(3S,12R,20S,24R)-20,24-Ep­oxy­dammarane-3,12,25-triol

Wen-Juan Li; Huan-Mei Guo; Chun-Mei Ji; Yi Bi; Qing-Guo Meng

doi:10.1107/S1600536811028418

. 2011 Jul 23;67(Pt 8):o2112. doi: 10.1107/S1600536811028418

(3S,12R,20S,24R)-20,24-Epoxydammarane-3,12,25-triol

Wen-Juan Li ^a, Huan-Mei Guo ^b, Chun-Mei Ji ^c, Yi Bi ^a, Qing-Guo Meng ^a,^*

PMCID: PMC3213554 PMID: 22091131

Abstract

In the title molecule, C₃₀H₅₂O₄, the three six-membered rings are in chair conformations, the cyclopentane ring is in an envelope form and the tetrahydrofuran ring has a conformation intermediate between half-chair and sofa. In the crystal, molecules are linked by intermolecular O—H⋯O hydrogen bonds into helical chains along [100]. Two intramolecular O—H⋯O hydrogen bonds are also present. One C atom of the tetrahydrofuran ring and its attached H atoms are equally disordered over two sets of sites.

Related literature

For the medicinal properties of Panax ginseng and Panax quinquefolium, see: Shibata et al. (1985 ▶); Takano et al. (1999 ▶); Yu et al. (2007 ▶); Wang et al. (2010 ▶). For related structures, see: Guo et al. (2011 ▶); Iljin et al. (1982 ▶); Meng et al. (2010 ▶).

Experimental

Crystal data

C₃₀H₅₂O₄
M _r = 476.72
Orthorhombic,
a = 7.6795 (14) Å
b = 13.067 (3) Å
c = 28.084 (5) Å
V = 2818.1 (9) Å³
Z = 4
Mo Kα radiation
μ = 0.07 mm⁻¹
T = 298 K
0.20 × 0.20 × 0.16 mm

Data collection

Bruker SMART CCD diffractometer
14876 measured reflections
5250 independent reflections
3460 reflections with I > 2σ(I)
R _int = 0.048

Refinement

R[F ² > 2σ(F ²)] = 0.062
wR(F ²) = 0.128
S = 1.06
5250 reflections
318 parameters
H-atom parameters constrained
Δρ_max = 0.15 e Å⁻³
Δρ_min = −0.20 e Å⁻³

Data collection: SMART (Bruker, 1997 ▶); cell refinement: SAINT (Bruker, 1997 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: SHELXTL.

Supplementary Material

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536811028418/lh5260sup1.cif

e-67-o2112-sup1.cif^{(29.1KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536811028418/lh5260Isup2.hkl

e-67-o2112-Isup2.hkl^{(257.1KB, hkl)}

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O4—H4A⋯O1ⁱ	0.82	2.09	2.905 (3)	172
O3—H3⋯O2	0.82	1.95	2.677 (3)	147
O1—H1⋯O3	0.82	2.14	2.948 (3)	170

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Symmetry code: (i) Inline graphic .

Acknowledgments

The authors thank Mr Lian-dong Liu (College of Chemistry, Chemical Engineering and Materials Science, Shandong Normal University, Jinan 250014, People’s Republic of China) for his invaluable support of the X-ray data collection. The authors would like to thank Shandong Provincial Natural Science Foundation, China (Y2007C138), the National Natural Science Foundation of China (No. 81001358) and the Promotive Research Fund for Excellent Young and Middle-aged Scientisits of Shandong Province (No. BS2010YY073) for research grants.

supplementary crystallographic information

Comment

Both Panax ginseng and Panax quinquefolium, belonging to the Araliaceae, are well known traditional medicinal herbs. They are used as tonics and the treatment for diseases, such as tumor and myocardial ischemia. Panax ginseng contains numbers of ginsenoside, including an oleanolic acid-type saponin in addition to the major protopanaxadiol and protopanaxatriol-type saponins (Shibata et al., 1985). Panax quinquefolium contains an ocotillol-type (20S, 24R-epoxyside) saponin with high anti-tumor activity (Takano et al., 1999), as well as an oleanolic acid-type saponin, protopanaxadiol and protopanaxatriol-type saponins. (3S,6S,12R,20S,24R)-20,24-epoxy-dammarane-3,6,12,25-tetraol and (3S,12R,20S,24R)-20,24-epoxy-dammarane-3,12,25-triol are found to possess cardioprotective effect on myocardial injury induced by isoproterenol in rats (Yu et al., 2007; Wang et al., 2010). As part of our ongoing investigation of ocotillol-type compounds and their cardioprotective effect on myocardial injury, we report herein the crystal structure of the title compound, (I).

In the molecule (Fig. 1), all bond lengths and angles are within normal ranges (Guo et al., 2011; Iljin et al., 1982; Meng et al., 2010) Rings A(C10/C11/C15-C18), B(C15/C16/C20-C23), and C(C22/C23/C25-C28) are in chair conformations. Ring D(C9-C13) has an envelope form with C11 as the flap. The tetrahydrofuran ring has a conformation intermediate between the half-chair and envelope forms. In the crystal, molecules are linked by intermolecular O—H···O hydrogen bonds into helical chains along [100]. Two intramolecular O—H···O hydrogen bonds are also present.

Experimental

20(S)-protopanaxadiol was degraded from Panax quinquefolium saponin with sodium methylate in DMSO at about 463-473K and seperated by silica colum chromatography. (3S,12R,20S,24R)-20,24-epoxy-dammarane-3,12,25-triol was synthesized from 20(S)-protopanaxadiol in the presence of N,N-dimethylaminopyridine, pyridine and acetic anhydride. The intermediate esters were oxidized by hydrogen dioxide 30% solution in methanoic acid, and the title compound was prepared by saponification with sodium hydroxide in methanol and seperated by silica colum chromatography. Finally, the crystals were dried at room temperature the title compound was crystallized from ethyl acetate and petroleum ether. Single crystals of compound (I) suitable for X-ray measurements were obtained by recrystallization from ethyl acetate and petroleum ether at room temperature.