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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

Disparate modes of action of juglone in the respiratory systems of sensitive and resistant plants

Boes, Teresa Katherine. January 1985 (has links)
Call number: LD2668 .T4 1985 B63 / Master of Science
2

Homeopatiškai paruošti preparatai iš Juglans nigra L. kevalo: biologiškai aktyvių junginių analizė ir antioksidacinio aktyvumo tyrimas / Homeopatically produced preparation from Juglans nigra L. shell: the analysis of biologically active compounds and the antioxidant activity study

Peleckytė, Urtė 01 July 2014 (has links)
Homeopatiniais vadinami preparatai, kurie yra pagaminti iš homeopatinių žaliavų, naudojant homeopatinės gamybos procedūras. Biologiniam homeopatinių preparatų aktyvumui tirti mokslininkai naudoja tuos pačius tyrimų metodus, kaip ir kitų rūšių cheminiams preparatams [32]. Šiam tyrimui pasirinkta homeopatinė juodojo riešuto (Juglans nigra L.) kevalo tinktūra ir jos D1 bei C1 praskiedimai – tai nedidelio laipsnio skiediniai, kuriuose veikliąsias medžiagas dar galima įdentifikuoti ir koncentracijas bei biologinį aktyvumą vertinti turimais tyrimo metodais. Mokslinės literatūros šaltiniuose skelbiama, jog juodojo riešuto kevale yra devynios pagrindinės cheminės medžiagos [29]. Nustatyta, jog riešuto viena iš pagrindinių veikliųjų medžagų yra juglonas, kuris turi citotoksinių savybių prieš melonomos, kepenų, plaučių, širdies, kraujo ląsteles [25,28,38,39]. Kadangi mokslinių tyrimų su preparatais, pagamintais iš juodojo riešuto, atlikta nedaug, todėl buvo pasirinkta ištirti polifenolinių junginių, juglono kiekį pagamintuose tirpaluose bei nustatyti jų antioksidacines savybes. Darbo tikslas: Homeopatiškai paruošti iš juodojo riešuto kevalo pradinę tinktūrą ir jos D1 bei C1 praskiedimus, ištirti polifenolinių junginių, juglono kiekį ir įvertinti antioksidantinį aktyvumą. Metodai: Pagaminta pradinė homeopatinė tinktūra (urtinktūra) ir jos skiediniai pagal Homeopatijos farmakopėjos reikalavimus (HAB 2000, 3a taisyklė). Spektrofotometriškai nustatytas polifenolinių junginių... [toliau žr. visą tekstą] / Preparations referred to as homoeopathic are those made of homoeopathic raw materials using homoeopathic manufacturing procedures. In order to measure biological activity of homoeopathic preparations scientists use the same investigation methods as with other kinds of chemical products [30]. For this study homoeopathic tincture of black walnut (Juglans nigra L.) shell and its D1and C1 dilutions have been selected as these produce low-grade solutions in which active substances still can be identified and concentrations as well as bioactivity can be assessed by available methods of testing. The scientific literature sources state that the black walnut shell contains nine basic chemical substances [29]. It is found that one of the basic active ingredients is juglone which possesses cytotoxic properties effective against melanoma, the liver, lung, heart and blood cells. [25,28,38,39]. As the studies of black walnut preparations are not so common, we have chosen to investigate the juglone amount and polyphenolic compounds in solutions and to measure their antioxidant properties. The aim of the research: To produce homoeopathically original tincture of the black walnut shell and its D1 and C1 dilutions, to explore polyphenolic compounds, the level of juglone and evaluate their antioxidant activity. The methodology: Original homoeopathic tincture (urtincture) and its solutions were produced following the specification of Homoeopathy Pharmacopoeia (HAB 2000, rule 3a)... [to full text]
3

Fytotoxicita vybraných naftochinonů na vybraném rostlinném modelu / Phytotoxicity of selected naphthoquinones on a selected plant model

