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Among the seven-membered ketals of pyridoxine containing hydroxymethyl groups in various positions of the pyridine ring, an unusual ability of selenium dioxide to catalyze the reaction of nucleophilic substitution of the hydroxyl group by N,O-nucleophiles was found. Quantum chemical calculations have shown the possibility of the formation of selenium dioxide adducts with substrates and the formation of reactive intermediates—ortho- and para-pyridinone methides. The antioxidant and antimycotic activity of the obtained compounds was determined. [ABSTRACT FROM AUTHOR]

The review considers new quaternary ammonium compounds based on pyridoxine derivatives, which were obtained and studied in 2013–2023 at the Research and Educational Center for Pharmacy of the Kazan (Volga Region) Federal University. Four structurally related classes of compounds are discussed, including mono- and bis-ammonium derivatives of pyridoxine, pyridoxine derivatives with cleavable linkers bearing an ammonium moiety, and ammonium derivatives of the unnatural pyridoxine mimetic, 3-hydroxypyridine. Synthetic schemes, biological properties, and key structure–activity relationships of the target structural series are described. For the lead-compounds belonging to specific structural chemotypes, a comprehensive profile of pharmacological properties is described, including antibacterial activity against a wide panel of Gram-positive and Gram-negative bacterial strains including clinical isolates; in vitro and in vivo toxicity; influence on the development of drug resistance. The mechanisms of action of the considered compounds as well as the prospects for their practical use are discussed. [ABSTRACT FROM AUTHOR]

An approach to the stereoselective oxidation of 5,6-bis(hydroxymethyl)-2,2,8-trimethyl-4H-[1,3]dioxino[4,5-c]pyridine and 5,6-bis(hydroxymethyl)-2,4-dimethyl-3-hydroxypyridine with manganese dioxide has been developed, intermediates and by-products have been isolated. In solutions, pyridoxine derivatives containing a carbaldehyde group exist in cyclic hemiacetal and open hydroxyaldehyde forms. [ABSTRACT FROM AUTHOR]

The oxidation of cage compounds derived from quinopimaric acid, namely γ-diketone, oxa-"bird cage," 18-chloro-15-oxa-"bird cage," and 16-sulfanyl-15-oxa-"bird cage," was studied using a number of oxidating agents, including sodium percarbonate in trifluoroacetic acid at 0°C, 36% hydrogen peroxide in acetone at room temperature, and tert-butyl hydroperoxide in the presence of MoCl5 in boiling benzene. It was shown for the first time that the oxidation of diterpene oxa-"bird cages" led to the formation of mixtures of keto lactones (Baeyer–Villiger oxidation products), in which 7,10-dioxo-6-oxaheptacyclo[11.8.0.03,8.04,12.05,11.09,13.016,21]heneicosane was the major component. [ABSTRACT FROM AUTHOR]

New linear hydrazinocarbonothioyl derivatives of maleopimarimides were synthesized in high yields by the interaction of acyl isothiocyanates of 2-allyl- and 2-benzylmaleopimarimides with acetohydrazide and hydrazide of 4-methoxybenzoic acid. 1,3,4-Thiadiazole derivatives were synthesized by boiling hydrazinocarbonothioyl derivatives of maleopimarimides with a catalytic amount of concentrated H2SO4 in ethanol. The structure of the synthesized compounds was determined using 1H,13C NMR, 1H–13C HSQC, 1H–13C HMBC, COSY, NOESY, and 1H-15N HMBC spectroscopy methods. [ABSTRACT FROM AUTHOR]

The reaction of acyl isothiocyanates of 2-allyl- and 2-benzylmaleopimarimides with ethyl-, benzylhydrazine, or ethyl ester of hydrazinoacetic acid leads to the formation of maleopimarimides containing the fragment of 5-thioxo-2,5-dihydro-1H-1,2,4-triazole. The structures of the synthesized compounds were determined by 1H, 13C, 1H–13C HSQC, 1H–13C HMBC, COSY, NOESY, and 1H-15N HMBC NMR spectroscopy methods. [ABSTRACT FROM AUTHOR]

