17 research outputs found
HYDROGENATION OF BROWN COAL AND PROCESSING OF LIQUID COAL PRODUCTS IN PRESENCE OF ACTIVATED IRON-ORE CONCENTRATES
The systematic investigation of influencing mechano-chemical modification of the iron-ore catalystes on their texture, chemical composition and catalytic properties in the processes of the coal hydrogenation, hydrocracking with steam of the high-boiling of the coal products has been carried out firstly. The correlations between activation parameters of the catalystes and transformation of the high-boiling fractions of coal products have been determined. The selection of the conditions for mechano-chemical activation of the iron-ore concentrates has been made. It has been proposed firstly to use the steam-cracking process for processing of the high-boiling coal hydrogenate part into the distillate fractions.Available from VNTIC / VNTIC - Scientific & Technical Information Centre of RussiaSIGLERURussian Federatio
Batzella, Crambe and Monanchora: Highly Prolific Marine Sponge Genera Yielding Compounds with Potential Applications for Cancer and Other Therapeutic Areas
Pyrroloquinoline and guanidine-derived alkaloids present distinct groups of marine secondary metabolites with structural diversity that displayed potentialities in biological research. A considerable number of these molecular architectures had been recorded from marine sponges belonging to different marine genera, including Batzella, Crambe, Monanchora, Clathria, Ptilocaulis and New Caledonian starfishes Fromia monilis and Celerina heffernani. In this review, we aim to comprehensively cover the chemodiversity and the bioactivities landmarks centered around the chemical constituents exclusively isolated from these three marine genera including Batzella, Crambe and Monanchora over the period 1981–2017, paying a special attention to the polycyclic guanidinic compounds and their proposed biomimetic landmarks. It is concluded that these marine sponge genera represent a rich source of novel compounds with potential applications for cancer and other therapeutic areas.© 2018 by the author
Biological Activity of Flavonoids and Rare Sesquiterpene Lactones Isolated From Centaurea ragusina L.
The endemic Croatian species Centaurea ragusina L., like other species from the genus Centaurea, has been traditionally used in Croatia as an antibacterial agent and for the treatment of gastrointestinal and urogenital disorders. In several chromatographic steps, three flavonoids and three sesquiterpene lactones (STLs) were isolated and identified from the most active fractions of the ethanol extract. Two STLs, one for which we created the trivial name ragusinin, and hemistepsin A are here reported for the first time as constituents of the genus Centaurea. All six compounds were screened for their effect on several tumor and one normal cell lines. Among them, ragusinin showed the best bioactivity and high specificity to affect tumor murine SCCVII, human HeLa and Caco-2 cell lines, but not the viability of normal V79 fibroblasts. Due to these characteristics the action of ragusinin was investigated in more detail. Since DNA is the primary target for many drugs with antibacterial and anticancer activity, we studied its interaction with ragusinin. Rather moderate binding affinity to DNA excluded it as the primary target of ragusinin. Due to the possibility of STL interaction with glutathione (GSH), the ubiquitous peptide that traps reactive compounds and other xenobiotics to prevent damage to vital proteins and nucleic acids, its role in deactivation of ragusinin was evaluated. Addition of the GSH precursor N-acetyl-cysteine potentiated the viability of HeLa cells, while the addition of GSH inhibitor L-buthionine sulfoximine decreased it. Moreover, pre-treatment of HeLa cells with the inhibitor of glutathione-S-transferase decreased their viability indicating the detoxifying role of GSH in ragusinin treated cells. Cell death, derived by an accumulation of cells in a G2 phase of the cell cylce, was shown to be independent of poly (ADP-ribose) polymerase and caspase-3 cleavage pointing toward an alternative cell death pathway.© 2018 Grienke, Radić Brkanac, Vujčić, Urban, Ivanković, Stojković, Rollinger, Kralj, Brozovic and Radić Stojkovi
In vivo evaluation of radiotracers targeting the melanin-concentrating hormone receptor 1: [11C]SNAP-7941 and [18F]FE@SNAP reveal specific uptake in the ventricular system
The MCHR1 is involved in the regulation of energy homeostasis and changes of the expression are linked to a variety of associated diseases, such as diabetes and adiposity. The study aimed at the in vitro and in vivo evaluation of [11C]SNAP-7941 and [18F]FE@SNAP as potential PET-tracers for the MCHR1. Competitive binding studies with non-radioactive derivatives and small-animal PET/CT and MRI brain studies were performed under baseline conditions and tracer displacement with the unlabelled MCHR1 antagonist (±)-SNAP-7941. Binding studies evinced high binding affinity of the non-radioactive derivatives. Small-animal imaging of [11C]SNAP-7941 and [18F]FE@SNAP evinced high tracer uptake in MCHR1-rich regions of the ventricular system. Quantitative analysis depicted a significant tracer reduction after displacement with (±)-SNAP-7941. Due to the high binding affinity of the non-labelled derivatives and the high specific tracer uptake of [11C]SNAP-7941 and [18F]FE@SNAP, there is strong evidence that both radiotracers may serve as highly suitable agents for specific MCHR1 imaging.© The Author(s) 201