Chemical and Phytocoenological Characteristics of Two Different Slovak Peatlands.

This paper presents the results of pedological and phytocoenological research focused on the detailed research of chemical parameters (pH, organic carbon, and nutrients), risk elements (As-metalloid, Cd, Co, Cr, Cu, Ni, Pb, and Zn), and species composition of the vegetation of two different peatlands on the territory of Slovakia-Belianske Lúky (a fen) and Rudné (a bog). Sampling points were selected to characterize the profile of the organosol within the peatland, the soil profile between the peatland and the agricultural land, and the soil profile of the outlying agricultural land, which is used as permanent grassland. Based on phytocoenological records, a semi-quantitative analysis of taxa in accordance with the Braun-Blanquet scale was performed. The study revealed that the thickness of the peat horizon of the fen in comparison with the bog is very low. In terms of the quality of organic matter, the monitored peatlands are dominated by fresh plant residues such as cellulose and lignin. Differences between individual types of peatlands were also found in the soil reaction and the supply of nitrogen to the organic matter of peat. The values of the soil exchange reaction were neutral on the fen, as well as slightly alkaline but extremely low on the bog. A significantly higher nitrogen supply was found in the organic matter of the fen in contrast to the bog. At the same time, extremely low content of accessible P and an above-limit content of As in the surface horizons were also found on the fen. From the phytocoenological point of view, 22 plant species were identified on the fen, while only five species were identified on the bog, which also affected the higher diversity (H') and equitability (e). The results of the statistical testing confirmed the diversity of the studied peatlands and the different impact of environmental variables on plant diversity.

Design and synthesis of anticancer 1-hydroxynaphthalene-2-carboxanilides with a p53 independent mechanism of action.

A series of 116 small-molecule 1-hydroxynaphthalene-2-carboxanilides was designed based on the fragment-based approach and was synthesized according to the microwave-assisted protocol. The biological activity of all of the compounds was tested on human colon carcinoma cell lines including a deleted TP53 tumor suppressor gene. The mechanism of activity was studied according to the p53 status in the cell. Several compounds revealed a good to excellent activity that was similar to or better than the standard anticancer drugs. Some of these appeared to be more active against the p53 null cells than their wild-type counterparts. Intercalating the properties of these compounds could be responsible for their mechanism of action.

Synthesis and homopolymerization kinetics of 7-(methacroyloxy)-2-oxo-heptylphosphonic acid and its copolymerization with methyl methacrylate.

The synthesis of polymerizable 7-(methacroyloxy)-2-oxo-heptylphosphonic acid M1 destined for self-etch adhesives is described. M1 is characterized by 1H, 13C and 31P-NMR spectroscopy. Its homopolymerization and copolymerization reactivity in the solvents methanol and dioxane between 45 and 70°C in the presence of azobisisobutyronitrile (AIBN) are examined. Polymerization proceeds readily through a thermal free radical initiation. The intensity exponents for the monomer and initiator are only slightly over 1 and approximately 0.5, respectively. This is in accordance with the results typically observed for an ideal free radical polymerization with termination mainly by disproportionation, which is typical for methyl methacrylate (MMA) homopolymerization. The kinetics of copolymerization with MMA are monitored by online 1H-NMR spectroscopy. Two copolymerization reactions for each pair of co-monomers are sufficient to evaluate the copolymerization parameters using the Jaacks method, the Fineman-Ross method and the nonlinear least-squares method. All three methods give similar results for particular monomer M1/MMA couple.

α-Glucosidase inhibitory effects of polyphenols from Geranium asphodeloides: Inhibition kinetics and mechanistic insights through in vitro and in silico studies.

