196,020 research outputs found
Analysis of monacolins and berberine in food supplements for lipid control: An overview of products sold on the italian market
Full text linkThe use of dietary supplements for the prevention and management of diseases associated with excess of lipids is spreading in Western countries. Supplements containing red yeast rice (RYR) and extracts from Berberis species, characterized, respectively, by the active compounds monacolin K (MK) and berberine (BBR), are sold in pharmacies as over the counter medicines (OTC) and in regular markets without the need of medical prescription and medical surveillance. However, MK is chemically identical to lovastatin, a drug commonly used to treat hypercholesterolemia, and is characterized by the same mechanism of action, pharmacokinetic profile and toxicity. On the other hand, although BBR-containing supplements are considered to be well-tolerated and safe, they frequently show poor standardization of active ingredients, and this could lead to lack of effects. In this work, with the aim to give an overview on the potency of RYR-and BBR-containing supplements available on the Italian market, we analyzed a pool of supplements bought from both local pharmacies and markets. Results confirm the data already published by other authors, showing scarce standardization of bioactives and discrepancy between the doses of bioactives reported by the manufacturers and the amounts resulting from analysis of the same products. Overall, our data represent a further proof that a strict legislation regulating the production and marketing of dietary supplements and a close monitoring of these products by food and drug regulatory organs is mandatory
Simultaneous microdetermination of chlorine, bromine and phosphorus in organic compounds by ion chromatography
No full textA procedure far the simultaneous microdetermination of chlorine, bromine and phosphorus in organic compounds is described. It consists of ion chromatographic analysis, after suitable dilution, of the solution resulting from the collection in water containing hydrogen peroxide of the combustion products obtained by decomposition of the sample in a Schoniger hash. Before analysis, this solution undergoes a post-combustion procedure involving further hydrolysis of the combustion products which allows a nearly quantitative recovery of phosphorus to be achieved even in the presence of other heteroatoms such as chlorine and bromine. This post-combustion step avoids negative errors in the microdetermination of phosphorus by ion chromatography owing to the minor but not insignificant amounts of both pyrophosphate and a cyclic metaphosphate which are formed together with the predominant orthophosphate in the conventional Schoniger combustion of organophosphorus compounds. The accuracy and precision of the overall procedure were evaluated
A non invasive approach to the characterization of natural inorganic colloids: the surface free energy characterization of geomaterials.
No full textMicrodetermination of Chlorine, bromine and phosphorus in organic compounds by ion cromatography
No full textTobramycin kinetics removal on renal replacement therapy by carpediem machine in vitro model
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Metal palladium supported on amphiphilic microporous synthetic organic supports. Part I. Material preparation and textural characterization
No full textStyrene, 2-methacryloxyethylsulfonic acid and methylenebisacrylamide are copolymerized in the presence of dimethylformamide under gamma-irradiation at room temperature to give potentially amphiphilic, microporous resins. The molar fraction of methylenebisacrylamide (the cross-linker) ranges from 1 to 6 mol%. The obtained resins, after grinding and sieving, are treated with solutions of Pd(AcO)(2) and the ion-exchanged polymers are then treated with NaBH4 in ethanol. The metal content in the materials ranges from 2.1% to 2.4% (w/w). X-ray microprobe analysis shows that Pd(0) is homogeneously dispersed throughout the particles of the polymeric materials. The polymer chain concentration and its distribution in the swollen macromolecular networks are assessed by means of Inverse Steric Exclusion Chromatography (ISEC). In spite of the higher molar proportion of styrene repeating units, the Pd(0)-resin composites swell comparably in water and tetrahydrofurane, Their amphiphilic character is the result of the different swelling properties of the hydrophilic and hydrophobic domains
Antiproliferative Homoleptic and Heteroleptic Phosphino Silver(I) Complexes: Effect of Ligand Combination on Their Biological Mechanism of Action
Full text linkA series of neutral mixed-ligand [HB(pz)3]Ag(PR3) silver(I) complexes (PR3 = tertiary phosphine, [HB(pz)3]- = tris(pyrazolyl)borate anion), and the corresponding homoleptic [Ag(PR3)4]BF4 compounds have been synthesized and fully characterized. Silver compounds were screened for their antiproliferative activities against a wide panel of human cancer cells derived from solid tumors and endowed with different platinum drug sensitivity. Mixed-ligand complexes were generally more effective than the corresponding homoleptic derivatives, but the most active compounds were [HB(pz)3]Ag(PPh3) (5) and [Ag(PPh3)4]BF4 (10), both comprising the lipophilic PPh3 phosphine ligand. Detailed mechanistic studies revealed that both homoleptic and heteroleptic silver complexes strongly and selectively inhibit the selenoenzyme thioredoxin reductase both as isolated enzyme and in human ovarian cancer cells (half inhibition concentration values in the nanomolar range) causing the disruption of cellular thiol-redox homeostasis, and leading to apoptotic cell death. Moreover, for heteroleptic Ag(I) derivatives, an additional ability to damage nuclear DNA has been detected. These results confirm the importance of the type of silver ion coordinating ligands in affecting the biological behavior of the overall corresponding silver complexes, besides in terms of hydrophilic-lipophilic balance, also in terms of biological mechanism of action, such as interaction with DNA and/or thioredoxin reductase
The importance on an integrated analytic approach to the study of physico-chemical characteristics of natural thermal waters used for pelotherapy aims: perspectives for reusing cooled thermal waters for treatments related to thermalism applications
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