National Repository of Grey Literature 85 records found  1 - 10nextend  jump to record: Search took 0.00 seconds. 
The study of secondary metabolites in plant tissue cultures I
Blahušová, Adriana ; Kašparová, Marie (advisor) ; Siatka, Tomáš (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department of Pharmacognosy Candidate: Adriana Blahušová Supervisor: PharmDr. Marie Kašparová, Ph.D. Title of diploma thesis: The study of secondary metabolites in plant tissue cultures I A principal precondition for successful elicitation used to increase the production of secondary metabolites is, among other, finding a suitable elicitor, its concentration and the optimal period of time of the action of the elicitor on the plant culture in vitro, which was the aim of the present diploma thesis. The effect was examined of a 6, 24, 48 and 168 hour action of the solution of chitosan (in four concentrations) on the production of flavonoids in the suspension culture Trifolium pratense L. (variety Sprint, Tempus and DO-8). The culture was cultivated in Gamborg medium to which 2 mg/l of 2,4- dichlorophenoxyacetic acid and 2 mg/l of 6-benzylaminopurine were added, at the temperature of 25řC and 16 hours light/8 hours dark period. The best elicitation effect of chitosan on the production of flavonoids was the lowest concentration of 1 mg/100ml in all three studied varieties after 48 hours of application.
Sulfates as phase II metabolites of natural phenolic compounds
Hetman, Anastasiia ; Mladěnka, Přemysl (advisor) ; Siatka, Tomáš (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology & Toxicology Student: Anastasiia Hetman Supervisor: Assoc. Prof. Přemysl Mladěnka, PharmD., Ph.D. Co-supervisor: Assoc. Prof. Kateřina Valentová, Ph.D. Title of diploma thesis: Sulfates as phase II metabolites of natural phenolic compounds Natural monophenolic compounds, which both occur in plants and are formed during gut microbiota metabolism of polyphenols, are absorbed and pass through phase II metabolism. This results in the formation of various conjugated metabolites, such as sulfates, whose biological activity was not studied as yet. This work focused on the preparation and isolation of pure sulfated metabolites of phenolic compounds, namely 4- methylcatechol, protocatechuic, homoprotocatechuic, and 2,3,4-trihydroxybenzoic acid, and phloroglucinol, using the aryl sulphotransferase from Desulfitobacterium hafniense. As a result, two sulfated products of sufficient purity were prepared, namely 4- methylcatechol-O-sulfate (an inseparable mixture of 4-methylcatechol-2-O-sulfate and 4- methylcatechol-1-O-sulfate) and phloroglucinol-O-sulfate. Their antioxidantactivity was evaluated and compared with the activity of the parent compounds using the following six in vitro tests: DPPH (1-diphenyl-2-picrylhydrazyl) and...
The study of secondary metabolites in plant tissue cultures I
Blahušová, Adriana ; Kašparová, Marie (advisor) ; Siatka, Tomáš (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department of Pharmacognosy Candidate: Adriana Blahušová Supervisor: PharmDr. Marie Kašparová, Ph.D. Title of diploma thesis: The study of secondary metabolites in plant tissue cultures I A principal precondition for successful elicitation used to increase the production of secondary metabolites is, among other, finding a suitable elicitor, its concentration and the optimal period of time of the action of the elicitor on the plant culture in vitro, which was the aim of the present diploma thesis. The effect was examined of a 6, 24, 48 and 168 hour action of the solution of chitosan (in four concentrations) on the production of flavonoids in the suspension culture Trifolium pratense L. (variety Sprint, Tempus and DO-8). The culture was cultivated in Gamborg medium to which 2 mg/l of 2,4- dichlorophenoxyacetic acid and 2 mg/l of 6-benzylaminopurine were added, at the temperature of 25řC and 16 hours light/8 hours dark period. The best elicitation effect of chitosan on the production of flavonoids was the lowest concentration of 1 mg/100ml in all three studied varieties after 48 hours of application.
Alkaloids of Narcissus species cultivars and their biological activity I.
