirmed. The ADMET profiling of all identified compounds revealed that most of them could be qualified as biologically active with good absorption and permeation. Overall, the results highlighted the efficiency of ZH against the tested clinical pathogenic strains. The antimicrobial potential and the potency displayed by the identified compounds could imply their further pharmacological applications. Communicated by Ramaswamy H. Sarma

Biological Characterization of Polystichum lonchitis L. for Phytochemical and Pharmacological Activities in Swiss Albino Mice Model.

Polystichum lonchitis L. is a fern belonging to the family Dryopteridaceae. The present study was conducted to evaluate its pharmacological, antioxidant, and phytochemical properties, and to conduct GC-MS screening of P. lonchitis. The acetic acid-induced writhing test, yeast-induced hyperpyrexia method, carrageenan-induced rat paw edema model, and charcoal meal test model were carried out to assess analgesic, antipyretic, anti-inflammatory, and antispasmodic activity, respectively. DPPH was used as an antioxidant, while the phytochemical screening was conducted using standard scientific methods. Among the pharmacological activities, the most significant effects were observed in the analgesic and anti-inflammatory activities, followed by the antipyretic and antispasmodic activities, at a dose of 450 mg/kg after the 4th hour, compared with 150 mg/kg and 300 mg/kg. For the evaluation of antioxidant activities, the most significant results were detected in the methanolic and aqueous extracts. The detection of flavonoids and phenol occurred most significantly in the methanolic extract, and then in the ethanolic and aqueous extracts. The main compounds detected using GC-MS analysis with a high metabolic rate was 𝛼-D-Galactopyranoside, which had a metabolic rate of 0.851, and methyl and n-hexadecanoic, which had a metabolic rate of 0.972. Overall, the results suggested that P. lonchitis had a strong potential for pharmacological activities. The suggested assessment provided a way to isolate the bioactive constituents and will help to provide new medicines with fewer side effects. Due to the fern's effectiveness against various diseases, the results provide clear evidence that they also have the potential to cure various diseases.

Phytochemical screening and GC-MS chemical profiling of an innovative anti-cancer herbal formula (PHF6)

The present investigation assessed the anticancer potential and chemical profile of the polyherbal formulation (PHF6) against human breast cancer cells. The plants (Alchemilla vulgaris, Cichorium pumilum, Crataegus azarolus, Eruca sativa, Ferula hermonis, and Hypericum triquetrifolium) were combined in equal quantities and extracted using soxhlet apparatus. The total polyphenolic (TPC) of the hexane and chloroform extract of PHF6 were 3.11 ± 0.004 and 7.88 ± 0.004 µg/mL (as gallic acid equivalent), respectively. The radical scavenging activity (RSA) values for the hexane and chloroform extract were 35.1 % ±0.01 and 36.9 % ±0.06, respectively. For hexane extract, the IC50 values were found to be 82.8 and 48.7 µg/mL against MCF-7ER(+)/PR(+) and MDA MB-231ER(−)/PR(−), respectively. Similarly, the IC50 value of chloroform extract was 44.4 µg/mL against both cell lines. The MDA MB-231ER(−)/PR(−) cells stained with DAPI post-treatment with hexane and chloroform extract showed cell shrinkage, nuclear fragmentation, and chromatin condensation. Moreover, GC–MS screening of the PHF6 revealed several compounds with different reported biological activities, such as phytol and octadecanoic acid. PHF6 showed promising anticancer activity against cancer cells tested, thus deserving more clinical studies in the future.

Identification of acidic degradation products of chemical warfare agents by methylation with trimethylsilyldiazomethane and gas chromatography–mass spectrometry

