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This article presents the first experimental data on the ability of microbial communities from sediments of the Gorevoy Utes natural oil seep to degrade petroleum hydrocarbons under anaerobic conditions. Like in marine ecosystems associated with oil discharge, available electron acceptors, in particular sulfate ions, affect the composition of the microbial community and the degree of hydrocarbon conversion. The cultivation of the surface sediments under sulfate-reducing conditions led to the formation of a more diverse bacterial community and greater loss of n-alkanes (28%) in comparison to methanogenic conditions (6%). Microbial communities of both surface and deep sediments are more oriented to degrade polycyclic aromatic hydrocarbons (PAHs), to which the degree of the PAH conversion testifies (up to 46%) irrespective of the present electron acceptors. Microorganisms with the uncultured closest homologues from thermal habitats, sediments of mud volcanoes, and environments contaminated with hydrocarbons mainly represented microbial communities of enrichment cultures. The members of the phyla Firmicutes, Chloroflexi, and Caldiserica (OP5), as well as the class Deltaproteobacteria and Methanomicrobia, were mostly found in enrichment cultures. The influence of gas-saturated fluids may be responsible for the presence in the bacterial 16S rRNA gene libraries of the sequences of "rare taxa": Planctomycetes, Ca. Atribacteria (OP9), Ca. Armatimonadetes (OP10), Ca. Latescibacteria (WS3), Ca. division (AC1), Ca. division (OP11), and Ca. Parcubacteria (OD1), which can be involved in hydrocarbon oxidation.

Diversity of methano- and methylotrophic bacteria in enrichments from the oxidized sediment layer maintained at 10°C in mineral media with nitrogen compounds ( $${\text{NO}}_{3}^{ - }$$ and $${\text{NH}}_{4}^{ + }$$ ) and methanol was studied using high-throughput sequencing of the V2–V3 region of the 16S rRNA gene. Methanotrophs of the bottom sediment belonged to the order Methylococcales, with predominance of the genus Methylobacter (6.4 and 4.6% of the total number of sequences, respectively). Members of the methylotrophic community belonged to the genus Methylotenera (family Methylophilaceae). Enrichments in the medium with ammonium and methane were characterized by the highest diversity of methanotrophs, containing 22 OTUs of the family Methylococcaceae, nine of which were not detected under other cultivation conditions. Altogether, only six out of 28 OTUs of methanotrophic bacteria exhibited similarity to cultured members of Methylobacter, Metyloglobulus, and Methylomicrobium, while others showed different levels of similarity (94–99%) to uncultured members of the family Methylococcaceae. The presence of 0.01% methanol promoted preferential development of methylotrophic bacteria, while 0.5% methanol suppressed the growth of methanotrophic bacteria irrespective of the nitrogen source added.

New insoluble polymer silver-containing nanocomposites are synthesized by the thermal treatment of a polymer complex based on polyacrylonitrile without the use of an additional reducing agent. The resulting composites are paramagnetic and have a spin concentration of about 1017−1018 spin/g and an average size of silver nanoparticles of 5−8 nm. The electron paramagnetic resonance is used to monitor the synthesis of nanosystems in time. It is found that the nanocomposite is formed via two main stages through the reduction of silver ions and the further development of nanoparticles, while the polymer matrix can undergo some changes and contribute to the overall magnetism of the resulting composite.

[Image: see text] Kratom is widely consumed in the United States for self-treatment of pain and opioid withdrawal symptoms. Mitragynine is the most abundant alkaloid in kratom and is a μ-opioid receptor agonist. 7-Hydroxymitragynine (7-HMG) is a mitragynine metabolite that is a more potent and efficacious opioid than its parent mitragynine. 7-HMG contributes to mitragynine’s antinociceptive effects in mice, but evidence suggests it may also have a higher abuse potential. This in vitro study demonstrates that 7-HMG is stable in rodent and monkey plasma but is unstable in human plasma. Surprisingly, in human plasma 7-HMG is converted to mitragynine pseudoindoxyl, an opioid that is even more potent than either mitragynine or 7-HMG. This novel metabolite is formed in human plasma to a much greater extent than in the preclinical species tested (mouse, rat, dog, and cynomolgus monkey) and due to its μ-opioid potency may substantially contribute to the pharmacology of kratom in humans to a greater extent than in other tested species.

Mitragynine is the most abundant psychoactive alkaloid derived from the leaves of Mitragyna speciosa (kratom), a tropical plant indigenous to regions of Southeast Asia. Mitragynine displays a moderate affinity to opioid receptors, and kratom is often self-prescribed to treat pain and/or opioid addiction. The purpose of this study was to investigate the safety and pharmacokinetic properties of mitragynine in the dog. Single dose oral (5 mg/kg) and intravenous (0.1 mg/kg) pharmacokinetic studies of mitragynine were performed in female beagle dogs. The plasma concentrations of mitragynine were measured using ultra-performance liquid chromatography coupled with a tandem mass spectrometer, and the pharmacokinetic properties were analyzed using non-compartmental analysis. Following intravenous administration, mitragynine showed a large volume of distribution (Vd, 6.3 ± 0.6 L/kg) and high clearance (Cl, 1.8 ± 0.4 L/h/kg). Following oral mitragynine dosing, first peak plasma (Cmax, 278.0 ± 47.4 ng/mL) concentrations were observed within 0.5 h. A potent mu-opioid receptor agonist and active metabolite of mitragynine, 7-hydroxymitragynine, was also observed with a Cmax of 31.5 ± 3.3 ng/mL and a Tmax of 1.7 ± 0.6 h in orally dosed dogs while its plasma concentrations were below the lower limit of quantification (1 ng/mL) for the intravenous study. The absolute oral bioavailability of mitragynine was 69.6%. Administration of mitragynine was well tolerated, although mild sedation and anxiolytic effects were observed. These results provide the first detailed pharmacokinetic information for mitragynine in a non-rodent species (the dog) and therefore also provide significant information for allometric scaling and dose predictions when designing clinical studies.

