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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.
21

Chemical analysis of color change and transcriptional profile in flavonoids biosynthesis during flower development of Tibouchina pulchra (Cham.) Cong. / Análises químicas da mudança de cor e perfil transcricional da biossíntese de flavonoides durante o desenvolvimento floral de Tibouchina pulchra (Cham.) Cong.

Rezende, Fernanda Mendes de 28 February 2018 (has links)
Floral color change is a widespread phenomenon in angiosperms, but poorly understood from the genetic and chemical point of view. This thesis aimed to investigate this phenomenon in Tibouchina pulcha, a native species whose flowers change from white to dark pink. To reach this goal, flavonoid biosynthetic gene expression and compounds were profiled. By using hyphenated techiniques (UPLC-HRMS and NMR), thirty phenolic compounds were quantified and identified, being sixteen described for the first time in T. pulchra. Moreover, an inedite compound was also identified. Five key genes of the flavonoid biosynthetic pathway were partially cloned, sequenced, and the mRNA levels were analyzed (RT-qPCR) along flower development. Collectively, the obtained results demonstrated that the flower color change in T. pulchra is regulated at transcriptional level. Additionally, a metal quantification suggests that Fe3+ ion might influence the saturation of the color at dark pink stage / A mudança de cor em flores é um fenômeno generalizado entre as angiospermas, mas pouco compreendido do ponto de vista genético e químico. Este estudo teve como objetivo investigar esse fenômeno em Tibouchina pulcha , uma espécie nativa brasileira, cujas flores mudam do branco para rosa escuro. Para alcançar o objetivo, os perfis dos compostos e de expressão de genes da via de biossíntese de flavonoides foram estudados. Utilizando técnicas hifenadas (UPLC-HRMS and NMR), trinta compostos foram quantificados e identificados, sendo: dezesseis descritos pela promeira vez em T. pulchra. Além idsso, um composto inédito foi identificado. Cinco genes que codificam para enzimas chaves da via foram parcialmente clonados, sequenciados, e os níveis de mRNA foram analisados (RT-qPCR) durante o desenvolvimento das flores. Coletivamente, os dados obtidos demonstram que a mudança de cor em flores de T. pulchra é regulada transcricionalmente. Além disso, quantificações de metais sugerem que o ion Fe3+ esteja relacionado a saturação da cor no estágio rosa escuro
22

Phytochemical investigation and biological activities of Sanicula europaea and Teucrium davaeanum : isolation and identification of some constituents of Sanicula europaea and Teucrium davaeanum and evaluation of the antioxidant activity of ethanolic extracts of both plants and cytotoxic activity of some isolated compounds

Talag, Agela Hussain Mohammed January 2016 (has links)
The aim of this research was to investigate the phytochemistry of two species Sanicula europaea and Teucrium davaeanum which are traditionally used in treatment of wounds. Four compounds were isolated from the 80% methanolic extract of S. europaea; bis-(2-ethylhexyl) phthalate (1), palmitic acid (2), rosmarinic acid (3), saniculoside N (4). Compounds 1 and 2 were isolated for the first time from this species. The structure elucidation of the isolated compounds was on the basis of 1D, 2D NMR spectroscopy and mass spectrometry measurements. Two compounds were isolated from the crude glycosides extract of T.davaeanum; 6 is a phenylethanoid glycoside and 8 is an iridoid glycoside, from the data available these may be new compounds for which the names davaeanuside A and davaeanuside B are proposed respectively." The total polyphenol content of S. europaea L, T. davaeanum leaves-flowers and T. davaeanum stem were found to be 5.0, 1.20 and 0.65 mg per 100 mg dried plant material respectively. A study of the antioxidant activity of the 50 % ethanol extracts of S. europaea and T. davaeanum showed that on a mg/mg basis S. europaea and T. davaeanum have approximately 5%, 8 % antioxidant capacity of Trolox respectively. A study of the cytotoxic activity of davaeanuside A (6), iridoid glycoside (7), davaeanuside B (8) and saponin compound (10) isolated from the crude glycosides extract of T. davaeanum revealed that saponin compound (10) inhibited the growth of Hela cells by 50 % at 50 μg/ml, P< 0.001, but the other compounds did not show activities against the tested cell lines at 100 μg/ml. The results of this work provide some basis for the traditional use of these species in the treatment of wounds.
23