Sensitive and reliable analysis of alkylphosphonic acids (APAs) and 2-(N,N-dialkylamino)ethanesulfonic acids (SAs), the degradation products of chemical warfare agents (CWAs), is one of the most important tasks for verification of the Chemical Weapons Convention (CWC). Unambiguous identification of these chemicals is required in a variety of environmental matrices, including soil and water. These acids with low volatility are very polar, and efficient and reliable methylation methods for their derivatization are needed for analysis with gas chromatography–mass spectrometry (GC–MS). In this study, the derivatization conditions for trimethylsilyldiazomethane (TMSDAM) methylation were optimized for rapid GC–MS screening. Optimized methylation of APAs and SAs with TMSDAM was compared with methylation with diazomethane. The TMSDAM methylation of SAs and benzilic acid was further compared with silylation with N-methyl-N-(tert-butyldimethylsilyl)trifluoroacetamide. The significance and necessity of cation exchange prior to derivatization and analysis were tested on samples with a high inorganic background. A recommendation to use the method for methylation of water samples and aqueous extracts using TMSDAM is given. The robustness of the method was illustrated by the successful identification of APAs and SAs in aqueous samples from proficiency tests organized by the Organisation for the Prohibition of Chemical Weapons.

Systematic Identification of Bioactive Compositions in Leaves of Morus Cultivars Using UHPLC-ESI-QTOF-MS/MS and Comprehensive Screening of High-Quality Resources

Morus spp. leaves (MSLs) show various beneficial effects in the treatment of metabolic-related diseases, which have created a growing interest in MSL development as dietary supplements and functional foods. The illustration of chemical compositions and screening of high-quality MSL resources are therefore necessary for further application. This study developed a new UHPLC-ESI-QTOF-MS/MS strategy of in-source collision-induced dissociation (IS-CID) and target collision-cell CID (TCC-CID) to quickly capture analogues with consistent skeleton, and combined global natural product social molecular networking (GNPS) to efficiently annotate bioactive phytochemicals in MSLs. For the results, 49 bioactive ingredients, including quercetin-type flavonoids, kaempferol-type flavonoids, chlorogenic acid isomers, 1-deoxynojirimycin, γ-aminobutyric acid, amino acids, and unsaturated fatty acids, were systematically identified in MSLs for the first time. Quantification for the typical components was simultaneously carried out in MSLs of 90 Morus resources collected from different locations. Partial least squares discriminant analysis (PLS-DA) indicated that quercetin-3-O-(6″-O-malonyl)-glucoside, rutin, kaempferol-3-O-(6″-O-malonyl)-glucoside, kaempferol-3-O-rutinoside, and chlorogenic acid showed high variable importance in the project (VIP &gt; 1) that were significant constituents for the differences between MSL species. Then, high-quality MSLs were comprehensively screened in multiple Morus cultivars based on the criteria importance through intercriteria correlation (CRITIC) method. This study presented an efficient strategy to annotate bioactive compounds, revealed the difference of bioactive components in MSLs, and provided important information for the high-value production of Morus cultivars in food and supplement fields.

UPLC/Q-TOF MS Screening and Identification of Antibacterial Compounds in Forsythia suspensa (Thunb.) Vahl Leaves.

Forsythia suspensa (Thunb.) Vahl (F. suspensa) is a traditional Chinese medical herb and only its fruit is currently used in clinical therapies. However, the discarded parts like leaves also contain a large number of active components. In this study, we used macroporous adsorption resin to enrich the effective components from F. suspensa leaves. The separated active compounds were then identified and quantified by ultra-performance liquid chromatography coupled with quadrupole time of flight mass spectrometry (UPLC/Q-TOF MS) and high-performance liquid chromatography Active components with antibacterial properties extracted from F. suspensa leaves were confirmed in vitro and the corresponding mechanisms were explored. In sum, a stable and effective method for extracting antibacterial active components from F. suspensa leaves was established in this study, which proved the practicability of F. suspensa leaves as traditional Chinese medicine and is conducive to the more comprehensive utilization of the plant.