Isoquinolines react with secondary phosphine oxides without catalyst (70–75 °C, 10–15 h, without solvent or in MeCN) to chemo- and regioselectively form previously unknown diadducts, 1,3-bis(diorganylphosphoryl)-1,2,3,4-tetrahydroisoquinolines, in high yields (85–95%).

The present work evaluates a multilayer structure based on epoxy resin for stealth technology. The structure consists of two absorber layers with nanoferrite and a resistive layer between them containing polyaniline (PANI) with and without carbon nanotube (CNT). The best reflection loss result multilayer structure analyzed was Ni-PANICNT-Fe with RL = –22dB at 11,9 GHz, justified by higher conductivity loss due to the CNT in PANI epoxy composite.

Although in sediments of Lake Baikal process of anaerobic oxidation methane was revealed by radioisotope techniques, by of the methane profile we know a little about the microorganisms carrying out this process. Here we studied diversity of archaeal communities in different types geological structures (methane seeps and mud volcano) on Lake Baikal with different composition of pore waters and the discharged fluid. In investigate were used different methods molecular biology including of high-throughput sequencing of gene 16S rRNA and PCR analysis different genes of AOM (mcrA). Molecular analysis did not reveal methane-oxidizing archaea ANME-1, -2, or -3, which are responsible for anaerobic oxidation of methane in marine sediments. Hydrogenotrophic methanogenic archaea representatives of the orders Methanomicrobiales, Methanococcales, as well as acetoclastic methanogens of the order Methanosarsinales were abundant in a mud volcano at Lake Baikal. In investigation sites we found divers M. nitroreducens-like archaea (ANME-2d subcluster) both in deep sediments of a methane seeps and in a mud volcanoes. Their closest homologues involved in process anaerobic oxidation of methane in different freshwater systems, bioreactors, paddy field soils.

Water purity was assessed at the site of a deep oil seepage near Cape Gorevoy Utes (Central Baikal). Polycyclic aromatic hydrocarbons (PAHs) and n-alkanes were determined in different types of oil-containing samples collected at this section of Lake Baikal. The set of studied samples included: (i) samples of water from the surface water layer; (ii) samples of water from different depths; (iii) oil on the water surface; (iv) oil from a sediment core. In the surface water layer and the water column, the total concentration of n-alkanes ranged from 0.2 to 5.3 µg/L and did not exceed the 0.1 maximum permissible concentration (MPCfish = 50 µg/L) established for hydrocarbons in water bodies of fishery importance. PAHs with carcinogenic properties were less than 0.1 ng/L. The total concentration of PAHs found in the water column did not exceed 110 ng/L; toxic equivalent (TEQ) values ranged from 0.001 to 0.110 ng/L. The distribution of petroleum hydrocarbons from the seepage site was limited, and water pollution was localised. The low level of water pollution is associated with natural mechanisms in the Baikal ecosystem. Microbiological community and phytoplankton make a decisive contribution to the purity of Baikal water, and oil fractionation during deep discharge contributes to the bioavailability of petroleum hydrocarbons.

Kratom alkaloids have mostly been evaluated for their opioid activity but less at other targets that could contribute to their physiological effects. Here, we investigated the in vitro and in vivo activity of kratom alkaloids at serotonin receptors (5-HTRs). Paynantheine and speciogynine exhibited high affinity for 5-HT(1A)Rs and 5-HT(2B)Rs, unlike the principal kratom alkaloid mitragynine. Both alkaloids produced antinociceptive properties in rats via an opioid receptor-independent mechanism, and neither activated 5-HT(2B)Rs in vitro. Paynantheine, speciogynine, and mitragynine induced lower lip retraction and antinociception in rats, effects blocked by a selective 5-HT(1A)R antagonist. In vitro functional assays revealed that the in vivo 5-HT(1A)R agonistic effects may be due to the metabolites 9-O-desmethylspeciogynine and 9-O-desmethylpaynantheine and not the parent compounds. Both metabolites did not activate 5-HT(2B)R, suggesting low inherent risk of causing valvulopathy. The 5-HT(1A)R agonism by kratom alkaloids may contribute to the mood-enhancing effects associated with kratom use.

The global climate change is related with greenhouse gas emission from cultivated soils – carbon dioxide, methane and nitrous oxide. The emissions of N2O also have negative influence on ozone layer of our planet. The major source of the nitrous oxide is denitrification process in soil, which controlled by specific soil microbe society. The pot experiment with flooding to accelerate the denitrification process and the application of the monosilicic acid as a source of soluble form of Si was carried out with barley. Several forms of nitrous oxide emission (unlimited carbon denitrification and potential denitrification with or without ethylene application) were measured. The obtained data showed that the application of monosilicic acid to brown soil when growing barley under conditions of soil flooding has a significant effect on nitrogen emission and can change the N2O:N2 ratio. The application of the monosilicic acid reduced the uC-D N2O emission, while increased the PD N emission. Generally the application of the water soluble Si decreased the N2O:N2 ratio. We suggested that the presence of monosilicic acid in the system provides a more complete denitrification process with the formation of N2 in the NO3− → NO2− → NO→N2O → N2 reaction sequence, while the deficiency of bioactive Si mainly provides the formation and emission of N2O. Considering that N2 is not a greenhouse gas, we can conclude that application of monosilicic acid to the soil can reduce greenhouse gas emissions and reduce the impact of global climate change on agricultural activity.

