A New Steroidal Saponin from Agave brittoniana and Its Biphasic Effect on the Na+-ATPase Activity

• Published in: Zeitschrift für Naturforschung C. A journal of biosciences Vol. 60; no. 1; pp. 121 - 127
• Main Authors: Silva, Graziela M., De Souza, Aloa M., Lara, Luciene S., Mendes, Tatiana P., da Silva, Bernadete P., Lopes, Anibal G., Caruso-Neves, Celso, Parente, José P.
• Format: Journal Article
• Language: English
• Published: Germany Verlag der Zeitschrift für Naturforschung 01.01.2005
• Subjects: Agave - chemistry; Agave brittoniana; Animals; Carbohydrate Conformation; Carbohydrate Sequence; Cell Membrane - enzymology; Kidney Tubules - enzymology; Kinetics; Methylation; Models, Molecular; Molecular Sequence Data; Na+-ATPase; Plant Extracts - chemistry; Plant Extracts - isolation & purification; Plant Extracts - pharmacology; Plant Leaves - chemistry; Saponins - chemistry; Saponins - isolation & purification; Saponins - pharmacology; Sodium - pharmacology; Sodium-Potassium-Exchanging ATPase - drug effects; Sodium-Potassium-Exchanging ATPase - metabolism; Steroidal Saponin; Steroids - chemistry; Steroids - isolation & purification; Steroids - pharmacology; Swine
• ISSN: 0939-5075; 1865-7125
• DOI: 10.1515/znc-2005-1-222

A new steroidal saponin, 3-{(O-6-deoxy-α-ʟ-mannopyranosyl-(1→4)-O-β-ᴅ-glucopyranosyl-( 1→3)-O-[O-β-ᴅ-glucopyranosyl-(1→3)-β-ᴅ-glucopyranosyl-(1→2)]-O-β-ᴅ-glucopyranosyl-( 1→4)-β-ᴅ-galactopyranosyl)oxy}-6-hydroxy-(3β,5α,6α,25R)-spirostan-12-one, was isolated from Agave brittoniana Trel. The structure was determined by extensive NMR spectroscopy studies and chemical conversions. Its effects on the Na -ATPase and (Na +K )-ATPase activities of the proximal tubule from pig kidney were evaluated. It was observed that this steroidal saponin exerts a biphasic effect on the Na -ATPase activity. It is concluded that the effect of the aqueous extract as a diuretic is due, at least in part, to the action of saponin on the ouabain-insensitive Na -ATPase.