National Repository of Grey Literature 5 records found  Search took 0.01 seconds. 
Bioactive compounds of fennel
Nentvichová, Aneta ; Vespalcová, Milena (referee) ; Veselá, Mária (advisor)
The aim of this bachelor thesis is to study the bioactive substances contained in fennel, to determine the content of polyphenols, flavonoids and to investigate the antioxidant and antimicrobial activity in aqueous and ethanol extracts of fennel. The theoretical part discusses the characteristics of fennel, its classification in the system, its use and especially the bioactive substances contained in it. The experimental part is divided into two sections, where the first part focuses on spectrophotometric determination of polyphenols, flavonoids and antioxidant activities. In the second part the antimicrobial effects of prepared extracts of fennel were examined. Two microorganisms Serratia marcescens and Bacillus cereus were exposed to the said extracts. Antioxidant activity and relatively high content of polyphenols and flavonoids were found in the extracts in the first experimental part. The second experimental part proved that the antimicrobial effect of the extracts was very low, in most cases almost negligible. Ethanol extracts showed higher antimicrobial activity, while hot water extracts found to support the growth of Bacillus cereus.
Bioactive substances of rose hip
Ďubašáková, Mária ; Skoumalová, Petra (referee) ; Veselá, Mária (advisor)
The aim of this master´s thesis was to determine the concentration of bioactive substances such as total polyphenols and flavonoids as well as the total antioxidant capacity in tea extracts from Rosa canina. In the second part, an experiment was found to detect antimicrobial activity and an effective concentration of ethanol against selected bacteria. The theoretical part is focused on description of natural antioxidants and their effect on free radicals, description of tea, description of rose hazel and possibilities of spectrophotometric determination of natural substances and eventually basic distribution of bacteria. In the experimental part, ethanol and aqueous extracts were prepared in which the total number of polyphenols, flavonoids and antioxidant effects. The results of the determination of polyphenols and flavonoids show that the solvent with ethanol is more suitable for flower fermentation and water is more suitable for dropping the rose. Comparison of the antioxidant activity of macerates showed no significant differences; slightly higher antioxidant activity showed macerates from pink flowers. The extracts showed antimicrobial activity against Micrococcus luteus and slightly against Bacillus cereus. The highest antimicrobial activity was determined for the micrococcus luteus
Bioactive compounds of fennel
Nentvichová, Aneta ; Vespalcová, Milena (referee) ; Veselá, Mária (advisor)
The aim of this bachelor thesis is to study the bioactive substances contained in fennel, to determine the content of polyphenols, flavonoids and to investigate the antioxidant and antimicrobial activity in aqueous and ethanol extracts of fennel. The theoretical part discusses the characteristics of fennel, its classification in the system, its use and especially the bioactive substances contained in it. The experimental part is divided into two sections, where the first part focuses on spectrophotometric determination of polyphenols, flavonoids and antioxidant activities. In the second part the antimicrobial effects of prepared extracts of fennel were examined. Two microorganisms Serratia marcescens and Bacillus cereus were exposed to the said extracts. Antioxidant activity and relatively high content of polyphenols and flavonoids were found in the extracts in the first experimental part. The second experimental part proved that the antimicrobial effect of the extracts was very low, in most cases almost negligible. Ethanol extracts showed higher antimicrobial activity, while hot water extracts found to support the growth of Bacillus cereus.
Bioactive substances of rose hip
Ďubašáková, Mária ; Skoumalová, Petra (referee) ; Veselá, Mária (advisor)
The aim of this master´s thesis was to determine the concentration of bioactive substances such as total polyphenols and flavonoids as well as the total antioxidant capacity in tea extracts from Rosa canina. In the second part, an experiment was found to detect antimicrobial activity and an effective concentration of ethanol against selected bacteria. The theoretical part is focused on description of natural antioxidants and their effect on free radicals, description of tea, description of rose hazel and possibilities of spectrophotometric determination of natural substances and eventually basic distribution of bacteria. In the experimental part, ethanol and aqueous extracts were prepared in which the total number of polyphenols, flavonoids and antioxidant effects. The results of the determination of polyphenols and flavonoids show that the solvent with ethanol is more suitable for flower fermentation and water is more suitable for dropping the rose. Comparison of the antioxidant activity of macerates showed no significant differences; slightly higher antioxidant activity showed macerates from pink flowers. The extracts showed antimicrobial activity against Micrococcus luteus and slightly against Bacillus cereus. The highest antimicrobial activity was determined for the micrococcus luteus
Characterization of antiobiotic activity of nonpathogenic streptomyces isolated from human tissue.
ŽLÁBKOVÁ, Zuzana
The bachelor thesis is focused on characterization of ten strains of streptomycetes isolated from human clinical samples. Streptomycetes are soil bacteria known for their production of secondary metabolites with characteristic antibiotic, antihelmitic, anti-cancerous and antiviral effects. The objective of my work is to characterise microbiologically the antibacterial and antifungal action of these circa ten taxonomically classified isolates on strains of typical human pathogens from the group of Gram-positive and Gram-negative bacteria, yeast and fungi.

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