Some Geranium species have been used to treat diabetes. To evaluate the scientific basis of this ethnopharmacological use, we aimed to isolate potent α-glucosidase inhibitory metabolites of Geranium asphodeloides Burm. through in vitro bioactivity-guided fractionation. All the tested extracts showed high α-glucosidase inhibitory effect compared to acarbose. Among the tested extracts, the ethyl acetate subextract showed the highest activity with an IC50 value of 0.85 ±â€¯0.01 µM. A hydrolysable tannin, 1,2,4-tri-O-galloyl-ß-d-glucopyranose (1), and five flavonoid glycosides, kaempferol-3-O-α-rhamnopyranoside (2), kaempferol-3-O-α-arabinofuranoside (3), quercetin-3-O-ß-glucopyranoside (4), quercetin-3-O-α-rhamnopyranoside (5), and quercetin-3-O-α-rhamnofuranoside (6), were isolated from the ethyl acetate subextract. Their structures were identified by 1D- and 2D-NMR experiments. 1 exhibited the highest α-glucosidase inhibitory effect, approximately 61 times more potent than positive control, acarbose, with an IC50 value of 0.95 ±â€¯0.07 µM. Also, 2 was more potent than acarbose. An enzyme kinetics analysis revealed that compounds 2, 3 and 4 were competitive, whereas 1 and 6 uncompetitive inhibitors. Molecular docking studies were performed to get insights into inhibition mechanisms of the isolated compounds in the light of the enzyme kinetic studies using various binding sites of the enzyme model.

Synthesis of Branched-Chain Sugars with a DHAP-Dependent Aldolase: Ketones are Electrophile Substrates of Rhamnulose-1-phosphate Aldolases.

Dihydroxyacetone phosphate (DHAP)-dependent rhamnulose aldolases display an unprecedented versatility for ketones as electrophile substrates. We selected and characterized a rhamnulose aldolase from Bacteroides thetaiotaomicron (RhuABthet) to provide a proof of concept. DHAP was added as a nucleophile to several α-hydroxylated ketones used as electrophiles. This aldol addition was stereoselective and produced branched-chain monosaccharide adducts with a tertiary alcohol moiety. Several aldols were readily obtained in good to excellent yields (from 76 to 95 %). These results contradict the general view that aldehydes are the only electrophile substrates for DHAP-dependent aldolases and provide a new C-C bond-forming enzyme for stereoselective synthesis of tertiary alcohols.

Potential of Potentilla inclinata and its polyphenolic compounds in α-glucosidase inhibition: Kinetics and interaction mechanism merged with docking simulations.

In the present study we aimed to identify the α-glucosidase enzyme inhibitory potential of Potentilla inclinata Vill. MeOH and n-BuOH extracts which possessed remarkable α-glucosidase enzyme inhibitory effects with IC50 values of 1.06±0.02 and 0.93±0.01µg/ml respectively, compared to that of acarbose (IC50 31.92±0.17). Thus, BuOH extract was chosen for further phytochemical investigations. A phenolic acid, six flavonol glycosides, and two hydrolysable tannins were isolated from the most active n-BuOH extract of the title plant. Structures of the isolated compounds were elucidated by 1D- and 2D-NMR experiments. All the compounds exhibited remarkable α-glucosidase inhibitory activity compared to the positive control, acarbose. Rutin (2) showed the highest activity with an IC50 value of 26.31±0.02µg/ml. An enzyme kinetics analysis revealed that compounds 5 and 7 were competitive, 4 and 6 noncompetitive, and 3 was uncompetitive inhibitors of α-glucosidase enzyme. Molecular docking studies were performed to get insights into inhibition mechanisms of the isolates considering their inhibition type using various binding sites of the enzyme model we previously reported.

Halogenated 1-Hydroxynaphthalene-2-Carboxanilides Affecting Photosynthetic Electron Transport in Photosystem II.

