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Showing 1 to 20 of 369 for “"Alkaloids"”.
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The synthesis of pyrrolizidine alkaloids
<p>The pyrrolizidine alkaloids constitute an exceptionally large class of naturally occurring compounds. A number of the alkaloids are hepatotoxic and carcinogenic, but some derivatives have potentially useful physiological properties;A promising but seldom used reaction in alkaloid synthesis is …
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Fungal biotransformation of morphine alkaloids
… of certain fungi to biotransform morphine alkaloids into medicinally relevant intermediates. Fungal strains screened for their ability to affect biotransformation of morphine alkaloids include Cunninghamella echinulata, Helicostylum pirijorme, Pycnoporus sanguinea, Pycnoporus cinnabarina, …
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Cytotoxic alkaloids from Tabernaemontana johnstonii
… chromatography on silica gel. Four crystalline alkaloids were isolated during the purification procedure. Two of these alkaloids, isovoacangine and perivine, were characterized by absorption spectroscopy and mass spectrometry. Their identity was verified by comparison with authentic samples. The …
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Synthesis of Dimeric Pyrrole-Imidazole Alkaloids
Dimeric pyrrole-imidazole alkaloids, also known as oroidin family of alkaloids, are a class of marine natural products with unique structural diversity and complexity. Focusing on the synthesis of the higher order dimeric pyrrole-imidazole alkaloids, my graduate work comprises two components: a …
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Synthesis of the Antimalarial Flindersial Alkaloids
… synthesis of all the anti-malarial Flindersia alkaloids. Previous work on the biosynthesis of the related natural products borreverine and isoborreverine inspired us to synthesize racemic flinderoles A, B, and C in as few as three synthetic steps from simple and readily available materials. The …
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Total Synthesis of Oligomeric Cyclotryptamine Alkaloids
I. Total Synthesis and Stereochemical Assignment of (–)-Psychotridine We report the first enantioselective total synthesis and stereochemical assignment of (–)-psychotridine. The application of our diazene-directed assembly of enantiomerically enriched cyclotryptamines afforded a highly convergent …
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Radical Approaches to Alangium and Mitragyna Alkaloids
… and concise syntheses of Alangium and Mitragyna alkaloids, and especial approaches towards (±)-protoemetinol (a), which is a key precursor of a range of Alangium alkaloids such as psychotrine (b) and deoxytubulosine (c). The approaches include the use of a key radical cyclisation to form the …
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Total synthesis and study of myrmicarin alkaloids
… Total Synthesis of Tricyclic Myrmicarin Alkaloids An enantioselective gram-scale synthesis of a key dihydroindolizine intermediate for the preparation of myrmicarin alkaloids is described. Key transformations in this convergent approach include a stereospecific palladium-catalyzed …
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Total synthesis of cyclotryptamine and diketopiperazine alkaloids
… synthesis of other members of this family of alkaloids. II. General Approach to Epipolythiodiketopiperazine Alkaloids: Total Synthesis of (+)- Chaetocins A and C and (+)-12,12'-Dideoxychetracin A A highly stereoselective and systematic strategy for the introduction of polysulfides in the …
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Synthesis of the bicyclic core of pyrrolizidine alkaloids
<p>Pyrrolizidine alkaloids are a large class of natural products whose members exhibit a variety of biological properties including potential applications toward the treatment of cancer, diabetes, and viral infections such as HIV. In addition, some of these compounds exhibit insect antifeedant …
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A comparison of some of the ergot alkaloids
The ergot alkaloids, other than those that are molecular compounds, fail into two groups, a laevorotatory physiologically active group, and a dextrorotatory group which is considerably less active. Smith and Timmis drew attention to this fact in their paper on isoergine and isolysergic acids (1).
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Rhizophoraceae alkaloids : studies in the synthesis of Gerrardine
Gerrardine, an alkaloid isolated from Cassipourea gerrardii was previously established as 1-methyl-2,5-bis( 4'-hydroxy-1',2'-dithiolan-3'-yl)-pyrrolidine. The aim of the present research was to study the ways in which 1-methyl-2-(4'-hydroxy-1', 2'-dithiolan-3'-yl)-pyrrolidine, as a model compound …
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Studies on the synthesis of bisindole Aspidosperma alkaloids
I. Introduction and Background on Aspidosperma Alkaloids A brief overview of monoterpene indole Aspidosperma alkaloids is discussed. The biosynthesis of the characteristic pentacyclic core from tryptamine and secologanin is summarized. Some representative examples of total syntheses of Aspidosperma …
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