20 research outputs found
Получение 1-(-β-нафтил)-3-ферроценилпиразол-4- карбальдегида и синтезы на его основе
Synthesis of 1-(β-naphthyl)-3-ferrocenyl pyrazole-4-carbaldehyde was carried out from acetylferrocene and naphthalen-2-ylhydrazine followed by intramolecular cyclization under Vilsmeier-Haack conditions. The reaction of reductive amination of aldehydes obtained with primary and secondary amines including methyl esters of amino acids was studied.Cинтезирован 1-β-нафтил-3-ферроценил-4-формилпиразол из гидразона ацетилферроцена и β-нафтилгидразина, взаимодействием с комплексом Вильсмеера. Изучена реакция прямого восстановительного аминирования альдегида с первичными и вторичными алифатическими аминами и метиловыми эфирами аминокислот
Signatures of Molecular Unification and Progressive Oxidation Unfold in Dissolved Organic Matter of the Ob-Irtysh River System along Its Path to the Arctic Ocean
The Ob-Irtysh River system is the seventh-longest one in the world. Unlike the other Great Siberian rivers, it is only slightly impacted by the continuous permafrost in its low flow. Instead, it drains the Great Vasyugan mire, which is the world largest swamp, and receives huge load of the Irtysh waters which drain the populated lowlands of the East Siberian Plain. The central challenge of this paper is to understand the processes responsible for molecular transformations of natural organic matter (NOM) in the Ob-Irtysh river system along the South-North transect. For solving this task, the NOM was isolated from the water samples collected along the 3,000?km transect using solid-phase extraction. The NOM samples were further analyzed using high resolution mass spectrometry and optical spectroscopy. The obtained results have shown a distinct trend both in molecular composition and diversity of the NOM along the South-North transect: the largest diversity was observed in the Southern “swamp-wetland” stations. The samples were dominated with humic and lignin-like components, and enriched with aminosugars. After the Irtysh confluence, the molecular nature of NOM has changed drastically: it became much more oxidized and enriched with heterocyclic N-containing compounds. These molecular features are very different from the aliphatics-rich permafrost NOM. They witnesses much more conservative nature of the NOM discharged into the Arctic by the Ob-Irtysh river system. In general, drastic reduction in molecular diversity was observed in the northern stations located in the lower Ob flow
THE ASSESSMENT OF ANALYTICAL DOUBLE-SHOT PYROLYSIS WITH GAS CHROMATOGRAPH-MASS SPECTROMETRY APPLICATION OPPORTUNITY FOR THE HUMIC MATTER INVESTIGATION IN SITU
Double-shot pyrolysis with gas chromatography and mass detection (Double-shot GC MS) was conducted for a sample of typical chernozem and humic acids separated from it. The humic acids preparations were pyrolyzed at 500, 600 and 700°C. The data were compared with the lignin pyrograms witch were obtained under similar conditions. It was shown that 500°C is the optimum temperature for pyrolysis of humic acids obtained from Chernozems. Toluene in pyrolysis products may be considered as a marker of excessively high temperature occurring during the experiment. The results of a Doubleshot pyrolysis for the soil itself and the humic acids which were extracted from it were compared. Eight products of the soil pyrolysis coincided with substances determined in humic acids (with a total of 41). In the case of thermal desorption of the soil, there were only three such substances, and they also were detected during subsequent pyrolysis of the soil sample. The data obtained speak about the predominantly macromolecular composition of humic substances. The conducted works demonstrate the posibility and perspective for using the Doubleshot pyrolysis GC MS for in situ investigation of soil organic matter, humus matter in general and humic acids in particular
The preparation of 1-(β-naphthyl)-3-ferrocenylpyrazole-4-carbaldehyde and syntheses on the base of it
Synthesis of 1-(β-naphthyl)-3-ferrocenyl pyrazole-4-carbaldehyde was carried out from acetylferrocene and naphthalen-2-ylhydrazine followed by intramolecular cyclization under Vilsmeier-Haack conditions. The reaction of reductive amination of aldehydes obtained with primary and secondary amines including methyl esters of amino acids was studied
Speciation of organosulfur compounds in carbonaceous chondrites.