Introduction. One of medical-social chronic consequences of diabetes mellitus is encephalopathy, with an advancing course and development of neurodegenerative disorders in the central nervous system. Objective: to examine carbacetam effect as a new modulator of gamma-aminobutyric acid activity on protein peroxide oxidation and morphological condition of the cerebral cortex and hippocampus in rats under conditions of experimental neurodegeneration in case of type 2 diabetes mellitus. Materials and methods. Changes in the content of protein peroxide oxidation in the cerebral cortex and hippocampus under effect of carbacetam (5 mg/kg) are examined in nonlinear laboratory albino male rats with neurodegeneration under conditions of type 2 diabetes mellitus simulated by streptozotocin and high-fat diet. Results. In rats with type 2 diabetes mellitus, the degree of protein peroxide oxidation in the cerebral cortex and hippocampus increases, which is associated with increased amount of cells with karyopyknosis, decreased relative density of staining of the neuron tigroid substance and partial denudation of vessels. After carbacetam administration during 14 days in rats with type 2 diabetes mellitus in the cerebral cortex and hippocampus the level of protein peroxide oxidation decreases, the amount of cells with karyopyknosis reduces, a relative density of staining of the neuron tigroid substance increases, and denudation of vessels is lacking. Conclusions. Decreased intensity of the protein peroxide oxidation processes, histological destruction of the cerebral cortex and hippocampus are indicative of a neuroprotective potential of carbacetam under conditions of neurodegeneration caused by type 2 diabetes mellitus.

Kratom (Mitragyna speciosa) is a psychoactive plant popular in the United States for the self-treatment of pain and opioid addiction. For standardization and quality control of raw and commercial kratom products, an ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed and validated for the quantification of ten key alkaloids, namely: corynantheidine, corynoxine, corynoxine B, 7-hydroxymitragynine, isocorynantheidine, mitragynine, mitraphylline, paynantheine, speciociliatine, and speciogynine. Chromatographic separation of diastereomers, or alkaloids sharing same ion transitions, was achieved on an Acquity BEH C18 column with a gradient elution using a mobile phase containing acetonitrile and aqueous ammonium acetate buffer (10mM, pH 3.5). The developed method was linear over a concentration range of 1-200 ng/mL for each alkaloid. The total analysis time per sample was 22.5 minutes. The analytical method was validated for accuracy, precision, robustness, and stability. After successful validation, the method was applied for the quantification of kratom alkaloids in alkaloid-rich fractions, ethanolic extracts, lyophilized teas, and commercial products. Mitragynine (0.7%-38.7% w/w), paynantheine (0.3%-12.8% w/w), speciociliatine (0.4%-12.3% w/w), and speciogynine (0.1%-5.3% w/w) were the major alkaloids in the analyzed kratom products/extracts. Minor kratom alkaloids (corynantheidine, corynoxine, corynoxine B, 7-hydroxymitragynine, isocorynantheidine) were also quantified (0.01%-2.8% w/w) in the analyzed products; however mitraphylline was below the lower limit of quantification in all analyses.

The research was aimed at detection of thermophilic microorganisms in Lake Baikal low-temperature sediments associated with discharge of gas-saturated fluids. Members of the order Clostridiales were revealed in enrichment cultures obtained from the bottom sediments at three sites (methane seep, oil-methane seep, and mud volcano). No thermophilic prokaryotes were found in the enrichment culture with sediment samples from a background area. The presence of thermophilic microorganisms at the sites of hydrocarbon discharge may result from their migration to the bottom surface with the gas-bearing mineralized fluid moving along the fracture zones. Unlike marine cold sediments, where the endospores of thermophilic bacteria belong to strict anaerobes existing due to fermentation of organic substrates or sulfate reduction, Lake Baikal sediments associated with discharge of gas-saturated fluids were found to contain facultatively anaerobic thermophilic prokaryotes.

Bioactive silver-containing (Ag content of about 6.8–8.2 wt %) polymer complexes based on the synthetic homopolymer of 1-vinyl-1,2,4-triazole and its copolymers have been synthesized and characterized. Structural features of macromolecular complexes were studied by magnetic resonance techniques (EPR, NMR) and other analytical methods (FTIR, SEM, UV–vis, atomic absorption analysis, etc.). The spatial structure of the polymer chain fragment and silver ion/1-vinyl-1,2,4-triazole complexes were investigated by quantum-chemical calculations. The formation of coordinatively saturated polymer complexes of Ag(I) and highly oxidized forms of Ag(II) silver was analyzed. The sites of ions localization and reduced metallic silver in the structure of the polymer matrix were determined.

The development of special autoclaves with automatic temperature control (Nikolaev Institute of Inorganic Chemistry) had enabled reproduction of Lake Baikal tectonically active zone typical conditions (80°C, 5 MPa). This article describes in details the equipment developed and demonstrates some results obtained using the equipment. In series of thermobaric experiments on the cultivation of bottom sediment microbial communities, we have determined the microbial community potential to transform organic matter via the formation of dibenzothiophenes, tri- and monoaromatic steroids as well as petroleum biomarkers (retene and gammacerene). The particular bottom sediment geochemical environment associated with hydrocarbon discharge imply the composition of microbial communities and, hence, the organic matter transformation degree as well as a compound spectrum resulting from the destruction of organic matter under thermobaric conditions. The presence of microorganisms with an unusual metabolism suggests the promising potential for such studies both in application to Lake Baikal and worldwide.

