National Repository of Grey Literature 163 records found  beginprevious99 - 108nextend  jump to record: Search took 0.00 seconds. 
Biological activity of plant metabolites XXIII. Alkaloids of Corydalis cava (L.) SCHWEIGG. & KÖRTE and their effect on acetylcholinesterase and butyrylcholinesterase.
Kaluzsná, Blanka ; Opletal, Lubomír (advisor) ; Cahlíková, Lucie (referee)
Charles University in Prague, Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Botany and Ecology Candidate: Bc. Blanka Kaluzsná Supervisor: Prof. RNDr. Lubomír Opletal, CSc. Title of Diploma Thesis: Biological activity of plant metabolites XXIII. alkaloids of Corydalis cava (l.) Schweigg. & Körte and their effect on acetylcholinesterase and butyrylcholinesterase An ether extract which contained tertiary basic alkaloids was prepared from the dry bulb of Corydalis cava (L.) SCHWEIGG. & KÖRTE. A subfaction labeled 2/B was obtained by column chromatography and crystallization. Three alkaloids were isolated by preparative TLC and they were identified by GC/MS and 1 H a 13 C NMR analyzes as (+)-canadine, (+)-tetrahydropalmatine and domestine. Isolated alkaloids were tested by spectrophotometric Ellman method for inhibitory activity against human erythrocyte acetylcholinesterase (HuAChE) and plasma butyrylcholinesterase (HuBuChE). In comparison with the refernce substances, from these isolated alkaloids only (+)-canadine showed an relatively high inhibitory activity against HuAChE (12,4 µM). (+)-Tetrahydropalmatine and (+)-domestine had no significant inhibitory activity in this direction, against both HuAChE and HuBuChE. Key words: Corydalis cava, (+)-canadine, (+)-tetrahydropalmatine,...
Characterization and application of some plant antimicrobial substances
Bendová, Agáta ; Bokrová, Jitka (referee) ; Skoumalová, Petra (advisor)
The main goal of this bachelor thesis was the study of antioxidant and antibacterial effects of natural plant extracts and liposomes. The theoretical part was focused on description of natural antimicrobial and antioxidant substances from selected herbs and spices. Also bacterial resistance and methods used in work were described. In the experimental part basic characteristics of extracts from 12 kinds of herbs and spices (oil, alcohol and aqueous) were analyzed. Mainly content of polyphenols, flavonoids and the total antioxidant activity were determined. All extracts were also encapsulated into liposomes and the encapsulation effectivity, long-term stability and size and stability of liposomes were determined. The size of prepared liposomes was in range of 100 nm to 200 nm. Stability of the liposome particles was measured using a zeta potential and all prepared particles exhibited very good stability, but in term of long term stability were liposomes relatively unstable. Antibacterial activity was tested against Gram-positive Micrococcus luteus and Gram-negative Serratia marcescens. Encapsulation of extracts into liposome particles has greatly increased their antimicrobial effect and liposomes containing oil extracts from the goat, nutmeg and pepper and liposomes containing alcoholic extracts from star anise and cloves were the most effective against both strains. The prepared liposomes could be used as alternative to antibiotics and could be found application in the form of various antimicrobial gels for the cosmetic or pharmaceutical industry.
Developement and optimalization of methods for extraction of selected compounds from Hypericum perforatum
Chytil, Dalibor ; Štursa, Václav (referee) ; Pořízka, Jaromír (advisor)
Bachelor's thesis deals with the optimization of processes for extraction of phenolic compounds from St. John´s Wort (Hypericum perforatum). The theoretical part of the work focuses on characterization of this herb, its botanical classification, traditional use, chemical composition and curative effects. Increased attention is further devoted to a theory of preparation of samples for extraction of phenolic compounds and suitable techniques for extraction and characterization of phenolic compounds from extracts of St. John´s Wort. The experimental part of the thesis deals with application of theoretical knowledge. When optimizing the emphasis was on influence of solvent (water acified to pH 4, pH 5, pH 6), influence of extraction technique (ultrasound extraction, subcritical water extraction, maceration) and influence of extraction period (10, 20, 30 min). Extracts were subjected to determination of selected parameters (total phenolic content, total flavonoid content, antioxidant activity) in leaves of St John´s Wort harvested in June 2016 using UV-VIS spectroscopy. The used extraction techniques are significantly different from each other.
