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Approach Toward The Total Synthesis Of Some Sarpagine Related Indole Alkaloids: Histrixnine, Gelsempervine A, Gelsempervine B, O-Methylmacusine B & 19,20-Dihydro-O-Methylmacusine B,Design, Synthesis & Biological Study Of Some Novel Gamma-Aminobutyric Acid Type (Gabaa) Receptor Ligands, Md Zubair Ahmed Khan

Theses and Dissertations

Indole alkaloids are chemically, biologically and commercially significant, as well as diversely distributed important group of natural products. These are of prominence because of their resemblance with various biologically essential molecules including tryptophan, tryptamine, and serotonin. The Sarpagine type indole alkaloids comprise one of the most diverse series of indole alkaloid natural products. These indole alkaloids are primarily isolated from three plant families: Apocynaceae, Rubiaceae, and Loganiaceae which have been used in traditional and folk medicines in many countries around the world. Biological screening of these alkaloids is not always possible, presumably, due to the paucity of the isolated natural …

Enantiospecific Stereospecific Strategy For The Total Synthesis Of Sarpagine And Macroline Related Oxindole Alkaloids: First Total Synthesis Of Affinisine Oxindole, Isoalstonisine, Alstofoline, Macrogentine, N(1)-Demethylalstonisine, Alstonoxine A And Second Generation Synthesis Of Alstonisine, German Oscar Fonseca Cabrera

Theses and Dissertations

The (7R)-sarpagine/macroline related oxindole alkaloids (-)-isoalstonisine (27) and (-)-macrogentine (31) together with the (7S)-sarpagine/macroline related oxindole alkaloids (-)-affinisine oxindole (24), (-)-alstonoxine A (19), (+)-alstonisine (8, second generation total synthesis), (+)-Na-demethylalstonisine (17) and (+)-alstofoline (18) were concisely synthesized during these studies.

These oxindole alkaloids were isolated from plants of the genus Alstonia which is characterized by the preponderance of sarpagine/macroline-type indole and oxindole alkaloids. Plants that belong to this genus are mainly distributed over tropical regions of Central America, Africa, and Asia where they are used locally in traditional medicine, for example, in the treatment of malaria and dysentery. The main …