TOF Mass Spectrometry Research Articles

Enhanced physicochemical properties of isoflavone derivatives through enzymatic encapsulation using cyclodextrin glucanotransferase

To establish the encapsulation parameters applicable to isoflavones, inclusion complexes (cycloamylose-genistein (CA-GNT), CA-daidzein (CA-DDZ), CA-equol (CA-EQ)) were synthesized for three varieties of plant-derived isoflavones via the cyclization catalysis of cyclodextrin glucanotransferase (CGTase; EC 2.4.1.19). Subsequently, an analysis of their physicochemical properties and functional characteristics was performed to ascertain their retained intrinsic activity within the encapsulated milieu. These encapsulation complexes were purified via preparative high-performance liquid chromatography and confirmed through MALDI TOF mass spectrometry for molecular weight analysis. The water solubility of CA-GNT, CA-DDZ, and CA-EQ increased approximately 15,000, 89,000, and 90 times, respectively, compared to the original compounds. Furthermore, in a 2,2′-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid radical scavenging activity assay, the CA-GNT, CA-DDZ, CA-EQ encapsulated complexes exhibited 6.4-, 6.9-, and 4.2-fold higher levels of scavenging activity compared to the original material in aqueous solution, respectively. The mRNA level of estrogen receptor α increased with increasing treatment concentration of the encapsulated complexes in MC3T3 cells, which was similar to the effect of the original compounds. CA-EQ remained stable under external conditions of varying pH and high temperature, and a decrease in nitric oxide (NO) production was observed as the treatment concentration increased in RAW 264.7 cells.

Provolone del Monaco PDO cheese: Lactic microflora, biogenic amines and volatilome characterization

One commercial production run of Provolone del Monaco − a long-ripened pasta filata cheese − was followed up to the end of ripening for a total of 20 samples. 371 LAB isolates were subject to genetic characterization followed by 16S rRNA gene sequencing. The dominant species were Lacticaseibacillus casei/paracasei (19.4 %), Streptococcus macedonicus (19.1 %) and Enterococcus faecalis (13.2 %). Strains were screened for features of technological interest or safety relevance. Tyramine-producing cultures were quite common, above all within enterococci. By MALDI TOF Mass Spectrometry, one Lactococcus lactis and one Enterococcus faecium strain proved to be bacteriocin producers.Four further cheese wheels from the same production run at 623 days of ripening were evaluated for volatile organic compounds, biogenic amines, and bacterial community by metagenomic sequencing. Three individual wheel samples shared a rather similar microbiome with Lactobacillus delbrueckii and Streptococcus thermophilus as the most represented species, while the fourth wheel appeared wholly different being dominated by Lentilactobacillus buchneri and St. infantarius. Additionally, this sample had the greatest content of biogenic amines and a different VOCs composition.Given the variance seen among cheese wheels processed and ripened under the same conditions, the search for adjunct cultures in the production of this cheese seems to be of utmost importance.

