Lanthanide(III) complexes are more active inhibitors of the Fenton reaction than pure ligands

OBJECTIVES: This study is an extension to our finding of direct anti-oxidant activities of lanthanide(III) complexes with the heterocyclic compound, 5-aminoorotic acid (AOA). In this experiment, we used AOA and coumarin-3-carboxylic acid as the two heterocyclic compounds with anti-oxidant potential, to produce the complexes with different lanthanides. METHODS: Lanthanide(III) complexes were tested on the iron-driven Fenton reaction. The product of this reaction, the hydroxyl radical, was detected by HPLC. RESULTS: All complexes as well as their ligands had positive or neutral effect on the Fenton reaction but their behavior was different. Both pure ligands in low concentration ratio to iron were inefficient in contrast to some of their complexes. Complexes of neodymium, samarium, gadolinium, and partly of cerium blocked the Fenton reaction at very low ratios (in relation to iron) but the effect disappeared at higher ratios. In contrast, lanthanum complexes appeared to be the most promising. Both blocked the Fenton reaction in a dose-dependent manner. CONCLUSION: Lanthanide(III) complexes were proven to block the iron-driven production of the hydroxyl radical. Second, the lanthanide(III) element appears to be crucial for the anti-oxidant effect. Overall, lanthanum complexes may be promising direct anti-oxidants for future testing

Nové chelátory železa a antioxidancia u modelu akutního infarktu myokardu a oxidačního stresu navozeného katecholaminy - vliv na základní biochemické parametry

I. SOUHRN ÚVOD: Železo je nezbytným prvkem pro celou řadu fyziologických procesů, mj. přenos kyslíku, syntézu DNA a tvorbu ATP. Osud železa v organismu je pečlivě regulován zejména na úrovni absorpce a distribuce pravděpodobně z důvodu neexistujícího specifického aktivního exkrečního mechanismu pro železo. Každé porušení homeostázy železa může vést k objevení se volného (nevázaného nebo slabě vázaného) železa, které je schopno katalyzovat tvorbu reaktivních forem kyslíku (ROS) prostřednictvím Haber-Weissova mechanismu. Kardiovaskulární onemocnění, zejména pak ischemická choroba srdeční (ICHS), zůstávají přes recentní vědecké pokroky vážným medicinálním problémem. Nejzávažnější formou ICHS je akutní infarkt myokardu (AIM). Jeho patofyziologie zahrnuje ve většině případů iniciální ischemickou periodu v důsledku poruchy koronárního krevního proudu způsobeného trombózou nasedající obvykle na ateroskleroticky postiženou koronární tepnu. Ischémie podstatně mění tkáňovou homeostázu s následným objevením se volného cytosolického železa. Obnova koronárního krevního průtoku (tzv. reperfúze) je jedinou možností k záchraně poškozeného myokardu, je ale na druhé straně spojena s uvolněním zmíněného volného železa do cirkulace a tvorbou ROS jak uvnitř tak vně buňky. Chelátory železa představují rozsáhlou skupinu léčiv s...I. SUMMARY Background: Iron is an essential element necessary for many physiological processes involving oxygen transport, DNA-synthesis and ATP-formation. The fate of iron in the organism is tightly regulated especially at the absorption and distribution level probably mainly due to lack of specific active iron excretion mechanism. Any derangement of iron homeostatis may lead to appearance of free (unbound or loosely bound) iron, which can catalyse reactive oxygen species (ROS) production by Haber-Weiss chemistry. Cardiovascular diseases, particularly coronary heart disease (CHD), remain notwithstanding recent scientific advances important therapeutic problem. The most serious form of CHD represents acute myocardial infarction (AMI). The pathophysiology of AMI involves in most cases initial ischaemic period caused by coronary blood flow derangement due to a thrombus formation. Ischaemia alters substantially tissue homeostasis with subsequent cytosolic free iron appearance. Reconstitution of coronary blood flow (reperfusion) represents the only way for myocardial tissue recovery although on the other hand, it is linked with a release of free redox-active iron in the circulation and formation of ROS both intracellularly as well extracellularly. Iron chelators are a large group of drugs with very...Katedra farmakologie a toxikologieDepartment of Pharmacology and ToxicologyFaculty of Pharmacy in Hradec KrálovéFarmaceutická fakulta v Hradci Králov

Green analytical chemistry (GAC) applications in sample preparation for the analysis of anthocyanins in products and by-products from plant sources

Agri-food industry manufacturing is an important source of environmental pollution and eutrophication, both intrinsically and due to the generation of significant amount of by-products. For this reason, green chemistry is currently at the forefront of efforts to make all steps of agri-food workflows more sustainable and environmentally friendly and to reduce their carbon footprint. Green analytical chemistry (GAC) is an integral part of these efforts, although it has been largely neglected until now, due to the fact that analytical procedures are mainly limited to quality control in this field, and thus produce just a small fraction of the overall environmental burden of agri-food processes. In this mini-review, the most recent developments of green analytical methods are described, relative to their applications for anthocyanin determination in agri-food products and by-products. Anthocyanins have been chosen as they are among the most valuable secondary plant metabolites, with a wide range of possible applications exploiting their preservative, antioxidant and coloring properties. Non-separative and separative analytical meth- ods are included in this mini-review. The former are mainly spectrometric in nature, and usually mostly allow to detect and/or quantify groups or classes of molecules. However, they also provide very high throughput and the greatest chance to develop low-energy, low-solvent consumption procedures, even to the point of enabling direct determinations in solid samples as such. On the other hand, separative methods provide far greater selectivity and far wider applicability, but at the price of higher energy and resource consumption and usually lower throughput