Rucký, Jakub January 2013 (has links)
The introductory part of this thesis is focused on the theoretical analysis of solved problems as examining the toxicity of naphthoquinones plumbagine and juglone, especially with regard to their allelopatic action. The next section is focuses on the plant stress, caused by the action of stress factors leading to their death. There is an experimental protocol and the possibilities of determination the effect of naphthoquinones on the plant model. Experimental section discusses changing growth parameters of the plant samples in different concentrations of the naphthoquinone. There is examined cell viability and changes in the synthesis of the secondary metabolites. Data obtained by using spectrophotometric and microscopic analysis are evaluated with STATISTICA software and statistical significance are plotted.
4

Exploring the metabolic intersection of juglone and phylloquinone biosynthesis

Rachel M McCoy (8802776) 06 May 2020 (has links)
<p>Juglone is a 1,4-naphthoquinone (1,4-NQ) and the allelochemical responsible for the well-known toxic effects of black walnut (<i>Juglans nigra</i>)<i> </i>and other members of the Juglandaceae. Juglone affects a variety of weed species via a mode of action unlike any commercially available herbicides, and thus has the potential to be used as a new natural product-based herbicide. However, lack of knowledge about its metabolism precludes introducing juglone biosynthesis traits into resistant crops through biotechnology. Herein, we established that juglone is derived from the phylloquinone pathway at the level of the intermediate 1,4-dihydroxy-2-naphthoic acid (DHNA). Phylloquinone is a primary 1,4-NQ made by all plants for photosynthetic electron transport. Despite the fundamental importance of phylloquinone, there are still unanswered questions about the subcellular architecture of the phylloquinone pathway. In chapter 3, we show that <i>o</i>-succinylbenzoate CoA-ligase is localized to both chloroplasts and peroxisomes and that its activity is vital in both organelles. The required dual localization of CoA ligase activity is a theme common to other plant pathways with CoA metabolic steps occurring in peroxisomes and thus leads us to propose a revised model of the phylloquinone pathway. Lastly, given the potential of introducing juglone biosynthesis as part of novel weed management strategies, we investigated the circumstances, costs, and benefits of producing allelochemicals in crops using an evolutionary game theory model. Together, this work (i) shows that the phylloquinone pathway provides crops with the biosynthetic framework to produce juglone, (ii) sheds new light on the phylloquinone pathway architecture, and (iii) reveals the circumstances in which producing an allelochemical will be an evolutionarily stable strategy. We envision these results will assist biotechnological efforts to utilize juglone as a novel, natural product-based herbicide.</p>
5

Skystųjų preparatų iš Juglans nigra L. lapų gamyba, biologiškai aktyvių junginių kiekio įvertinimas ir antioksidacinio aktyvumo tyrimas / Biologically active compounds and antioxidant activity evaluation of liquid Black walnut (Juglans nigra L.) leaf preparations

