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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.
1

Propolio ekstrakcija nevandeniniais tirpikliais ir propolio fenolinių junginių atpalaidavimo iš modelinių sistemų tyrimas in vitro / Propolis extraction with non-aqueous solvents and propolis phenolic compounds release study from model systems in vitro

Dzedzevičiūtė, Rasa 18 June 2014 (has links)
Darbo tikslas. Parinkti tinkamą nevandeninį tirpiklį propolio ekstrakcijai bei ekstrakcijos sąlygas; įvertinti propolio fenolinių junginių atpalaidavimą iš skystų modelinių sistemų biofarmaciniu tyrimu in vitro. Darbo uždaviniai. Parinkti nevandeninius propolio ekstrahentus bei įvertinti jų gebą ekstrahuoti polifenolinius propolio junginius. Nustatyti ekstraktų kokybę lemiančius fizikocheminius rodiklius. Parinkti technologinius parametrus ir ištirti jų įtaką propolio ekstraktų kokybei. Įvertinti ekstraktų su propoliu stabilumą. Atlikti biofarmacinį tyrimą in vitro, siekiant nustatyti propolio fenolinių junginių atpalaidavimą iš skystos modelinės sistemos su tiriamuoju propolio ekstraktu (PE). Tyrimo metodai. Ekstraktai gaminti maceracijos metodu, bendras polifenolinių junginių kiekis (BFK) pagal kumaro rūgšties ekvivalentą (KRE) nustatytas ultravioletiniu (UV) spektrofotometru, taikant Folin-Ciocalteu metodą. Propolio ekstraktuose esančių polifenolinių junginių kiekio atpalaidavimas iš modelinių sistemų vykdytas in vitro metodu naudojant modifikuotas Franc tipo difuzines celes [4]. Rezultatai ir išvados. Tyrimo metu propolio ekstrakcijai parinkti trys nevandeniniai tirpikliai - izopropilo miristatas (IPM arba I), ricinos aliejus (R), etanolis, bei sistemos, sudarytos iš ricinos aliejaus ir izopropilo miristato, sumaišytų masės dalimis – 25R:75I, 50R:50I ir 75R:25I. Nustatytas tiesioginis ryšys tarp propolio koncentracijos ištraukose bei BFK naudojant skirtingus... [toliau žr. visą tekstą] / The aim of the study is to find out the most appropriate non-aqueous solvent and conditions for the propolis extraction; evaluate how propolis phenolic compounds release from the liquid model systems during the biopharmaceutical research called in vitro. The task of the study is to evaluate the ability of non-aqueous propolis extractions to extract poly-phenolic propolis compounds. Then find out physic-chemical characteristics which determine the quality of extracts. Next examine how selected technological parameters influence the quality of propolis extracts and evaluate the stability of propolis extracts. Conduct the biopharmaceutical research in vitro to determine the release of propolis phenolic compounds with propolis extract (PE) as an object of the study from the liquid model systems. Research methods. Extracts were produced using the maceration method. The ultraviolet (UV) spectrophotometer and Folin - Ciocalteu method were used to get the total quantity of poly-phenolic compounds (TFK) in accordance to the coumaric acid equivalent (KAE). The release of polyphenol compounds from the model systems in propolis extracts was carried out by in vitro method with modified Franc -type diffusion cells [4]. Results and Findings. The study of propolis extraction included three non-aqueous solvents, such as isopropyl myristate, castor oil and ethanol), as well as, systems made up with castor oil and isopropyl myristate, mixed in such ratios: 25R:75I , 50R:50I and 75R:25I. The... [to full text]
2

Optimalizace podmínek a postupů při získávání bylinných extraktů. / Optimization of conditions and procedures for plant extraction.

SMUTNÍKOVÁ, Kateřina January 2012 (has links)
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.

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