Herbal Medicine Must Be Treated with Care—A Case Report on Aconitine

Pathologists usually only request a screening for natural toxic substances if plant material has been observed during autopsy or if there exists a hint in the police investigation file. This situation is aggravated by the fact that most toxins are not covered by typical immunoassays and gas chromatography–mass spectrometry (GC–MS) profiling systems. In addition, only a few forensic toxicological libraries based on liquid chromatography coupled to high-resolution tandem mass spectrometry (LC–HRMS/MS) exist. In the following case, femoral blood and urine were applied to systematic toxicological analysis (STA). However, the concentrations determined in blood did not lead to death. Consequently, a liquid chromatography high-resolution tandem mass spectrometry (LC–HRMS/MS) screening approach was applied. Aconitine was quantitated in all specimens taken during autopsy and urine and bile fluid screened for aconitine metabolites. Aconitine, jesaconitine, hypaconitine, and mesaconitine were found in the root piece collected from the duodenum. Apart from aconitine, no other alkaloids were detected in the urine or in the femoral blood sample. The highest concentrations of aconitine were found in gastric content (55.2 μg/mL), bile fluid (11.7 μg/mL), and liver (9.14 μg/g), and least in femoral blood (0.15 μg/mL) and cerebrospinal fluid (0.07 μg/mL). The liver/peripheral blood ratio amounted to 61 L/kg and indicated that aconitine undergoes postmortem redistribution. During our metabolism investigation, we found 3-dehydrogen-aconitine in the urine and bile fluid sample and N-deethyl-aconitine only in the bile fluid sample. If the routine GC–MS screening approach does not come up with a toxin, then LC–HRMS/MS profiling could represent the method of choice. In this case aconitine was identified. The concentrations determined were compared to those reported in literature and clearly indicate that the deceased died due to an aconitine overdose.

GC-MS screening and antiparasitic action of Putranjiva roxburghii leaves against sensitive and resistant strains of Leishmania donovani.

Looming drug resistance cases of leishmaniasis infection are an undeniably serious danger to worldwide public health, also jeopardize the efficacy of available drugs. Besides this, no successful vaccine is available till date. Since the ancient era, many plants and their parts have been used as medicines against various ailments. Hence, the importance of drug development for new molecules against Leishmania infection is significant that is a cost-effective and safer drug preferably from the natural herbal resources. We evaluated the GC-MS screening and efficacy of Putranjiva roxburghii (PR) against the sensitive and resistant promastigotes of L. donovani. GC-MS profiling revealed that the extract was rich in myo-inositol-4-C-methyl, azulene and desulphosinigrin. Quantitative investigation of phytoconstituents confirmed that PR was rich in phenols, flavonoids and terpenoids. We found an IC50 25.61 ± 0.57µg/mL and 29.02 ± 1.21µg/mL of PR against sodium stibogluconate sensitive and resistant strain respectively. It was found to be safer in cytotoxicity assay and generated ROS mediated oxidative stress in the parasitic cells which was evidenced by the increased and decreased levels of superoxide radicals, lipid peroxidation products, lipid bodies and levels of thiol, plasma membrane integrity respectively. Therefore, our results support the importance of P. roxburghii as a medicinal plant against L. donovani and showed potential for exploration as an antileishmanial agent.

Enzymatic-fingerprinting workflow of polysaccharides in Hericium erinaceus fruiting bodies: From HILIC-ESI−-MS screening to targeted MIM profiling

In this study, an uncommon enzymatic-fingerprinting workflow, was proposed for characterization and discrimination of mushroom polysaccharides (MPs) by hydrophilic interaction liquid chromatography-negative electrospray mass spectrometry (HILIC-ESI–-MS). Firstly, the HILIC-ESI–-MS was used to screen and identify the enzymatic digestion products of MPs using HILIC-Orbitrap based on full scan and MS/MS modes. Secondly, a targeted structural-fingerprinting of polysaccharides (SFP) was built in a multiple-ion monitoring (MIM) mode using the same HILIC separation with a triple quadrupole MS. Thirdly, a case study of polysaccharides in Hericium erinaceus fruiting bodies (HEP) was performed to obtain the expected SFP based on dextranase digestion that allows for visual discrimination of polysaccharides from other five edible mushrooms attributed to Agrocybe cylindracea, Arimillaria mellea, Flammulina velutipes, Pleurotus eryngii, and Lentinula edodes. Furthermore, a major structural backbone of HEP was unveiled by occurrence of → 6(Hex)1 → along with multiple possible substitutions including of terminal GalA, Fuc, acetyl, → 4Hex1 →, and → 3Hex1 →. Finally, the similarity analysis, hierarchical cluster analysis (HCA), and partial least squares discriminant analysis (PLS-DA) were performed to visualize various MPs. As a result, the enzymatic-fingerprinting workflow presents an effective example for quality evaluation of fungi polysaccharides using a SFP strategy.