Keturakytė, Vytautė 18 June 2014 (has links)
Tyrimo tikslas - pagaminti vandenines ir etanolines ištraukas iš Junglans nigra L. lapų ir įvertinti bendrą fenolinių junginių, bendrą flavonoidų, juglono kiekį bei nustatyti antioksidacinį aktyvumą. Metodika: 1. Tyrimo objektai: 70% etanolinė juodojo riešutmedžio tinktūra, vandeninė juodojo riešutmedžio lapų ištrauka bei gamyklinis “Black Walnut” 1:1 ekstraktas (gamintojas „Nature's Answer”, JAV). 2. Ištraukų iš J. nigra lapų gamyba. 1) Etanolinės tinktūros gamyba. Pritaikius perkoliacijos metodą iš juodojo riešutmedžio lapų žaliavos, naudojant 70% etanolį, buvo pagaminta tinktūra (santykis 1:10). 2) Vandeninė ištrauka. 10 g smulkintos lapų žaliavos buvo užpilta 120 ml verdančio vandens ir kaitinta 1 val. Ištrauka nufiltruota pro 4 nr. Vatmano filtrą. 3. Kokybinės flavonoidų įvertinimo reakcijos. 4. Bendras fenolinių junginių nustatymas naudojant Folin – Ciocalteu metodą (standartas – galo r.) 5. Bendras flavonoidų kiekio nustatymas spektrofotometriniu būdu, naudojant AlCl3 tirpalą (standartas - rutinas). 6. Juglono kiekio nustatymas spektrofotometriniu būdu. 7. Antioksidacinio aktyvumo įvertinimas fluorimetriniu būdu, naudojant 10-acetil-3,7-dihidroksifenoksazinas (AMR) ir krienų peroksidazę (HPR). Rezultatai. Bendram fenolinių junginių, bendram flavonoidų bei juglono išekstrahuoto kiekio palyginimui buvo pagamintos J. nigra lapų etanolinė ir vandeninė ištraukos. Tiriamų objektų biologiškai aktyvių komponentų kiekiai buvo palyginti su gamykliniu „Black Walnut“ ekstraktu... [toliau žr. visą tekstą] / Aim of the work - produce aqueous and ethanolic extracts of Junglans nigra leaves, evaluate the total phenolic and total flavonoids content, juglone concentration and identify antioxidant activity. Methods: 1. Objects of study: ethanolic tincture and aqueous extract of black walnut leaves, “Black Walnut” extract, 1:1 („Nature's Answer”, USA). 2. Liquid preparations of J. nigra leaves production: 1) Ethanolic tincture production. Tincture was produced of black walnut leaves applying the method of percolation. The 70% ethanol was used. Tincture ratio is 1:10. 2) Aqueous exract production. 10 g shredded leaves of black walnut were extracted with 120 ml of boiling wather for 1 hours. After boiling extract was filtered throught the Whatman paper no. 4. 3. Qualitative evaluation of flavonoids. 4. Total phenolic content was determined by spectrophotometric (Folin - Ciocalteau) method. 5. Total flavonoids content was measured with an aluminum chloride colorimetric assay using spectrophotometer. 6. Juglone determination by spectrophotometric method. 7. Fluorimetric antioxidant activity assay by using N-Acetyl-3,7-dihydroxyphenoxazine (Amplex Red) and horseradish peroxidase (HPR). Results. Ethanolic and aqueous extracts of J. nigra leaves were made to compare total phenolic, total flavonoids content, juglone concentration. Biologically active components study results of ethanolic and aqueous extracts were compared with “Black Walnut” extract. The highest total phenolic and total... [to full text]
6

Aspects of the chemistry of 1,4-naphthoquinones : an investigation of nucleophilic substitution reactions of alkylamines and hydroxyalyklamines on 1,4 napthoquinones and the role of solvent on the position of substitution

Mahmood, Tariq January 2012 (has links)
Nucleophilic substitution reactions of alkylamines, cyclic alkylamines, and hydroxyalkylamines with 5-substituted-1,4-naphthoquinones have been studied. It has been found that the nature of the solvent employed in the reaction influences the position of mono-substitution at either the 2- or 3-position. Although both regioisomers were produced in all the reactions, protic polar solvents favoured the formation of the 3-regioisomer, whereas non-protic solvents favoured the formation of the 2-regioisomer. It has also been found that formation of 2,3-diaminoalkyl derivatives is normally unlikely. A series of hydroxyalkylamino-1,4-naphthoquinones were also synthesised. The collision-induced dissociation mass spectra of protonated hydroxyalkylamino-1,4- naphthoquinones showed fragmentation patterns which were dependent on the nature and length of the side chain and the presence and nature of the adjacent group on the 3-position on the 1,4-naphthoquinone ring. A total of 27 novel compounds were synthesised during the course of this research, the structures of which were confirmed via 1D and 2D NMR spectroscopy, mass spectrometry (ESI), IR spectroscopy and high resolution mass spectrometry (HRESIMS and HREIMS).
7

