20-O-β-d-Xylopyranos­yl(1→6)-β-d-glucopyranosyl-20(S)-protopanaxadiol methanol solvate

Xing-Wei Li; Wei Zhou; Qin Yan; Pei Zhou

doi:10.1107/S1600536807063118

. 2007 Dec 6;64(Pt 1):o165. doi: 10.1107/S1600536807063118

20-O-β-d-Xylopyranosyl(1→6)-β-d-glucopyranosyl-20(S)-protopanaxadiol methanol solvate

Xing-Wei Li ^a, Wei Zhou ^a, Qin Yan ^a, Pei Zhou ^a,^*

PMCID: PMC2915232 PMID: 21200730

Abstract

The title compound, C₄₁H₇₀O₁₂·CH₄O, was prepared by microbial transformation. Within the steroid skeleton of the molecule, three six-membered rings exhibit a chair conformation, while the five -membered ring adopts an envelope conformation. The two pyranosyl rings also adopt chair conformations. The molecules are held together by an extensive O—H⋯O hydrogen-bonding network.

Related literature

For general background, see: He et al. (2005 ▶); Hu et al. (2007 ▶). For related literature, see: Li et al. (2006 ▶).

Experimental

Crystal data

C₄₁H₇₀O₁₂·CH₄O
M _r = 787.01
Orthorhombic,
a = 8.3044 (7) Å
b = 13.2927 (11) Å
c = 38.964 (3) Å
V = 4301.1 (6) Å³
Z = 4
Mo Kα radiation
μ = 0.09 mm⁻¹
T = 293 (2) K
0.43 × 0.31 × 0.21 mm

Data collection

Bruker SMART APEX CCD area-detector diffractometer
Absorption correction: none
25549 measured reflections
5269 independent reflections
3467 reflections with I > 2σ(I)
R _int = 0.084

Refinement

R[F ² > 2σ(F ²)] = 0.045
wR(F ²) = 0.099
S = 0.89
5269 reflections
505 parameters
H-atom parameters constrained
Δρ_max = 0.21 e Å⁻³
Δρ_min = −0.16 e Å⁻³

Data collection: SMART (Bruker, 1999 ▶); cell refinement: SAINT (Bruker, 1999 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997 ▶); molecular graphics: SHELXTL (Bruker, 1997 ▶); software used to prepare material for publication: SHELXTL.

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536807063118/xu2351sup1.cif

e-64-0o165-sup1.cif^{(32.2KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536807063118/xu2351Isup2.hkl

e-64-0o165-Isup2.hkl^{(252.8KB, 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
O1—H1⋯O11ⁱ	0.82	2.38	2.996 (3)	133
O2—H2⋯O3	0.83	1.96	2.752 (3)	160
O5—H5A⋯O1ⁱ	0.84	2.14	2.839 (3)	140
O6—H6⋯O12ⁱⁱ	0.83	2.04	2.781 (3)	147
O7—H7⋯O8ⁱⁱⁱ	0.83	2.31	3.009 (3)	142
O10—H10⋯O13^iv	0.82	2.05	2.824 (4)	156
O11—H11⋯O5^v	0.81	1.92	2.703 (3)	162
O12—H12A⋯O11^vi	0.84	2.02	2.827 (3)	162
O13—H13A⋯O2^vii	0.85	1.98	2.823 (3)	173

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Symmetry codes: (i) Inline graphic ; (ii) ; (iii) ; (iv) ; (v) ; (vi) ; (vii) .

Acknowledgments

We gratefully acknowledge financial support from the SK Shanghai Foundation. We sincerely thank Dr J. Sun of Shanghai Institute of Organic Chemistry for assistance with the data collection.

supplementary crystallographic information

Comment

20-O-β-D-xylopyranosyl(1→6)-β-D-glucopyranosyl-20(S)- protopanaxadiol is a kind of rare gensenoside, found existing in notoginseng. In recent studies, the compound has been related to an anticancer agent. It is believed to have activities including: cytotoxicity to and partial reversal of multidrug resistance of human tumor cells (He et al., 2005). Besides that, the compound may be an important precurosor metabolite of Compound K, which is also a potential anticancer agent, during the process of microbial transformation of gisenoside Rb₃ (Hu et al., 2007). In this article, the crystal structure is reported.

The structure mainly consists of a protopanaxadiol moiety with a disaccharide group. The bond distances and angels are normal. The C24?C25 of 1.313 (5) Å shows a typical double bound. Within the steroid skeleton of the molecule, three six membered rings all display the chair conformation, while a five membered ring displays an envelope conformation. Two pyranosyl rings are also exist in chair conformation. Extensive O—H···O hydrogen bonding occurs in the crystal structure (Table 1), which helps to stabilize the crystal structure.

Experimental

The Fermentation broth of ginsenoside Rb₃ (300 mg) was centrifuged and the precipitation was extracted with EtOH for 24 h. Removal of the EtOH from the extract under reduced pressure gave crude extract. And the extract was subjected to silica gel column chromatography, eluting with HCCl₃:CH₃OH (10:1→7:3→5:1) to afford 12 fractions. Recrystallizing of fractions 8~10 yielded ginsenoside Rb₃ 100 mg. Solvent loss technique was then employed for the growth of crystals at room temperature, using methanol as the solvent.