Halophilic and halotolerant microorganisms have a high biotechnological potential. They are producers of biologically active substances, stress-protective agents, hydrolytic enzymes, and are used for environmental bioremediation. At the same time, the characterization of novel halotolerant bacteria and determination of their salt tolerance strategies are important basic problems. The present work reports the isolation of a new strain, MX2, from the salt well brine of the Yakshinskoe potassium−magnesium salt deposit. The isolate was an aerobic, gram-positive, nonmotile bacterium that did not form spores. The cell morphology varied from cocci to short rods capable of producing V-shaped forms. The colonies on agar were circular, with an entire edge and raised center, glistening and orange. Bacteria of strain MX2 were halotolerant microorganisms capable of growing at NaCl concentrations up to 9%. The genome of strain MX2 was sequenced. Its estimated size was 3 747 717 bp, and the number of protein-coding genes was 3562. Strain MX2 was identified as belonging to the species Dietzia maris based on analysis of the 16S rRNA, gyrB, rpoB, recA, and ppk gene sequences and using time-of-flight mass spectrometry (MALDI-TOF-MS). D. maris MX2 had complete metabolic pathways for the synthesis of ectoine, hydroxyectoine, and trehalose, as well as the transport systems for ectoine, hydroxyectoine, trehalose, glycerol, glycerol-3-phosphate, L-proline, and glycine-betaine. Thus, to ensure the osmotic balance, D. maris MX2 used the strategy of accumulating compatible organic solutes. [ABSTRACT FROM AUTHOR]

A new method for the synthesis of 6-hydroxypyridoxine and its seven-membered acetals has been developed. The synthesized compounds have high antioxidant activity, which is not inferior to the reference drugs, i.e., ascorbic acid and trolox. The seven-membered ketal of 6-hydroxypyridoxine effectively penetrates the cytoplasmic membrane of cells. [ABSTRACT FROM AUTHOR]

The work shows the effect of the metabolic modulator uridine on the functioning and ultrastructure of heart mitochondria in dystrophin-deficient mdx mice. Intraperitoneal administration of uridine (30 mg/kg/day for 28 days) improved K+ transport and increased its content in the heart mitochondria of mdx mice to the level of wild-type animals. This was accompanied by a significant decrease in the level of malondialdehyde and an increase in the number of mitochondria in the heart of mdx mice. At the same time, uridine did not affect the hyperfunctionality of mitochondria in mdx mice, which manifested in an increase in the calcium retention capacity. Nevertheless, we noted that uridine causes a significant decrease in the level of fibrosis in the heart of mdx mice, which attested to a positive effect of therapy. [ABSTRACT FROM AUTHOR]

The reaction of maleopimaric acid and its acid chloride with 3-, 6-, and 8-aminoquinolines afforded quinoline containing maleopimarimides and carboxamides in high yields, respectively. Structure of the synthesized compounds was determined by 1Н, 13С, 1H–13C HSQC, 1H–13C HMBC, COSY, NOESY, and 1Н–15N HMBC NMR spectroscopy methods. [ABSTRACT FROM AUTHOR]

Reaction of acyl isothiocyanates of 2-allyl- and 2-benzylmaleopimarimides with 3-carboxy- and 2,4-dinitrophenylhydrazines and hydrazides of some aromatic acids (benzoic, 4-hydroxy- and 4-methoxybenzoic, nicotinic, isonicotinic) furnished linear hydrazinocarbonothioyl derivatives of these maleopimarimides in high yields. Structure of the synthesized compounds was determined by 1H,13C, 1H–13C HSQC, 1H–13C HMBC, COSY, NOESY, and 1H–15N HMBC NMR spectroscopy methods. [ABSTRACT FROM AUTHOR]

Abstract—The transition of embryos in air-dried seeds from a state of dormancy to a state with highly active metabolism during germination is accompanied by significant changes in both spatial and temporal patterns of gene expression and is controlled by multilevel regulatory networks. The character and degree of acetylation of chromatin proteins depend on the transcriptional activity of chromatin and are also associated with DNA replication and the cell cycle. Obtaining a complete picture of the involvement of histone modification in seed germination will be useful for increasing crop yields, as a way to assess the quality and viability of seeds before sowing, and will also allow the development of methods for managing plant genetic potential. [ABSTRACT FROM AUTHOR]