Study of rose hip bioactive compounds
Konderla, Patrik ; Skoumalová, Petra (referee) ; Veselá, Mária (advisor)
Purpose of this thesis was research the content of biologically active substances in herbal rosehip extracts and also determination of antimicrobial and antioxidant activity of these extracts. Teoretical part describes informations about Rosa canina L., detailed specification of biologically active substances, specification of antioxidation and overview of methods determine antioxidant compound and antimicrobial activity. In the practical part was by combination of different solvents, procedures and herbal materials, made 21 extracts of Rosa canina L.. From measuring of these extracts, was made extraction curves and also was determined antimicrobial efficiency against bacterial strains Serratia marcescesns, Bacillus subtilis, Bacillus cereus and Micrococcus luteus. Results shows, that also all extracts has some antimicrobial activity, but only against microorganisms Micrococcus luteus and Bacillus cereus. Also was found that bud extracts contains more bioactive compounds soluble in ethanol, meanwhile rose hip extracts contains more bioactive compounds soluble in water.
Aronia – the source of bioactive compounds
Štumarová, Klára ; Vespalcová, Milena (referee) ; Veselá, Mária (advisor)
The aim of this bachelor thesis is to research the possible antimicrobial activity of aqueous and ethanolic extracts of aronia berries and tea mixture containing aronia. Also, the antioxidant activity and the concentration of the biologically active substances - polyphenols, flavonoids and anthocyanins was determined. Theoretical part contains a summary of basic information about Aronia melanocarpa, chemical composition, use and health effects of substances contained in its fruits. The experimental part focuses on the antimicrobial activity of the extracts on microorganisms Bacillus subtilis, Serratia marcescens and Micrococcus luteus. Farther there is spectrophotometrical determination of antioxidant activity, polyphenolic compounds, flavonoids and anthocyanins. From the experiment results flow that the extracts have almost none antimicrobial ability except tea mixture extracted with hot water. This extract has inhibitory effect on M. luteus and growth supportive effect on B. subtilis. It has been found that aronia fruits and tea mixture are rich in polyphenols and flavonoids.
Biological effects of various hemp fractions
Vacková, Hana ; Skoumalová, Petra (referee) ; Němcová, Andrea (advisor)
Cannabis is the only plant which contains cannabinoids and thanks to these compounds it has enormous potential. This thesis deals with the analysis of technical hemp. Effects of cannabinoids and methods used for cannabis analysis are discussed in the theoretical part. The experimental part includes spectrophotometric characterization of cannabis, it´s antimicrobial effects and thin layer chromatography analysis. Three sorts of Cannabis sativa L. were analyzed, namely Finola, Fedora and Kompolti. Firstly, the content of polyphenols, flavonoids and antioxidant activity in prepared tinctures were determined. Moreover, antimicrobial test were performed using disk test and turbidity determination. Gram-positive and Gram-negative bacteria and yeast organism were tested. It was found that cannabis tinctures possess good antimicrobial effects. Some of them are comparable with synthetic antibiotics. Finally, thin layer chromatography enabled visualization of cannabinoids in prepared tinctures.
Development of a new type of energy drinks containing natural active components
Vysoká, Marie ; Němcová, Andrea (referee) ; Skoumalová, Petra (advisor)
The aim of this thesis is the development and preparation of a new energy drink. The theoretical part of the thesis focuses on the comparison of the drinks available in market, the presentation of the main active ingredients and the proposal of enriching the new energy drink. It also describes the possibility of using an encapsulation and the method used to determine specific compound in energy drink or encapsulated particles. In the experimental part of the work, at the beginning, the main content of energy drinks were characterized, for instance caffeine, sugar, polyphenol and vitamin C. Subsequently the energy drink based on selected types of loose teas that were enriched with the encapsulated extract of acai, acerola, maca, goji and ginseng was designed. All extracts contained large amounts of polyphenols and antioxidants. In addition, acerola extracts contained very high amounts of vitamin C. Two types of particles, alginate particles and liposomes were prepared for encapsulation. For all particles, encapsulation efficiency, size, stability, and antioxidant activity were determined. Long-term stability was then monitored within three months. The particles were also exposed to artificial gastric, pancreatic and bile juice. All tested particles showed very good encapsulation efficiency. In terms of long-term storage stability in an aqueous environment. Particularly liposome particles, which also showed high stability by zeta potential measurement, were suitable. On the contrary, in case of alginate particles, when stored in an aqueous medium, the release of active substances occurred. Finally, an energy drink was created and subjected to sensory analysis. The best energy drink was based on black or green tea with alginate particles acai, goji and ginseng.