Phytochemical investigation of Pimpinella serbica

The plant species Pimpinella serbica (Vis.) Drude, endemic to West Balkans, belongs to the genus Pimpinella L. (Apiaceae) according to newer botanical classification. Initially, the plant was described as Pancicia serbica Vis. and long considered as a monotypic genus. Previous phytochemical investigations of this plant were limited to the essential oil analysis by the GC?MS method. This is first study that includes LC-DAD?MS screening of the extracts of the roots and aerial parts, followed by isolation of secondary metabolites using chromatographic techniques. Five compounds belonging to phenylpropanoids and polyacetylenes, well known for their bioactivities, were isolated and structurally determined by combined spectroscopic methods (UV, NMR, MS). Dillapiole (1), nothoapiole (2) and oplopantriol A 18-acetate (4) were found in both extracts, while falcarindiol (3) was isolated from the roots and dendrotrifidol (5) from the aerial parts only. The phytochemical profile of P. serbica L. supports its position in the Pimpinella L. genus.

Aminated Fullerene Abrogates Cancer Cell Migration by Directly Targeting Myosin Heavy Chain 9.

Functional fullerene derivatives exhibit fantastic inhibitory capabilities against cancer survival and metastasis, but the absence of clarified biological molecular targets and ambiguous regulation mechanisms set barriers for their clinical transformation. Cancer metastasis is the primary cause of mortality and initiated with increased cell migration, making cell motility regulation a high-value therapeutic target in precision medicine. Herein, a critical molecular target of the aminated fullerene derivative (C70-EDA), myosin heavy chain 9 (MYH9), was initially identified by a pull-down assay and MS screening. MYH9 is a cytoplasm-located protein and is responsible for cell motility and epithelial-mesenchymal transition regulation. Omics data from large-scale clinical samples reveals that MYH9 gets overexpressed in various cancers and correlates with unfavorable prognosis, indicating that it is a potential antineoplastic target. It is unveiled that C70-EDA binds to the C-terminal of MYH9, triggering the transport of MYH9 from the cytoplasm to the cell edge, blocking the MYH9-involved cell mobility, and inhibiting the metastasis-associated EMT process. This work provides a precise biological target and new strategies for fullerene applications in cancer therapy.

Development of a Clinical MALDI-ToF Mass Spectrometry Assay for SARS-CoV-2: Rational Design and Multi-Disciplinary Team Work.

The COVID-19 pandemic caused by the SARS-CoV-2 coronavirus has stretched national testing capacities to breaking points in almost all countries of the world. The need to rapidly screen vast numbers of a country’s population in order to control the spread of the infection is paramount. However, the logistical requirement for reagent supply (and associated cost) of RT-PCR based testing (the current front-line test) have been hugely problematic. Mass spectrometry-based methods using swab and gargle samples have been reported with promise, but have not approached the task from a systematic analysis of the entire diagnostic process. Here, the pipeline from sample processing, the biological characteristics of the pathogen in human biofluid, the downstream bio- and physical-chemistry and the all-important data processing with clinical interpretation and reporting, are carefully compiled into a single high-throughput and reproducible rapid process. Utilizing MALDI-ToF mass spectrometric detection to viral envelope glycoproteins in a systems biology-multidisciplinary team approach, we have achieved a multifaceted clinical MALDI ToF MS screening test, primarily (but not limited to) SARS-CoV-2, with direct application to other future epidemics/pandemics that may arise. The clinical information generated not only includes SARS-CoV-2 coronavirus detection–(Spike protein fragments S1, S2b, S2a peaks), but other respiratory viral infections detected as well as an assessment of generalised oral upper respiratory immune response (elevated total Ig light chain peak) and a measure of the viral immune response (elevated intensity of IgA heavy chain peak). The advantages of the method include; (1) ease of sampling, (2) speed of analysis, and much reduced cost of testing. These features reveal the diagnostic utility of MALDI-ToF mass spectrometry as a powerful and economically attractive global solution

Biomarkers of photosynthetic sulfur bacteria in Lower Cretaceous crude oils, East Brazilian marginal basin