A library of 31 mono- and bis-quaternary ammonium compounds based on 3-hydroxypyridine was synthesized. Primary screening of their antibacterial activity in vitro in six archival strains of bacteria revealed four highly active lead compounds surpassing commercial antiseptics benzalkonium chloride, miramistin, and chlorhexidine in their activity. Further in-depth study of the antibacterial activity of the lead compounds in vitro in 16 clinical bacterial strains and the study of their toxicity in vitro and in vivo showed that 2,6-bis(N,N-dimethyl-N-dodecylammoniomethyl)-3-methoxypyridine dichloride was the most active and least toxic and manifested a higher activity in comparison with benzalkonium chloride, miramistin, and chlorhexidine in clinical isolate of both gram-positive and gram-negative bacteria, as well as a moderate toxicity in vivo (LD50 = 82 6 mg kg−1, mice, oral administration). The quaternary ammonium compounds based on 3-hydroxypyridine are of undoubted interest for the further development of antibacterial drugs. [ABSTRACT FROM AUTHOR]

Substituted ureides and thioureides of maleopimaric acid (MPA) were synthesized via two methods: reaction of MPA chloride with monosubstituted ureas and thioureas and reaction of MPA chloride with KSCN and then in situ with various amines. The structures of all synthesized compounds were proven using NMR spectroscopy, X-ray crystal structure analyses, and mass spectroscopy. [ABSTRACT FROM AUTHOR]

The condensation of maleopimaric acid or its chloride with 2-aminothiazole or 2-aminobenzothiazole afforded new maleopimaric acid imides and amides containing thiazole or benzothiazole fragments. Maleo-pimaric acid chloride reacted with 2-aminothiazole at room in anhydrous methylene chloride at room tempera-ture to give a mixture of the corresponding N-thiazolyl amide and a maleopimaric acid derivative containing a thiazole ring in both carboxylic acid and anhydride moieties at a ratio of 7:2. [ABSTRACT FROM AUTHOR]

The condensation of maleopimaric acid with 2-aminoethane-1-thiol, 2-aminoethan-1-ol, and 3-amino-propan-1-ol afforded in high yields new maleopimarimides containing a thiol or alcohol functionality. The structure of the synthesized compounds was confirmed by NMR and mass spectra. [ABSTRACT FROM AUTHOR]

MPA acid chloride ( B 4 b ) [[4]] was reacted with the amino-derivatives of triazole and antipyrine to form the corresponding carboxamides B 5 b and B 6 b in yields of 95 and 99%, respectively. The reaction of MPA chloride with the amino-derivatives of triazole and antipyrine at room temperature in CH SB 2 sb Cl SB 2 sb gave the corresponding MPA carboxamides. The resonance of these methyl protons in the SP 15 sp N-H HMBC spectrum coupled with N-1' ( SB N sb 129.15 ppm) while the N-1' methyl protons coupled to N-2' ( SB N sb 180.05 ppm). [Extracted from the article]

Three new maleopimaric acid derivatives were synthesized. The antiviral activity of 14 synthesized maleopimaric acid derivatives was tested against influenza virus A/PuertoRico/8/34 (H1N1). Several compounds were found to be potentially active etiotropic antiviral compounds. [ABSTRACT FROM AUTHOR]

A Pd(acac)2-catalyzed reaction of allyl esters of maleopimaric and diketocage quinopimaric acid derivative with diazomethane was studied for the first time with the aim to obtain cyclopropylmethyl derivatives of the pimaric acid series as potential pharmacologically active compounds. It was shown that the reaction proceeds under mild conditions and provides the desired cyclopropylmethyl derivatives in yields of 84–98%. [ABSTRACT FROM AUTHOR]

Erratum [ABSTRACT FROM AUTHOR]