SELECTION OF LACTIC ACID BACTERIA FOR RYE BREAD SOURDOUGH

Lactic acid bacteria are widely used to produce diverse type of fermented products. One of conventional applications for lactic acid bacteria is inclusion into sourdough for bread baking. These microorganisms play a key role in dough fermentation of rye flour or wheat and rye mixture since the yield of stable and well-leavened rye dough is possible only in acidic environment. Lately, despite the development of accelerated baking technologies and technological improvements, which in some cases eliminate the need for sourdough, interest in the tradition of making bread using sourdough as a source of flavoring, nutrient and health-enhancing compounds is constantly growing across the globe. It is natural therefore that focus of the researchers is centered on seeking new strains of lactic acid bacteria attractive as potential constituents of rye bread sourdough. Screening of strains-candidates to be included in the consortia for rye flour fermentation was conducted among collection cultures (23 strains), isolates from rye flour samples (154 strains) and among craft rye dough cultures for spontaneous fermentation kindly provided by private households of Minsk, Turov, Zhitkovichi (21 strains). Identification of lactic acid bacteria following examination of morphological, cultural, physiological and biochemical characteristics of the cultures and guided by the data of MALDI TOF mass spectrometry indicated that the compared microorganisms represented genera Lactiplantibacillus, Limosilactobacillus, Pediococcus, Weissella, Lactococcus. The majority of lactic acid bacteria isolated from rye flour samples belonged to genera Lactiplantibacillus and Pediococcus. Representatives of genera Lactiplantibacillus and Levilactobacillus prevailed among domestic variants of rye bread sourdoughs. Evaluation of acidogenic capacity of analyzed cultures upon 16 h fermentation in water-flour suspension by Neumann technique and organoleptic assessment of the obtained solutions sorted out for further studies 10 strains of lactic acid bacteria referred to species Levilactobacillus brevis (4 strains) Lactiplantibacillus plantarum (3 strains) and singular strains of species Lactiplantibacillus paraplantarum, Limosilactobacillus fermentum, Weissella cibaria. Glycosyl-hydrolases produced by lactic acid bacteria constituting starter cultures largely determine biochemical processes during fermentation of flour mixtures. Chromogenic substrates o-nitrophenyl-β-D-galactopyranoside, o-nitrophenyl-α-D-galactopyranoside, 4-nitrophenyl-β-D-glucopyranoside were used in 1 mmol concentration to assay activities of β-galactosidase, α-galactosidase, β-glucosidase, respectively. It was found that all tested bacteria of species Levilactobacillus brevis and Limosilactobacillus fermentum were characterized by synthesis of proteins with α-galactosidase and β-galactosidase activities in the course of growth on media with glucose and maltose. β-glucosidase activity was revealed in all representatives of species Lactiplantibacillus plantarum, Levilactobacillus brevis and Lactiplantibacillus paraplantarum. Amylolytic activity was detected in two Lactiplantibacillus plantarum strains, whereas bacteria of species Weissella cibaria displayed a weak β-glucosidase activity. An important criterion to select microbial constituents for dough fermentation is antagonistic activity toward contaminating microbiota. Antagonistic response of lactic acid bacterial cultures to causal agents of bread spoilage was demonstrated, including epidemiologically significant fungi of genera Fusarium, Aspergillus, Penicillium, etc. Analysis of obtained data has enabled to compose microbial consortia promising for further elaboration of technologies for producing active bread-making starter formulas with upgraded biotechnological properties and enhanced alimentary, nutritional and biological value.

Pseudocin 196, a novel lantibiotic produced by Bifidobacterium pseudocatenulatum elicits antimicrobial activity against clinically relevant pathogens

ABSTRACT Bacteriocins are broad or narrow-spectrum antimicrobial compounds that have received significant scientific attention due to their potential to treat infections caused by antibiotic-resistant pathogenic bacteria. The genome of Bifidobacterium pseudocatenulatum MM0196, an antimicrobial-producing, fecal isolate from a healthy pregnant woman, was shown to contain a gene cluster predicted to encode Pseudocin 196, a novel lantibiotic, in addition to proteins involved in its processing, transport and immunity. Following antimicrobial assessment against various indicator strains, protease-sensitive Pseudocin 196 was purified to homogeneity from cell-free supernatant. MALDI TOF mass spectrometry confirmed that the purified antimicrobial compound corresponds to a molecular mass of 2679 Da, which is consistent with that deduced from its genetic origin. Pseudocin 196 is classified as a lantibiotic based on its similarity to lacticin 481, a lanthionine ring-containing lantibiotic produced by Lactococcus lactis. Pseudocin 196, the first reported bacteriocin produced by a B. pseudocatenulatum species of human origin, was shown to inhibit clinically relevant pathogens, such as Clostridium spp. and Streptococcus spp. thereby highlighting the potential application of this strain as a probiotic to treat and prevent bacterial infections.

A highly selective Ru(II) complex-based phosphorescent probe for the sequential sensing Cu2+ and H2S and its applications