Diagenetic aromatic carotenoids and degradation products, which are derived from the carotenoids of photosynthetic sulfur bacteria, were characterized in the aromatic fraction of Brazilian Cretaceous crude oils (NE Brazil, Sergipe-Alagoas Basin) by high-temperature comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry (HT-GC × GC–TOFMS). Unresolved complex mixtures (UCM), coeluting compounds, and limited mass spectrometric identification were noted by traditional one-dimensional (1D) GC–MS screening of aromatic compounds. Group-type separation on a two-dimensional chromatographic plane, first- and second-dimension retention times (1tR and 2tR, respectively), and mass spectra enabled the assignment of alkylated mono-, di-, tri-, and tetra-aryl hydrocarbons with confidence. A series of diagenetic C40 carotenoids and degraded products, which are likely indicators for green-brown sulfur bacteria, were detected. This finding corroborates previous results, and isorenieratane was relatively more abundant than 2,3,6-trimethylaryl isoprenoids. Moreover, atropisomeric biphenyls (m/z 237), which coeluted using 1D GC–MS analyses, were resolved by GC × GC and identified by mass spectrometry. The identification of minor abundances of chlorobactane, diagenetic biphenyl chlorobactane, and related compounds, for the first time in these Brazilian Cretaceous oils, may indicate a contribution of green sulfur bacteria (Chlorobiaceae) and photic zone euxinia in shallow waters.

RP-HPLC-PDA-ESI-MS/MS screening of bioactive compounds from Degla-Beida dates: Conventional and green extraction technologies

Date fruits have vital therapeutic properties, in the way that they represent an inexhaustible source of bioactive compounds such as polyphenols. Therefore, the objective of this work was to evaluate the phytocomposition by High Performance Liquid Chromatography (RP-HPLC-PAD-ESI-MS/MS) of the optimized microwaveassisted extraction (MAE) phenolic extract by using the response surface methodology (RSM) compared to the ultrasound-assisted and conventional extractions (UAE and CE), and to test its antioxidant activity in vitro. The resulting regression model indicated that a quadratic polynomial model was best suited for the spectrophotometrically determined total phenolics. The maximum total phenolic content, TPC, (4.27±0.09 mg GAE/g DW) was obtained with a 50% (v/v) ethanol’s concentration, a 700 W microwave power and an extraction time of 2.42 minutes. HPLC analysis revealed the presence of organic sugars and acids, nucleoside, carotenoids, proanthocyanidins, lignans, flavonols, flavones, saponin and sterol glucosides. The MAE phenolic extract showed 58.72±0.29% DPPH radical scavenging activity and a 1.88±0.09 mg AscAE/mL reducing power.

Prevalence and distribution pattern of mood swings in Thai adolescents: a school-based survey in the central region of Thailand

BackgroundMood swings (MS) are a widely discussed psychiatric ailment of youthful patients. However, there is a lack of research about MS in this population.MethodsA school-based, cross-sectional study was conducted to investigate the prevalence and distribution pattern of mood swings due to personal and contextual determinants in Thai adolescents in the central region of Thailand. Participants were 2598 students in high schools and vocational schools in Bangkok and three provinces in the central region of Thailand.ResultsThe prevalence of mood swings was 26.4%. It was highest among vocational students in Bangkok at 37.1%. MS were more common in adolescents who exhibited risk behaviors and who resided in hazardous situations. The probabilities of MS by characteristic in 15–24 years olds were: bullying involvement 36.9% (n = 1293), problematic social media use 55.9%(n = 127), high expressed emotion in family 36.6% (n = 1256), and studying in a vocational program 29.5% (n = 1216) and school located in Bangkok 32.4% (n = 561). Also, substance use was a risk for MS with cannabis use at 41.8%(n = 55) and heroin use at 48.0% (n = 25). Hierarchical logistic regression analysis showed that female gender, having a family history of mental problems, bullying involvement, problematic social media use, high expression of emotion in the family, and the interaction between vocational program enrollments and metropolitan/urban residence associated adolescent mood swings (p < .05).ConclusionsFindings indicate that the pattern of mood swings was associated with significant bullying involvement, social media use, family circumstance, and school characteristics. The public needs greater awareness of MS patterns and the positive implications of MS screening. Early preventive interventions that may limit later mental illness are needed.