Development and Validation of an Analytical Method for Phenolic Acid Extraction from Cereals and Quantification using HPLC-UV / Entwicklung und Validierung einer analytischen Methode für Phenolsäure-Extraktion aus Getreide und Quantifizierung mittels HPLC-UV

Amann, Laura January 2018 (has links)
Cereals are rich in phenolic acids, a group of secondary plant metabolites that are associated with reduced risk of chronic diseases. The objective was to develop and internally validate a method for extraction and quantification of phenolic acids in cereals using HPLC-UV and to apply this method for quantification of the content of phenolic acids in several species of Swedish cereals. Different procedures for extraction of phenolic acids from cereal grains using acid or base hydrolysis with and without subsequent enzymatic treatment were tested. Both the extraction procedure and the chromatographic conditions for quantification with HPLC-UV were optimized. Phenolic acids from 14 cereal samples, representing different cultivars of rye, wheat, barley, and oat, were extracted and analyzed under optimized conditions. Using the optimized method, 15 phenolic acids could be quantified with limits of detection and quantification ranging from 0.4 to 11.4 µg/g and from 1.3 to 38.0 µg/g, respectively. The hydrolysis procedure and further sample treatment showed a substantial effect on the yield of phenolic acids from cereals. The highest yield was achieved by 90‑minute base hydrolysis at room temperature using sodium hydroxide solution containing ascorbic acid and EDTA. Mean recoveries ranged from 88 to 108%. The following phenolic acids were found in the analyzed cereal grains with ferulic acid being the most abundant one: p‑hydroxybenzoic acid, vanillic acid, vanillin, caffeic acid, syringic acid, ferulic acid, sinapic acid, and 3,4‑dihydroxybenzaldehyde. A further compound was p‑coumaric acid or the co‑eluting syringaldehyde or a mixture of both. The content of phenolic acids in Swedish cereals ranged from 6 µmol/g DM in rye to 3 µmol/g DM in oat and a barley cultivar. In conclusion, a simple and accurate method for extraction and quantification of phenolic acids in cereals was developed and successfully applied. / Getreide ist reich an Phenolsäuren, einer Gruppe pflanzlicher Sekundärmetabolite, die mit einem verringerten Risiko für chronische Erkrankungen in Verbindung gebracht wird. Ziel war es, eine Methode zur Phenolsäure-Extraktion aus Getreide und Quantifizierung mittels HPLC-UV zu entwickeln, intern zu validieren und diese im Anschluss anzuwenden, um den Phenolsäure-Gehalt in mehreren schwedischen Getreidearten zu quantifizieren. Verschiedene Verfahren zur Phenolsäure-Extraktion aus Getreide unter Verwendung von Säure- oder Basenhydrolyse mit oder ohne nachfolgender enzymatischer Hydrolyse wurden getestet. Es wurden sowohl das Extraktionsverfahren als auch die chromatographischen Bedingungen zur Quantifizierung mittels HPLC-UV optimiert. Phenolsäuren von 14 Getreideproben, darunter Kultivare von Roggen, Weizen, Gerste und Hafer, wurden unter optimierten Bedingungen extrahiert und analysiert. Mit der optimierten Methode konnten 15 Phenolsäuren mit Nachweisgrenzen von 0,4 bis 11,4 µg/g und Bestimmungsgrenzen von 1,3 bis 38,0 µg/g quantifiziert werden. Hydrolyseverfahren und weitere Probenbehandlung haben die Phenolsäure-Ausbeute von Getreide wesentlich beeinflusst. Die höchste Ausbeute wurde durch eine 90‑minütige Basenhydrolyse bei Raumtemperatur unter Verwendung von Natronlauge mit Ascorbinsäure und EDTA erzielt. Die mittlere Wiederfindung betrug 88 bis 108%. In den untersuchten Getreideproben wurden folgende Phenolsäuren gefunden mit Ferulasäure als häufigster Verbindung: p-Hydroxybenzoesäure, Vanillinsäure, Vanillin, Kaffeesäure, Syringasäure, Ferulasäure, Sinapinsäure und 3,4‑Dihydroxybenzaldehyd. Eine weitere Verbindung war p‑Cumarsäure oder der co‑eluierende Syringaldehyd oder eine Mischung aus beiden. Der Phenolsäure-Gehalt reichte von 6 µmol/g DM in Roggen bis 3 µmol/g DM in Hafer und einem Gerstenkultivar. Zusammenfassend wurde eine einfache und genaue Methode zur Phenolsäure-Extraktion und Quantifizierung in Getreide entwickelt und erfolgreich angewendet.
24