Elektroforetické a imunofluorescenční metody ve studiu rostlinných buněčných kultur / Electrophoretic and immunofluorescence methods for study of plant cell cultures

Klimešová, Marie January 2013 (has links)
In all organisms are rising a reactive oxygen and nitrogen species by the effects of various stress factors and these species have a negative impact on the organism. Due to this species plants have built up an efficient antioxidant system, that helps them to resist negative effects of reactive oxygen and nitrogen species. In this work was researched the effect of hydrogen peroxide and sodium benzoate on the production of hydrogen peroxide, superoxide, reactive nitrogen species and malondialdehyde, contained in the root and above-ground part of maize (Zea mays L.). By use of the fluorescence microscopy there were obtained images of cross-cut of root from which was determined the intensity of fluorescence of individual parts of the root and was examined the effect of the intensity of fluorescence markers of oxidative stress in dependence on the type of the fluorescence filter used.
8

Aspects of the chemistry of 1,4-naphthoquinones. An investigation of nucleophilic substitution reactions of alkylamines and hydroxyalyklamines on 1,4 napthoquinones and the role of solvent on the position of substitution.

Mahmood, Tariq January 2012 (has links)
Nucleophilic substitution reactions of alkylamines, cyclic alkylamines, and hydroxyalkylamines with 5-substituted-1,4-naphthoquinones have been studied. It has been found that the nature of the solvent employed in the reaction influences the position of mono-substitution at either the 2- or 3-position. Although both regioisomers were produced in all the reactions, protic polar solvents favoured the formation of the 3-regioisomer, whereas non-protic solvents favoured the formation of the 2-regioisomer. It has also been found that formation of 2,3-diaminoalkyl derivatives is normally unlikely. A series of hydroxyalkylamino-1,4-naphthoquinones were also synthesised. The collision-induced dissociation mass spectra of protonated hydroxyalkylamino-1,4- naphthoquinones showed fragmentation patterns which were dependent on the nature and length of the side chain and the presence and nature of the adjacent group on the 3-position on the 1,4-naphthoquinone ring. A total of 27 novel compounds were synthesised during the course of this research, the structures of which were confirmed via 1D and 2D NMR spectroscopy, mass spectrometry (ESI), IR spectroscopy and high resolution mass spectrometry (HRESIMS and HREIMS).
9