Despite broad application of different analytical techniques for studies on organic matter of chondrite meteorites, information about composition and structure of individual compounds is still very limited due to extreme molecular diversity of extraterrestrial organic matter. Here we present the first application of isotopic exchange assisted Fourier transform ion cyclotron resonance mass spectrometry (FTICR MS) for analysis of alkali extractable fraction of insoluble organic matter (IOM) of the Murchison and Allende meteorites. This allowed us to determine the individual S-containing ions with different types of sulfur atoms in IOM. Thiols, thiophenes, sulfoxides, sulfonyls and sulfonates were identified in both samples but with different proportions, which contribution corroborated with the hydrothermal and thermal history of the meteorites. The results were supported by XPS and thermogravimetric analysis coupled to FTICR MS. The latter was applied for the first time for analysis of chondritic IOM. To emphasize the peculiar extraterrestrial origin of IOM we have compared it with coal kerogen, which is characterized by the comparable complexity of molecular composition but its aromatic nature and low oxygen content can be ascribed almost exclusively to degradation of biomacromolecules
Static harmonization of dynamically harmonized Fourier transform ion cyclotron resonance cell
Dissection of the Deep-blue Autofluorescence Changes Accompanying Amyloid Fibrillation
Pathogenesis of numerous diseases is associated with the formation of amyloid fibrils. Extrinsic fluorescent dyes, including Thioflavin T (ThT), are used to follow the fibrillation kinetics. It has recently been reported that the so-called deep-blue autofluorescence (dbAF) is changing during the aggregation process. However, the origin of dbAF and the reasons for its change remain debatable. Here, the kinetics of fibril formation in model proteins were comprehensively analyzed using fluorescence lifetime and intensity of ThT, intrinsic fluorescence of proteinaceous fluorophores, and dbAF. For all systems, intensity enhancement of the dbAF band with similar spectral parameters (∼350 nm excitation; ∼450 nm emission) was observed. Although the time course of ThT lifetime (indicative of protofibrils formation) coincided with that of tyrosine residues in insulin, and the kinetic changes in the ThT fluorescence intensity (reflecting formation of mature fibrils) coincided with changes in ThT absorption spectrum, the dbAF band started to increase from the beginning of the incubation process without a lag-phase. Our mass-spectrometry data and model experiments suggested that dbAF could be at least partially related to oxidation of amino acids. This study scrutinizes the dbAF features in the context of the existing hypotheses about the origin of this spectral band
Examination of molecular space and feasible structures of bioactive components of humic substances by FTICR MS data mining in ChEMBL database
Interlaboratory comparison of humic substances compositional space as measured by Fourier transform ion cyclotron resonance mass spectrometry (IUPAC Technical Report).
Interlaboratory comparison on the determination of the molecular composition of humic substances (HS) was undertaken in the framework of IUPAC project 2016-015-2-600. The analysis was conducted using high resolution mass spectrometry, nominally, Fourier transform ion cyclotron resonance mass spectrometry (FTICR MS) with electrospray ionization. Six samples of HS from freshwater, soil, and leonardite were used for this study, including one sample of humic acids (HA) from coal (leonardite), two samples of soil HA (the sodpodzolic soil and chernozem), two samples of soil fulvic acids (FA) (the sod-podzolic soil and chernozem), and one sample of freshwater humic acids (the Suwannee River). The samples were analyzed on five different FTICR MS instruments using the routine conditions applied in each participating laboratory. The results were collected as mass lists, which were further assigned formulae for the determination of molecular composition. The similarity of the obtained data was evaluated using appropriate statistical metrics. The results have shown that direct comparison of discrete stoichiometries assigned to the mass lists obtained by the different laboratories yielded poor results with low values of the Jaccard similarity score - not exceeding 0.56 (not more than 56 % of the similar peaks). The least similarity was observed for the aromatics-rich HA samples from leonardite (coal) and the chernozem soil, which might be connected to difficulties in their ionization. The reliable similarity among the data obtained in this intercomparison study was achieved only by transforming a singular point (stoichiometry) in van Krevelen diagram into a sizeable pixel (a number of closely located stoichiometries), which can be calculated from the population density distribution. The conclusion was made that, so far, these are descriptors of occupation density distribution, which provide the metrics compliant with the data quality requirements, such as the reproducibility of the data measurements on different instruments
Effects of Isoflavone-Rich NADES Extract of Pueraria lobata Roots and Astaxanthin-Rich Phaffia rhodozyma Extract on Prostate Carcinogenesis in Rats
Prostate cancer (PCa) is one of the most common male malignancies worldwide. In the current study, we evaluated the effects of a natural deep eutectic solvent (NADES) extract of Pueraria lobata roots rich in isoflavones (ISF) and Phaffia rhodozyma extract rich in astaxanthin (ASX) on an N-methyl-N-nitrosourea plus testosterone PCa model in rats. ISF consisted of puerarin, daidzein, genistein, formononetin and other polyphenols, while ASX contained lipids and unsaturated species in addition to astaxanthin. Extracts were administered through a whole promotion period in daily doses shown by our group to successfully inhibit benign prostate hyperplasia (BPH) development — 200 mg/kg for ISF and 25 mg/kg for ASX. Though a similar effect was found for BPH processes accompanying PCa induction, the incidence of PCa in animals treated with placebo, ISF and ASX was 37%, 37% and 41%, respectively, showing no chemopreventive activity of ISF and ASX. PCa development was associated with a decrease in the Ca/Mg ratio in serum and an increase in prostate tissue. Treatment with both extracts produced a normalization effect on Ca balance in serum, which, combined with a decrease in the prostatic index, suggests some positive health effects of ISF and ASX