Influence of genetic variability on specialty potato functional components and their effect on prostate cancer cell lines

Reddivari, Lavanya 15 May 2009 (has links)
The influence of genotype (selection), location, and year on antioxidant activity (AOA), total phenolics (TP), total carotenoids (TC), phenolic and carotenoid composition was studied using specialty (colored) potatoes (Solanum tuberosum L.) from the Texas Potato Variety Development Program, grown at two Texas locations (McCook and Dalhart), and in two years (2003 and 2004). Chlorogenic acid, gallic acid, catechin, caffeic acid, and malvidin-3-(p-coumaryl rutinoside)–5-galactoside were the major phenolics, and lutein and violaxanthin were the major carotenoids identified. The AOA, TP, and TC and phenolic composition differed significantly with genotype, location and year. However, genotypic effects were larger than location and year effects. Selection CO112F2-2 was high in all the measured parameters and also stable across locations and years, suggesting that this selection could be used as a parent in breeding varieties with improved health benefits. The AOA, TP and chlorogenic acid content were highly significantly correlated with one another. The effects of whole specialty potato extracts, fractions and individual compounds on LNCaP (androgen-dependent) and PC-3 (androgen-independent) prostate cancer cells were also investigated. Ethanol extract of the selection CO112F2-2 (5 µg chlorogenic acid eq/ml), the anthocyanin fraction (AF; 5 µg chlorogenic acid eq/ml), gallic acid and chaconine showed potent anti-proliferative properties and increased the cyclin-dependent kinase inhibitor p27 levels in LNCaP and PC-3 cells. Induction of apoptosis was cell context dependent and associated with JNK (c-Jun NH2-terminal Kinase) and Erk (extracellular signal regulated kinase) activation. Cell death pathways, induced by potato extract and the AF, were associated with Erk and JNK activation, and these kinases activated caspase-independent apoptosis through nuclear translocation of endonuclease G (endo G) and apoptosis-inducing factor (AIF) in both cell lines. Induction of caspase-dependent apoptosis was also kinase-dependent but was observed only in LNCaP cells. Kinase inhibitors reversed this nuclear translocation of endo G and AIF. This is the first report showing that the cytotoxic activities of potato extract/AF in cancer cells were due to activation of caspase-independent apoptosis.
25

Flavonoidų ir fenolinių rūgščių analizė kanadinės jakšūnės Desmodium canadense (L.) DC. žolėje / Analysis of flavonoids and phenolic acids in grass of Desmodium canadense (L) DC

Kamandulis, Mintautas 06 July 2006 (has links)
Plants have many useful substances – and one of them is flavonoids with other phenolic compounds. This is a very big group of biological active compounds. Flavonoids have been referred to as "nature's biological response modifiers" because of their ability to modify the body's reaction to other compounds such as allergens, viruses, and carcinogens. They show anti-allergic, anti-inflammatory, and anti-cancer activity. In addition, flavonoids act as powerful antioxidants, providing remarkable protection against oxidative and free radical damage. As a result, consumers and food manufacturers have become increasingly interested in flavonoids for their healthful properties, especially their potential beneficial role in the prevention of cancer and cardiovascular diseases. Phenolic acids are interesting of their protective role against oxidative damage diseases (coronary heart disease, stroke, and cancers). One of possible sources of flavonoids and phenolic acids – Canadian thick-trefoil (showy trefoil) – Desmodium canadense (L) DC. This plant is not researched as good as many other plants, but there are some works on it. In Lithuania, KUM, there were some research works on Desmodium canadense (L.) DC. There was performed analysis of grass, collected in different phase of vegetation. Also was researched influence of mineral fertilising to amounts of flavonoids and phenolic acids.
26