The objective of the study was to investigate the changes of the kidney functions in mature rats with rapid acetylation type, under conditions of subacute cadmium-nitrate intoxication and preventive introduction of Echinacea purpurea. Methods. Male rats, 6 months of age, with rapid acetylation type, were divided into 3 groups: І – control; ІІ – rats with of subacute cadmium-nitrate intoxication model; ІІІ – rats receiving intragastric alcohol tincture of fresh rhizomes with roots of Echinacea purpurea (LC “State Municipal Enterprise “Pharmaceutical Plant Vishpha””, Ukraine; 0,25 mk/rg). Results. Under the effect of preventive introduction of Echinacea purpurea in rats with rapid acetylation type and cadmium-nitrate lesion of the kidneys, diuresis and glomerular filtration rate became normal; distal transport of sodium ions increased; hyponatraemia and decreased natriuresis remained without changes; concentrations of creatinine in the blood plasma, potassium ions in the blood plasma and urine, kaliuresis decreased. Similar to the group of rats without Echinacea purpurea, proximal reabsorption of sodium ions, which is standardized by glomerular filtration, decreased. Conclusion. Under conditions of preventive introduction of Echinacea purpurea, volume regulating kidney function is maintained in mature rats with rapid acetylation type and subacute cadmium-nitrate intoxication, but it does not prevent the development of toxic nephropathy, with prevailing lesion of the nephron proximal portion, disorders of ion regulating kidney function and water-electrolytic balance.

BACKGROUND AND OBJECTIVES: 7-Hydroxymitragynine (7-HMG) is an oxidative metabolite of mitragynine, the most abundant alkaloid in the leaves of Mitragyna speciosa (otherwise known as kratom). While mitragynine is a weak partial μ-opioid receptor (MOR) agonist, 7-HMG is a potent and full MOR agonist. It is produced from mitragynine by the cytochrome P450 (CYP) 3A, a drug-metabolizing CYP isoform predominate in the liver that is also highly expressed in the intestine. Given the opioidergic potency of 7-HMG, a single oral dose pharmacokinetic and safety study of 7-HMG was performed in beagle dogs. METHODS: Following a single oral dose (1 mg/kg) of 7-HMG, plasma samples were obtained from healthy female beagle dogs. Concentrations of 7-HMG were determined using ultra-performance liquid chromatography coupled with a tandem mass spectrometer (UPLC-MS/MS). Pharmacokinetic parameters were calculated using a model-independent non-compartmental analysis of plasma concentration-time data. RESULTS: Absorption of 7-HMG was rapid, with a peak plasma concentration (C(max), 56.4 ± 1.6 ng/mL) observed within 15 min post-dose. In contrast, 7-HMG elimination was slow, exhibiting a mono-exponential distribution and mean elimination half-life of 3.6 ± 0.5 h. Oral dosing of 1 mg/kg 7-HMG was well-tolerated with no observed adverse events or significant changes to clinical laboratory tests. CONCLUSIONS: These results provide the first pharmacokinetic and safety data for 7-HMG in the dog, and therefore contribute to the understanding of the putative pharmacological role of 7-HMG resulting from an oral delivery of mitragynine from kratom.

Kratom, Mitragyna speciosa Korth., is being widely consumed in the United States for pain management and the reduction of opioid withdrawal symptoms. The central nervous system (CNS) active alkaloids of kratom, including mitragynine, 7-hydroxymitragynine, and numerous additional compounds, are believed to derive their effects through opioid receptor activity. There is no literature describing the systemic exposure of many of these alkaloids after the consumption of kratom. Therefore, we have developed and validated a bioanalytical method for the simultaneous quantitation of 11 kratom alkaloids (mitragynine, 7-hydroxymitragynine, corynantheidine, speciogynine, speciociliatine, paynantheine, corynoxine, corynoxine-B, mitraphylline, ajmalicine, and isospeciofoline) in rat plasma. The validated method was used to analyze oral pharmacokinetic study samples of lyophilized kratom tea (LKT) and a marketed product, OPMS liquid shot, in rats. Among the 11 alkaloids, only mitragynine, 7-hydroxymitragynine, speciociliatine, and corynantheidine showed systemic exposure 8 h postdose, and the dose-normalized systemic exposure of these four alkaloids was higher (1.6-2.4-fold) following the administration of the commercial OPMS liquid. Paynantheine and speciogynine levels were quantifiable up to 1 h postdose, whereas none of the other alkaloids were detected. In summary, the method was successfully applied to quantify the exposure of individual kratom alkaloids after an oral dose of traditional or commercial products. This information will contribute to understanding the role of each alkaloid in the overall pharmacology of kratom and elucidating the pharmacokinetic differences between traditional and commercial kratom products.

Methane production by microbial communities from Lake Baikal bottom sediments with different chemical composition of pore water was studied. Methane production was more active in the media supplemented with H2: CO2 and H2 + CH3COONa, rather than on media with acetate as the sole source of carbon and energy. Addition of methanol stimulated methane production only in the case of microbial communities from upper silts. Ability of the communities to produce methane correlated reliably with the concentrations of the NO3–, SO42−, Cl–, and CH3COO– ions in the pore water of the relevant sediments. Cultivation of communities from the mud volcano sediments resulted in development of methanogenic archaea of the family Methanocellaсеае in the media supplemented with H2: CO2 and H2 + CH3COONa, while methanogenic archaea in the communities cultivated without additional substrates belonged to the genera Methanoregula, Methanobacterium, and Methanosaeta.