A highly selective Ru(II) complex-based phosphorescent probe Ru-Cyclen for the sequential sensing Cu2+ and H2S in pure aqueous medium was synthesized and characterized. Probe Ru-Cyclen exhibited a turn-off phosphorescence response toward Cu2+ by using a complex formation with a 1:1 binding mode, and the resulting complex enabled to specifically detect H2S based on the displacement approach with a turn-on phosphorescence response. Also, Ru-Cyclen possessed high selectivity and sensitivity with a low detection limit of 0.045 μM and 0.44 μM for Cu2+ and H2S respectively, and worked best in the range of pH 3–11. The kinetics response toward Cu2+ and H2S were very fast, completing within 4 min and 10 s, respectively. Additionally, the sensing mechanism was confirmed by fluorescence Job’s plot analysis, 1H NMR titration, EPR, TOF-mass spectrometry and phosphorescence lifetime analysis. Moreover, Ru-Cyclen showed low cell toxicity and successfully detected Cu2+ and exogenously or endogenously generated H2S in living zebrafish. Finally, combining the unique merits of the probe, including excellent water-solubility, a long emission wavelength of 600 nm, large Stoke shift of 150 nm and rapid response, probe Ru-Cyclen was applied in real water samples, human serum and test strips successfully.

Combining plasma Aβ and p-tau217 improves detection of brain amyloid in non-demented elderly

BackgroundMaximizing the efficiency to screen amyloid-positive individuals in asymptomatic and non-demented aged population using blood-based biomarkers is essential for future success of clinical trials in the early stage of Alzheimer’s disease (AD). In this study, we elucidate the utility of combination of plasma amyloid-β (Aβ)-related biomarkers and tau phosphorylated at threonine 217 (p-tau217) to predict abnormal Aβ-positron emission tomography (PET) in the preclinical and prodromal AD.MethodsWe designed the cross-sectional study including two ethnically distinct cohorts, the Japanese trial-ready cohort for preclinica and prodromal AD (J-TRC) and the Swedish BioFINDER study. J-TRC included 474 non-demented individuals (CDR 0: 331, CDR 0.5: 143). Participants underwent plasma Aβ and p-tau217 assessments, and Aβ-PET imaging. Findings in J-TRC were replicated in the BioFINDER cohort including 177 participants (cognitively unimpaired: 114, mild cognitive impairment: 63). In both cohorts, plasma Aβ(1-42) (Aβ42) and Aβ(1-40) (Aβ40) were measured using immunoprecipitation-MALDI TOF mass spectrometry (Shimadzu), and p-tau217 was measured with an immunoassay on the Meso Scale Discovery platform (Eli Lilly).ResultsAβ-PET was abnormal in 81 participants from J-TRC and 71 participants from BioFINDER. Plasma Aβ42/Aβ40 ratio and p-tau217 individually showed moderate to high accuracies when detecting abnormal Aβ-PET scans, which were improved by combining plasma biomarkers and by including age, sex and APOE genotype in the models. In J-TRC, the highest AUCs were observed for the models combining p-tau217/Aβ42 ratio, APOE, age, sex in the whole cohort (AUC = 0.936), combining p-tau217, Aβ42/Aβ40 ratio, APOE, age, sex in the CDR 0 group (AUC = 0.948), and combining p-tau217/Aβ42 ratio, APOE, age, sex in the CDR 0.5 group (AUC = 0.955), respectively. Each subgroup results were replicated in BioFINDER, where the highest AUCs were seen for models combining p-tau217, Aβ42/40 ratio, APOE, age, sex in cognitively unimpaired (AUC = 0.938), and p-tau217/Aβ42 ratio, APOE, age, sex in mild cognitive impairment (AUC = 0.914).ConclusionsCombination of plasma Aβ-related biomarkers and p-tau217 exhibits high performance when predicting Aβ-PET positivity. Adding basic clinical information (i.e., age, sex, APOE ε genotype) improved the prediction in preclinical AD, but not in prodromal AD. Combination of Aβ-related biomarkers and p-tau217 could be highly useful for pre-screening of participants in clinical trials of preclinical and prodromal AD.

