60 research outputs found

    Interactions of vanadium(V)–citrate complexes with the sarcoplasmic reticulum calcium pump

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    Among the biotargets interacting with vanadium is the calcium pump from the sarcoplasmic reticulum (SR). To this end, initial research efforts were launched with two vanadium(V)–citrate complexes, namely (NH4)6[V2O4(C6H4O7)2] Æ 6H2O and (NH4)6[V2O2(O2)2(C6H4O7)2] Æ 4H2O, potentially capable of interacting with the SR calcium pump by combining kinetic studies with 51V NMR spectroscopy. Upon dissolution in the reaction medium (concentration range: 4–0.5 mM), both vanadium(V):citrate (VC) and peroxovanadium(V):citrate (PVC) complexes are partially converted into vanadate oligomers. A 1 mM solution of the PVC complex, containing 184 lM of the PVC complex, 94 lM oxoperoxovanadium(V) (PV) species, 222 lM monomeric (V1), 43 lM dimeric (V2) and 53 lM tetrameric (V4) species, inhibits Ca2+ accumulation by 75 %, whereas a solution of the VC complex of the same vanadium concentration, containing 98 lM of the VC complex, 263 lM monomeric (V1), 64 lM dimeric (V2) and 92 lM tetrameric (V4) species inhibits the calcium pump activity by 33 %. In contrast, a 1 mM metavanadate solution, containing 460 lM monomeric (V1), 90.2 lM dimeric (V2) and 80 lM tetrameric (V4) species, has no effect on Ca2+ accumulation. The NMR signals from the VC complex ( 548.0 ppm), PVC complex ( 551.5 ppm) and PV ( 611.1 ppm) are broadened upon SR vesicle addition (2.5 mg/ml total protein). The relative order for the half width line broadening of the NMR signals, which reflect the interaction with the protein, was found to be V4 > PVC > VC > PV > V2 = V1 = 1, with no effect observed for the V1 and V2 signals. Putting it all together the effects of two vanadium( V)–citrate complexes on the modulation of calcium accumulation and ATP hydrolysis by the SR calcium pump reflected the observed variable reactivity into the nature of key species forming upon dissolution of the title complexes in the reaction media

    Strategi Pengembangan USAha Agrowisata di Kebun Benih Hortikultura, Tohudan, Colomadu, Karanganyar

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    : The purpose of the research are to know the revenue in one year, knowing the factors internally and externally which became strengths, weaknesses, opportunities and threats, knowing a good alternative strategies to be formulated and know the priority good strategy to be applied in Kebun Benih Hortikultura Tohudan, Colomadu, Karanganyar. The basic methode of research is a descriptive analysis. Location of research in Kebun Benih Hortikultura Tohudan, Colomadu, Karanganyar. The data used are primary and secondary data. The analysis of the data used are (1) Revenue analysis, (2) Internal Factor Evaluation (IFE), (3) External Factor Evaluation (EFE), (4) SWOT, (5) QSPM. The result showed that income received by Kebun Benih Hortikultura Tohudan, Colomadu, Karanganyar in one year is Rp 65.766.000,00. Internal Factor Evaluation (IFE) showed the garden have six strengths and nine weaknesses. External Factor Evaluation (EFE) showed the garden have six opportunities and five threats. SWOT analysis showed the alternatives strategies that can be applied are utilize advances in technology information to promoting and marketing, building a relationship of cooperation with the investor, expand marketing production result and improve the situation of the garden to make it more interesting. QSPM showed a good strategy priorities to be applied is improve the situation of the garden to make it more interesting

    In-depth synthetic, physicochemical and in vitro biological investigation of a new ternary V(IV) antioxidant material based on curcumin.

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    Curcumin is a natural product with a broad spectrum of beneficial properties relating to pharmaceutical applications, extending from traditional remedies to modern cosmetics. The biological activity of such pigments, however, is limited by their solubility and bioavailability, thereby necessitating new ways of achieving optimal tissue cellular response and efficacy as drugs. Metal ion complexation provides a significant route toward improvement of curcumin stability and biological activity, with vanadium being a representative such metal ion, amply encountered in biological systems and exhibiting exogenous bioactivity through potential pharmaceuticals. Driven by the need to optimally increase curcumin bioavailability and bioactivity through complexation, synthetic efforts were launched to seek out stable species, ultimately leading to the synthesis and isolation of a new ternary V(IV)-curcumin-(2,2’-bipyridine) complex. Physicochemical characterization (elemental analysis, FT-IR, Thermogravimetry (TGA), UV-Visible, NMR, ESI-MS, Fluorescence, X-rays) portrayed the solid-state and solution properties of the ternary complex. Pulsed-EPR spectroscopy, in frozen solutions, suggested the presence of two species, cis- and trans-conformers. Density Functional Theory (DFT) calculations revealed the salient features and energetics of the two conformers, thereby complementing EPR spectroscopy. The well-described profile of the vanadium species led to its in vitro biological investigation involving toxicity, cell metabolism inhibition in S. cerevisiae cultures, Reactive Oxygen Species (ROS)-suppressing capacity, lipid peroxidation, and plasmid DNA degradation. A multitude of bio-assays and methodologies, in comparison to free curcumin, showed that it exhibits its antioxidant potential in a concentration-dependent fashion, thereby formulating a bioreactivity profile supporting development of new efficient vanado-pharmaceuticals, targeting (extra)intra-cellular processes under (patho)physiological conditions