Under laboratory conditions, the microbial communities of bottom sediments of a mud volcano Peschanka (Lake Baikal) were found to carry out anaerobic methane oxidation (AOM). After 16 days of anaerobic cultivation of the enrichment cultures, methane content in the gas phase decreased, and microbial consortia were established. The content of carbon, nitrogen, and oxygen determined by energy dispersive X-ray spectroscopy (EDS) was higher than in the nearby sediment particles. The presence of bacteria of the NC10 phylum and archaea of the ANME-2d cluster was established by fluorescent in situ hybridization (FISH).

Bottom sediments were studied from 10 central sites within the pelagic zone of the three basins of Lake Baikal, and 16 sites in other regions of the lake. The composition of pore waters in the first two meters of the sedimentary cover was analyzed at 1–3 cm intervals. It was established that the salt composition of pore waters in the sediments was uniform across the entire lake. Background concentrations of each ion in the pore waters was determined from equations using concentration data profiles obtained from all sites of the three lake basins (1250 samples at 26 sites within the entire lake). Similar to the lake waters, background pore waters of Lake Baikal were dominated by calcium bicarbonate with low mineralization. The total concentration of ions in pore waters increased with depth during diagenetic transformations as did the concentrations of bicarbonate and calcium ions. Biogeochemical processes that affect the chemical composition of pore water in Lake Baikal sediments are discussed.

The mechanism of polysaccharide arabinogalactan sulfation was studied. Potassium persulfate in dimethyl sulfoxide was used as a sulfating agent. Sulfation of the biopolymer proceeds via its reaction with the SO3—DMSO complex, which is formed upon the reduction of the persulfate anion in DMSO.

The phosphine, generated together with hydrogen from red phosphorus and aqueous KOH, reacts with 1-bromonaphthalene in the t -BuOK/DMSO system under mild conditions (70 °C, atmospheric pressure) to give di(1-naphthyl)phosphine, which is easily oxidized in the presence of air to afford di(1-naphthyl)phosphine oxide in 45% preparative yield. Tri(1-naphthyl)phosphine and naphthalene are also formed in the reaction in 23 and 27% yield, respectively. According to ESR and UV data, the studied phosphination of 1-bromonaphthalene involves a single electron transfer process.

This study aimed to analyze the relationship between chlorophyll potential, chlorophyll content, and grain yield of different wheat cultivars by using ground remote sensing and laboratory data. Chlorophyll potential is the difference between the reflectance factor integrals with and without chlorophyll absorption (in the 550–730 nm wavelength range). Ground-truth data were obtained at the experimental fields located in the Krasnoyarsk region, Russia (2002–2012). Experiments were conducted in different seasons under various lighting conditions by controlling plants states and soil types. Spectral measurements were obtained using a double-beam spectroradiometer, which was installed on a mobile work platform at a height of 5–18 m. The photometric area varied from 0.5 to 2 m 2 . The study showed good correlation (R 2 = 0.9) between chlorophyll potential and chlorophyll content for different wheat cultivars. However, the correlation between chlorophyll potential and grain yield was less (R 2 = 0.8). The values of chlorophyll potentials depended on the type of wheat during the growing season. The novelty of the approach is that it calculates the chlorophyll potential with additional spectral regions when compared with normalized difference vegetation index. We used a spectroradiometer with high spectral resolution. This increased the accuracy and stability of measurements in rapidly changing conditions.

The results of the assessment of the relationship between the chlorophyll content, crop yield and chlorophyll potential of crops of wheat, barley, and oat are presented. The results of a ground-based remotesensing technique and laboratory data were used to accomplish this assessment. The spectral reflectance data of agricultural crops obtained using a ground-based remote-sensing technique in the Krasnoyarsk region were used to calculate the chlorophyll potential. Long-standing experiments have been carried out in different seasons, under various lighting conditions. Spectral measurements were performed using a double-beam spectroradiometer, which was installed on a mobile work platform at a height from 5 to 18 m. A good correlation between the chlorophyll content, grain yield, and chlorophyll potential of different cultivars of wheat, barley, and oat has been shown. It was also shown that the values of chlorophyll potential are different for wheat, barley, and oat cultivars in the growing season.

Three new spin probes containing polyamine chains (2 or 3 nitrogen atoms) and nitroxide were synthesized. These compounds are stable in aqueous media at pH 5–10, and shape and intensity of their ESR spectra do not depend on pH in this range. The involvement of the spin probes in association in solution results in decrease of the spin mobility which appears as spectral anisotropy. The polyamine spin probes bind to siliceous nanoparticles in solution resulting in a reversible decrease in spectral intensity. These observations open a new way for monitoring silicic acid condensation. Sorption of the spin probes on solid silica gives rise to anisotropic spectra. The polyamine spin probes penetrate into growing cells of diatom algae in a similar manner to polyamine-containing fluorescent dyes.

In vitro cytochrome P450 inhibition of major kratom alkaloids: mitragynine (MTG), speciogynine (SPG), speciocilliatine (SPC), corynantheidine (COR), 7-hydroxymitragynine (7HMG) and paynantheine (PAY) was evaluated using human liver microsomes (HLMs) to understand their drug-drug interaction potential. CYP450 isoform-specific substrates of CYP1A2, 2C8, 2C9, 2C19, 2D6, and 3A4/5 were incubated in HLMs with or without alkaloids. Preliminary CYP450 inhibition (IC(50)) data were generated for each of these isoforms. In addition, the type of inhibition and estimation of the inhibition constants (K(i)) of MTG and COR were determined. Among the tested alkaloids, MTG and COR were potent inhibitors of CYP2D6 (IC(50), 2.2 and 4.2 μM, respectively). Both MTG and COR exhibited competitive inhibition of CYP2D6 activity and the K(i) were found to be 1.1 and 2.8 μM, respectively. SPG and PAY showed moderate inhibition of CYP2D6 activity. Additionally, moderate inhibitory effects by SPC, MTG, and SPG were observed on CYP2C19 activity. Interestingly, inhibition of only midazolam hydroxylase CYP3A4/5 activity by COR, PAY, and MTG was observed while no inhibitory effect was observed when testosterone was used as a probe substrate. In conclusion, MTG and COR may lead to clinically significant adverse drug interactions upon coadministration of drugs that are substantially metabolized by CYP2D6.