Intact cell mass spectrometry coupled with machine learning reveals minute changes induced by single gene silencing

Intact (whole) cell MALDI TOF mass spectrometry is a commonly used tool in clinical microbiology for several decades. Recently it was introduced to analysis of eukaryotic cells, including cancer and stem cells. Besides targeted metabolomic and proteomic applications, the intact cell MALDI TOF mass spectrometry provides a sufficient sensitivity and specificity to discriminate cell types, isogenous cell lines or even the metabolic states. This makes the intact cell MALDI TOF mass spectrometry a promising tool for quality control in advanced cell cultures with a potential to reveal batch-to-batch variation, aberrant clones, or unwanted shifts in cell phenotype. However, cellular alterations induced by change in expression of a single gene has not been addressed by intact cell mass spectrometry yet. In this work we used a well-characterized human ovarian cancer cell line SKOV3 with silenced expression of a tumor suppressor candidate 3 gene (TUSC3). TUSC3 is involved in co-translational N-glycosylation of proteins with well-known global impact on cell phenotype. Altogether, this experimental design represents a highly suitable model for optimization of intact cell mass spectrometry and analysis of spectral data. Here we investigated five machine learning algorithms (k-nearest neighbors, decision tree, random forest, partial least squares discrimination, and artificial neural network) and optimized their performance either in pure populations or in two-component mixtures composed of cells with normal or silenced expression of TUSC3. All five algorithms reached accuracy over 90 % and were able to reveal even subtle changes in mass spectra corresponding to alterations of TUSC3 expression. In summary, we demonstrate that spectral fingerprints generated by intact cell MALDI-TOF mass spectrometry coupled to a machine learning classifier can reveal minute changes induced by alteration of a single gene, and therefore contribute to the portfolio of quality control applications in routine cell and tissue cultures.

Fully genotyping and screening of clinically important blood-group antigens by MALDI TOF mass spectrometry.

Several molecular biology methods are available for high-throughput blood typing. In this study, we aimed to build a high-throughput blood-group genetic screening system for high-frequency blood-group antigen-negative rare-blood groups in donors and patients. The amplification primers for all blood-type gene fragments involving the selected alleles were designed for detection. Single-base extend primers were also designed based on specific loci. DNA fragments were detected by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MS) for the last nucleotide identification of amplification products in the extend step. The accuracy was verified by known samples. Thirty-six random samples were detected by serological tests and sequencing to verify the system stability. After verification, according to the collected known rare-blood-type samples, all the alleles designed to be detected matched with the validated single-nucleotide polymorphisms. The verification tests showed that all genotyping results of the random samples were in accordance with the findings of serotyping and sequencing. Then, 1258 random donor samples were screened by the built typing system after the verification. Three Fy(a-) and four s- were screened out in 1258 random blood samples. The multiple polymerase chain reaction-based MS detection system can be used in rare-blood-type screening with good accuracy and stability.

Simple One–Pot Synthesis of Hexakis(2-alkoxy-1,5-phenyleneimine) Macrocycles by Precipitation–Driven Cyclization

Hexakis(2-alkoxy-1,5-phenyleneimine) macrocycles were synthesized using a simple one-pot procedure through precipitation-driven cyclization. The acetal-protected AB–type monomers, 2-alkoxy-5-aminobenzaldehyde diethyl acetals, underwent polycondensation in water or acid-containing tetrahydrofuran. The precipitation–driven cyclization, based on imine dynamic covalent chemistry and π–stacked columnar aggregation, played a decisive role in the one–pot synthesis. The progress of the reaction was analyzed using MALDI–TOF mass spectrometry. The macrocycles with alkoxy chains were soluble in specific organic solvents, such as chloroform, allowing their structures to be analyzed using NMR. The shape-anisotropic, nearly planar, and shape-persistent macrocycles aggregated into columnar assemblies in polymerization solvents, driven by aromatic π-stacking. The octyloxylated macrocycle OcO–Cm6 exhibited an enantiotropic columnar liquid crystal-like mesophase between 165 °C and 197 °C. In the SEM image of (S)-(–)-3,7-dimethyloctyloxylated macrocycle (–)BCO–Cm6, columnar substances with a diameter of 200–300 nm were observed. The polymerization solution for the 2-(2-methoxyethoxy)ethoxy)ethoxylated macrocycle (TEGO–Cm6) gelled, and showed thixotropic properties by forming a hydrogen bond network.

