Dereplication of New Saponins from Agave bracteosa

Abstract

The genus Agave comprises over 400 species that are known for their diverse applications, which include being sources of fiber, food, and beverages. There has recently been increased interest in exploring the metabolic content of this genus, and in this respect, saponins are the main compounds of interest. Saponins for Agave bracteosa have not been described to date, and the current work addresses the dereplication of a saponin-rich fraction to identify the structures of six compounds. The dereplication methods involve the use of UPLC-MSE analysis, NMR spectroscopy and published data for Agave saponins. A green extraction and isolation provided ten pure saponins. Remarkably, nine of these saponins have not been reported previously, namely (25S)-cantalasaponin-1 and bractofuranosides A–H. These compounds were tested for cytotoxic activity. Bractofuranosides B (5) and G (10) displayed 57% and 53% cell viability on HeLa cells at 100 µM, respectively.