During development, growth cones are essential for axon pathfinding by sensing numerous guidance cues in their environment. Retinoic acid, the metabolite of vitamin A, is important for neurite outgrowth during vertebrate development, but may also play a role in axon guidance, though little is known of the cellular mechanisms involved. Our previous studies showed that retinoid-induced growth cone turning of invertebrate motorneurons requires local protein synthesis and calcium influx. However, the signalling pathways that link calcium influx to cytoskeletal dynamics involved in retinoid-mediated growth cone turning are not currently known. The Rho GTPases, Cdc42 and Rac, are known regulators of the growth cone cytoskeleton. Here, we demonstrated that inhibition of Cdc42 or Rac not only prevented growth cone turning toward retinoic acid but could also induce a switch in growth cone responsiveness to chemorepulsion or growth cone collapse. However, the effects of Cdc42 or Rac inhibition on growth cone responsiveness differed, depending on whether the turning was induced by the all-trans or 9-cis retinoid isomer. The effects also differed depending on whether the growth cones maintained communication with the cell body. These data strongly suggest that Cdc42 and Rac are downstream effectors of retinoic acid during growth cone guidance.

Highlights • We have synthesized a wide range of tris-(2-hydroxyethyl)ammonium arylchalcogenylacetates, “protatranes”. • “Protatranes” are growth stimulators of hydrocarbon-oxidizing Rhodococcus erythropolis bacteria isolated from Lake Baikal. • The effect of “protatranes” on growth of Pseudomonas fluorescens is less obvious. • The effect of stimulants on Rhodococcus erythropolis is likely due to the structure of protatranes and the cell wall of bacteria., Under natural conditions, biodegradation processes proceed slowly, especially in regions with low temperature. To activate vital processes in hydrocarbon-oxidizing microorganisms at low temperatures, biologically active compounds can be employed as growth stimulants. A low-temperature (10 °C) study has shown that tris-(2 hydroxyethyl) ammonium arylchalcogenylacetates, “protatranes” exert an effect on the growth of hydrocarbon-oxidizing strains of Rhodococcus erythropolis and Pseudomonas fluorescens, isolated from natural oil seepage on Lake Baikal. It has been found that “protatranes”, at microconcentrations, increase the growth rate of R. erythropolis bacteria by 2–16 times. It has been established that compounds slightly effect the growth of P. fluorescens. The positive effect of “protatranes” compounds on the growth rate of hydrocarbon-oxidizing microorganisms at low positive temperatures can be used for the development of environmentally benign methods for the restoration of natural objects after their contamination with oil.

1. Mitragynine is the major indole-based alkaloid of Mitragyna speciosa (kratom). Decoctions (teas) of the plant leaves have been used traditionally for cough, diarrhoea, pain, hypertension and for the treatment of opioid addiction. In the West, kratom has become increasingly utilized for mood elevation, pain treatment and as a means of self-treating opioid addiction. 2. Metabolic pathways of mitragynine were identified in human liver microsomes (HLM) and S9 fractions. A total of thirteen metabolites were identified, four oxidative metabolites and a metabolite formed by demethylation at the 9-methoxy group were the major metabolites of mitragynine. 3. The cytochrome P450 enzymes involved in the metabolism of mitragynine were identified using selective chemical inhibitors of HLM and recombinant cytochrome P450. The metabolism of mitragynine was predominantly carried out through the CYP3A4 with minor contributions by CYP2D6 and CYP2C9. The formation of five oxidative metabolites (Met2, Met4, Met6, Met8 and Met11) was catalyzed by the CYP3A4. 4. In summary, mitragynine was extensively metabolized in HLM primarily to O-demethylated and mono-oxidative metabolites. The CYP3A4 enzyme plays a predominant role in the metabolic clearance of mitragynine and also in the formation of 7-hydroxymitragynine (Met2), a known active minor alkaloid identified in the leaf material.

Insoluble silver-containing nanocomposites based on 1-vinyl-1,2,4-triazole and acrylonitrile copolymer was synthesized and characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, atomic absorption, X-ray diffraction, and thermogravimetric data analysis. The silver content of the nanocomposites varied from 8.0 to 23.5% (the silver content depends on the ratio of the copolymer-silver salt). Synthesis of silver nanocomposites was carried out by thermal treatment of a polymer complex of copolymer-silver salt without the use of an additional reducing agent. X-ray diffraction was used to control the formation of silver nanoparticles at different temperatures (210°С, 220°С, and 250°С). Synthesis of nanocomposites shows a developed porous structure with a channel diameter in most cases of 1-4 microns. The EPR monitoring of the nanoparticle germination and growth reveals that the generation of the nanocomposites proceeds via a stage of complex formation between the polymeric matrix and silver ions. The synthesized nanocomposites possess paramagnetic properties and show a narrow EPR symmetric signal with the concentration of unpaired electrons of 1020 spin/g, a g-factor 2.0050, and signal width 5-6 Gs. Thermal stability of silver-containing nanocomposites is up to 270-320°C.