While searching for pharmacologically active compounds among 4,5-dihydrooxazole derivatives of maleopimaric acid, we studied for the first time the reaction between allyl-substituted maleopimaric acid derivatives and aromatic nitrile oxides that were generated from oximes by oxidation with sodium hypochlorite with or without ultrasonication of the biphasic system. The reaction occurred under mild conditions and regiospecifically provided 4,5-dihydroisoxazol-5-ylmethyl derivatives of maleopimaric acid in 77-99% yields. [ABSTRACT FROM AUTHOR]

A new synthetic method for 16-sulfanyl-15-oxa scaffold derivatives of quinopimaric acid was developed. The structures of all synthesized compounds were elucidated using NMR spectroscopy and elemental analysis. [ABSTRACT FROM AUTHOR]

New 2- and 3-methoxyquinopimaric-acid derivatives were synthesized by a Diels-Alder reaction of levopimaric acid and 2-methoxy-1,4-benzoquinone. The reaction rate and regioselectivity of the cycloaddition were increased significantly by using a Bmim·BF4 catalyst. Photolysis of 3-methoxyquinopimaric acid produced new scaffold derivatives. The compounds were characterized by NMR spectroscopy and elemental analysis. [ABSTRACT FROM AUTHOR]

New S-containing maleopimaric acid derivatives were synthesized. The structures of all synthesized compounds were elucidated using NMR spectroscopy and elemental analyses. [ABSTRACT FROM AUTHOR]

Methods for the synthesis of quaternary phosphonium salts based on 3-hydroxypyridine and 4-deoxypyridoxine were developed. Some of obtained compounds possess high antibacterial and antitumor activity in vitro. [ABSTRACT FROM AUTHOR]

We solve the Schwarz problem for boundary contours consisting of countable sets of segments with limit point at infinity, including the periodic case. The solution is a result of a reduction to corresponding Riemann boundary-value problems. [ABSTRACT FROM AUTHOR]

The antihypoxic activity of a series of quinopimaric acid scaffold derivatives was studied. It was shown that compounds 3, 5, and 8 increased the lifespan of mice in various hypoxia models. [ABSTRACT FROM AUTHOR]

New 4a-quinopimaric acid derivatives were synthesized via a Diels-Alder reaction of levopimaric acid with 2-acetyl- or 2-(methoxycarbonyl)-1,4-benzoquinone and were characterized using elemental analysis and NMR spectroscopy. Thermodynamic and activation parameters of the Diels-Alder reactions of levopimaric acid and a model diene (7-isopropyl-1,2,3,4,4a,5-hexahydronaphthalene) with 2-acetyl- or 2-(methoxycarbonyl)-1,4-benzoquinone were calculated by density-functional theory in order to explain the observed regioselective cycloaddition. [ABSTRACT FROM AUTHOR]

The hepatoprotective and choleretic activities of three levopimaric acid derivatives were studied experimentally using a CCl-induced acute hepatitis model in rats. It was established that all investigated levopimaric acid derivatives tended to increase bile secretion whereas (5 R,9 R,13 S,18 S)-20-isopropyl-5,9-dimethyl-17-{[(4-methylphenyl)sulfonyl]imino}-14-oxopentacyclo[10.6.2.0.0.0]eicosa-15,19-diene-5-carboxylic acid ( I) and dimethyl (4b S,8 R)-2-isopropyl-3-4b,8-trimethyl-2,4-dioxo-4,4a,4b,5,6,7,8,8a,9,10-decahydro-3 H- spiro[3,10a-ethanophenanthrene-11,5-[1,3]thiazolidine]-8,12-dicarboxylate ( II) reduced transaminase enzyme levels in blood serum. [ABSTRACT FROM AUTHOR]

Novel quinopimaric acid scaffold derivatives were synthesized. Their antiviral activity against influenza A/California/07/09 (H1N1) was studied. It was found that several of the synthesized quinopimaric acid scaffold derivatives were potentially active etiotropic antiviral compounds. [ABSTRACT FROM AUTHOR]

Sulfur-containing quinopimaric acid scaffold derivatives were synthesized. The structures of all synthesized compounds were proved using NMR spectroscopy and elemental analysis. [ABSTRACT FROM AUTHOR]

