Oxyresveratrol from Mulberry as a dihydrate

Deng, H.; He, X.; Xu, Y.; Hu, X.

doi:10.1107/S1600536812014018

organic compounds

CRYSTALLOGRAPHIC
COMMUNICATIONS

ISSN: 2056-9890

Volume 68| Part 5| May 2012| Pages o1318-o1319

doi:10.1107/S1600536812014018

Open

access

Oxyresveratrol from Mulberry as a dihydrate

Hui Deng,^a Xixin He,^b Yujuan Xu ^b and Xiaopeng Hu ^a ^*

^aSchool of Pharmaceutical Science, Sun Yat-sen University, Guangzhou 510006, People's Republic of China, and ^bCollege of Chinese Materia Medica, Guangzhou University of Chinese Medicine, Guangzhou 510006, People's Republic of China
^*Correspondence e-mail: huxpeng@mail.sysu.edu.cn

(Received 30 March 2012; accepted 31 March 2012; online 6 April 2012)

The title compound {systematic name: 4-[(E)-2-(3,5-dihydroxyphenyl)ethenyl]benzene-1,3-diol dihydrate}, C₁₄H₁₂O₄·2H₂O, a derivative of resveratrol, was isolated from mulberry. The linking C=C double bond has a trans conformation and allows the formation of a conjugated system throughout the molecule. The dihedral angle between the benzene rings is 9.39 (9)°. In the crystal, molecules are connected into a three-dimensional architecture through O—H⋯O hydrogen bonds between hydroxy groups of oxyresveratrol and solvent water molecules.

Related literature

For medicinal properties and the biological activity of oxyresveratrol, see: Mongolsuk et al. (1957 ); Charoenlarp et al. (1981 , 1989 ); Zheng et al. (2010 , 2011 ); Kim et al. (2002 , 2004 ); Shin et al. (1998 ); Lipipun et al. (2011 ); Galindo et al. (2011 ); Sasivimolphan et al. (2009 ); Chuanasa et al. (2008 ); Likhitwitayawuid (2008 ); Likhitwitayawuid et al. (2005 , 2006 ); Liu et al. (2009 ); Breuer et al. (2006 ); Chung et al. (2003 ); Chao et al. (2008 ); Ban et al. (2006 , 2008 ); Breuer et al. (2006); Andrabi et al. (2004 ). For related structures, see: Piao et al. (2009 ); Qiu et al.(1996 ); Hano et al. (1986 ).

Experimental

Crystal data

C₁₄H₁₂O₄·2H₂O
M_r = 280.27
Triclinic, $[P \overline 1]$
a = 6.6523 (5) Å
b = 9.2005 (9) Å
c = 11.5294 (8) Å
α = 72.533 (7)°
β = 78.686 (6)°
γ = 79.651 (7)°
V = 654.51 (9) Å³
Z = 2
Cu Kα radiation
μ = 0.95 mm⁻¹
T = 293 K
0.40 × 0.30 × 0.20 mm

Data collection

Agilent Xcalibur Onyx Nova diffractometer
Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2010 ) T_min = 0.704, T_max = 0.834
4145 measured reflections
2297 independent reflections
2002 reflections with I > 2σ(I)
R_int = 0.022

Refinement

R[F² > 2σ(F²)] = 0.042
wR(F²) = 0.141
S = 1.13
2297 reflections
197 parameters
5 restraints
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.50 e Å⁻³
Δρ_min = −0.44 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O1—H1⋯O4ⁱ	0.84	1.90	2.7329 (18)	173
O2—H2⋯O6ⁱⁱ	0.84	1.89	2.720 (2)	171
O3—H3A⋯O6ⁱⁱⁱ	0.84	1.97	2.8045 (19)	169
O4—H4⋯O5^iv	0.84	1.89	2.7259 (19)	170
O5—H5A⋯O1ⁱ	0.89 (2)	1.90 (2)	2.7879 (19)	172 (2)
O5—H5B⋯O2^v	0.89 (2)	1.88 (2)	2.7449 (19)	161 (2)
O6—H6B⋯O2ⁱⁱ	0.90 (3)	1.95 (3)	2.720 (2)	143 (4)
O6—H6C⋯O6^vi	0.90 (4)	1.87 (4)	2.7583 (19)	172 (5)
Symmetry codes: (i) -x, -y+1, -z+2; (ii) -x, -y+2, -z+1; (iii) -x+2, -y+1, -z+1; (iv) x+1, y, z; (v) x+1, y-1, z; (vi) -x+1, -y+1, -z+1.