Retinoic acid (RA), the active metabolite of vitamin A, functions through nuclear receptors, one of which is the retinoic acid receptor (RAR). Though the RAR is essential for various aspects of vertebrate development, little is known about the role of RAR in nonchordate invertebrates. Here, we examined the potential role of an invertebrate RAR in mediating chemotropic effects of retinoic acid. The RAR of the protostome Lymnaea stagnalis is present in the growth cones of regenerating cultured motorneurons, and a synthetic RAR agonist (EC23), was able to mimic the effects of retinoic acid in inducing growth cone turning. We also examined the ability of the natural retinoids, all-trans RA and 9-cis RA, as well as the synthetic RAR agonists, to disrupt embryonic development in Lymnaea. Developmental defects included delays in embryo hatching, arrested eye, and shell development, as well as more severe abnormalities such as halted development. Developmental defects induced by some (but not all) synthetic RAR agonists were found to mimic those induced by addition of high concentrations of the natural retinoid isomers. These pharmacological data support a possible physiological role for the RAR in axon guidance and embryonic development of an invertebrate protostome species.

Speciociliatine is a minor indole alkaloid found in kratom, a southeast Asian medicinal plant, used for centuries to increase energy, enhance mood, and mitigate pain and opioid dependence. An ultra-performance liquid chromatography tandem mass spectrometry method was developed and validated to quantify speciociliatine in rat plasma. The quantitation range was 3-600 ng/mL. The validated method was applied to a preclinical pharmacokinetic study in male Sprague-Dawley rats after 2.5 mg/kg intravenous (I.V.) and 20 mg/kg oral (P.O.) dosing. The plasma was analyzed to obtain concentration-time profiles and results were subjected to non-compartmental analysis to determine pharmacokinetic parameters including volume of distribution (6.2 ± 2.3 L/kg I.V.), clearance (0.7 ± 0.2 L/hr/kg), and absolute oral bioavailability (20.7 %). Speciociliatine had higher systemic exposure and lower clearance compared to the other kratom alkaloids mitragynine and corynantheidine. The speciociliatine pharmacokinetic parameters described here will help to better understand the overall effects reported with kratom product use.

Fullerene C60 reacts with phosphine (PH3) under free radical initiation conditions (azobis(isobutyronitrile), xylene, 65°C, 6–11 h) to give in the presence of air oxygen functional oligofullerenes (yield up to 32%) containing functional groups of phosphinic and phosphonic acids.

The first representatives of a previously unknown class of highly reactive functionalized pyrrole compounds, 3-(pyrrol-2-yl)propiolaldehydes, have been synthesized by the transition metal-free, mechanoactivated ethynylation of pyrroles with 3-iodopropiolaldehyde using a solid K 2 CO 3 medium under mild conditions (room temperature, 4 h) in yields of up to 71%.

The oligomerization of N-vinylpyrroles (N-vinyl-4,5,6,7-tetrahydroindole, N-vinyl-2-[1-(1-4,5,6,7-tetrahydroindole)ethyl]-4,5,6,7-tetrahydroindole, N-vinyl-2-phenylpyrrole, N-vinyl-3-heptyl-2-phenylpyrrole, N-vinyl-2,3-diphenylpyrrole, and N-vinyl-2-(2-naphthyl)pyrrole) under the action of iodine vapor leads to the formation of iodine-containing oligomers with an iodine content of 17–52% and a yield of up to 99%. The oligomers are paramagnetic and possess conductivity; they are readily soluble in organic solvents (benzene, dioxane, and chloroform) and are stable up to 110–260°C.

Early diagenesis of organic matter in bottom sediments of Lake Baikal is a focus of many geochemical studies, because it is one of the few sites of petroleum formation in a nonmarine environment. Although Baikal is a rift lake and considered one of the prospective fields for deep biosphere investigations, the transformation processes of organic matter by microbial communities from deep bottom sediments and likely entering of the microorganisms from deep sediments into the near-surface sediments were not previously studied in Lake Baikal. The natural microbial community from near-surface sediments of the cold methane seep Goloustnoe (Southern Baikal Basin) was incubated with methane and the diatom Synedra acus at 80°C and 49.5 atm to simulate catagenesis. The 11-month incubation yielded the enrichment culture of viable thermophilic microorganisms. Their presence in low-temperature sediment layers may be indicative of their migration through fault zones together with gas-bearing fluids. After cultur...

The effects of high-intensity light (HIL) on the activity of photosystem II (PSII) and photosynthesis in wild-type (WT) and single (phyB2, phyB1, phyA and cry1), double (phyB1B2, phyAB2 and phyAB1) and triple (phyAB1B2 and cry1phyAB1) mutants of Solanum lycopersicum were studied. In addition, changes in the activity of the antioxidant enzymes ascorbate peroxidase, glutathione reductase and guaiacol peroxidase as well as the photosynthetic pigment and anthocyanin contents in the leaves of phyB2 and cry1phAB1 mutants under HIL were examined. When plants were irradiated with HIL (2 h), the PSII resistance of the cry1phyAB1 mutant was the lowest, while the resistance of WT and single mutants excluding cry1 was the highest. The effect of HIL on PSII activity in all double mutants and the phyAB1B2 mutant was intermediate between the effects on the WT and the cry1phyAB1 mutant. The intensity of oxidative processes in the cry1phyAB1 mutant was higher than that in WT and phyB2, but in cry1phyAB1, the activity of antioxidant enzymes and the anthocyanin content were lower. The low resistance of the cry1phyAB1 mutant to HIL may be due to the low antioxidant activity of key enzymes and the reduced pigment content, which are consistent with the reduced expression of CHS and sAPX genes in the cry1phyAB1 mutant.

