Spirostane-type saponins from Dracaena fragrans "Yellow Coast"
Natural Product Communications
|April 30, 2015
Abstract:
Three steroidal glycosides were isolated from the bark of Dracaena fragrans (L.) Ker Gawl. "Yellow Coast", and a fourth from the roots and the leaves. Their structures were characterized on the basis of extensive 1D and 2D NMR experiments and mass spectrometry, and by comparison with NMR data of the literature. These saponins have the spirostane-type skeleton and are reported in this species for the first time.
Related Concept Videos
Esters to Carboxylic Acids: Saponification
7.3K
Esters can be hydrolyzed to carboxylic acids under acidic or basic conditions. Base-promoted hydrolysis of esters is a nucleophilic acyl substitution reaction in which esters react with an aqueous base, followed by an acid to give carboxylic acids. This reaction is also known as saponification because it forms the basis for making soaps from fats.
The reaction requires a base in stoichiometric amounts, which participates in the reaction and is not regenerated later. So, the base acts as a...
The reaction requires a base in stoichiometric amounts, which participates in the reaction and is not regenerated later. So, the base acts as a...
7.3K
Seed Structure and Early Development of the Sporophyte
31.9K
Seed structures are composed of a protective seed coat surrounding a plant embryo, and a food store for the developing embryo. The embryo contains the precursor tissues for leaves, stem, and roots. The endosperm and cotyledons—seed leaves—act as the food reserves for the growing embryo.
31.9K
Antifungal Agents
89
Amphotericin B is a broad-spectrum antifungal agent that exploits structural differences between fungal and mammalian cell membranes. Its amphipathic structure—featuring a hydrophobic polyene-lactone ring and a hydrophilic region containing mycosamine and carboxylic acid groups—enables selective binding to ergosterol, a sterol predominantly found in fungal plasma membranes. This selective interaction underlies the drug’s antifungal activity, although weak binding to...
89


