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Helvetica Chimica Acta – Vol. 98 (2015)
Gal at C(28) in 1 occurs in several saponins isolated only from Acanthophyllum species
of Caryophyllaceae, such as A. glandulosum, A. sordidum, and A. lilacinum [3][6].
These conclusions suggested that this sequence might represent a chemotaxonomic
marker for the genus Acanthophyllum.
Experimental Part
General. TLC and HP-TLC: silica gel 60 F254 (SiO2; Merck); identification of saponins with 1%
vanillin in EtOH/H2SO4 50 :1. VLC/MPLC: SiO2 60 (15 – 40 mm; Merck), RP-18 (75 – 200 mm; SiliCycle).
MPLC: Alltech pump, Büchi column (460 Â 15 mm and 230 Â 15 mm), Büchi precolumn (110 Â 15 mm).
GC: ThermoQuest gas chromatograph, DB-1701 cap. column (30 m  0.25 mm i.d; J&W Scientific);
detector, FID; detector temp., 2508; injection temp., 2308; initial temp., 808 for 5 min and then increased
to 2708 at a rate of 158/min; carrier gas, He [12]. Optical rotations: AA-OR automatic polarimeter. 1H-
and 13C-NMR spectra: Varian Unity-600 and Inova-600 instruments equipped with a Sun-4-L-X
computer system (at 600 and 150 MHz, resp.); for details see [1]; d in ppm rel. to Me4Si as internal
standard, J in Hz. ESI-MS (pos.): MicrOTOF spectrometer; in m/z. HR-ESI-MS (pos.): Q-TOF-1
Micromass spectrometer; in m/z.
Plant Material. The roots of A. laxiusculum Schiman-Czeika were collected from Torbat-e
Heydarieh, Khorasan Province, Iran, in July 2012, and identified by Dr. Atefeh Pirani, plant taxonomist
at the Traditional Medicine and Materia Medica Research Center, Shahid Beheshti University of
Medical Sciences, where a voucher specimen (No. 09092013) was deposited.
Extraction and Isolation. Air-dried powdered roots of A. laxiusculum (30 g) were extracted with
H2O (3 Â 500 ml) for 6 h under reflux to yield 8.5 g of a crude H2O extract after evaporation. An aliquot
of this extract (1.96 g) was submitted to VLC (SiO2 60; CHCl3/MeOH/H2O 60 :32 :7 and 0 :100 :0
(300 ml each)) to give six fractions, Frs. 1 – 6. Fr. 2 (186 mg; eluted with CHCl3/MeOH/H2O 60 :32 :7)
was separated by MPLC (SiO2 60; CHCl3/MeOH/H2O 60 :32 :7) to give 15 subfractions, Frs 2.1 – 2.15
(Fr. 2.14: 2 (7 mg) and Fr. 2.9: 5 (12 mg)). Furthermore, Fr. 4 (350 mg) was subjected to VLC (RP-18;
MeOH/H2O 0 :100 ! 100 :0) to give six subfractions, Frs. 4.1 – 4.6. Frs. 4.4 and 4.5 were combined
(210 mg) and separated by MPLC (SiO2 60; CHCl3/MeOH/H2O 60 :32 :7) to give ten subfractions,
Frs. 4.4.1 – 4.4.10. Fr. 4.4.6 was purified by MPLC (RP-18; MeOH/H2O 20 :80 ! 60 :40) to give 1
(11 mg). Fr. 2.5 (59 mg) was separated by MPLC (RP-18; MeOH/H2O 30 :70 ! 80 :20) to give 3 (7 mg)
and 4 (9 mg).
23-O-b-d-Galactopyranosylgypsogenic Acid 28-O-{b-d-Glucopyranosyl-(1 ! 2)-6-O-[4-carboxy-3-
hydroxy-3-methyl-1-oxobutyl]-b-d-glucopyranosyl-(1 ! 6)}-[b-d-glucopyranosyl-(1 ! 3)]-b-d-galacto-
pyranosyl Ester (¼O-b-d-Glucopyranosyl-(1 ! 3)-O-[O-b-d-glucopyranosyl-(1 ! 2)-6-O-(4-carboxy-3-
hydroxy-3-methyl-1-oxobutyl)-b-d-glucopyranosyl-(1 ! 6)]-1-O-[(3b)-23-(b-d-galactopyranosyloxy)-3-
hydroxy-23,28-dioxoolean-12-en-28-yl]-b-d-galactopyranose; 1). White amorphous powder. [a]D25
¼
À10.2 (c ¼ 0.09, MeOH). 1H- and 13C-NMR: Tables 1 and 2. ESI-MS (pos.): 1479 ([M þ K]þ), 1463
([M þ Na]þ). HR-ESI-MS (pos.): 1463.6311 ([M þ Na]þ, C66H104NaO3þ4 ; calc. 1463.6301).
Gypsogenic Acid 28-O-{b-d-Glucopyranosyl-(1 ! 2)-6-O-[4-carboxy-3-hydroxy-3-methyl-1-oxobu-
tyl]-b-d-glucopyranosyl-(1 ! 6)}-[b-d-glucopyranosyl-(1 ! 3)]-b-d-galactopyranosyl Ester (¼O-b-d-
Glucopyranosyl-(1 ! 3)-O-[O-b-d-glucopyranosyl-(1 ! 2)-6-O-(4-carboxy-3-hydroxy-3-methyl-1-oxo-
butyl)-b-d-glucopyranosyl-(1 ! 6)]-1-O-[(3b)-3,23-dihydroxy-23,28-dioxoolean-12-en-28-yl]-b-d-galac-
topyranose; 2). White amorphous powder. [a]2D5 ¼ À16.8 (c ¼ 0.07, MeOH). 1H- and 13C-NMR: Tables 1
and 2. ESI-MS (pos.): 1301 ([M þ Na]þ). HR-ESI-MS (pos.): 1301.5774 ([M þ Na]þ, C60H94NaO2þ9 ; calc.
1301.5773).
Acid Hydrolysis and GC Analysis. Compounds 1 and 2 (3 mg) were hydrolyzed with 2n aq.
CF3COOH (5 ml) for 3 h at 958. After extraction with CH2Cl2 (3 Â 5 ml), the aq. layer was repeatedly
evaporated to dryness until neutral by addition of MeOH, and then analyzed by TLC (SiO2; CHCl3/
MeOH/H2O 8 :5 :1), followed by comparison with authentic samples. Further, the residue of sugars was
dissolved in anh. pyridine (100 ml), and l-cysteine methyl ester hydrochloride (0.06 mol l–1) was added.
The mixture was stirred at 608 for 1 h, then 150 ml of hexamethyldisilazane (HMDS)/Me3SiCl; 3 :1) were