Anaerobic oxidation of methane (AOM) reduces methane emissions from marine ecosystems, but we know little about AOM in freshwater reservoirs. Lake Baikal is the world&rsquo, s only freshwater reservoir where gas hydrates (GH) are found. Despite that AOM has been demonstrated in deep sediments of Lake Baikal did not reveal methane-oxidizing archaea ANME1, 2, or 3, which are responsible for AOM in marine sediments. A search for representatives Candidatus Methylomirabilis oxyfera (M. oxyfera)-like bacteria (NC10) and Candidatus Methanoperedens nitroreducens (M. nitroreducens)-like archaea (ANME-2d) has been carried out in the different types of Lake Baikal methane enriched sediments. We used different molecular biology methods including high-throughput sequencing and PCR analysis, using 16S rRNA genes as well as different functional genes of AOM (mcrA and pmoA). We found diverse M. oxyfera-like bacteria and M. nitroreducens-like archaea in various geological structures in Lake Baikal (methane seep and mud volcano), which were different from the composition of the discharged fluid. We also considered possible electron acceptors for this process in the sediments of Lake Baikal.

Recent studies suggest both beneficial and detrimental role of increased reactive oxygen species and oxidative stress in heart failure (HF). However, it is not clear at which stage oxidative stress and oxidative modifications occur in the endothelium in relation to cardiomyocytes in non-ischemic HF. Furthermore, most methods used to date to study oxidative stress are either non-specific or require tissue homogenization. In this study, we used immuno-spin trapping (IST) technique with fluorescent microscopy-based detection of DMPO nitrone adducts to localize and quantify oxidative modifications of the hearts from Tgαq*44 mice; a murine model of HF driven by cardiomyocyte-specific overexpression of Gαq* protein. Tgαq*44 mice and age-matched FVB controls at early, transition, and late stages of HF progression were injected with DMPO in vivo and analyzed ex vivo for DMPO nitrone adducts signals. Progressive oxidative modifications in cardiomyocytes, as evidenced by the elevation of DMPO nitrone adducts, were detected in hearts from 10- to 16-month-old, but not in 8-month-old Tgαq*44 mice, as compared with age-matched FVB mice. The DMPO nitrone adducts were detected in left and right ventricle, septum, and papillary muscle. Surprisingly, significant elevation of DMPO nitrone adducts was also present in the coronary endothelium both in large arteries and in microcirculation simultaneously, as in cardiomyocytes, starting from 10-month-old Tgαq*44 mice. On the other hand, superoxide production in heart homogenates was elevated already in 6-month-old Tgαq*44 mice and progressively increased to high levels in 14-month-old Tgαq*44 mice, while the enzymatic activity of catalase, glutathione reductase, and glutathione peroxidase was all elevated as early as in 4-month-old Tgαq*44 mice and stayed at a similar level in 14-month-old Tgαq*44. In summary, this study demonstrates that IST represents a unique method that allows to quantify oxidative modifications in cardiomyocytes and coronary endothelium in the heart. In Tgαq*44 mice with slowly developing HF, driven by cardiomyocyte-specific overexpression of Gαq* protein, an increase in superoxide production, despite compensatory activation of antioxidative mechanisms, results in the development of oxidative modifications not only in cardiomyocytes but also in coronary endothelium, at the transition phase of HF, before the end-stage disease.

International audience; Early diagenetic carbonates are rare in Lake Baikal. Siderite (Fe carbonate) concretions in the sediments were discovered only recently. Here, we discuss the first finding of rhodochrosite concretions (Mn carbonate) discovered in the near-bottom sediments of the gas hydrate-bearing seepage structure St. Petersburg-2 in the deep water environment of the Central Baikal Basin. The crystal lattice of rhodochrosite contains iron and calcium substituting to manganese. Based on pore water geochemistry and of δ13C values of rhodochrosite (− 23.3 and − 29.4‰), carbon dioxide (+ 3.8 to − 16.1‰) and methane (− 63.2 to − 67.8‰), we show that carbonate crystallization most likely occurred during microbial anaerobic oxidation of organic matter, and that part of the oxygen making up the rhodochrosite seems to be derived from the 18O-rich water released from dissociating gas hydrates.

For the first time, a study has been performed on specific small biocenoses of bitumen mounds formed in the region of natural oil seeps in the abyssal zone of Lake Baikal. These biocenoses consist of diatom detritus populated by archaea, bacteria, aquatic fungi, nematodes, and ostracods. Fungi and bacteria decompose petroleum hydrocarbons, thereby contributing to biodegradation of crude oil. Microorganisms together with planktonic diatoms settling onto bitumen form a substrate for invertebrates. It is hypothesized that the cohabitation of three distinctive nematode species (Eutobrilus mirandus, Monhystera naphthera, and Eumonhystera abyssalis) in the same bitumen biocenosis is possible due to their different feeding strategies and the presence of bacterial symbionts.

Secondary phosphine chalcogenides react with diacetone-d-glucose (DAG) in the system CCl4/Et3N (70°C, 4–24 h) to afford DAG chalcogenophosphinates in up to 79% yield, thus paving a short way to optically active chalcogenophosphinates with glucose moieties. As an example, a mild regioselective hydrolysis (70°C, aqueous MeCOOH) of DAG bis(2-phenylethyl)selenophosphinate) obtained leads to monoacetone-d-glucose bis(2-phenylethyl)selenophosphinate.

Silver-containing nanocomposites based on sulfated arabinogalactan have been prepared under mild conditions. The products contain 2–12 nm silver nanoparticles stabilized by the polymer. The composites are readily water-soluble and reveal antimicrobial activity against a wide range of bacteria and fungi.