Tkáčová, Beáta ; Breiterová, Kateřina (advisor) ; Siatka, Tomáš (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department: Department of Pharmaceutical Botany (16-16130) Author: Tkáčová Beáta Supervisor: PharmDr. Kateřina Breiterová, Ph.D. Title of thesis: Alkaloids of Narcissus species cultivars and their biological activity I. Key words: Narcissus, alkaloids, biological activity, Alzheimer's disease. The main aim of this diploma thesis was to obtain summary alkaloid extracts from bulbs of five species cultivars (Narcissus cv. Acropolis, Delta, White Marvel, Kedron, Scarlet Gem) and one variety (Narcissus albus var. plenus odoratus), labeled as AL-450, AL-457, AL-460, AL-463, AL-467 and AL-508, from which samples were subsequently prepared for GC-MS analysis and screening of biological activities (cholinesterase inhibitory activity and cytotoxicity). Totally, 18 alkaloids were identified by GC-MS analysis, comparing their mass spectra. Identified alkaloids include 3-O-demethylmaritidine, 11,12-dehydroanhydrolycorine, assoanine, dehydroassoanine, galanthamine, galanthine, haemanthamine, hippeastrine, incartine, lycoramine, lycorine, narwedine, norpluvine, pancracine, pluvine, pseudolycorine and tazettine. Samples of cultivars AL-457, AL-460, AL-463 and AL-508, showed relatively promising hAChE inhibitory activity in screening assay (c = 50 µg/ml),...
Isolation of alkaloids of the species Geissospermum vellosii Allemão and study of their biological activity I.
Buláková, Anna ; Šafratová, Marcela (advisor) ; Siatka, Tomáš (referee)
Buláková, A: Isolation of alkaloids of the species Geissospermum vellosii Allemão and study of their biological activity I. Diploma thesis, Charles University, Faculty of Pharmacy in Hradec Králové, Department of Pharmacognosy, Hradec Králové, 2020. Key words: Geissospermum vellosii, bark, alkaloidal extracts, isolation of alkaloids, GC/MS analysis, biological activity, acetylcholinesterase, butyrylcholinesterase. Geissospermum vellosii as a plant belongs to the Apocynaceae family, whose bark is characterized by the content of indole alkaloids, which can also act as acetylcholinesterase inhibitors. The aim of this thesis was to process the pool of ethereal and chloroformic alcaloids from the plant Geissospermum vellosii. By means of column chromatography, the ethereal pool was processed into subfractions GV-1 to GV-16. Taking advantage of preparational method TLC, the subfraction GV-11 was processed, of which one alcaloid-based substance was isolated. Its structure was determined based on GC-MS and NMR analysis and after comparing obtained data with the literature, the substance was identified as Normacusin B. The substance, we extracted, was of unstable nature and because of that, we could not research its biological activity further in relation to AChE and BuChE. Due to the instable nature of...
The effect of pyrazine derivatives on secondary metabolites content in plant cultures in vitro I.
Graclíková, Bohumila ; Tůmová, Lenka (advisor) ; Siatka, Tomáš (referee)
1 Abstract Elicitation method is one way to increase the production of secondary metabolites in in vitro of plant cultures and this work deals with this problem. Its aim was to find the positive effect of 2-hydroxy-4-(imidazo[1,2-a]pyrazine-2-carboxamide)benzoic acid from the group of pyrazine derivates on the production of isoflavonoids in in vitro cultures of Genista tinctoria L. Isoflavonoids play an important role in therapy of climacteric problems or they are promising substances of therapy various cancer types due to their affinity to estrogens β-receptors. This plant or rather its in vitro cultures are a potencial sources of isoflavonoids. Suspension and callus cultures of Genista tinctoria L. were used for elicitation. They were cultivated on Schenk & Hildebrant medium with the addition of 2,4-dichlorophenoxyacetic acid (2,4-D) as growth regulator at a concentration of 1 ml/l. The elicitor solution was added to the cultures at three concentrations: 3.3642 × 10-3 mol/l; 3.3642 × 10-4 mol/l; 3.3642 × 10-5 mol/l. The samples were taken at intervals of 6, 24, 48, 72 and 168 hours and then they were analyzed by HPLC method. At the same time intervals the samples of medium, where isoflavonoids were released, were analyzed. The biggest production of isoflavonoid was reached in suspension culture. The...
Podophyllotoxin in eastern red cedar (Juniperus virginiana)
Olšar, Jiří ; Siatka, Tomáš (advisor) ; Kastner, Petr (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacognosy Student: Jiří Olšar Supervisor: doc. PharmDr. Tomáš Siatka, CSc. Title of diploma thesis: Podophyllotoxin in eastern red cedar (Juniperus virginiana) This thesis describes the optimisation of the extraction process for quantity determination of podophyllotoxin in the leaves of Juniperus virginiana L. This determination was conducted through three different methods: the extraction in ultrasound bath, the extraction in the orbital shaker and the maceration in cold environment of 4 řC. Extractions were affected by various factors which were monitored, for instance time of extraction, temperature, and extraction solvents. The most efficient method appears to be the extraction in ultrasound bath with the use of methanol or a combination of phosphate buffer with ethyl-acetate.
