Raspberry seed extract effect on the ferroxidase activity of ceruloplasmin isolated from plasma

In this study, the effect of the raspberry seed extract (RSE) on the ferroxidase activity of ceruloplasmin (Cp) isolated from healthy male subject serum was analyzed. The ferroxidase activity of Cp was determined by spectrophotometry using Fe(II) – histidine complex and ferrozine as a chromogenic reagent. The ferroxidase activity of ceruloplasmin was demonstrated in dose-dependent way within the range 22–66 μg/ml. The effect of RSE on Fe(II) concentration, measured as the decrease of Fe(II) concentration in samples and expressed as ΔFe(II), was found to be a dose-dependent within the range 1.20–51.56 μg dm/ml. The ferroxidase activity of Cp was influenced by the RSE within its studied range. However, the addition of the highest concentration of RSE (51.56 μg dm/ml) to the sample containing the highest level of Cp (66 μg/ml) did not affect its ferroxidase activity. It may be suggested that the competition for Fe(II) as the substrate limits the effect of RSE on Cp activity and causes no further changes in Fe(II) elimination.     

Modulation of Prostanoids Profile and Counter-Regulation of SDF-1α/CXCR4 and VIP/VPAC2 Expression by Sitagliptin in Non-Diabetic Rat Model of Hepatic Ischemia-Reperfusion Injury

Molecular mechanisms underlying the beneficial effect of sitagliptin repurposed for hepatic ischemia-reperfusion injury (IRI) are poorly understood. We aimed to evaluate the impact of IRI and sitagliptin on the hepatic profile of eicosanoids (LC-MS/MS) and expression/concentration (RTqPCR/ELISA) of GLP-1/GLP-1R, SDF-1α/CXCR4 and VIP/VPAC1, VPAC2, and PAC1 in 36 rats. Animals were divided into four groups and subjected to ischemia (60 min) and reperfusion (24 h) with or without pretreatment with sitagliptin (5 mg/kg) (IR and SIR) or sham-operated with or without sitagliptin pretreatment (controls and sitagliptin). PGI₂, PGE₂, and 13,14-dihydro-PGE₁ were significantly upregulated in IR but not SIR, while sitagliptin upregulated PGD₂ and 15-deoxy-12,14-PGJ₂. IR and sitagliptin non-significantly upregulated GLP-1 while Glp1r expression was borderline detectable. VIP concentration and Vpac2 expression were downregulated in IR but not SIR, while Vpac1 was significantly downregulated solely in SIR. IRI upregulated both CXCR4 expression and concentration, and sitagliptin pretreatment abrogated receptor overexpression and downregulated Sdf1. In conclusion, hepatic IRI is accompanied by an elevation in proinflammatory prostanoids and overexpression of CXCR4, combined with downregulation of VIP/VPAC2. Beneficial effects of sitagliptin during hepatic IRI might be mediated by drug-induced normalization of proinflammatory prostanoids and upregulation of PGD₂ and by concomitant downregulation of SDF-1α/CXCR4 and reinstating VIP/VCAP2 signaling.     

Catalytic Cracking of Rapeseed Oil with Binary Oxide Systems: An Alternative to Production of Petrochemicals

The aim of this work is to evaluate analytical tools for fast assessment of the catalysts’ ability to conduct a catalytic cracking process with the use of vegetable oils. The practical context of the presented concept relates to the use of cracking reaction products as valuable chemical raw materials. The proposed analytical tools allow for quick assessment of reaction products, indication of the molecular weight range, or the presence of specific functional groups. We want to emphasize that vegetable oils can not only be raw products for biofuels but also an alternative to petrochemicals. The study was undertaken to determine the influence of acid–base properties of catalysts on the rapeseed oil conversion process at 500°C. The effect of these properties on the character of the process and quality of the products obtained was shown to be very high. Basic correlations between the formation of coke, gaseous products and dehydrogenation products, and acid–base parameters of the individual catalysts have been observed. The use of spectroscopic methods (FTIR - Fourier Transform Infrared Spectroscopy, ¹H NMR - Nuclear Magnetic Resonance) for fast qualitative analysis of the products is described.     

Synthesis of metal-carbonyl-dendrimer-antibody immunoconjugates: towards a new format for carbonyl metallo immunoassay

We report the preparation of metal-carbonyl-dendrimer-antibody conjugates. These metal-carbonyl-multilabeled antibodies are designed to be used in a new solid-phase-format carbonyl metallo immunoassay (CMIA). A fourth-generation polyamidoamine dendrimer was labeled with 10-25 (eta5-cyclopentadienyl)iron dicarbonyl (eta1-N-succinimidyl) entities. An antibody was chemically modified at its carbohydrate chains by a site-directed process used to preserve the antigen-antibody binding site. The antibody was then coupled with the dendrimer labeled with 10 metal carbonyl groups. An average of 1.4 labeled dendrimers were grafted per antibody molecule. These metal-carbonyl-dendrimer-antibody conjugates were used as new universal detection reagents that recognize their specific antigens. The antigens were spotted onto nitrocellulose membranes and detected by using the conjugates in combination with Fourier transform infrared spectroscopy. A detection level in the range 5-200 pmol per membrane was achieved. This approach opens the way to a new CMIA format.     

Kinetics study and crystallization process design for scale‐up of UiO‐66‐NH2 synthesis

A comprehensive scale‐up procedure for amine‐functionalized UiO‐66 is implemented, which leads to the development of a novel flow‐through metal‐organic framework synthesis process. Products are characterized via BET modeling of N₂ adsorption at 77 K and powder XRD to confirm crystal porosity and phase, respectively. Batch syntheses are conducted to examine the effects of polytetrafluoroethylene and glass vessel materials on crystal yield and quality. Intermediate samples from sealed‐vessel trials at 373, 383, and 393 K are collected and characterized, which show a high degree of product consistency. Nucleation rates are determined at the same temperatures, and the Arrhenius relationship is used to predict the activation energy of nucleation, E_aNuc. A continuous‐flow reactive crystallization process is developed using a draft‐tube type reactor. As a proof of concept, the reactor is operated for three retention times. The cumulative product, material retained within the crystallizer, and intermediate samples are collected and characterized to confirm UiO‐66‐NH₂ production. © 2012 American Institute of Chemical Engineers AIChE J, 59: 1255–1262, 2013     

Cysteine-specific, covalent anchoring of transition organometallic complexes to the protein papain from Carica papaya

Site-directed and covalent introduction of various transition metal-organic entities to the active site of the cysteine endoproteinase, papain, was achieved by treatment of this enzyme with a series of organometallic maleimide derivatives specially designed for the purpose. Kinetic studies made it clear that time-dependent irreversible inactivation of papain occurred in the presence of these organometallic maleimides as a result of Michael addition of the sulfhydryl of Cys25. The rate and mechanism of inactivation were highly dependent on the structure of the organometallic entity attached to the maleimide group. Combined ESI-MS and IR analysis indicated that all the resulting papain adducts contained one organometallic moiety per protein molecule. This confirmed that chemospecific introduction of the metal complexes was indeed achieved. Thus, three novel reagents for heavy-atom derivatization of protein crystals, which include ruthenium, rhenium and tungsten, are now available for the introduction of electron-dense scatterers for phasing of X-ray crystallographic data.