    Structural speciation in chemical reactivity profiling of binary-ternary systems of Ni(II) with iminodialcohol and aromatic chelators

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    The importance of structural speciation in the control of chemical reactivity in Ni(II) binary-ternary systems, involving (O,O,N)-containing substrates (1,1’-iminodi-2-propanol), and aromatic chelators (2,2’-bipyridine, 1,10-phenanthroline), prompted the systematic synthesis of new crystalline materials characterized by elemental analysis, FT-IR, UV-Visible, Luminescence, TGA, magnetic susceptibility, and X-ray crystallography. The structures contain mononuclear octahedral assemblies, the lattice architecture of which exemplifies reaction conditions under which conformational variants and solvent-associated lattice-imposed complexes are assembled. Transformations between complex species denote their association with reactivity pathways, suggesting alternate synthetic methodologies for their isolation. Theoretical work (Hirshfeld, Electrostatic Potential, DFT) signifies the impact of crystal structure on energy profiles of the generated species. The arisen physicochemical profiles of all compounds portray a well-configured interwoven network of pathways, projecting strong connection between structural speciation and Ni(II) reactivity patterns in organic-solvent media. The collective results provide well-defined parameterized profiles, poised to influence the synthesis of new Ni(II)-iminodialcohol materials with specified structural-magneto-optical properties

    Delving into the complex picture of Ti(IV)-citrate speciation in aqueous media: Synthetic, structural, and electrochemical considerations in mononuclear Ti(IV) complexes containing variably deprotonated citrate ligands

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    The aqueous reaction of TiCl4 with citric acid at pH 4 (KOH), led to the surprising isolation of a species assembly K3[Ti(C6H6O7)2(C6H5O7)] K4[Ti(C6H5O7)2(C6H6O7)] 10H2O (1). The same system at pH 3 (neocuproine), led to the crystalline material (C14H13N2)2[Ti(C6H6O7)3] 5H2O (2), while at pH 5.0 (NaOH), afforded Na3[Ti(C6H6O7)2(C6H5O7)] 9H2O (3). Analytical, spectroscopic and structural characterization of 1, 2 and 3 revealed their distinct nature exemplified by mononuclear complexes bearing variably deprotonated citrates bound to Ti(IV). Solid-state 13C MAS NMR spectroscopy in concert with solution 13C and 1 H NMR on 3 provided ample evidence for the existence of bound citrates of distinct coordination mode to the metal ion. Cyclic voltammetry defined the electrochemical signature of complex 2, thereby projecting the physicochemical profile of the species formulated by the aforementioned properties. Comparison of cyclic voltammetric data on available discrete Ti(IV)–citrate species depicts the electrochemical profile and an E1/2 value trend of the species in that binary system’s aqueous speciation, further substantiating the redox behavior of mononuclear Ti(IV)–citrate species in a pH-sensitive fashion. Collectively, the well-defined discrete species in 1–3 reflect and corroborate a synthetically challenging yet complex pH-specific picture of the aqueous Ti(IV) chemistry with the physiological citric acid, and shed light on the pH-dependent speciation in the binary Ti(IV)–citrate syste

    A unique ternary Ce(III)-quercetin-phenanthroline assembly with antioxidant and anti-inflammatory properties.

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    From PubMed via Jisc Publications RouterHistory: received 2022-06-19, revised 2022-07-15, accepted 2022-07-24Publication status: ppublishQuercetin is one of the most bioactive and common dietary flavonoids, with a significant repertoire of biological and pharmacological properties. The biological activity of quercetin, however, is influenced by its limited solubility and bioavailability. Driven by the need to enhance quercetin bioavailability and bioactivity through metal ion complexation, synthetic efforts led to a unique ternary Ce(III)-quercetin-(1,10-phenanthroline) (1) compound. Physicochemical characterization (elemental analysis, FT-IR, Thermogravimetric analysis (TGA), UV-Visible, NMR, Electron Spray Ionization-Mass Spectrometry (ESI-MS), Fluorescence, X-rays) revealed its solid-state and solution properties, with significant information emanating from the coordination sphere composition of Ce(III). The experimental data justified further entry of 1 in biological studies involving toxicity, (Reactive Oxygen Species, ROS)-suppressing potential, cell metabolism inhibition in Saccharomyces cerevisiae (S. cerevisiae) cultures, and plasmid DNA degradation. DFT calculations revealed its electronic structure profile, with in silico studies showing binding to DNA, DNA gyrase, and glutathione S-transferase, thus providing useful complementary insight into the elucidation of the mechanism of action of 1 at the molecular level and interpretation of its bio-activity. The collective work projects the importance of physicochemically supported bio-activity profile of well-defined Ce(III)-flavonoid compounds, thereby justifying focused pursuit of new hybrid metal-organic materials, effectively enhancing the role of naturally-occurring flavonoids in physiology and disease. [Abstract copyright: Copyright © 2022 Elsevier Inc. All rights reserved.
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