Data collection: CrysAlis PRO (Agilent, 2010); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: publCIF (Westrip, 2010 ).

Supporting information

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536812014018/tk5080sup1.cif

Supporting information file. DOI: 10.1107/S1600536812014018/tk5080Isup2.mol

Structure factors: contains datablock I. DOI: 10.1107/S1600536812014018/tk5080Isup3.hkl

Supporting information file. DOI: 10.1107/S1600536812014018/tk5080Isup4.cml

checkCIF report

Comment top

Oxyresveratrol was firstly isolated from the heartwood of Artocarpus lakoocha Roxb as a abundant trans-tetrahydroxystilbene (Mongolsuk et al., 1957). Oxyresveratrol is responsible for the anthelmintic activity of the traditional Thailand anthelmintic drug "Puag-Haad" prepared from A. lakoocha (Charoenlarp et al., 1989; Charoenlarp et al., 1981). Recent investigations have revealed several interesting bioactivities of oxyresveratrol, such as tyrosinase inhibitory activity (Zheng et al., 2011; Zheng et al., 2010; Kim et al., 2004; Kim et al., 2002; Shin et al., 1998), in vitro anti-viral activity (Lipipun et al., 2011; Galindo et al., 2011; Sasivimolphan et al., 2009; Chuanasa et al., 2008; Likhitwitayawuid et al., 2006; Likhitwitayawuid et al., 2005), strong anti-oxidative and anti-inflammatory (Liu et al., 2009; Breuer et al., 2006; Chung et al., 2003), and neuroprotective properties (Chao et al., 2008; Ban et al., 2008; Ban et al., 2006; Breuer et al., 2006; Andrabi et al., 2004). These medicinal properties indicate several areas of therapeutic potential for oxyresveratrol and the compound has been recommended as a drug candidate for the treatment of neurodegenerative disorders (Breuer et al., 2006; Andrabi et al., 2004) and a skin-whitening agent in cosmetic preparations (Likhitwitayawuid, 2008). Mulberry (Morus alba L.) is a medicinal plant in east Asia. Its branch, leaf, ripe fruit and root bark are well known traditional Chinese drugs and contain a large amounts of trans-hydroxystilbenes such as mulberroside A, phaponticin, phapontigenin, resveratrol, pterostilbene, piceatannol, piceid, astringin, kuwanon Y, kuwanon Z, oxyresveratrol and its derivatives (Qiu et al., 1996; Hano et al., 1986; Piao et al., 2009). In this paper, we isolated oxyresveratrol from mulberry (Morus alba L.) and report the structure of oxyresveratrol dihydrate.

In the title compound (Fig. 1), the benzene rings form a dihedral angle of 9.39 (9)°. The presence of the trans C═C double bond allows the formation of a conjugated system, strongly stabilized through π-electron delocalization. The trans-double bond is the same as found in similar structures (Piao et al., 2009; Qiu et al., 1996; Hano et al., 1986). The molecules of the oxyresveratrol are connected into a three-dimensional architecture through O—H—O hydrogen bonds formed between its hydroxyl group and the solvent water molecules (Fig. 2 and Table 1).

Related literature top

For medicinal properties and the biological activity of oxyresveratrol, see: Mongolsuk et al. (1957); Charoenlarp et al. (1981, 1989); Zheng et al. (2010, 2011); Kim et al. (2002, 2004);Shin et al. (1998); Lipipun et al. (2011); Galindo et al. (2011); Sasivimolphan et al. (2009); Chuanasa et al. (2008); Likhitwitayawuid (2008); Likhitwitayawuid et al. (2005, 2006, 2008); Liu et al. (2009); Breuer et al. (2006); Chung et al. (2003); Chao et al. (2008); Ban et al. (2006, 2008); Breuer et al. (2006); Andrabi et al. (2004). For related structures, see: Piao et al. (2009); Qiu et al.(1996); Hano et al. (1986).

