Possibilities of determination of metalocompounds present in living systems

Tato bakalářská práce pojednává o problematice metalomiky. Jsou zde vysvětleny základní pojmy a definice, rozdíly mezi proteiny vázanými s kovem a metaloproteiny. Práce se také zabývá metalothioneiny a jejich základním rozdělením. Práce popisuje způsoby interakcí kovů s organickými sloučeninami. Pozornost je věnována vazbě kovů s peptidy a bílkovinami. V práci jsou uvedeny příklady některých esenciálních kovů, které jsou vázány v důležitých organických sloučeninách, které jsou nutné pro správné fungování organismu. Především jsou popsány enzymy nezbytné pro lidský organismus. Uvedeny jsou i organické sloučeniny toxických kovů. Další část práce je věnována analytickým metodám používaným při stanovení metalosloučenin. Jsou popsány separační a detekční metody, které se vzájemně kombinují, aby bylo možné metalosloučeniny kvalitativně i kvantitativně stanovit. Uvedeny jsou příklady stanovení vybraných metalosloučenin.This bachelor thesis deals with the topic of metallomics. There are explained basic concepts and definitions, differences between the metal-binding proteins and metalloproteins. This thesis also deals with metallothioneins and theirs basic types. The study describes possible interactions of metals and organic compounds. Attention is paid to interactions between metals and peptides or proteins. There are given examples of some essential metals, which are linked to important organic compounds, which are necessary for the proper function of the organism. Mainly there are described enzymes necessary for the human body. There are also referred organic compounds of toxic metals. Another part of the thesis is devoted to analytical methods used for determination of metallocompounds. There are described methods for separation and detection, which are combined for qualification and quantification of metallocompounds. There are referred examples of the determination of some metallocompounds.

Determination of selected metals in fruit compotes

Tato diplomová práce je zaměřena na stanovení vybraných kovů v ovocných kompotech balených v plechových konzervách. Je v ní popsána výroba ovocných kompotů a kovových obalových materiálů, legislativa týkající se studované problematiky, možnosti kontaminace potraviny složkami obalu, koroze obalů, migrace kovů z obalů a techniky používané pro analýzu kovů v potravinářství. V experimentální části byly pomocí techniky ICP-MS stanoveny koncentrace kovů v 14 různých ovocných kompotech z obchodní sítě ČR. Koncentrace kovů byla zjišťována pouze ve šťávě z kompotů, protože ta je v přímém kontaktu s povrchem obalu, a kovy přecházejí nejprve do ní. Naměřené hodnoty byly porovnány s maximálními přípustnými hodnotami kovů v ovocných kompotech, které určuje evropská legislativa. U cínu byly v některých případech zjištěny zvýšené koncentrace, u ostatních kovů hodnoty nepřekračovaly povolená množství. Koncentrace kovů v kompotech se lišila v závislosti na druhu kompotu, což mohlo být způsobeno jiným chemickým složením náplně v závislosti na původu potraviny a způsobem pěstování vybraného ovoce, či různou povrchovou úpravou plechovky.This diploma thesis deals with the determination of some metals in fruit compotes packed in cans. There is described the production of fruit compotes and metal packaging legislation relating to the studied issues, the possibility of contamination of food packaging components, packaging corrosion, metal migration from packaging and techniques used for the analysis of metals in the food industry. Concentrations of metals in 14 different fruit compotes from a commercial network in the Czech Republic were determined by ICP-MS technique in the experimental part. Concentrations of metals were detected only in the juice of stewed fruit, because the juice is in direct contact with the surface of packaging, and metals are transferred first into it. The measured values were compared with the maximum permissible levels of metals in fruit compote determined by European legislation. In some cases there were found higher concentrations of tin, but other metals did not exceed the allowable amounts. Concentrations of metals in the compote varied depending on the kind of compote, which could be due to a different chemical composition of compotes depending on the origin of food and process of the fruit production, or a different cans coating material.

Formulation, antibacterial activity, and cytotoxicity of 1-monoacylglycerol microemulsions

Antibacterial activity of stable 1-monoacylglycerol (1-MAG) microemulsions (MEs) of capric (C10:0), undecanoic (C11:0), lauric (C12:0), and myristic (C14:0) acids against the growth of gram-positive and gram-negative bacteria was tested and their inhibition effect was compared to that of neat 1-MAG. To reveal their behavior with respect to eukaryotic cells, the cytotoxicity on mouse fibroblasts was also determined. The MEs were studied via pseudo-ternary phase diagrams in order to find out the miscibility areas of all components used. The results indicated that at 1-MAG concentrations of 1000-1900mg/L, an inhibition of gram-negative strains was improved compared to neat 1-MAG and depended on the fatty acid type; however, at lower 1-MAG concentrations, both systems showed comparable effect. The opposite trend was detected on gram-positive bacteria, where 1-MAGs showed better performance compared to corresponding MEs. The best antibacterial activity against both bacterial types was observed in 1-MAG C12:0 MEs. MTT assay revealed significant cytotoxicity of all MEs. The threshold of 10mg/L was determined as the limit for moderate toxicity, which represents 40-60% cell survival. All prepared MEs were transparent, stable during the storage period of 6 months and their particle sizes were between 15 and 20nm. Practical applications: 1-MAGs belong to safe and efficient antimicrobial agents and their application may be a convenient alternative to usage of synthetic antimicrobials; however, one of their limitations for certain applications is their insolubility in aqueous systems. This drawback can be reduced by encapsulation of 1-MAGs in suitable ME system. The presented study has confirmed that 1-MAG MEs possess suitable inhibitory activity against both gram-negative and gram-positive bacteria. Efficacy of MEs against gram-negative strains was enhanced compared to 1-MAG alone. Although the growth of gram-positive bacteria was less affected by MEs when compared to neat 1-MAG, the results can be closely related to potential industrial applications of the MEs as effective agents for cosmetics, dermatology, food industry, paint or coatings where water-based systems are frequently used and desired. The application of studied systems might be to some extent limited due to the potential health risk caused by the observed cytotoxicity.Operational Program Research and Development for Innovations; European Regional Development Fund (ERDF); national budget of Czech Republic, within the framework of project Centre of Polymer Systems [CZ.1.05/2.1.00/03.0111]; TBU in Zlin [IGA/FT/2013/016