(22E,24R)-3β,5α,9α-Trihy­droxy­ergosta-7,22-dien-6-one monohydrate

Zhi-Hong Xu; Xiao-Ping Peng; Yi Wang; Wei-Ming Zhu

doi:10.1107/S160053681101347X

. 2011 Apr 16;67(Pt 5):o1141–o1142. doi: 10.1107/S160053681101347X

(22E,24R)-3β,5α,9α-Trihydroxyergosta-7,22-dien-6-one monohydrate

Zhi-Hong Xu ^a, Xiao-Ping Peng ^a, Yi Wang ^a, Wei-Ming Zhu ^a,^*

PMCID: PMC3089332 PMID: 21754450

Abstract

The title ergosterol compound, C₂₈H₄₄O₄·H₂O, is composed of four fused rings (three six-membered and one five-membered) and a side chain. It is a derivative of ergosterol and was isolated from a marine-derived halotolerant fungus, Cladosporium cladosporioides PXP-49. In the crystal, molecules are assembled by classical O—H⋯O hydrogen bonds, forming a two-dimensional network, with base vectors [100] and [010]. The absolute configuration was assigned from the measured optical rotation and reference to the literature. An intramolecular O—H⋯O hydrogen bond occurs.

Related literature

For general background to the cytotoxic activity of similar compounds, see: Valisolalao et al. (1983 ▶); Kawagishi et al. (1988 ▶); Takaishi et al. (1991 ▶); Ishizuka et al. (1997 ▶); Yaoita et al. (1998 ▶); Sun et al. (2006 ▶); Tang et al. (2007 ▶); Cui et al. (2010 ▶). For details of ring conformations and puckering parameters, see: Cremer & Pople (1975 ▶); Baginski et al. (1989 ▶); Gonzalez et al. (2002 ▶).

Experimental

Crystal data

C₂₈H₄₄O₄·H₂O
M _r = 462.65
Monoclinic,
a = 6.7605 (8) Å
b = 7.2626 (11) Å
c = 28.461 (2) Å
β = 96.083 (1)°
V = 1389.5 (3) Å³
Z = 2
Mo Kα radiation
μ = 0.07 mm⁻¹
T = 298 K
0.40 × 0.35 × 0.17 mm

Data collection

Bruker SMART CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ▶) T _min = 0.971, T _max = 0.988
7040 measured reflections
2641 independent reflections
1557 reflections with I > 2σ(I)
R _int = 0.057

Refinement

R[F ² > 2σ(F ²)] = 0.051
wR(F ²) = 0.108
S = 1.02
2641 reflections
304 parameters
1 restraint
H-atom parameters constrained
Δρ_max = 0.14 e Å⁻³
Δρ_min = −0.15 e Å⁻³

Data collection: SMART (Bruker, 2007 ▶); cell refinement: SAINT (Bruker, 2007 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: XP (Siemens, 1994 ▶); software used to prepare material for publication: WinGX (Farrugia, 1999 ▶).

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S160053681101347X/su2267sup1.cif

e-67-o1141-sup1.cif^{(27.2KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S160053681101347X/su2267Isup2.hkl

e-67-o1141-Isup2.hkl^{(129.7KB, 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⋯O5ⁱ	0.82	1.93	2.749 (4)	180
O2—H2⋯O5	0.82	1.90	2.716 (4)	177
O4—H4⋯O2	0.82	1.97	2.642 (4)	139
O5—H5C⋯O1ⁱⁱ	0.85	1.81	2.642 (4)	165
O5—H5D⋯O3ⁱⁱⁱ	0.85	1.93	2.761 (4)	165

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Symmetry codes: (i) Inline graphic ; (ii) ; (iii) .

Acknowledgments

This work was supported by grants from the Special Fund for Marine Scientific Research in the Public Interest of China (No. 2010418022–3) and from the PCSIRT (No. IRT0944).

supplementary crystallographic information

Comment

The title ergosterol compound was first isolated from the fungus Polyporus versicolor as a cytotoxic principle to hepatoma cells (Valisolalao et al., 1983). This compound, and other related compounds from different genera of mushrooms, for eg. Bugula neritina L., and endophytic fungi derived from marine red alga, are of interest due to their cytotoxic activity (Kawagishi et al., 1988; Ishizuka et al., 1997; Takaishi et al., 1991; Yaoita et al., 1998; Sun et al., 2006; Tang et al., 2007; Cui et al., 2010). We isolated the title compound as part of our ongoing studies on characterizing bioactive metabolites from marine-derived halotolerant fungi, and we report herein on its crystal structure.

As illustrated in Fig. 1 the title compound is composed of four fused rings, three six-membered and one five-membered, and a side chain in which the terminal methyl groups undergo a certain amount of thermal motion. One of the six-membered rings (C1-C5,C10) adopts a chair conformation, with puckering parameters (Cremer & Pople, 1975) of Q = 0.559 (4) Å, θ = 0.1 (4) ° and φ = 109 (19) °, the second six-membered ring (C5-C10) adopts a half-chair conformation, with puckering parameters Q = 0.500 (4) Å, θ = 51.1 (5) ° and φ = 326.3 (6) °, while the third six-membered ring (C8,C9,C11-C14) adopts a boat conformation, the puckering parameters are Q = 0.541 (4) Å, θ = 13.1 (4) ° and φ = 233 (2) °. The five-membered ring (C13-C17) has an envelope conformation on atom C13 (Baginski et al., 1989; Gonzalez et al., 2002), the corresponding puckering parameters are Q = 0.435 (4) Å and φ = 187.6 (6) °.

In the crystal the molecules are linked, via the water molecule of crystallization, by classical O—H···O hydrogen bonds to form a two-dimensional network with base vectors [100] and [010] (Fig. 2 and Table 1).

Experimental

The isolated halotolerant fugal strain Cladosporium cladosporioides PXP-49, was isolated from roots of Rhizophora stylosa collected in the mangrove conservation area of Wenchang, Hainan, China. The working strain was cultured under static conditions at 298 K for 45 days in two hundred 1 L conical flasks containing the liquid medium (300 ml/flask) composed of maltose (20 g/L), mannitol (20 g/L), glucose (10 g/L), monosodium glutamate (10 g/L), KH₂PO₄ (5 g/L), MgSO₄ (0.3 g/L), yeast extract (3 g/L), corn steep liquor (1 g/L), NaCl (100 g/L) after adjusting its pH to 10.0. The fermented whole broth (60 L) was filtered through cheese cloth to separate into supernatant and mycelia. The mycelia was extracted three times with acetone. The acetone solution was concentrated under reduced pressure to afford an aqueous solution. The aqueous solution was extracted three times with ethyl acetate to give an ethyl acetate solution which was concentrated under reduced pressure to give a crude extract (28 g).The crude extract was subjected to chromatography over silica gel column using a stepwise gradient elution of CHCl₃-petroleum ether (0–100%) and then MeOH-CHCl₃ (0–50%), to yield five fractions (Fr.1-Fr.5). The Fr.2 was further purified by another silica gel column using a step gradient elution of petroleum ether:acetone, followed by chromatographing on a Sephadex LH-20 eluting with CHCl₃—MeOH (1:1) to afford three subfractions (Fr.2–6-1-Fr.2–6-3). The title compound (5.5 mg) was purified by extensive preparative HPLC using MeOH-H₂O (9:1) from Fr.2–6-1. The single crystals were obtained by slow evaporation of CHCl₃—MeOH (1:1) solution at 298 K.