6-Chloro-, 6-chloroacetoxy-, and 16-(2-bromoacetyl)framework derivatives were synthesized from a photoadduct of quinopimaric acid. [ABSTRACT FROM AUTHOR]

Optically active amides, ureas, and thioureas were synthesized from cage acid chloride derived from quinopimaric acid. [ABSTRACT FROM AUTHOR]

A method for preparing optically active diterpene compounds of the aza-birdcage type that was based on reaction of oxa-scaffold derivatives of quinopimaric acid with primary amines, amides, and carbamides was developed. [ABSTRACT FROM AUTHOR]

New 6- O-glycosides of quinopimaric acid scaffold derivatives were synthesized. [ABSTRACT FROM AUTHOR]

A genetic epidemiological study has been performed in five districts of the Republic of Tatarstan, Russia: Arsky, Atninsky, Kukmorsky, Buinsky and Drozhzhanovsky raions. The total size of the population surveyed is 188397 people. Tatars accounted for 77.13% of the population analyzed (145466 people) and were represented by two main ethnic groups: Kazan Tatars and Mishars. The medical genetic study encompassed the total population of the districts, irrespective of ethnicity, and was carried out according to the standard protocol developed in the Laboratory of Genetic Epidemiology of the Research Center for Medical Genetics of the Russian Academy of Medical Sciences. After segregation analysis, the prevalence rates of the main types of monogenic hereditary disorders (MHDs), i.e., autosomal dominant (AD), autosomal recessive (AR), and X-linked diseases, have been calculated for the total population of the five districts and for Tatars alone. The prevalence rates of AD, AR, and X-linked diseases considerably vary in different subpopulations. The largest difference in the MHD prevalence rate has been found between the rural and urban populations. The overall prevalence rate of MHDs was one patient per 293 urban residents and populations and one patient per 134 rural residents, with a wide variation between subpopulations, from 1: 83 people in the rural population of Atninsky raion to 1: 351 people in the town of Kukmor. Comparison of the MHD prevalence rate in Tatars with those in populations surveyed earlier has shown that the characteristics of the load of MHDs in the Tatar population are similar to those in some districts of the republics of Bashkortostan, Udmurtia, Mari El, and Chuvachia. In Russian populations of European Russia, the MHD prevalence rates are substantially lower. Correlation analysis has shown high ( r = 0.5-0.9) significant correlations between the local inbreeding ( a), the im index, the random inbreeding ( F), and the AD and AR prevalence rates in the Tatar population. This analysis has demonstrated that genetic drift is the main population dynamic factor determining the MHD load in the Tatar population. [ABSTRACT FROM AUTHOR]

New nitrogen-containing and hydroxy derivatives of quinopimaric acid were synthesized, and their structure was determined by H and C NMR spectroscopy. [ABSTRACT FROM AUTHOR]

A total sample of 31 837 marriage records made in 13 raions (districts) of Tatarstan in 1990-2000 have been used to determine the endogamy index and parameters of Malecot's isolation by distance model. The endogamy index varied from 0.45 in Pestrechinsky raion to 0.74 in Aktynashsky raion. The parameters of Malecot's isolation by distance model varied in Tatars as follows: random inbreeding, from 0.00014 to 0.00076; root mean square migration, from 46 to 110 km. [ABSTRACT FROM AUTHOR]

Ethnically assortative marriage rates have been calculated for Tatars (1.16) and Russians (8.37) on the basis of 14 729 marriage records made in 1990-2000 in seven raions of Tatarstan (Arsky, Atninsky, Drozhzhanovsky, Alkeevsky, Musljumovsky, Aktanyshsky, and Baltasinsky). The outbreeding rate of Tatars (5.35%) has been found to be lower than in a number of other populations studied in this respect. [ABSTRACT FROM AUTHOR]

Photolysis was inverstigated of quinopimaric acid derivatives under various conditions. The structure of the photolysis products was proved with H, C, and mass spectra and XRD analysis. [ABSTRACT FROM AUTHOR]

