Study of total antioxidant capacity of red raspberry (Rubus idaeous L.) shoots

BACKGROUND: Today, cardiovascular, oncological, and neurodegenerative diseases are the main causes of death in the world, according to official World Health Organization (WHO) statistics. Antioxidants are used to treat and prevent these diseases. In order to develop optimal technology for obtaining drugs based on plant extracts with antioxidant action, it is necessary to determine the total antioxidant capacity of raspberry shoots. OBJECTIVES: The study aimed to determine the total antioxidant capacity of red raspberry shoots, study the content of biologically active substances (BAS), and the antioxidant activity of red raspberry shoot extracts obtained during subsequent exhaustive extraction. METHODS: The number of phenolic compounds, catechins, flavonoids, and hydroxycinnamic acids was determined by a spectrophotometric analysis method, whereas organic acids were determined by the alkalimetric method in red raspberry shoot extracts; the antioxidant activity of obtained extracts was evaluated by potentiometric method. RESULTS:  The total antioxidant capacity of red raspberry shoots was 164.12 mmol-equiv./m dry weight, the sum of the total content of phenolic compounds was 24.40 mg gallic acid (GA)/mL, catechins – 21.36 mg epigallocatechin-3-O-gallate (EGCG)/mL, flavonoids – 0.77 mg rutin (R)/mL, hydroxycinnamic acids derivatives – 2.56 mg chlorogenic acid (ChA)/mL and organic acids – 1.88 mg citric acid (CA)/mL in red raspberry shoot extracts obtained during subsequent exhaustive extraction. The analysis showed that there is a very high positive correlation between antioxidant activity and total phenolic compounds, catechin, flavonoid, hydroxycinnamic acids derivatives, and organic acids content in red raspberry shoot extracts. CONCLUSIONS: Total red raspberry shoots' antioxidant capacity has been determined. The study results can be used to develop optimal technology for obtaining drugs based on the extract of red raspberry shoots, which has an antioxidant effect

Microbiome Responses to an Uncontrolled Short-Term Diet Intervention in the Frame of the Citizen Science Project

Personalized nutrition is of increasing interest to individuals actively monitoring their health. The relations between the duration of diet intervention and the effects on gut microbiota have yet to be elucidated. Here we examined the associations of short-term dietary changes, long-term dietary habits and lifestyle with gut microbiota. Stool samples from 248 citizen-science volunteers were collected before and after a self-reported 2-week personalized diet intervention, then analyzed using 16S rRNA sequencing. Considerable correlations between long-term dietary habits and gut community structure were detected. A higher intake of vegetables and fruits was associated with increased levels of butyrate-producing Clostridiales and higher community richness. A paired comparison of the metagenomes before and after the 2-week intervention showed that even a brief, uncontrolled intervention produced profound changes in community structure: resulting in decreased levels of Bacteroidaceae, Porphyromonadaceae and Rikenellaceae families and decreased alpha-diversity coupled with an increase of Methanobrevibacter, Bifidobacterium, Clostridium and butyrate-producing Lachnospiraceae- as well as the prevalence of a permatype (a bootstrapping-based variation of enterotype) associated with a higher diversity of diet. The response of microbiota to the intervention was dependent on the initial microbiota state. These findings pave the way for the development of an individualized diet.</p

Genetic comparison of salmon (Salmo salar L.) from the White Sea and the Atlantic ocean

Samples of salmon (Salmo salar) from River Kachkovka and R. Nilma in northem Russia were analysed by starch gel electrophoresis and compared to three Norwegian stocks, R. Neiden in northern Norway and R. Øyre and R. Hop on the west-coast. The aim of the study is to calibrate population genetic methods in Norwegian and Russian laboratories. The initial step in this process is to compare starch gel electrophoresis and polyacrylamide gel electrophoresis of salmon stocks, to facilitate comparison of data sets obtained by laboratories in Russia and Westem Europe thereby increasing the knowledge about the genetic relationship between salmon populations from the East-Atlantic and the Kola peninsula and the White Sea. The comparison includes the following polymorphic loci: AAT-4*, IDDH-2*. IDHP-3*, MDH- 3, 4*, MEP-2*, ESTD* as well as the newly discovered polymorphic loci FBAW-3* and TPI- 3*. Samples were run side by side on gels, and the results show that the alleles found in the Russian stocks are the same as those found in the Norwegian stocks, although the two electrophoretic methods lead to differences in designations of alleles. A polymorphism in ESTD* which involves a *94 allele was observed in salmon from the two Russian stocks and in R. Neiden. This allele was absent in the two other Norwegian stocks and in a major brood stock of farmed salmon in Norway. The IDHP-3* 116 allele was found in unusual high frequencies in the Russian stocks and in R. Neiden. Thus, the variability observed at these two loci gives some promise for the possibility in the future to distinguish salmon stocks from the northern part of Norway and Russia from stocks further south along the Norwegian coast