Probiotic potential and safety analysis of lactic acid bacteria isolated from Ethiopian traditional fermented foods and beverages

BackgroundProbiotics are live microorganisms that effectively combat foodborne pathogens, promoting intestinal health when consumed in sufficient amounts. This study evaluated the probiotic potential and safety of lactic acid bacteria isolated from selected Ethiopian traditional fermented foods and beverages (Kotcho, Bulla, Ergo, Cabbage-Shamita, Borde, and Bukuri). To assess the isolates’ probiotic activity, tolerance, and survival rate under various stressful conditions, including low pH, intestinal inhibitory substances, salt concentration, bile salt, and simulated gastric/intestinal juice. The isolates were also tested for antagonistic activities against common bacterial and fungal pathogens (Staphylococcus aureus, Salmonella Typhimurium, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, and Candida albicans) and safety (auto-aggregation, co-aggregation, cell source hydrophobicity, hemolytic activity, DNase, and antibiotic susceptibility). The best probiotic lactic acid bacteria (LAB) were characterized to species level following standard MALDI TOF/mass spectrometry analysis.ResultsA total of 125 potentially probiotic LAB were isolated of which 17 (13.60%) isolates survived low pH (2, 2.5, and 3), bile salt (0.3%), intestinal inhibitory chemicals (phenol, bile, low acidity, pepsin, and pancreas), and simulated gastro-intestinal settings with near 60–94% survival rate. In addition, 11 best LAB isolates were further screened based on additional screening including their antimicrobial efficacy, preservative efficiency, bacteriocin production besides resistance to low acid and bile salts, and survival potential under simulated gastrointestinal conditions. All 11 LAB isolates were resistant to ampicillin, vancomycin, gentamicin, kanamycin, clindamycin, and chloramphenicol, while they were susceptible to streptomycin and tetracycline. The MALDI TOF mass spectrometry analysis result of efficient probiotic LAB grouped them under the genus Pediococcus, Enterococcus, and Lactococcus including Pediococcus pentosaceus, Enterococcus faecium, Lactococcus lactis, and Pediococcus acidilactici.ConclusionEthiopian traditional fermented foods and beverages are good sources of promising probiotic lactic acid bacteria. These isolates could serve as potential starter cultures and bio-preservative for the enhancement of the shelf life of foods. This study established the groundwork for the selection of excellent probiotics for the development and application of LAB for antibacterial action, starter culture production, and preservation activities.

Influence of environmental settings in geographically distinct ports on the protein profiles of cultivable bacteria using MALDI–TOF mass spectrometry

AbstractThe protein profiles of bacteria are useful markers in their identification. In this study, we examined the influence of environmental settings on the protein profiles of culturable bacteria using matrix‐assisted laser desorption ionization‐time of flight mass spectrometry (MALDI–TOF MS). We compared the protein profiles of bacteria collected from geographically distinct port environments (Kolkata, a freshwater port, and Kandla, a marine port) from India. The results indicated that bacterial species were distinctly different between the two ports, except for a few bacteria, that were common, such as Bacillus cereus, Enterobacter cloacae, Micrococcus luteus, Pseudomonas aeruginosa, P. putida, P. stutzeri, P. mosselii and Vibrio parahaemolyticus. Mass spectra of these common bacterial species, a few pathogenic among them, differed in their protein profiles and relative intensity of peaks. These variations point out that environmental settings/factors have a significant role in the protein expression and can result in differentiated virulence of pathogens. Identifying these risk factors is crucial in developing appropriate environmental port management practices.

Modulation of the Activity of the Insulin-Degrading Enzyme by Aβ Peptides.

The insulin-degrading enzyme (IDE) is an evolutionarily conserved protease implicated in the degradation of insulin and amyloidogenic peptides. Most of the biochemical and biophysical characterization of IDE's catalytic activity has been conducted using solutions containing a single substrate, i.e., insulin or Aβ(1-40). IDE's activity toward a particular substrate, however, is likely to be influenced by the presence of other substrates. Here, we show by a kinetic assay based on insulin's helical circular dichroic signal and MALDI TOF mass spectrometry that Aβ peptides modulate IDE's activity toward insulin in opposing ways. Aβ(1-40) enhances IDE-dependent degradation of insulin, whereas Aβ(pyroE3-42), the most pathogenic pyroglutamate-modified Aβ peptide in AD, inhibits IDE's activity. Intriguingly, Aβ(pyroE3-42) also inhibits IDE's ability to degrade Aβ(1-40). Together, our results implicate Aβ peptides in the abnormal catabolism of IDE's key substrates.

