Planta Med 2010; 76 - P446
DOI: 10.1055/s-0030-1264744

New steroidal saponins from Agave angustifolia

S Abdel Khalik 1, F Melek 2, T Miyase 3, N Gaber 1, S Mina 1
  • 1Faculty of Pharmacy, Helwan University, Pharmacognosy, Ein Helwan, Helwan, Egypt, 59711 Helwan, Egypt
  • 2National Research Center, Chemistry of Natural Products, National Research Center, Dokki, Giza, Egypt, 12622 Giza, Egypt
  • 3School of Pharmaceutical Sciences, University of Schizuoka, Schizuoka,422, Japan., School of Pharmaceutical Sciences, University of Schizuoka, Schizuoka, Japan., 422 Schizuoka, Japan

Extraction of the dried leaves of Agave angustifolia with aqueous methanol gave a crude material that was purified by Diaion HP-20 and silica gel column chromatography to yield 1 and 2. The structure of 1 was proposed by positive ion FABMS, 1D and 2D NMR techniques and acid hydrolysis as a steroidal saponin with new pentasaccharide chain. The structure of the aglycone bearing 27 carbons was determined 25R 5 α spirostan-12 -one 3 β -ol 3 -O [β– D- xylopyranosyl (1–>4) β -D- galactopyranosyl (1–>3) {β -D- xylopyranosyl (1–>3) β -D- glucopyranosyl (1–>2)}β -D- glucopyranoside]Acid hydrolysis as well as1H and 13C NMR data of 1 revealed the presence of five monosaccharide units, two β -D- glucopyranose, one β -D- galactopyranose and two β -D-xylopyranose assigned by 1H- 1H COSY, HMQC and HMBC spectra. Compound 2 showed similar NMR signals except the absence of those due to the terminal β -D- xylopyranose attached to the outer β-D- glucopyranose, it was characterized as Cpd 2: 25R 5 α spirostan-12 -one 3 β -ol 3 -O [β -D- xylofuranosyl (1–>4) β -D- galactopyranosyl (1–>3) {β -D- glucopyranosyl (1–>2)}β -D- glucopyranoside] Further two known saponins were isolated from Agave angustifolia. The methanol extract and the saponin fraction of this plant proved to exhibit marked anti-inflammatory, analgesic, schistosomicidal, cercaricidal & miracidicidal activities.