Series of seventeen new multihalogenated 1-hydroxynaphthalene-2-carboxanilides was prepared and characterized. All the compounds were tested for their activity related to the inhibition of photosynthetic electron transport (PET) in spinach (Spinacia oleracea L.) chloroplasts. 1-Hydroxy-N-phenylnaphthalene-2-carboxamides substituted in the anilide part by 3,5-dichloro-, 4-bromo-3-chloro-, 2,5-dibromo- and 3,4,5-trichloro atoms were the most potent PET inhibitors (IC50 = 5.2, 6.7, 7.6 and 8.0 µM, respectively). The inhibitory activity of these compounds depends on the position and the type of halogen substituents, i.e., on lipophilicity and electronic properties of individual substituents of the anilide part of the molecule. Interactions of the studied compounds with chlorophyll a and aromatic amino acids present in pigment-protein complexes mainly in PS II were documented by fluorescence spectroscopy. The section between P680 and plastoquinone QB in the PET chain occurring on the acceptor side of PS II can be suggested as the site of action of the compounds. The structure-activity relationships are discussed.

In vivo magnetic resonance approach to trimethyltin induced neurodegeneration in rats.

Trimethyltin (TMT) is commonly used to induce neurodegeneration in mice and rats; however, only scarce data of in vivo magnetic resonance (MR) spectroscopy and imaging characterizing TMT neurotoxicity are available. Our aim was to assess brain metabolite changes and brain atrophy by in vivo MR in the rat model of neurodegeneration induced by TMT. Adult male Wistar rats exposed to TMT (8mg/kg, i.p.) were used in the study. Proton MRS was applied on the dorsal hippocampus to reveal changes in neurochemical profile, and MR imaging was used to assess the volume of the entire hippocampus, ventricles and whole brain. Hippocampal levels of N-acetylaspartate (NAA), glutamate (Glu), total creatine (tCr) and taurine (Tau) significantly decreased, while the levels of myo-Inositol (mIns) and glutamine (Gln) significantly increased in TMT treated rats compared to controls. No changes in choline metabolites (tCho), glutathione (GSH), and GABA were observed. MR volumetry revealed a substantial loss of hippocampal mass, cerebral volume shrinkage and ventricular enlargement in the TMT treated group in comparison to the control group. To the best of our knowledge, this is the first study characterizing TMT induced neurodegeneration in the rat by in vivo MRS. Our findings suggest that TMT exposed rats may serve as a reliable animal model of neurodegeneration and MR based parameters could serve as potential in vivo biomarkers of therapeutic response.

N-Alkoxyphenylhydroxynaphthalenecarboxamides and Their Antimycobacterial Activity.

A series of nineteen N-(alkoxyphenyl)-2-hydroxynaphthalene-1-carboxamides and a series of their nineteen positional isomers N-(alkoxyphenyl)-1-hydroxynaphthalene-2-carboxamides were prepared and characterized. Primary in vitro screening of all the synthesized compounds was performed against Mycobacterium tuberculosis H37Ra, M. kansasii and M. smegmatis. Screening of the cytotoxicity of the compounds was performed using human monocytic leukemia THP-1 cells. Some of the tested compounds showed antimycobacterial activity comparable with or higher than that of rifampicin. For example, 2-hydroxy-N-(4-propoxyphenyl)-naphthalene-1-carboxamide showed the highest activity (MIC = 12 µM) against M. tuberculosis with insignificant cytotoxicity. N-[3-(But-2-yloxy)phenyl]- and N-[4-(but-2-yloxy)phenyl]-2-hydroxy-naphthalene-1-carboxamide demonstrated high activity against all tested mycobacterial strains and insignificant cytotoxicity. N-(Alkoxyphenyl)-1-hydroxynaphthalene-2-carboxamides demonstrated rather high effect against M. smegmatis and M. kansasii and strong antiproliferative effect against the human THP-1 cell line. Lipophilicity was found as the main physicochemical parameter influencing the activity. A significant decrease of mycobacterial cell metabolism (viability of M. tuberculosis H37Ra) was observed using MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide) assay. Structure-activity relationships are discussed.

In Vitro Metabolomic Approach to Hippocampal Neurodegeneration Induced by Trimethyltin.

