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Stanovení biologicky aktivních substancí v rostlinném materiálu
Dobeš, Jiří
This thesis is focused on the determination of antioxidants and antioxidant activity. In the first work DMPD method was optimized to determine the antioxidant activity of antioxidants standards and the reaction was monitored depending on the time, temperature and concentration. In the second work automated determination of antioxidant activity of phenolic compounds standards rutin, quercitrine and standards of phenolic acids gallic acid and ferulic acid was tested using five different methods used in the determination of antioxidant activity using an automated pipetting machines and spectrophotometer. In the third work phenolic profile and total antioxidant capacity (TAC) was determined in apricot cultivars with methods high frequency liquid chromatography with tandem electrochemical and UV spectrometric detection and these two methods were compared. In the fourth work electrochemical methods used for the determination of phenolic compounds were described. In the fifth work oxidative stress induced by silver ions in the Staphylococcus aureus bacterial culture was investigated using spectrophotometric and electrochemical methods.
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Content of selected phenolic compounds in spice plants.
BERANOVÁ, Zuzana
This work concerns the amount of certain phenols in some of the representatives of families Alliaceae, Lamiaceae and Apiaceae. Phenols in plants are widely represented and highly concentrated. Flavonoids are one of the smallest, yet quite significant classes of phenols. Ingestion of food containing flavonoids can prevent certain diseases such as Arteriosclerosis. cardiovascular and tumor diseases. This work focuses, for their special biological effects, on five flavonoids: Kaempferol, Quercetin, Myricetin, Apigenin and Luteolin. For determining the content of phenols a method of High-performance liquid chromatography (HPLC) was used. Three representative of the family Alliaceae, two representatives of the family Lamiaceae and three representatives of the family Apiaceae were analysed. Only edible parts of the plants were used for the analysis and the amount of phenols was compared in certain plants planted in beddings to the plants planted in greenhouses. At first, the qualitative representantion of phenols was ascertained by the HPLC method. The result is chromatographic profiles, which were then used in calculating the amount of particular phenols. Then the total amounts of kaempferol, quercetin, myricetin, apigenin and luteolin were found out thanks to HPLC method. The biggest amount of total kaempferol was determined in petroselium hortense planted in beddings (588 mg/kg of fresh sample) and in a greenhouse (340 mg/kg of fresh sample). The biggest amount of quercetin was determined in red onion planted in a greenhouse (773 mg/kg of fresh sample) and in ocimum basilicum planted in beddings (535 mg/kg of fresh sample). The biggest amount of apigenin was determined in petroselium hortense planted in a greenhouse (1790 mg/kg of fresh sample) and in petroselium chrispum planted in beddings (3690 mg/kg of fresh sample).
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Optimization of conditions and procedures for plant extraction.
SMUTNÍKOVÁ, Kateřina
The thesis deals with the content of selected phenolic compounds in some species of the genus Amaranthus, in black elderberry (Sambucus nigra L.) and buckwheat (Fagopyrum esculentum M.). Phenolic compounds are a group of natural compounds exclusively vegetable character. Flavonoids represent only one group of phenolic compounds. Flavonoids show many positive biological effects, in particular act as antioxidants. Natural flavonoids may cause to prevent from coronary- heard diseases and other diseases associated with older age. In recent years the increased attention is paid to flavonoid investigation due to its biological effects. For the determination of phenolic substances there were used two independent analytical methods. There are the high-performance liquid chromatography (HPLC) and micellar electrokinetic capillary chromatography (MECC). The MECC method was used for determination rutin and free quercetin. The highest content of rutin was found in leaves of buckwheat (76,400 mg/kg of dry weight) and the lowest content of rutin was determined in buckwheat hulls. The highest content of rutin was observed in teas from buckwheat leaves and inflorescence. This amount of rutin corresponds with rutin content in more than two pills of Ascorutin (the most favourite flavonoid medicament in the Czech Republic) The HPLC method was used for quantitative determination of phenolic acids. The content of free quercetin was monitored in all samples. No free quercetin was found both in plant material and in samples of teas. The ethanolic extract from the elderberry inflorescence didn´t contain any free quercetin. Free quercetin wasn?t found in any further samples of teas, which were prepared by described methods.
