Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 30 for “"triterpenoids"”.
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Diversity of polycyclic triterpenoids in Rhodospirillum rubrum
… bicyclic, tricyclic, tetracyclic and pentacyclic triterpenoids, derived from the enzymatic cyclization of squalene and produced in amounts comparable to diploptene. Identified compounds included bicyclic polypodatetraenes, malabaricatriene, euphadiene, adianane, and fernene. Prior to this work, …
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Studies of anti-trypanosomal active triterpenoids from some African propolis
There is a drastic need for new and improved drugs for parasitic diseases such as African Trypanosomiasis which is a major global health problem with high endemicity in developing countries due to the alarming rate of resurgence of the disease, drug related adverse effects and drawbacks of the …
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Total synthesis of 19,20-epoxydocosapentaenoic acid-ethanolamide (19,20-EDP-EA) and strategies towards the total synthesis of malabaricane triterpenoids
… the Das group at UIUC. Malabaricane triterpenoids belong to a class of molecules defined by a 6-6-5 tricyclic carbon backbone with a trans-anti-trans ring fusion. Although they have demonstrated only limited biological activities and efficient synthetic methods already exist for the …
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Composition of cuticular wax on the leaves of kalanchoe daigremontiana
… authentic standards led to the identification of triterpenoids including glutinol, friedelin, germanicol, epifriedelanol, glutinol acetate and β-amyrin as well as very long chain fatty acid (VLCFA) derivatives including alkanes, primary alcohols, aldehydes, fatty acids, and alkyl esters. Cuticular …
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Pharmacognostic study of 5 medicinal plant species from Western Cape Province (South Africa) for anti-tubercular activity
… led to the identification of pentacyclic triterpenoids, ursolic acid (UA) and oleanolic acid as major antitubercular constituents of B. saligna, L. gnaphaloides, and 1. graveolens. The in vitro cytotoxicity assays of the isolated bioactive constituents showed no cytotoxicity against …
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Anti-platelet aggregation activity of melaleuca bracteata var.revolution gold derived betulinic acid and its derivatives
… was used for antithrombin activity of the triterpenoids. The release of ATP and calcium mobilization from the cytosol, as platelets aggregate, was investigated using a commercial kit and Fura 2/AM respectively. The anti-acetylcholinesterase activity of the triterpenes was also investigated …
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Studies of Bioactive Natural Products and Mechanism-Based Bioassays
… β. From this extract, four isomalabaricane triterpenoids were isolated and characterized, three of which were active in the binding assay. All compounds were active in the A2780 ovarian cancer cell line assay. Bioassay-guided fractionation of an extract of a sponge of species <i>Dysidea</i> …
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Evaluation of camphor derivatives in terpenoid synthesis
… in the synthesis of the lanostane group of triterpenoids whereas its enantiomer (ent-232) derived from (+)-4-methylcamphor (ent-178) could gain access to the euphane group of triterpenoids.
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Characterizing the role of ATP-binding cassette transporters in triterpenoid wax bloom production
… by ABC transporters with specificity for triterpenoids rather than aliphatics. Kalanchoe is a genus of succulent plants that vary in their ability to produce wax blooms, with some species producing the triterpenoid wax blooms of interest. Here, I investigated the role of ABC transporters …
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Tannin geochemistry of natural systems: method development and application
… units, in addition to flavones, flavanones, triterpenoids, and carboxylic acids.Molecular tannin signatures were obtained from 117 source tissues, including leaves, needles, woods, and barks from tropical and temperate forests, coasts, and grasslands. Conifer needles were distinguished by …
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Spectroscopic and synthetic studies of lichen metabolites
… spectra of a number of stictane and hopane triterpenoids yielded structurally significant correlations. Two depsidonal constituents of N. australe were demonstrated to be hypostictic acid and hyposalazinic acid. The reactions of mercuric acetate with unsaturated compounds are reviewed and …
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Phytochemical studies on traditional medicinal plants with antimalarial activities
… The types of compounds isolated included: three triterpenoids (20(29)-Lupene-3α,28- diol (30), 20(29)-Lupene-3α, 16β,28-triol (32) and 3β-Hydroxy-20(29)-Lupen-28-oic acid (42)); two diterpenoids (8-Abietene-7 β,13 β -diol (45) and cariocal (51)); one flavonoid ( 5-Hydroxy:.4' ,6, …
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Phytochemical screening and antibacterial testing of selected Namibian medicinal plants against laboratory and clinical bacteria that cause Diarrhoea
… solvents and screened for the presence of triterpenoids, saponins, flavonoids, steroids, coumarins, tannins and alkaloids by thin layer chromatography (TLC). Antibacterial activities of the organic and aqueous extracts were determined against laboratory strains of Escherichia coli, Shigella …
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Analysis of Hopanoids From Three Psychrophilic Marine Bacterial Strains
Hopanoids are pentacyclic triterpenoids that are associated with the plasma membrane of some bacteria. These amphiphilic molecules, which share structural similarities with sterols, are believed to regulate the thermodynamic and mechanical properties of phospholipid packing in the cell membranes of …
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Synthesis of Limonoid and Steroidal intermediates
… starting material for the synthesis of numerous triterpenoids. Prepared from (+)-endo-3-bromocamphor (2) in a four-step sequence, 4 has been converted into two advanced triterpenoid intermediates. In an eleven-step sequence 4 was transformed into the bicyclic intermediate (42) that could be used …
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A study of compounds having antibacterial activity isolated from Rubus pinfaensis Levl. et Vant.
… guided by biological monitoring. Four known triterpenoids, gallic acid, beta-sitosterol and three novel triterpene glycosides have been isolated and characterised. One new compound after enzymatic hydrolysis yielded a new aglycone, which has been named pinfaensic acid. Acylation and …
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Protecting Healthy Cells Against the Negative Effects of Radiation Therapy for Lung Cancer
… damage both cancer and healthy cells. Synthetic triterpenoids, including CDDO-Me, act as anti-inflammatory, antioxidant modulators primarily by inducing the Nrf2/ARE pathway. In the documented series of experiments, I show that CDDO-Me can be used as a radioprotector in normal non-cancerous human …
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Studies toward the synthesis of celastrol and the late-stage hydroxylation of arenes mediated by 4,5-dichlorophthaloyl peroxide
… cyclization strategies to assemble friedelin triterpenoids. As a result of these problems residing at the interface of chemistry and biology, a purely synthesis-based strategy for polyene cyclizations to rapidly construct the pentacyclic core of the friedelin and celastroid natural products …
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Saponin Removal from Quinoa by Abrasion Processing
… with a thin layer of saponins, glycosylated triterpenoids, that produce a bitter flavor when consumed. The average saponin content in commercial varietals from Bolivia average around 2.7% saponins and organoleptic testing shows the threshold for noticing a bitter flavor is below 0.12% …
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Investigation onto the Mechanism Behind the Hepatoprotective Effect of Cucurbitacin Compounds
… for treatment. Cucurbitacins (Cucs) are natural triterpenoids known for their potent anticancer and antiinflammatory activities. Recent studies showed that Cucs protect the HepG2 cell line against CCl4 induced toxicity. The mechanism behind this cytoprotection is unknown. The hepatoprotective …
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