Search for indicators of neurodegenerative disorders is a hot topic where much research remains to be done. Our aim was to determine proton nuclear magnetic resonance ((1)H-NMR) spectra of brain metabolites in the trimethyltin (TMT) model of neurodegeneration. Male Wistar rats were subjected to TMT or saline and were sacrificed on day 3 or 24 after administration. (1)H-NMR spectrum was measured on the 600 MHz Varian VNMRS spectrometer in nano-probe in the volume of 40 µl of hippocampal extracts. TMT administration resulted in reduction of the hippocampal weight on day 24. Of the sixteen identified metabolite spectra, decreased aspartate and increased glutamine contents were observed in the initial asymptomatic stage of neurodegeneration on day 3 in hippocampal extracts of TMT exposed rats compared to sham animals. Increased myo-inositol content was observed on day 24. The presented data provide further knowledge about this experimental model and putative indicators of neuronal damage.

Phytochemical Content, Antioxidant and Cytotoxic Activities of Sedum spurium.

Sedum L. species are used for their hemostatic, antidiarrheal, antifungal, diuretic and wound healing properties, and there is growing interest in these species because of their usage in folk medicine. DPPH, SO, NO, and ABTS radical scavenging activities and protective effects against H(2)(02) induced cytotoxicity, as well as cytotoxic activities against the Hep-2 cell line of various extracts from Sedum spurium Bieb. were investigated. Besides, the total phenol, flavonoid, and flavonol contents of the extracts were determined to clarify their biological and phytochemical properties. Chromatographic studies on the most active extract led to the isolation of the major compound, identified as 2-methyl-erythritol by (1)H and (13)C NMR techniques. The EtOAc extract is found to be the most active extract in all tests. However, major compound of EtOAc extract did not possess tested activities. The EtOAC extract of S. spurium could be effective to improve antihemolytic defences of erythrocytes, and radical scavenging potential of the antioxidant mechanism. The extracts should be investigated in detail for their cytotoxic activities because of their possible pro-oxidant effects at high concentrations.

Ring-substituted 8-hydroxyquinoline-2-carboxanilides as potential antimycobacterial agents.

In this study, a series of twenty-two ring-substituted 8-hydroxyquinoline-2-carboxanilides was prepared and characterized. Primary in vitro screening of the synthesized compounds was performed against Mycobacterium tuberculosis H37Ra, Mycobacterium avium complex and M. avium subsp. paratuberculosis. Some of the tested compounds showed the antimycobacterial activity against M. avium subsp. paratuberculosis comparable with or higher than that of rifampicin. 8-Hydroxy-N-[3-(trifluoromethyl)phenyl]- and 8-hydroxy-N-[4-(trifluoromethyl)phenyl]quinoline-2-carboxamide showed MIC=24 µM against all tested mycobacterial strains. 3-Methoxyphenyl- and 3-methylphenyl derivatives expressed MIC=27 or 29 µM also against all the tested strains. Their activity against M. avium subsp. paratuberculosis was 4-fold higher than that of rifampicin. 2-Bromophenyl- and 2-(trifluoromethyl)phenyl derivatives had MIC=23 or 24 µM against M. tuberculosis. A significant decrease of mycobacterial cell metabolism (viability of M. tuberculosis H37Ra) was observed using MTT assay. Screening of cytotoxicity of the compounds was performed using the THP-1 cells, and no significant lethal effect was observed up to tested concentration 30 µM. The structure-activity relationships are discussed.

Synthesis and antimycobacterial properties of ring-substituted 6-hydroxynaphthalene-2-carboxanilides.

In this study, a series of twenty-two ring-substituted 6-hydroxynaphthalene-2-carboxanilides was prepared and characterized. Primary in vitro screening of the synthesized compounds was performed against Mycobacterium tuberculosis H37Ra, Mycobacterium avium complex and M. avium subsp. paratuberculosis. Derivatives substituted by trifluoromethyl, bromo, methyl and methoxy moieties in C'(3) and C'(4) positions of the anilide ring showed 2-fold higher activity against M. tuberculosis than isoniazid and 4.5-fold higher activity against M. avium subsp. paratuberculosis than rifampicin. 6-Hydroxy-N-(2-methylphenyl)naphthalene-2-carboxamide had MIC=29 µM against M. avium complex. A significant decrease of mycobacterial cell metabolism (viability of M. tuberculosis H37Ra) was observed using MTT assay. Screening of the cytotoxicity of the most effective antimycobacterial compounds was performed using the THP-1 cells, and no significant lethal effect was observed. The structure-activity relationships are discussed.

