Structure Elucidation of Three Triterpene Glycosides from the Trunk of Argania spinosa Ali Oulad-Ali, Vale ´rie Kirchner, Annelise Lobstein, Bernard Weniger, and Robert Anton* Laboratoire de Pharmacognosie, Faculte ´ de Pharmacie, Universite ´ Louis Pasteur, B.P. 24, 67401 Illkirch Cedex, France Dominique Guillaume Laboratoire de Chimie The ´ rapeutique, URA 1310 du CNRS, Faculte ´ de Pharmacie, Universite ´ R. Descartes, 4 Avenue de l’observatoire, 75270 Paris Cedex 06, France Zoubida Charrouf Laboratoire de Chimie des Plantes, Faculte ´ des Sciences, B.P. 1014, Rabat, Morocco Received July 10, 1995 X The structures of three novel saponins from Argania spinosa, named arganines G, H, and J, have been elucidated by MS and NMR techniques as 3-O--D-apiofuranosyl-(1f4)--D- glucopyranosyl-28-O--D-glucopyranosylbayogenin (1), 3-O--D-apiofuranosyl-(1f4)--D-glu- copyranosyl-28-O-R-L-arabinopyranosylbayogenin (2), and 3-O--D-apiofuranosyl-(1f4)--D- glucopyranosyl-28-O-[-D-apiofuranosyl-(1f3)--D-xylopyranosyl-(1f4)-R-L-rhamnopyranosyl- (1f2)-R-L-arabinopyranosyl]bayogenin (3), respectively. Argania spinosa (L.) Maire (Sapotaceae) is a slow- growing endemic tree of southwestern Morocco. Tra- ditionally, its seeds are eaten by cattle and also furnish an oil used as a cosmetic or human food. 1 Currently, A. spinosa is still grown for its industrial cosmetic uses. As part of our continuing interest in the saponins from the Sapotaceae, 2-4 we studied the trunk of the title plant. We report herein the isolation and identification of three novel triterpene glycosides named arganines G(1), H (2), and J (3). The methanolic extract of the dried and powdered trunk was partitioned between n-BuOH and water. The BuOH layer was further extensively chromatographed to give 1-3. The FABMS of arganine G (1) displayed a quasimolecular ion peak at m/z 967 [M + Na] + , allow- ing the determination of the molecular formula as C 47 H 76 O 19 . The 13 C NMR spectrum of 1 showed 47 signals that were categorized by a DEPT experiment as six methyls, 14 methylenes, 18 methines, and nine quaternary carbons. Among the quaternary resonances, one could be directly assigned to a carbonyl signal (δ 178.0) and another to an olefinic signal (δ 144.9). The 14 methylene resonances included five CH 2 O(δ 61.4, 62.4, 64.6, 65.5, 74.9) groups and nine more shielded signals (Table 1). The methyl groups were shown to be at angular positions from the 1D 1 H NMR spectrum (six singlets at δ 0.99, 1.08, 1.10 × 2, 1.34, and 1.46), indicating that they belonged to the aglycon of 1. A2D COSY spectrum rapidly established that C-2 and C-3 were both substituted by an oxygen atom [δ 4.50 (H-2), δ 3.72 (H-3)]. Comparison of the 13 C NMR data with literature values demonstrated that the aglycon of 1 was bayogenin substituted at positions C-3 and C-28. 5,6 The 13 C and 1 H NMR spectra of 1 also displayed signals for three sugar residues (Table 1). One of these was easily identified from its quaternary carbon at δ 80.2 as a -D-apiose (api) moiety (J H1-H2 ) 3.6 Hz), as observed for sideroxylosides B and C. 3 The two other sugar residues were identified as -D-glucose (glc) units. The anomeric protons of these two glc residues appeared as two doublets at δ 5.54 (J ) 7.7 Hz) and 4.62 (J ) 7.8 Hz), with the former chemical shift indicating that this residue (glc′) was esterified at C-28. Analysis of the 13 C- NMR chemical shifts of this glc′ moiety, conducted by a combination of homo- and heteronuclear COSY spectra, indicated its unsubstituted nature. 7 A similar analysis made on the carbon atoms of the second glc residue showed that it was substitued at the C-4 position (δ C-4 X Abstract published in Advance ACS Abstracts, February 1, 1996. 193 J. Nat. Prod. 1996, 59, 193-195 0163-3864/96/3259-0193$12.00/0 © 1996 American Chemical Society and American Society of Pharmacognosy