The study of secondary metabolites in plant tissue cultures I
Blahušová, Adriana ; Kašparová, Marie (advisor) ; Siatka, Tomáš (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department of Pharmacognosy Candidate: Adriana Blahušová Supervisor: PharmDr. Marie Kašparová, Ph.D. Title of diploma thesis: The study of secondary metabolites in plant tissue cultures I A principal precondition for successful elicitation used to increase the production of secondary metabolites is, among other, finding a suitable elicitor, its concentration and the optimal period of time of the action of the elicitor on the plant culture in vitro, which was the aim of the present diploma thesis. The effect was examined of a 6, 24, 48 and 168 hour action of the solution of chitosan (in four concentrations) on the production of flavonoids in the suspension culture Trifolium pratense L. (variety Sprint, Tempus and DO-8). The culture was cultivated in Gamborg medium to which 2 mg/l of 2,4- dichlorophenoxyacetic acid and 2 mg/l of 6-benzylaminopurine were added, at the temperature of 25řC and 16 hours light/8 hours dark period. The best elicitation effect of chitosan on the production of flavonoids was the lowest concentration of 1 mg/100ml in all three studied varieties after 48 hours of application.
Alkaloids of the family Amaryllidaceae and their biological activity 1.
Klímová, Kamila ; Cahlíková, Lucie (advisor) ; Siatka, Tomáš (referee)
Mišáková K: Alkaloids of the Amaryllidaceae family and their biological activity 1. Diploma thesis, Charles University in Prague, Faculty of Pharmacy in Hradec Králové, Department of Pharmaceutical Botany and Ecology, Hradec Králové, 2014, 63 p. The aim of the diploma thesis was a preparation of alkaloidal extract from Nerine Bowdenii to izolation of 2 pure alkaloids by column and thin layer chromatography. Subsequently these two alkaloids were subjected to structural MS and NMR analysis and tested for biological activity against human cholinesterases (HuAChE and HuBuChE) and for antioxidant and cytotoxic activity. Isolated substances were identified as ambelline and undulatine alkaloids, which have been already described previously in this plant. In the test for determining cholinesterase inhibitory activity of ambelline and undulatine the following values were measured; for ambelline: IC50, HuAChE = 169 ± 7 μM a IC50, HuBuChE = 985 ± 25 μM, for undulatine: IC50, HuAChE = 23,52 ± 1,19 μM a IC50, HuBuChE > 1000 μM. Galanthamin (IC50, HuAChE = 1,71 ± 0,007 μM, IC50, HuBuChE = 42,30± 1,30 μM), huperzin A (IC50, HuAChE = 0,033 ± 0,001 μM, IC50, HuBuChE > 1000 μM) and eserin (IC50, HuAChE = 0,063 ± 0,001 μM, IC50, HuBuChE = 0,130 ± 0,004 μM) were used like a positive controls. In the test for...
Screening of various plant taxa and their influence on human enzyme systems I.
Šikola, Václav ; Šafratová, Marcela (advisor) ; Siatka, Tomáš (referee)
Šikola V.: Screening of various plant taxa and their influence on human enzyme systems I. Diploma thesis, Charles University, Faculty of Pharmacy in Hradec Králové, Department of Pharmacognosy, Hradec Králové 2018, 52 pages. The object of this diploma thesis was the screening of 5 chosen plant taxa (Desmodium adscendens, Codonopsis pilosula, Centella asiatica, Bacopa monnieri, Epimedium sagittatum) to identify chemical constituents (alkaloids) and to define inhibitory activity against human acetylcholinesterase (HuAChE) and butyrylcholinesterase (HuBuChE). Summary extract of plants was prepared by extraction to ethanol, the presence of alkaloids was verified by control TLC (UV, Dragendorff's reagent). Alkaloidal extracts were prepared by extraction of an alkaline solution of summary extracts to ethyl acetate. Alkaloidal extracts were subjected to GC/MS analysis and tested for their inhibitiory activity on human cholinesterases by Ellman's method. Results of GS/MS analysis did not provide information on contained alkaloids - the alkaloids did not gasify or were not contented. Conclusions of measuring inhibition activity of extracts in comparison to standards (galantamine, huperzine A) eliminated an usage of alkaloids in a clinical praxis because the activity was many times lower than standards. The...

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