An Original HPLC Method with Coulometric Detection to Monitor Hydroxyl Radical Generation via Fenton Chemistry

Hydroxyl radicals (•OH) can be generated via Fenton chemistry catalyzed by transition metals. An in vitro Fenton system was developed to test both the inhibition and stimulation of •OH formation, by monitoring salicylate aromatic hydroxylation derivatives as markers of •OH production. The reaction was optimized with either iron or copper, and target analytes were determined by means of an original HPLC method coupled to coulometric detection. The method granted good sensitivity and precision, while method applicability was tested on antioxidant compounds with and without chelating properties in different substance to metal ratios. This analytical approach shows how Fenton's reaction can be monitored by HPLC coupled to coulometric detection, as a powerful tool for studying molecules' redox behavior

Infusion and decoction of wild German chamomile: bioactivity and characterization of organic acids and phenolic compounds

Natural products represent a rich source of biologically active compounds and are an example of molecular diversity, with recognised potential in drug discovery. Herein, the methanol extract of Matricaria recutita L. (German chamomile) and its decoction and infusion (the most consumed preparations of this herb) were submitted to an analysis of phytochemicals and bioactivity evaluation. The antioxidant activity was determined by free radicals scavenging activity, reducing power and inhibition of lipid peroxidation; the antitumour potential was tested in human tumour cell lines (breast, lung, colon, cervical and hepatocellular carcinomas), and the hepatotoxicity was evaluated using a porcine liver primary cell culture (non-tumour cells). All the samples revealed antioxidant properties. The decoction exhibited no antitumour activity (GI(50)>400 μg/mL) which could indicate that this bioactivity might be related to compounds (including phenolic compounds) that were not extracted or that were affected by the decoction procedure. Both plant methanol extract and infusion showed inhibitory activity to the growth of HCT-15 (GI(50) 250.24 and 298.23 μg/mL, respectively) and HeLa (GI(50) 259.36 and 277.67 μg/mL, respectively) cell lines, without hepatotoxicity (GI(50)>400 μg/mL). Infusion and decoction gave higher contents of organic acids (24.42 and 23.35 g/100g dw). Otherwise, the plant methanol extract contained the highest amounts of both phenolic acids (3.99 g/100g dw) and flavonoids (2.59 g/100g dw). The major compound found in all the preparations was luteolin O-acylhexoside. Overall, German chamomile contains important phytochemicals with bioactive properties (mainly antitumour potential selective to colon and cervical carcinoma cell lines) to be explored in the pharmaceutical, food and cosmetics industries.The authors are grateful to strategic project PEst-OE/AGR/UI0690/2011 for financial support to CIMO. R. Guimaraes, L. Barros and R. Calhelha thank FCT, POPH-QREN and FSE for their Grants (SFRH/BD/78307/2011, SFRH/BPD/4609/2008 and SFRH/BPD/68344/2010). The GIP-USAL is financially supported by the Consolider-Ingenio 2010 Programme (FUN-C-FOOD, CSD2007-00063). M. Duenas thanks the Spanish "Ramon y Cajal" Programme for a contract

System for information and knowledge management in law firms

Práce se zabývá některými aspekty řízení informací a znalostí v prostředí právních firem a advokátních kanceláří. V obecné rovině se zabývá specifiky informací a znalostí potřebných pro výkon této profese. Neboť se předpokládá, že znalosti jsou nositeli vyšší užitné hodnoty než informace, je patřičná pozornost věnována vybraným teoretickým aspektů znalostního managementu. Na základě zkoumané typologie informací a znalostní, jejich zdrojů nebo formy se práce snaží o navržení optimální struktury celého systému managementu znalostí v právní praxi. Z analýzy vybraných úkolů, spojených se zaváděním principů znalostního managementu, se práce snaží o vyvození závěrů pro navržení optimálního organizačního a personálního zajištění dílčích úkolů. Významná část práce je také věnována otázkám využití tradičních informačních služeb ve spojení s možnostmi moderních informačními a komunikačních technologií

Comparison in information literacy between German and Czech

Import 21/02/2008Prezenční155 - Katedra aplikované informatikyNeuveden

Impact of ICT on economy and the role of state in the information society

Práce se zabývá vybranými aspekty vlivu informačních technologií na ekonomiku především v prostředí národní ekonomiky. Významná část práce je věnována výzvám tzv. nové ekonomiky, proměnám tradičních ekonomických mechanismů a informační asymetrii s naznačením současného krizového prostředí. Dále jsou zhodnoceny zdroje ekonomického růstu a příspěvek ICT k produktivitě, především pak ve státní správě a ve vnitropodnikové praxi. Rozebírány jsou sociální důsledky a dopady používání současných informačních a komunikačních technologií na společnost a úloha státu z několika různých pohledů. Naznačeno je působení globalizace a vliv Evropské unie na sektor informačních technologií