16S rRNA gene sequencing and MALDI TOF mass spectroscopy identification of Leuconostoc mesenteroides isolated from Algerian raw camel milk

BackgroundEighty-three strains of Leuconostoc mesenteroides were isolated from Algerian raw camel milk. Based on morphological, biochemical, and physiological characters tests, strains were identified as Ln. mesenteroides subsp. mesenteroides. Seven strains had a remarkable antagonistic and probiotic characterization. The present study aims at identifying these strains by means of 16 s rRNA gene sequencing and Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), extending phenotypic and genotypic studies done previously. ResultsThe phyloproteomic dendrograms of the studied strains based on MALDI-TOF MS provided the same identification with more intraspecific information from the 16S rRNA gene sequencing based on phylogenetic analysis. The latter were in agreement with the previous biochemical/physiological identification, the seven isolated strains were Ln. mesenteroides subsp. mesenteroides. ConclusionsRemarkably, MALDI-TOF MS fingerprinting was found to be effective enough as 16S rRNA gene sequencing identification, allowing faster and more reliable analysis than biochemical/physiological methods.

Biocontrol potential of lipopeptides produced by the novel Bacillus subtilis strain Y17B against postharvest Alternaria fruit rot of cherry.

The use of synthetic fungicides against postharvest Alternaria rot adversely affects human health and the environment. In this study, as a safe alternative to fungicides, Bacillus subtilis strain Y17B isolated from soil exhibited significant antifungal activity against Alternaria alternata. Y17B was identified as B. subtilis based on phenotypic identification and 16S rRNA sequence analysis. To reveal the antimicrobial activity of this strain, a PCR-based study detected the presence of antifungal lipopeptide (LP) biosynthetic genes from genomic DNA. UPLC Q TOF mass spectrometry analysis detected the LPs surfactin (m/z 994.64, 1022.68, and 1026.62), iturin (m/z 1043.56), and fengycin (m/z 1491.85) in the extracted LP crude of B. subtilis Y17B. In vitro antagonistic study demonstrated the efficiency of LPs in inhibiting A. alternata growth. Microscopy (SEM and TEM) studies showed the alteration of the morphology of A. alternata in the interaction with LPs. In vivo test results revealed the efficiency of LPs in reducing the growth of the A. alternata pathogen. The overall results highlight the biocontrol potential of LPs produced by B. subtilis Y17B as an effective biological control agent against A. alternata fruit rot of cherry.

Isolation and Identification of Bacterial Communities in Neutral Mine Drainage in Central Slovakian Neovolcanites (Slovakia)

There are several sources of mine drainage left over from past mining sites in the Central Slovakian neovolcanites. The neutral pH and high concentrations of sulphates and multiple potentially hazardous elements, such as zinc or manganese, are typical in this region. However, this environment could be home to specific microbiota. The aim of the study was to characterize bacterial populations in mine drainage in the Central Slovakian neovolcanites. Direct microscopic observations, cultivation methods, MALDI TOF mass spectrometry, and 16S rRNA gene sequencing of isolates were used for identification. Gram-positive and Gram-negative bacteria were almost equally represented in the mine water samples. The most abundant bacterium was the genus Bacillus spp. (43.48%). Another large group of bacteria consisted of Proteobacteria (34.78%), represented by Pseudomonas spp. (17.39%), Serratia spp. (13.04%), and Providencia spp. (4.35%). Our data confirm the presence of Bacillus spp. and Pseudomonas spp. as bacterial species occurring in an environment polluted by potentially hazardous elements, which may indicate their bioremediation potential.

Semi-supervised learning for MALDI–TOF mass spectrometry data classification: an application in the salmon industry

Semi-supervised learning for MALDI–TOF mass spectrometry data classification: an application in the salmon industry

Elevation of truncated (48 kDa) form of unconventional myosin 1C in blood serum correlates with severe Covid-19