Neuronal marker recovery after Simvastatin treatment in dementia in the rat brain: in vivo magnetic resonance study.

The aim of study was to search for new biomarkers with a magnetic resonance technique to identify the early stages of dementia, induced by D-galactose, and evaluate Simvastatin therapy. Localized proton magnetic resonance spectroscopy measurements showed a significant decrease in the concentration of N-acetylaspartate+N-acetylaspartylglutamate and myo-inositol in the D-galactose group compared to the control group, and, conversely, an increase of N-acetylaspartate+N-acetylaspartylglutamate in the D-galactose/Simvastatin group. Using a saturation transfer experiment, with phosphorus magnetic resonance spectroscopy, we observed a significant elevation of the forward rate constant of the creatine kinase reaction in the brains of the D-galactose group compared to controls, and subsequently, a significant reduction of this reaction in the D-galactose/Simvastatin group. Spatial learning and memory were evaluated using the modified Morris water maze test. The dynamics of the learning process represented by the learning index revealed a significant reduction in learning in the D-galactose group, but the deficits as a consequence of the D-galactose effects were recovered in the D-galactose/Simvastatin group, in which the learning dynamics resembled those of the control group. By determining the thiobarbituric acid reactive substances and total coenzyme Q9 in plasma, we have shown that long-term administration of D-galactose created conditions for oxidative stress, and that the administration of Simvastatin decreased oxidative stress in plasma. Volumetry analyses from the hippocampal area show a reduction in the segmented area in the D-galactose group, compared with the control group, and an enlarged area in the hippocampus in the d-galactose/Simvastatin group.

Changes in metabolome and in enzyme activities during germination of Trichoderma atroviride conidia.

The aim of this work was to study the metabolic changes during germination of Trichoderma atroviride conidia along with selected marker enzyme activities. The increase in proteinogenic amino acid concentrations together with the increase in glutamate dehydrogenase activity suggests a requirement for nitrogen metabolism. Even though the activities of tricarboxylic acid cycle enzymes also increased, detected organic acid pools did not change, which predisposes this pathway to energy production and supply of intermediates for further metabolism. The concentrations of many metabolites, including the main osmolytes mannitol and betaine, also increased during the formation of germ tubes. The activities of H(+)-ATPase and GDPase, the only marker enzymes that did not have detectable activity in non-germinated conidia, were shown with germ tubes.

Isolation of an oleanane-type saponin active from Bellis perennis through antitumor bioassay-guided procedures.

CONTEXT: Bellis perennis L. (Asteraceae) (common daisy) is a herbaceous perennial plant known as a traditional wound herb; it has been used for the treatment of bruises, broken bones, and wounds. Bellis perennis has also been used in the treatment of headache, common cold, stomachache, eye diseases, eczema, skin boils, gastritis, diarrhea, bleeding, rheumatism, inflammation, and infections of the upper respiratory tract in traditional medicine. OBJECTIVE: Antitumor activities of different fractions of B. perennis flowers at different concentrations were evaluated and through bioassay-guided fractionation and isolation procedures a saponin derivative (1) was isolated from the active fraction obtained from the n-butanol extract of flowers of the title plant by column chromatography. MATERIALS AND METHODS: Antitumor activities of different fractions of B. perennis flowers at different concentrations were evaluated using Potato Disc Tumor Induction Bioassay. Structure elucidation of 1 was accomplished by spectroscopic methods [1D- and 2D-NMR, and LC-ESI(APCI)-TOF-MS(MSn)]. RESULTS: The present study showed the antitumor activity of fractions obtained from B. perennis flowers for the first time. The most active fraction showed 99% tumor inhibition at 3000 mg/L. An oleanane-type saponin was isolated through bioassay-guided studies. DISCUSSION AND CONCLUSION: Through antitumoral bioassay-guided fractionation and isolation procedures, 1 was isolated from the active fraction of B. perennis. The detailed NMR data of compound 1 is given for the first time.

