National Repository of Grey Literature 135 records found  beginprevious126 - 135  jump to record: Search took 0.02 seconds. 
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).
Electrochemical Study of Rhamnazin
Ramešová, Šárka ; Sokolová, Romana ; Degano, I.
The natural flavonoid compound rhamanzin (3,5,4’-trihydroxy-7,3’-dimethoxyflavone) is important bioactive compound with antioxidative, anti-allergic, and anti-inflammatory properties. The cyclic voltammetry is used for the electrochemistry behavior of rhamnazin. The determination of oxidation pathways is supported by the identification of degradation products using separation technique.
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.
The content changes of selected phenolic compounds during processing of medicinal plants
GROŠAFTOVÁ, Blanka
This work was aimed to the problem of change of the content of selected phenolic substances during treatment and storage of medical plants. Flavonoids represent small, but very important group of phenolic compounds. The biggest attention was paid to quercetin and rutine.Content of phenolic substances was determined by method of micellar electrokinetic capillary chromatography (MECC) in case of 6 medicinal plants usually used in traditional and modern medicine.
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).
Expression analysis of selected regulation factors in hop with relation to symptoms of viroid pathogenesis
FÜSSY, Zoltán
The aim of this work was to determine whether there are besides morphogenetic and metabolomic changes in viroid-infected plants also some alterations in the expression of transcription factors (TFs) known from our previous work to be involved in the secondary metabolites production, namely HlMyb1, HlMyb3, HlbHLH, HlbZIPA and HlbZIP2 TFs. Infectious vectors were prepared containing dimers of two closely related viroids- hop stunt viroid (HSVd) and cucumber pale fruit viroid (CPFVd). To achieve infection of hop (Humulus lupulus L.), biolistic inoculation of young shoots was performed. Hop cv. Admiral was chosen as a model for our experiments, because of its high flavonoid content in leaves. Infection of hop with both of these viroid species was proven by means of Northern hybridization and dot-blot techniques. Plants infected with HSVd showed serious symptoms such as stunted growth, epinasty and rugosity of leaves. Interestingly, decoloration of the petioles of the plants infected with HSVd was observed, maybe as a result of lower anthocyanins production. These symptoms were similar but milder in CPFVd-infected hops. On plants bearing symptoms, HPLC analyses were performed and compared to controls to detect changes in the levels of flavonol glycosides, phenolic acids, bitter acids and xanthohumol. In HSVd-infected hop leaves and petioles, significant decrease in the contents of flavonol glycosides and phenolic acids was observed. On the other hand, an increase in the amount of xanthohumol and bitter acids was detected in HSVd-infected tissues compared to healthy controls. Unlike to HSVd infection, the decrease of all analyzed secondary metabolites was observed in CPFVd-infected material. This difference suggests an alternative response of metabolome pathways to CPFVd-caused pathogenesis in comparison to HSVd. Semiquantitative RT PCR was performed to assay levels of TFs in healthy and infected hop tissues. Quantitative RealTime analyses of putative hop transcription factors HlbZIPA and HlbZIP2 were carried out using RNA isolated from HSVd-infected petioles. Increased mRNA levels of bZIP TFs were detected in infected material, suggesting an involvement of these factors in the response of the host plants to HSVd infection. Using thermodynamic methods of TGGE and heteroduplex analysis, several sequence variants of HlbZIP2 were idetified. According to aminoacid sequence alignment, this putative factor belongs to a group of bZIP proteins known for ABA/stress signalling in A. thaliana.
Influence of genotype on rutin content in plants from genus \kur{(Fagopyrum)}
KRÁLOVÁ, Martina
The bachelor work is focused on evaluation of the influence of buckwheat species and variety on rutin containt in particular plant parts, on the total rutin yield per hectare production and on comparison varietal differences between both species, common buckwheat \kur{(Fagopyrum)}esculentum)} Moench) and tartary buckwheat \kur{(Fagopyrum tataricum)}. Rutin is a flavonol (quercetin-3-O- rutinosid) which is also called P vitamin. As well as it is known as the permeability factor or factor allowing permeability of the blood vessel. Rutin stimulates the C vitamin effect. Rutin has as well a high influence on hypertension, hypercholesterolemia and other cardiovascular diseases due to antioxidant properties. Buckwheat is the most important source of rutin. It is annual plant which belongs to Polygonaceae family and has a beneficial effect on human body. The common grown type is common buckwheat \kur{(Fagopyrum)}esculentum)} Moench) and less used type is buckwheat tartary \kur{(Fagopyrum tataricum)}. Tartary buckwheat \kur{(Fagopyrum tataricum)} contains several times higher amount of rutin than common buckwheat \kur{(Fagopyrum)}esculentum)} Moench). The highest amount of rutin is presented in the leaves and blossoms and the lowest one in seeds. Tartary buckwheat \kur{(Fagopyrum tataricum)} has much higher amount of rutin in seeds than common buckwheat \kur{(Fagopyrum)}esculentum)} Moench). The varietal differences in rutin content are considerable.
The rutin content in amaranth (Amaranthus sp.)
BERANOVÁ, Kristina
This work was aimed to the determination of the flavonoids of rutin in the leaves, stems and seeds of different kinds and species of amarant. Rutin is a phenolic substance, which belongs to big group of secondary plant metabolites. Most recently lot of attention is paid to quercetin and its glycoside {--} rutin because of its demonstrable positive effect on the human organism, mainly the antioxidant effects which prevents the atherosclerotic plaque and preroxidation of lipids and antiviral activities. The research orients to its potential anti-carcinogen activities. Thanks to these properties it became a common part of the human daily diet. Amarant could be a beneficial source of these substances. Content of rutin was determined by the micelar electrokinetic capillary chromatography (MECC) in the group of seven genotypes of amaranth. For the analysis a samples of leaves, stems and seeds were used, because of its high contents of flavonoids. The highest content of rutin was found in the leaves of the species A. cruentus {--} genotype Olpir (27 400 mg/kg of dry matter) and the lowest in the seeds of A. cruentus {--} genotype Monatana (25,3 mg/kg of dry matter). Results of this research are unique as they were never published before.
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.
Extraction and determination of flavonoids in Stevia rebaudiana leaves by pressurized solvent and HPLC
Hohnová, Barbora ; Omelková, J. ; Vespalcová, M. ; Karásek, Pavel
Determination of selected flavonoids in Stevia rebaudiana leaves by HPLC. Comparison of extraction techniques, PFE, soxhlet extraction and ultrasound assisted extraction.

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