In Covid-19 and autoimmune patients, there are several similarities revealed in the immune responses (Liu et al., 2021; Woodruff et al., 2020). Earlier, we firstly detected a truncated (48 kDa) form of the unconventional Myosin 1C (48/Myo1C) in a fraction of proteins soluble in 10% 2,2,2-trichloroacetic acid (TCA). These proteins were obtained from blood serum of patients with autoimmune diseases, such as multiple sclerosis, systemic lupus erythematosus, and rheumatoid arthritis (Kit et al., 2018). Here, we demonstrated that content of 48/Myo1C was also elevated in blood serum of the severe Covid-19 patients. Whereas in blood of 28 clinically healthy human individuals regularly tested for Covid-19 infection, the amount of this protein was undetectable or very low, in blood of 16 of 28 patients hospitalized with severe course of this disease, its amount was significantly increased. Dexamethasone, steroid hormone which is widely used for treatment of severe Covid-19 patients, induced time-dependent elevation of the 48/Myo1C in blood of such patients. The 48/Myo1C dose-dependently suppressed the viability of anti-CD3-activated lymphocytes of human peripheral blood. Recently, we used affinity chromatography on the magnetic poly(glycidyl-methacrylate) (mag-PGMA–NH2) microparticles functionalized with Myo1C and MALDI–TOF mass spectrometry with molecular modeling in silico in order to identify potential molecular partners of the 48/Myo1C. It was found that 48/Myo1C might bind to component 3 of the complement system and the anti-thrombin-III (Starykovych et al., 2021). Thus, the mechanisms of the pathogenic action of truncated form of Myo1C in severe COVID-19 patients may involve a suppression of the immune cells, as well as modulation of complement and coagulation cascades.

Synthesis and Characterization of New Potential Hypoxia-Sensitive Azo-thiacalix[4]arenes Derivatives

The subject of this article is new potential hypoxia-sensitive azo-thiacalix[4]arenes derivatives in the 1,3-alternate configuration. Previously, it was shown that azo derivatives of calix[4]arene in the cone conformation form complexes with rhodamine dyes. The present work is devoted to the synthesis of new azo derivatives using the thiacalix[4]arene platform. A new highly productive method for the synthesis of thiacalixarene with four anionic sulfonate azo fragments on the lower rim (compounds 2a–b) for further complexation with the most common cationic dyes is reported. The chemical structures of the products obtained were established based on 1H and 13C NMR, IR spectroscopy, MALDI TOF mass spectrometry, and elemental analysis.

A self-healable metallohydrogel for drug encapsulations and drug release.

A self-healable metallohydrogel (MOG) of Mn(ii) has been prepared using a low molecular weight gelator, Na2HL {H3L = l-(3,5-di-tert-butyl-2-hydroxy-benzyl)amino aspartic acid}. The MOG has been characterized by MALDI TOF mass spectrometry, rheological studies, IR spectroscopy, and microscopic techniques. Non-steroidal anti-inflammatory drug (NSAID), indomethacin (IND) and anti-cancer drug gemcitabine (GEM) were encapsulated into the metallohydrogel. The GEM-loaded metallogel (MOG_GEM) shows better delivery and more adverse cytotoxicity than the drug against breast cancer cell lines MDA-MB-468 and 4T1. The anti-cancer property was evaluated with in vitro MTT cytotoxic assay, live-dead assay and cell migration assay. In vitro cytotoxicity assay against RAW 264.7 cell line with the treatment of MOG_IND shows the improved anti-inflammatory response in the case of MOG_IND compared to the drug alone.

Почвенные бактерии - потенциальные контаминанты растительных масел

Bacterial strains capable of using vegetable oil as the sole source of carbon have been isolated from the soil by the enrichment culture method followed by isolation into pure cultures. Using MALDI TOF mass spectrometry, representatives of the genera Acinetobacter (Acinetobacter pittii), Pseudomonas (Pseudomonas antarctica, Pseudomonas koreensis), Rhodococcus (Rhodococcus erythropolis) were identified. To the share of the representatives of the genus Acinetobacter accounted for 25% of the isolated strains, representatives of the genera Pseudomonas and Rhodococcus - 37.5% of isolated strains each. Rhodococcus erythropolis has been shown to grow in vegetable oil at the temperature range of 12°C to 35°C with a generation time of about 16 hours at 12°C and about 11 hours at 35°C. The growth curve corresponds to diauxia. Keywords: VEGETABLE OIL, SOIL BACTERIA, CONTAMINATION, ACINETOBACTER PITTII, PSEUDOMONAS ANTARCTICA, PSEUDOMONAS KOREENSIS, RHODOCOCCUS ERYTHROPOLIS