Structural analysis of an impurity of the drug landiolol.

In a course of development and preparation of landiolol (1a), a known ultra-short-acting ß-blocker, process quality control by HPLC and LC-MS analysis consistently showed an impurity peak ranging from 0.05% to 0.15 % and exhibiting a molecular mass m/z 887. To identify the hitherto unknown impurity, we prepared one of the possible landiolol derivatives with the same molecular mass for proper spectral characterization (NMR and MS). Its equivalence with the unknown impurity was then confirmed by LC-MS analysis. Ultimately, using fragmentation patterns in LC-MS and selective two-dimensional NMR experiments, the structure of the impurity was assigned as [(4S)-2,2-dimethyl-1,3-dioxolan-4-yl]methyl 3-{4-[(2S)-2-hydroxy-3-(3-{4-[(2S)-2-hydroxy-3-[(2-{[(morpholin-4-yl)carbonyl]amino}ethyl)amino]propoxy]phenyl}-N-(2-{[(morpholin-4-yl)carbonyl]amino}ethyl)propanamido)propoxy]phenyl}propanoate (2). It was found that the impurity was present in two rotameric forms at room temperature. The synthesis and NMR characterization of (2) are discussed.

Polyphenol fatty acid esters as serine protease inhibitors: a quantum-chemical QSAR analysis.

We investigated the ability of polyphenol fatty acid esters to inhibit the activity of serine proteases trypsin, thrombin, elastase and urokinase. Potent protease inhibition in micromolar range was displayed by rutin and rutin derivatives esterified with medium and long chain, mono- and polyunsaturated fatty acids (1e-m), followed by phloridzin and esculin esters with medium and long fatty acid chain length (2a-d, 3a-d), while unmodified compounds showed only little or no effect. QSAR study of the compounds tested provided the most significant parameters for individual inhibition activities, i.e. number of hydrogen bond donors for urokinase, molecular volume for thrombin, and solvation energy for elastase. According to the statistical analysis, the action of elastase inhibitors is opposed to those of urokinase and thrombin. Cluster analysis showed two groups of compounds: original polyphenols together with rutin esters with short fatty acid chain length and rutin esters with long fatty acid chain length.

A new acylated neohesperidoside from Geranium purpureum.

A new acylated neohesperoside derivative, 1-octyl-4'-isovaleroyl-neohesperoside (1), was isolated from Geranium purpureum Vill. (Geraniaceae) together with the known compounds quercetin-3-rutinoside and gallic acid. The identification of the isolated compounds was carried out by spectroscopic analysis including 1D- and 2D- NMR (1H, 13C, COSY, HSQC and HMBC) spectroscopy and ESI-TOF-MS.

Isolation, structure elucidation and biological activity of angucycline antibiotics from an epiphytic yew streptomycete.

In the course of study of epiphytic microorganisms occurring on the surface of roots of Taxus baccata L. a new strain Streptomyces sp. AC113 was isolated. According to 16S ribosomal DNA-based identification the new strain is 99% identical with Streptomyces flavidofuscus. This strain cultivated in an arginine glycerol medium produced three major metabolites identified as (-)-8-O -methyltetrangomycin (1), 8-O -methyltetrangulol (2) and 8-O -methyl-7-deoxo-7-hydroxytetrangomycin (3). The chemical structures of these angucyclines were elucidated by 1D and 2D NMR as well as by mass spectrometry. Isolated angucycline metabolites showed significant antimicrobial activity against Bacillus cereus and Listeria mocytogenes. Cytotoxic activities of compounds 1, 2 and 3 against four cell lines (B16, HT-29 and non - tumor V79, L929) were evaluated. Compound 3 was the most potent anticancer agents with IC(50) 0.054 microg/ml against cell line B16.