Analysis of biologically active substances in apricot oil
Valasová, Denisa ; Márová, Ivana (referee) ; Němcová, Andrea (advisor)
The Master’s thesis is focused on the analysis of biologically active substances in apricot kernel oil. Apricot oil has recently begun to be widely used in the cosmetics industry, particularly as a part of massage oils or as part of moisturizing creams. The aim of this thesis is to characterize and assess the quality of apricot oil, determination of the content of selected active ingredients, through a series of analytical methods, and subsequent use of this oil in cosmetics and food industry. The thesis is based on the comparison of the quality of pure apricot oil and the oil after the fermentation process. It has been found that apricot kernel oil actually contains large amounts of unsaturated fatty acids. The excellent antioxidant activity of apricot kernels was proven too, especially those after fermentation. In addition to antioxidant activity, the samples contain a relatively large amount of tocopherol after the fermentation. Tocopherol is important for the uptake of free radicals in lipid bilayers, thus slowing down aging, protect the membranes and also prevent from possible cardiovascular and oncological diseases. Furthermore, in the Master’s thesis there were confirmed not only the hydration effects of creams with apricot oil, but also their ability of inhibic transepidermal loss of water from the epidermis. Creams were tested on five probands, aged 23–24, with different skin types. After the application of creams to their skin, these properties greatly improved, the skin has been regenerated and hydrated for 24 hours after the treatment.
Natural compounds and their biological activity I. Antioxidant activity of selected potentially toxic herbal drugs
Římanová, Elena ; Opletal, Lubomír (advisor) ; Siatka, Tomáš (referee)
Charles University in Prague Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Botany and Ecology Candidate: Mgr. Elena Římanová Consultant: Doc. RNDr. Lubomír Opletal, CSc. Title of Thesis: Natural compounds and their biological activity I. Antioxidative activity of selected potentially toxic herbal drugs. 14 dried samples of morphological parts of potentially toxic plants, or plants with other type of restriction for common use, eventually obsolete plants (comfrey root, calamus root black locust flower, peony flower, red weed poppy flower, leaf of hawthorn with flowers, coldsfood leaf, mistletoe herb, melilot herb, woodfuff herb, pulmonaria herb, motherwort herb, St. John's wort herb, hawthorn fruit), were chosen for the evaluation of their antioxidant activity. These samples were collected from 3 regions of medicinal herbs purchases (Nepomuk, Slatiňany, Strážnice). The standardised extracts from these morphological parts were tested for their antioxidant activity (DPPH assay, EC50 values), and total phenolics were measured (Folin-Ciocalteau reagent, GAE/mg of extract). Relatively significant correlation was determined between total phenolics content and antioxidant activity by regression analysis (R2 =0,7825). Most of the samples, used for analysis, and practically no matter...
Biochemistry of polyphenols effects in the treatment of vascular disease
Kondrashov, Alexey ; Štípek, Stanislav (advisor) ; Pecháňová, Olga (referee) ; Matouš-Malbohan, Ivan (referee)
This Ph.D. thesis deals with the deep analysis of polyphenols effects toward vascular disorders. This work provides a number of experimental results of studying both the effects of natural bioactive compounds in red wines and potatoes, and their application to the experiments which includes experimental animal models with spontaneous hypertension. Methods and equipment used in experimental studies allowed us to make several new statements regarding the universal nature of the relationships between the antioxidant capacity and the polyphenolic content in examined foodstuffs. Besides this it is also recognized that food is a source of minerals which also contribute to the total antioxidant capacity and therefore may have influence the endogenous antioxidant enzyme system by providing the essential cofactors. Experimentally we have found that the concentrations of magnesium known for its therapeutic action in wine and red wine extract are comparable to the mineral waters recommended for the treatment and prevention of cardiovascular and metabolic diseases. Moreover, synergistic interactions between selected minerals have been found. The key issue of bioavailability of polyphenols for supporting the idea of the beneficial effects of diet rich in fruits and vegetables toward vascular disease prevention...

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