Structure and Mechanical Properties of Titanium Processed by Twist Extrusion and Subsequent Rolling

The article considers one of the combined methods of severe plastic deformation (SPD), which includes twist extrusion (TE) and subsequent rolling. The use of combined forming methods is promising for industrial use. Titanium grade 1 was used as a material in the experiments. Rolling was carried out in three stages with a decrease in temperature from 350°C to 180°C for a number of passes with one heating. The accumulated strain degree was e = 4.6 at twist extrusion and e = 3 in rolling. Increasing the reduction per pass decreases the number of heatings and increases the efficiency of the rolling process in whole. At the same time, it is necessary to set the maximum processing modes at which recrystallization processes do not occur in the billet. When rolling, the deformation degree in one pass was taken in the range of 5–20% with an increase in successive passes. The use of such deformation degrees allowed reducing the grain size in titanium grade 1 significantly. Twist extrusion reduces the grain size to 300–500 nm. Subsequent rolling allowed reducing the size of structural elements to 50–100 nm and provided a significant increase in the mechanical characteristics of the billet material (up to 869 MPa) while maintaining satisfactory ductility (up to 11.6%). It was found that increasing the deformation degree in one pass up to 40% at cross-rolling and simultaneously increasing the temperature to 385°C led to a decrease in the UFG structure quality and reduced strength of the deformable material by starting the dynamic recrystallization process

Unusual Cytochrome c552 from Thioalkalivibrio paradoxus: Solution NMR Structure and Interaction with Thiocyanate Dehydrogenase

The search of a putative physiological electron acceptor for thiocyanate dehydrogenase (TcDH) newly discovered in the thiocyanate-oxidizing bacteria Thioalkalivibrio paradoxus revealed an unusually large, single-heme cytochrome c (CytC552), which was co-purified with TcDH from the periplasm. Recombinant CytC552, produced in Escherichia coli as a mature protein without a signal peptide, has spectral properties similar to the endogenous protein and serves as an in vitro electron acceptor in the TcDH-catalyzed reaction. The CytC552 structure determined by NMR spectroscopy reveals significant differences compared to those of the typical class I bacterial cytochromes c: a high solvent accessible surface area for the heme group and so-called “intrinsically disordered” nature of the histidine-rich N- and C-terminal regions. Comparison of the signal splitting in the heteronuclear NMR spectra of oxidized, reduced, and TcDH-bound CytC552 reveals the heme axial methionine fluxionality. The TcDH binding site on the CytC552 surface was mapped using NMR chemical shift perturbations. Putative TcDH-CytC552 complexes were reconstructed by the information-driven docking approach and used for the analysis of effective electron transfer pathways. The best pathway includes the electron hopping through His528 and Tyr164 of TcDH, and His83 of CytC552 to the heme group in accordance with pH-dependence of TcDH activity with CytC552

Unusual Cytochrome c552 from Thioalkalivibrio paradoxus: Solution NMR Structure and Interaction with Thiocyanate Dehydrogenase

The search of a putative physiological electron acceptor for thiocyanate dehydrogenase (TcDH) newly discovered in the thiocyanate-oxidizing bacteria Thioalkalivibrio paradoxus revealed an unusually large, single-heme cytochrome c (CytC552), which was co-purified with TcDH from the periplasm. Recombinant CytC552, produced in Escherichia coli as a mature protein without a signal peptide, has spectral properties similar to the endogenous protein and serves as an in vitro electron acceptor in the TcDH-catalyzed reaction. The CytC552 structure determined by NMR spectroscopy reveals significant differences compared to those of the typical class I bacterial cytochromes c: a high solvent accessible surface area for the heme group and so-called &ldquo;intrinsically disordered&rdquo; nature of the histidine-rich N- and C-terminal regions. Comparison of the signal splitting in the heteronuclear NMR spectra of oxidized, reduced, and TcDH-bound CytC552 reveals the heme axial methionine fluxionality. The TcDH binding site on the CytC552 surface was mapped using NMR chemical shift perturbations. Putative TcDH-CytC552 complexes were reconstructed by the information-driven docking approach and used for the analysis of effective electron transfer pathways. The best pathway includes the electron hopping through His528 and Tyr164 of TcDH, and His83 of CytC552 to the heme group in accordance with pH-dependence of TcDH activity with CytC552