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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Využití separačních technik ve fytochemické analýze / The use of separation techniques in phytochemical analysis

Víchová, Simona January 2021 (has links)
Charles University, Faculty of Pharmacy in Hradec Králové Department: Department of Pharmaceutical Botany Candidate: Simona Víchová Supervisor: RNDr. Jaroslav Jenčo, Ph.D. Title of dissertation thesis: The use of separation techniques in phytochemical analysis The alkaloid extract obtained from stems with immature capsules from Papaver rhoeas L. was subjected to a phytochemical study. The summary extract was separated into individual fractions by Flash chromatography. After performing biological tests for inhibitory activities of acetylcholinesterase and butyrylcholinesterase, the fraction PPR-11 and PPR-12 was selected. The fraction showed the highest activity against butyrylcholinesterase (95.55 ± 0.96 and 97.03 ± 0.79% inhibition of butyrylcholinesterase at 50 /g / ml). The combined PPR 11-12 fractions were purified by preparative chromatography to individual subfractions, which were purified by preparative thin layer chromatography. A monocomponent crystalline substance of alkaloid origin was obtained from the subfraction named PPR 11-12Fr # 8-A. Based on instrumental analysis, the analyte was identified as an alkaloid of the aporphine type (+)-caaverine. The inhibitory activities against acetylcholinesterase and butyrylcholinesterase for (+)-caaverine, were determined and compared with...
12

Examining the competitive abilities of cornflower (Centaurea cyanus) in a growth chamber experiment. / Studie av den relativa konkurrensförmågan hos blåklint (Centaurea cyanus) odlad i växtkammare.

Karlsson, Emil January 2019 (has links)
Competition between different species (interspecific competition) is an important factor to consider when estimating population trends, geographic distributions, and management options of species. Many historically common vascular plant species found in agricultural environments have been negatively affected by changes in community composition and in turn, changes in competition pressures. Even so, the relative importance of plant competition in an ecological context is still unclear. In this study I examine the competitive ability of the meadow plant cornflower (Centaurea cyanus L.) when grown together with common oat (Avena sativa) and common poppy (Papaver rhoeas), during a seven-week long growth chamber experiment. Seeds were sown in pots in four different setups; 1) C. cyanus control, 2) C. cyanus + P. rhoeas, 3) C. cyanus + A.sativa, 4) All three species. Six different growth parameters were measured (aboveground dry-weight, belowground dry-weight, root length, leaf area, number of leaves and above/belowground dry-weight ratio). I found that growth rates of C. cyanus were significantly inhibited according to all six growth parameters when C. cyanus competed solely with A. sativa. Competition from P. rhoeas had an insignificant effect on C. cyanus growth in five out of six growth parameters. Finally, I discuss the possibility that historically common meadow plants have declined in abundance in part because of weak competitive abilities, and that rare vascular plant species are negatively affected by growing in proximity with cereal crops.

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