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Effect of available P and phenolics on mineral N release in acidified spruce forest: connection with lignin-degrading enzymes and bacterial and fungal communities
VANĚK, Daniel
Annotation We conducted over four months a shortterm laboratory incubation experiment to find the best prediction parameters (i.e. initial chemical characteristics) to explain differences in microbial respiration rates and mineral N (DIN) release in different litter in an acidified spruce forest. In addition, we wanted to find the link between the activity of key extracellular ligninolytic enzymes, phenoloxidases (PhOx) and peroxidases (PerOx), microbial respiration and composition of fungal and bacterial communities. Samples of spruce needles (Picea abies) and litter of four dominant understorey vegetation; lady fern (Athyrium alpestre), blueberry (Vaccinium myrtillus), reedgrass (Calamagrostis villosa) and hair grass (Avenella flexuosa), were collected in 2005, 2006 and 2007 from six sites located in watersheds of two glacial lakes (Plešné Lake and Čertovo Lake) in the Bohemian Forest, Czech Republic. Litter samples were incubated at 0 and 10 °C in laboratory controlled conditions for 90 days. Activities of PhOx and PerOx, and C mineralization rate were measured regularly each 14 days. Litter quality characteristics and endophytic microbial community structure, based on 16SrDNA-DGGE fingerprint of bacteria and ITS-DGGE of fungi, were determined at the beginning and end of litter incubation. Our results showed a close correlation of phenolics/POX with DIN release (r ? 0.74, p ? 0.001). Using multivariate analyses, POX seems to play an important role in the change of litter fungal and bacterial community composition. At 0 °C the fungal and bacterial communities of reedgrass and blueberry litter changed in relation to POX and PerOx activity, while at 10 °C the fungal communities after the incubation were additionally affected by the phenolics/NTOT and phenolics/PTOT ratios.
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Does ligninolytic enzyme activity depend on phenolics content during the litter decomposition?
APPLOVÁ, Markéta
The aim of the study was to determine the influence of phenolics content and inoculation with soil extract on microbial respiration, on the phenoloxidase (PhOx), peroxidase (PerOx) and newly Mn-peroxidase (MnP) activity in two dominating litter samples (Calamagrostis villosa and Picea abies) differing in phenolics content from Plešné and Čertovo lake watersheds. At PhOx and PerOx activity, the dependence on incubation temperature with L-DOPA was estimated. PhOx and MnP activities significantly increased with higher content of hardly decomposable phenolics, but decreased with water extractable phenolics content. Inoculation with soil extract had no influence on microbial respiration, enzyme activity, nor on decomposition of phenolics. Microbial respiration was significantly higher at 10°C, but average enzyme activity was comparable at 0 and 10°C. PhOx activities had temperature optimum higher than 22°C, while PerOx activities had temperature optimum at 0 - 15°C.
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The content of selected phenolic compounds in representatives of Chenopodium L and Atriplex L genera.
DĚKANOVÁ, Zdeňka
The thesis deals with measuring the content of chosen phenolic substances in some specimen of the genera Chenopodium L. and Atriplex L. Two independent analytical methods were used to determine the content of phenolic substances, namely the Micellar Electrokinetic Capillary Chromatography (MECC) method and the High - Performance Liquid Chromatography (HPLC) method. Two cultured species of the genera Spinacia and Atriplex, three freely growing specimen of the genus Chenopodium and three freely growing species of the genus Atriplex were analysed. The analysis concerned the leaves and the inflorescence of these species.The total content of quercetin and rutin was determined by the MECC method. The highest total content of quercetin was found in the leaves of the Garden Orache (4240 mg/kg of dry matter), the lowest total content of quercetin was found in the inflorescence of the Atriplex prostrata DC. (19.6 mg/kg of dry matter). Rutin was only found in four samples, the rest of the samples contained rutin in quantities below the limit of quantification. The highest content of rutin was found in the leaves of the Lamb´s Quarters (868 mg/kg of dry matter).
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The content of selected fenolic compounds in medicinal plants.
KREJČÍ, Zuzana
The work has been inquired into the problem of content determination of phenolic substances in medicinal plants traditionally used in Czech Republic. Phenolic substances belong to a group of natural compounds, which are purely plant origin. Flavonoids are a part of this extensive group of compounds. As for flavonoids, most attention is paid to quercetin and rutin. It is caused by their easy availability and very significant biological activity. These compounds embody a lot of positive biological effects. They have expressive antioxidant properties, inhibit lipid peroxidation, scavenge free oxygen radicals and bond into the chelates they inactivate some prooxidant metal ions. The latest researches have shown that thanks to their properties natural flavonoids can occurence of chronical diseases, such as arterosklerosis, cardiovascular or tumor disorder. Flavonoids are exploited both in traditional and modern medicine. Same other studies have evidenced that valuable sources of these biologically effective substances are traditionally used medicinal plants. Content of phenolic substances was determined by method of micellar electrokinetic capillary chromatography (MECC) and liquid chromatography (HPLC) in collection of 8 medicinal plants usually used in Czech Republic. For analysis was used freeze-dried and dried plant material. In freeze-dried material was found the highest content of total quercetin in Filipendula ulmaria L. (14200 mg/kg of dry weight) and in Betula pendula Roth. (11800 mg/kg of dry weight). The highest content of rutin contained Sambucus nigra L. (17700 mg/kg of dry weight). Similar values was measured in dried plant material. The content of total quercetin and rutin during drying was unchanged.
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