Rausvažiedės ežiuolės (Echinacea Purpurea (L.) Moench) ekstraktų, gautų skirtingais metodais, palyginimas / Comparison of purple coneflower (Echinacea purpurea (L.) Moench) extracts obtained by different extraction methods

Maleckienė, Rūta 26 June 2008 (has links)
Rausvažiedė ežiuolė (Echinacea purpurea (L.) Moench) apibūdinama kaip priemonė skatinanti medžiagų apykaitą; stimuliuojanti metabolizmo pakitimus ir ląstelių natūralią gynybą esant lėtinėms ir ūmioms ligoms; antiseptikas; dezinfekuojantis žaizdas agentas; vaistas. Darbo tikslas buvo atlikti fenolinių junginių analizę rausvažiedės ežiuolės (Echinacea purpurea (L.) Moench) ekstraktuose, gautuose skirtingais metodais, naudojant spektrofotometrinį metodą ir efektyviąją skysčių chromatografiją. Darbo uždaviniai buvo optimizuoti ekstrakcijos sąlygas (maceracijos metodu) įvertinant skirtingas metanolio koncentracijas ir ekstrakcijos trukmės įtaką fenolinių junginių kiekybinei sudėčiai ekstraktuose; paruošti ekstraktus maceracijos, soksleto ir ekstrakcijos superkritiniais skysčiais metodais; optimizuoti efektyviosios skysčių chromatografijos sąlygas; atlikti kokybinę ir kiekybinę fenolinių junginių analizę Rausvažiedės ežiuolės ekstraktuose, įvertinant a) skirtingas ekstraktų paruošimo metodikas; b) skirtingas augalo dalis. Tyrimo metu optimizuotos ekstrakcijos sąlygos (maceracijos metodu); nustatyta, kad daugiausiai fenolinių junginių išekstrahuota naudojant 70 % metanolį per pirmas 4 ekstrakcijos valandas. Paruošti ekstraktai maceracijos, soksleto ir ekstrakcijos superkritiniais skysčiais metodais. Spektrofotometru nustatyta, kad daugiausiai fenolinių junginių išekstrahuojama maceracijos metodu — 3 kartus daugiau nei soksleto metodu ir 14 kartų daugiau nei ekstrakcija... [toliau žr. visą tekstą] / Echinacea purpurea (L.) Moench (family Asteraceae) herbal medicines and dietary supplements are traditionally used as immunostimulants in the treatment of inflammatory and viral diseases. Employed are roots and aerial parts. The main active compounds of Echinacea purpurea (L.) Moench are alkamides and polyacetylenes, caffeic acid derivatives, polysaccharides and glycoproteins. With regard to caffeic acid derivatives, several compounds have been identified from the hydrophilic fractions of Echinacea extracts, such as caftaric acid, chlorogenic acid, caffeic acid and cichoric acid. Cichoric acid is found to be the main phenolic compound in E. purpurea. From the caffeic acid derivatives, only cichoric acid has shown immunostimulatory properties, promoting phagocyte activity in vitro and in vivo. In addition, cichoric acid has antihyaluronidase activity, and has a protective effect on the free-radical-induced degradation of collagen. Cichoric acid has also shown antiviral activity and has recently been found to inhibit HIV-1 integrase and replication. Tasks of investigation: to prepare samples for phenolic acids analysis by supercritical fluid, soxhlet extractions and maceration methods and optimize SPE parameters. Evaluate amount of cichoric acid and compare it in different parts of plant by spectrophotometric method. Optimize HPLC analysis conditions and identify the main phenolic acids by HPLC. Compare amounts of phenolic acids between plant parts and extraction methods... [to full text]
27

Control of Listeria monocytogenes and Heat-Resistant Escherichia coli on Vacuum-Packaged Beef

