Helvetica Chimica Acta – Vol. 95 (2012)
591
The known compounds were identified as buddlejoside B (4) [14], 10-O-
benzoylcatalpol (5) [15], and pakiside A (6) [16] by comparison of their physical and
spectral data with those reported in the literature.
Experimental Part
General. Column chromatography (CC): silica gel (SiO2; 230 – 400 mesh; E. Merck, Darmstadt,
Germany). TLC: SiO2 60-F254 plates (E. Merck, Darmstadt, Germany). GC: Schimadzu gas chromato-
graph (GC-9A); 3% OV-1 silanized Chromosorb-W column; column temp. 1808; injection port and
detector temp. 275 – 3008; flow rate 35 ml/min; flame-ionization detector. Optical rotations: Jasco-P-2000
polarimeter. UV Spectra: Hitachi-UV-3200 spectrophotometer; lmax (log e) in nm. IR Spectra: Jasco-302-
A spectrometer; in KBr; ˜n in cmꢀ1. NMR Spectra: Bruker-AMX-500 instrument; d in ppm rel. to Me4Si as
internal standard, J in Hz. EI-MS: Finnigan-MAT-312 mass spectrometer. HR-FAB-MS: Jeol-JMS-HX-
110 mass spectrometer, glycerol as matrix. HR-ESI-MS: QSTAR-XL spectrometer; in m/z (rel. %).
Elemental analysis: PerkinꢀElmer 2400 series II CHN/S.
Plant Material. The whole plant material of Eremostachys loasifolia Benth (Lamiaceae) (20 kg) was
collected from the Ziarat Valley of the Balochistan Province, Pakistan, in April 2005, and identified by
R. B. Tareen, plant taxonomist, Department of Botany, University of Balochistan, Quetta, where a
voucher specimen has been deposited with the herbarium (voucher No. el. Rbt. 01. 2005).
Extraction and Isolation. The shade-dried whole plant material (20 kg) was chopped, ground, and
extracted with EtOH (3 ꢁ 20 l, 10 d each) at r.t. The combined EtOH extract was concentrated to yield a
residue (500 g), which was suspended in H2O (1.0 l) and successively partitioned into hexane- (130 g),
CHCl3- (100 g), AcOEt- (60 g), and BuOH-soluble (80 g) fractions. The AcOEt-soluble subfraction
(60 g) was subjected to CC (SiO2, hexane, hexane/CHCl3, CHCl3, and CHCl3/MeOH in increasing order
of polarity). The fraction obtained with CHCl3/MeOH 9.9 :0.1 (1.2 g) was resubjected to CC (SiO2,
CHCl3/MeOH). The fraction obtained with CHCl3/MeOH 9.85 :0.15 was further purified by prep. TLC
(CHCl3/MeOH 9.5 :0.5): 5 (15.1 mg) and 4 (10.3 mg). The fraction obtained with CHCl3/MeOH 9.8 :0.2
(44.9 mg) was resubjected to CC (SiO2, CHCl3/MeO): 2 (8.0 mg). The fraction obtained with CHCl3/
MeOH 9.7:0.3 (2.6 g) was triturated with MeOH, and the residue was resubjected to CC (SiO2; CHCl3/
MeOH 9.75 :0.25): 1 (20.2 mg) and 6 (15.1 mg), from the head and tail fractions, resp. The fraction
obtained with CHCl3/MeOH 9.4 :0.6 (2.6 g) was triturated with MeOH, and the residue was resubjected
to CC (SiO2; CHCl3/MeOH 9.4 :0.6): 3 (10.9 mg).
Eremoside A (¼6-O-(3,4-Dimethoxybenzoyl)paulownioside ¼ [(1S,4aR,5S,6S,7S,7aS)-1-(b-d-Glu-
copyranosyloxy)-1,4a,5,6,7,7a-hexahydro-6,7-dihydroxy-7-(hydroxymethyl)cyclopenta[c]pyran-5-yl 3,4-
Dimethoxybenzoate ¼ (1S,4aR,5S,6S,7S,7aS)-5-[(3,4-Dimethoxybenzoyl)oxy]-6,7-dihydroxy-7-(hydroxy-
methyl)cyclopenta[c]pyran-1-yl b-d-Glucopyranoside; 1): Colorless gummy solid. [a]2D3 ¼ ꢀ12 (c ¼ 0.20,
MeOH). IR (KBr): 3402 – 3245, 1709, 1645, 1602, 1540, 1500. UV (MeOH): 204 (2.1), 216 (2.0), 229
(3.4), 266 (2.9), 296 (4.1). 1H- and 13C-NMR: Table 1. EI-MS: 382 (10, [M ꢀ Glc]þ), 379 (9, [M ꢀ
dimethoxybenzoyl]þ), 364 (21, [M ꢀ Glc ꢀ H2O]þ), 216 (22), 201 (25), 181 (65), 165 (100). HR-FAB-
MS (pos.): 545.1850 ([M þ H]þ, C24H33O1þ4 ; calc. 545.1870).
Eremoside B (¼10-O-(3,4-Dimethoxybenzoyl)-6-O-methylcatalpol ¼ [(1aS,1bS,2S,5aR,6S,6aS)-2-
(b-d-Glucopyranosyloxy)-1b,5a,6,6a-tetrahydro-6-methoxyoxireno[4,5]cyclopenta[1,2-c]pyran-1a(2H)-
yl]methyl 3,4-Dimethoxybenzoate ¼ (1aS,1bS,5aR,6S,6aS)-1a-{[(3,4-Dimethoxybenzoyl)oxy]methyl}-
1a,1b,2,5a,6,6a-hexahydro-6-methoxyoxireno[4,5]cyclopenta[1,2-c]pyran-2-yl b-d-Glucopyranoside; 2):
Colorless gummy solid. [a]2D5 ¼ ꢀ102 (c ¼ 0.18, MeOH). IR (KBr): 3437 – 3405, 1705, 1638, 1606, 1542,
1503. UV (MeOH): 207 (2.3), 217 (1.9), 232 (3.8), 263 (3.1), 298 (4.2). 1H- and 13C-NMR: Table 1. EI-
MS: 378 (8, [M ꢀ Glc]þ), 375 (12, [M ꢀ dimethoxybenzoyl]þ), 360 (17, [M ꢀ Glc ꢀ H2O]þ), 345 (10), 212
(15), 197 (25), 181 (70), 165 (100). HR-FAB-MS (pos.): 541.1945 ([M þ H]þ, C25H33O1þ3 ; calc. 541.1921).
Eremoside C (¼ Bis(6-O-veratroylcatalpol-10-yl) Ether¼ (1aS,1’aS,1bS,1’bS,2S,2’S,5aR,5’aR,6S,6’
S,6aS,6’aS)-1a,1’a-[Oxybis(methylene)]bis[6-[(3,4-dimethoxybenzoyl)oxy]-1a,1b,2,5a,6,6a-hexahydro-
oxireno[4,5]cyclopenta[1,2-c]pyran-2-yl b-d-Glucopyranoside]; 3): Colorless gummy solid. [a]2D5 ¼ ꢀ79
(c ¼ 0.08, MeOH). IR (KBr): 3425 – 3401, 1707, 1635, 1605, 1539, 1500. UV (MeOH): 205 (2.0), 218 (2.1),