Etude sur la biosynthèse de Naphtoquinones végétales et bactériennes

Dansette, Patrick M 12 October 1972 (has links) (PDF)
Les quinones sont des composés largement répandus dans la nature, aussi bien dans le règne végétal, qu'animal ou microbien. Ces molécules sont biosynthétisées à partir d'un petit nombre d'intermédiaires simples. Le noyau des naphtoquinones, en particulier, peut être synthétisé à partir de quatre précurseurs principaux l'acétate, la toluhydroquinone, le p-hydroxybenzoate et le shikimate. L'objet du présent travail est l'étude de la biosynthèse des naphtoquinones végétales ou bactériennes dérivant de l'acide shikimique (acide trihydroxy-3,4,5 cyclohexène-1 carboxylique), et la recherche des intermédiaires de cette voie de biosynthèse. Etant donné, à l'origine, l'absence quasi-totale de résultats expérimentaux dans ce domaine et le développement important qu'il a acquis en même temps que nous commencions notre travail, celui-ci a été constamment lié dans son développement aux données les plus récentes parues dans la littérature. Quelques études antérieures avaient montré que l'acide shikimique devait être le précurseur commun des acides aminés aromatiques et de plusieurs facteurs de croissance aromatiques (acide dihydroxy-2,3 benzoique, dihydroxy-3,4 benzoique, p-aminobenzoique et p-hydroxybenzoique) ainsi que de la ménaquinone de Escherichia coli (16,17). Lorsque nous commençons ce travail, on sait seulement que l'acide shikimique est incorporé in toto dans les ménaquinones bactériennes, de telle sorte que son carboxyle devient un des carbonyles de la quinone. Trois questions se posent alors: - Sur lequel des carbones 2 ou 6 adjacents au carboxyle, le cycle naphtoquinonique se ferme-t-il ? - Quelle est la molécule qui fournit les trois carbones nécessaires à la fermeture du cycle quinonique de la naphtoquinone, et quel est le mécanisme de cette fermeture ? - Le cycle naphtoquinonique ainsi formé est-il incorporé de façon symétrique ou non dans les ménaquinones, c'est-à-dire le carboxyle de l'acide shikimique est-il incorporé indifféremment dans les deux carbonyles quinoniques, ou sélectivement dans l'un des deux ? Pour résoudre la première question, LEISTNER et ZENK d'une part et M. LEDUC dans notre laboratoire d'autre part, ont utilisé l'acide shikimique [14 C-1,6]. Cette méthode nécessite une dégradation laborieuse des quinones formées. Nous avons, quant à nous, synthétisé un acide shikîmique [3H-3] marqué au tritium en une position spécifique, ce qui permet une dégradation simple et univoque. Une réponse partielle à la deuxième question a été donnée par CAMPBELL. Il montrait, en 1969, que le glutamate est capable d'apporter ses carbones 2, 3 et 4 pour la fermeture du cycle naphtoquinonique, mais il ne disposait pas alors des résultats de notre laboratoire lui permettant d'induire correctement le mécanisme de cette biosynthèse. Nous avons pu postuler la formation d'un intermédiaire, I'acide ortho-succinoylbenzoique OBS, dont nous avons pu prouver l'existence par synthèse et incorporation dans les quinones étudiées . L'existence de cet intermédiaire et la possibilité que nous avons eue de réaliser sur l'OSB différents marquages spécifiques nous ont permis de répondre à la troisième question, à savoir, l'incorporation orientée ou non de l'OSB dans les quinones. En même temps, différentes équipes montraient que d'autres quinones existant dans les végétaux telles que la lawsone, la juglone et différentes anthraquinones dérivaient aussi de l'acide shikimique; il nous a semblé intéressant d'appliquer nos techniques à l'étude très voisine de la biosynthèse de ces quinones. Pour la clarté de l'exposé, nous présentons dans le premier chapître les méthodes de synthèse des précurseurs radioactifs, dans le deuxième, les méthodes d'isolement et de dégradation des quinones. Les trois chapîtres suivants rapportent l'incorporation dans les ménaquinones, les naphtoquinones végétales et les anthraquinones végétales. Dans le sixième chapître, nous discutons nos résultats et proposons un schéma général de biosynthèse des quinones dérivant de l'acide shikimique. La partie expérimentale de ce travail est rassemblée après l'exposé théorique.
10

Investigating the production of secondary metabolites effective in lowering blood glucose levels in Euclea Undulata Thunb. Var Myrtina (Ebenaceae)

Botha, Lynette Elizabeth 03 1900 (has links)
Euclea undulata Thunb. var myrtina is a widely distributed shrub in South Africa. The roots are used by traditional healers for the treatment of diabetes. Research indicates that roots contain epicatechin, lupeol as well α-amyrin-3O-β-(5-hydroxy) ferulic acid. It was found that α-amyrin-3O-β-(5-hydroxy) ferulic acid inhibits α-glucosidase while epicatechin lowers glucose levels in the blood. Existing literature also indicates the presence of the naphthoquinone 7-methyl-juglone in the roots, although it was not detected in all cases. Due to its cytotoxic nature, 7-methyl-juglone poses a potential threat when E. undulata is used as medicinal treatment. In order to assist the effective and safe use of this plant as a treatment for diabetes, this project aims to determine whether the presence of these metabolites is seasonal. It further aims to contribute to more sustainable harvesting methods by investigating stems and leaves in addition to the roots for the presence of these metabolites. / Environmental Sciences / M. Sc. (Environmental Science)

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