Socholotuik, Mandi R Unknown Date
No description available.
28

Proanthocyanidins, anthocyanins and phenolic acids in food barleys of diverse origin

Hambira, Chipo 11 January 2010 (has links)
Phytochemicals found in grains complement those found in fruits and vegetables. These phytochemicals, though minor compounds, contribute to the antioxidant properties which are related to the health benefits associated with the consumption of whole grain. In this thesis project, nine barley genotypes of diverse origin namely CI2230 from Nepal, CI1248 from Israel, 3 Peruvian genotypes; Peru 3, Peru 16 and Peru 35, Hokuto Hadaka from Japan, EX116; a cross between Moroccan and Canadian genotype, EX83; a cross between two Canadian genotypes and EX127; a cross between Canadian and German genotypes were studied. The genotypes were categorized based on appearance into purple, black and yellow grains. Phenolic acids and flavonoids were identified and quantified in these diverse genotypes using HPLC-ESI-MS analysis. The main classes of dietary flavonoids studied in the barleys were anthocyanins and flavan-3-ols. Phenolic acids were identified and quantified (p-coumaric, ferulic, sinapic, caffeic, vanillic). Three ferulic acid dehydrodimers (8-0-4’ DFA, 8-5’ benzofuran form and 5-5’ DFA) were also identified. The most abundant dimeric flavan-3-ols were procyanidins B3 and prodelphinidin B3. The monomeric unit, (+)-catechin, was the most abundant while catechin glucoside (m/z 451) was also identified. Among the Peruvian genotypes, Peru 16 and Peru 35 exhibited relatively high levels of total PA content. Total phenolic content and antioxidant activities of methanolic, acetone and alkali hydrolyzed extracts of the nine barley genotypes was determined by the Folin- Ciocalteau assay, DPPH radical scavenging assay and oxygen radical absorbance capacity (ORAC assay).The acetone extract exhibited the highest antioxidant capacity using all the methods of analysis. Furthermore, dark colored grains were found to exhibit higher contents of phenolic compounds. The phenolic acids, PAs and anthocyanins identified and quantified had significant contribution to the overall antioxidant capacity of the barley whole grain. Four hull-less genotypes namely CI2230, EX127, CI1248 and Peru 35 were further partially sprouted to establish the effects of sprouting on phenolic acid composition. Partial sprouting was observed to significantly increase the soluble conjugated phenolic acids. The barley genotypes studied were found to contain different quantities of phytochemicals and had high proanthocyanidin content thereby rendering them as alternative sources of antioxidants. Barley sprouts present a possible novel food ingredient with improved properties such as phenolic acid composition and other benefits such as easier incorporation into food products under development.
29

Proanthocyanidins, anthocyanins and phenolic acids in food barleys of diverse origin

Hambira, Chipo 11 January 2010 (has links)
Phytochemicals found in grains complement those found in fruits and vegetables. These phytochemicals, though minor compounds, contribute to the antioxidant properties which are related to the health benefits associated with the consumption of whole grain. In this thesis project, nine barley genotypes of diverse origin namely CI2230 from Nepal, CI1248 from Israel, 3 Peruvian genotypes; Peru 3, Peru 16 and Peru 35, Hokuto Hadaka from Japan, EX116; a cross between Moroccan and Canadian genotype, EX83; a cross between two Canadian genotypes and EX127; a cross between Canadian and German genotypes were studied. The genotypes were categorized based on appearance into purple, black and yellow grains. Phenolic acids and flavonoids were identified and quantified in these diverse genotypes using HPLC-ESI-MS analysis. The main classes of dietary flavonoids studied in the barleys were anthocyanins and flavan-3-ols. Phenolic acids were identified and quantified (p-coumaric, ferulic, sinapic, caffeic, vanillic). Three ferulic acid dehydrodimers (8-0-4’ DFA, 8-5’ benzofuran form and 5-5’ DFA) were also identified. The most abundant dimeric flavan-3-ols were procyanidins B3 and prodelphinidin B3. The monomeric unit, (+)-catechin, was the most abundant while catechin glucoside (m/z 451) was also identified. Among the Peruvian genotypes, Peru 16 and Peru 35 exhibited relatively high levels of total PA content. Total phenolic content and antioxidant activities of methanolic, acetone and alkali hydrolyzed extracts of the nine barley genotypes was determined by the Folin- Ciocalteau assay, DPPH radical scavenging assay and oxygen radical absorbance capacity (ORAC assay).The acetone extract exhibited the highest antioxidant capacity using all the methods of analysis. Furthermore, dark colored grains were found to exhibit higher contents of phenolic compounds. The phenolic acids, PAs and anthocyanins identified and quantified had significant contribution to the overall antioxidant capacity of the barley whole grain. Four hull-less genotypes namely CI2230, EX127, CI1248 and Peru 35 were further partially sprouted to establish the effects of sprouting on phenolic acid composition. Partial sprouting was observed to significantly increase the soluble conjugated phenolic acids. The barley genotypes studied were found to contain different quantities of phytochemicals and had high proanthocyanidin content thereby rendering them as alternative sources of antioxidants. Barley sprouts present a possible novel food ingredient with improved properties such as phenolic acid composition and other benefits such as easier incorporation into food products under development.
30