By oxidation of ( Z)-4,7-dihydro-1,3-dithiepines with meta-chloroperbenzoic acid the corresponding 4,7-dihydro-1λ4,3-dithiepine 1-oxides were synthesized in ∼85% yield. A complete assignment of signals in the 1H and 13C NMR spectra of the compounds obtained was established. According to XRD analysis the seven-membered heterocycles crystallized in conformations chair or boat. The calculations by DFT method in the B3LYP/6-31G( d,p) version showed the possibility of conformational equilibrium of these forms in the gas phase. [ABSTRACT FROM AUTHOR]

Serratia marcescens are well-known Gram-negative bacteria capable of excreting extracellular hydrolases, such as the nuclease-an enzyme that catalyzes hydrolysis of both DNA and RNA chains with a high efficiency. The nuclease has a number of attractive properties for use in biotechnology industry-outstanding enzymatic activity and low production cost. The existing protocols for purification of nuclease yield only limited amounts of protein and require complicated multistage procedures. Here, we report a chromatographic protocol for elegant one-step purification procedure resulting in a pure homogenous enzyme, as confirmed by gel electrophoresis and mass spectrometry. [ABSTRACT FROM AUTHOR]

Diels-Alder reactions of levopimaric acid with quinones are strongly accelerated in the presence of ionic liquids (imidazolium salts) as catalyst. [ABSTRACT FROM AUTHOR]

A procedure was developed for the synthesis of pyrrolizidine-and indolizidinediones derivatives from the keto-stabilized sulfonium α-and β-ylides of N-phthalylaspartic acid. [ABSTRACT FROM AUTHOR]

Abstract  Alginic acid is localised in the cell walls and intercellular spaces of the brown alga, Laminaria japonica Aresch., and the salts of this compound occur mainly as calcium alginates. However, the alginates in this alga do not have the viscosity and the ability to create and stabilise structural products. Hence, the structure and properties of the alginates in Laminaria were changed by chemical modification to produce new products such as sodium alginates and other substances capable of forming gels. The rheological properties of the algal gel from Laminaria depended on the properties of the sodium alginate. Heating the algal product up to 90�C did not change its physical and chemical properties; the viscosity did not differ from that of the initial product. The viscosity and molecular weight of the sodium alginate isolated from the algal gel were stable from 20�C up to 95�C. However, about 30% of the viscosity was lost at 100�C. Recipes and various methods of preparing the gel products as fish sauces, jelly-like fish products, fruit jellies, drinks, cosmetic and pharmaceutical products are presented. The algal gel and the gel products did not lose their integrity with heat processing. [ABSTRACT FROM AUTHOR]

Spiro[cyclohexane-1,4′-[3,5]dioxabicyclo[5.1.0]octanes] were synthesized, and their conformational behavior was studied by dynamic 13C NMR spectroscopy. Anancomeric displacement of conformational equilibrium toward two nonequivalent twist conformers with close energies was revealed. The relative Gibbs energies Δ Go and enthalpies of formation Δ Ho of twist and chair-like conformers with endo and exo orientation of the three-membered ring of structurally related formaldehyde and acetone acetals were calculated in terms of the density functional theory at the B3LYP/6-31G( d,p) level. Like spiro-cyclohexane analogs, they were shown to have a non- chair conformation. [ABSTRACT FROM AUTHOR]

Conformationally heterogeneous 2-substituted 1,3-dithiacyclohept-5-enes (R = Ph, Me, t-Bu), which exist in solution as chair and boat conformers, react with dimethyl 1,2,4,5-tetrazine-3,6-dicarboxylate with high exo-diastereoselectivity: only the chair conformer is involved. The steric structure of 4-methyl-3,5-dithia-9,10-diazabicyclo[5.4.0]undeca-7,10-diene was determined by X-ray analysis. Its crystal packing and supramolecular structure were also analyzed. [ABSTRACT FROM AUTHOR]

Reduction of 6-acetoxy-3-benzyl-l-ethoxycarbonyl-3-azabicyclo[3.3.1]nonan-9-one with sodium borohydride was investigated in various conditions. The stereochemistry of reduction products was deduced from 1H and 13C NMR and mass spectra. [ABSTRACT FROM AUTHOR]