Šermukšnio (Sorbus L.) genties augalų fenolinių junginių tyrimas / Research of Phenolic Compounds in Plants of Genus Sorbus L

Gaivelytė, Kristina 04 September 2014 (has links)
Sorbus L. gentis yra plačiai paplitusi pasaulyje. Šermukšnio genties augalų augalinės žaliavos fitocheminė sudėtis tiriama pasaulio mokslininkų, tačiau duomenys apie galimą fenolinių junginių įvairavimą yra nepakankami. Siekiant ištirti Lietuvoje natūraliai augančių ir auginamų kolekcijose šermukšnių (Sorbus L.) rūšių ir veislių lapų, žiedų ir vaisių flavonoidų ir fenolinių rūgščių kokybinės ir kiekinės sudėties įvairavimą, optimizuota efektyviosios skysčių chromatografijos (ESC) metodika. Ištirta paprastųjų šermukšnių (S. aucuparia L.) lapų, žiedų ir vaisių ėminių flavonoidų ir fenolinių rūgščių kokybinė ir kiekinė sudėtis bei nustatyti įvairavimo ypatumai augalo vegetacijos periodo metu. Ištirta Lietuvoje natūraliose augavietėse augančių S. aucuparia L. lapų ėminių flavonoidų ir fenolinių rūgščių kokybinė ir kiekinė sudėtis. Nustatyta kolekcijose auginamų Sorbus L. genties rūšių ir veislių augalų flavonoidų ir fenolinių rūgščių kokybinė ir kiekinė sudėtis bei jų kaupimosi dėsningumai. Atlikti Sorbus L. genties rūšių ir veislių vaisių fenolinių junginių antioksidacinio aktyvumo tyrimai taikant pokolonėlinės reakcijos metodą, nustatytas ryšys tarp fenolinių junginių kiekio šermukšnių vaisiuose ir antioksidacinio aktyvumo. / Sorbus L. genus is widespread in the world. In the course of research carried out in various countries, analysis of the phytochemical composition of Sorbus L. species has been performed, however, information about possible variation of phenolic compounds is insufficient. In order to investigate qualitative and quantitative composition of phenolic acids and flavonoids in leaves, inflorescences and fruits of Sorbus L. growing in natural habitats and grown in collection in Lithuania HPLC method was developed. Variation patterns of the contents of phenolic compounds flavonoids in leaves, inflorescences and fruits of S. aucuparia L. during the growth season were determined. Qualitative and quantitative composition of phenolic acids and flavonoids in leaves of S. aucuparia L. growing in natural habitats in Lithuania was investigated. Qualitative and quantitative composition of phenolic acids and flavonoids of species and varieties of genus Sorbus L. plants, grown in collections, was investigated. Antioxidant activity of fruits of species and varieties of genus Sorbus L. was investigated applying postcolumn HPLC method and relationship between the amount of phenolic compounds and antioxidant activity was revealed.

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