Experimental top

The dried root bark of Morus alba L. (1 kg) was powdered and extracted with 95% ethanol at room temperature for 48 h. After removal of the solvent under reduced pressure, a brown extract was suspended with water, and sequentially partitioned with petroleum ether, acetyl acetate and n-butanol. The acetyl acetate extract (9 g) was subjected to column chromatography on silica gel (200–300 mesh) with increasing concentrations of ethyl acetate in petroleum ether. Oxyresveratrol was afforded from the fraction (petroleum ether-ethyl acetate 6/4, v/v). The title compound was colourless to light-yellow crystal with M.pt: 474–476 K,. Crystals suitable for X-ray analysis were obtained by slow evaporation from its chloroform–methanol (4/1, v/v) solution. ¹H NMR (400 MHz, MeOD) δ 7.33 (d, J = 9.2 Hz, 1H), 7.27 (d, J = 16.5 Hz, 1H), 6.82 (d, J = 16.4 Hz,1H), 6.46 (d, J = 2.1 Hz, 2H), 6.34 – 6.32 (m, 1H), 6.31 (s, 1H), 6.15 (t, J = 2.2 Hz, 1H); O—H not observed.

Computing details top

Data collection: CrysAlis PRO (Agilent, 2010); cell refinement: CrysAlis PRO (Agilent, 2010); data reduction: CrysAlis PRO (Agilent, 2010); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: publCIF (Westrip, 2010).

Figures top

Fig. 1. A view of the molecular structure of compound (I). The displacement ellipsoids are at the 50% probability level and H atoms are shown as small spheres of arbitrary radii.

4-[(E)-2-(3,5-dihydroxyphenyl)ethenyl]benzene-1,3-diol dihydrate top

Crystal data top

C₁₄H₁₂O₄·2H₂O	Z = 2
M_r = 280.27	F(000) = 296
Triclinic, P1	D_x = 1.422 Mg m⁻³
Hall symbol: -P 1	Cu Kα radiation, λ = 1.54178 Å
a = 6.6523 (5) Å	Cell parameters from 2627 reflections
b = 9.2005 (9) Å	θ = 4.1–71.3°
c = 11.5294 (8) Å	µ = 0.95 mm⁻¹
α = 72.533 (7)°	T = 293 K
β = 78.686 (6)°	Block, colourless
γ = 79.651 (7)°	0.40 × 0.30 × 0.20 mm
V = 654.51 (9) Å³

Data collection top

Agilent Xcalibur Onyx Nova diffractometer	2297 independent reflections
Radiation source: Nova (Cu) X-ray Source	2002 reflections with I > 2σ(I)
Mirror monochromator	R_int = 0.022
Detector resolution: 8.2417 pixels mm^-1	θ_max = 66.6°, θ_min = 4.1°
ω scans	h = −7→8
Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2010)	k = −10→8
T_min = 0.704, T_max = 0.834	l = −13→13
4145 measured reflections

Refinement top

Refinement on F²	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F² > 2σ(F²)] = 0.042	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.141	H atoms treated by a mixture of independent and constrained refinement
S = 1.13	w = 1/[σ²(F_o²) + (0.081P)² + 0.176P] where P = (F_o² + 2F_c²)/3
2297 reflections	(Δ/σ)_max < 0.001
197 parameters	Δρ_max = 0.50 e Å⁻³
5 restraints	Δρ_min = −0.44 e Å⁻³

Crystal data top

C₁₄H₁₂O₄·2H₂O	γ = 79.651 (7)°
M_r = 280.27	V = 654.51 (9) Å³
Triclinic, P1	Z = 2
a = 6.6523 (5) Å	Cu Kα radiation
b = 9.2005 (9) Å	µ = 0.95 mm⁻¹
c = 11.5294 (8) Å	T = 293 K
α = 72.533 (7)°	0.40 × 0.30 × 0.20 mm
β = 78.686 (6)°

Data collection top

Agilent Xcalibur Onyx Nova diffractometer	2297 independent reflections
Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2010)	2002 reflections with I > 2σ(I)
T_min = 0.704, T_max = 0.834	R_int = 0.022
4145 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.042	5 restraints
wR(F²) = 0.141	H atoms treated by a mixture of independent and constrained refinement
S = 1.13	Δρ_max = 0.50 e Å⁻³
2297 reflections	Δρ_min = −0.44 e Å⁻³
197 parameters

Special details top

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq	Occ. (<1)
C1	−0.1126 (3)	0.9054 (2)	0.76812 (16)	0.0253 (4)
C2	−0.2896 (3)	0.8772 (2)	0.85658 (16)	0.0251 (4)
C3	−0.4773 (3)	0.9699 (2)	0.84350 (16)	0.0260 (4)
H3	−0.5945	0.9490	0.9051	0.031*
C4	−0.4925 (3)	1.0933 (2)	0.73988 (17)	0.0270 (4)
C5	−0.3191 (3)	1.1277 (2)	0.65217 (18)	0.0304 (4)
H5	−0.3286	1.2143	0.5825	0.036*
C6	−0.1329 (3)	1.0347 (2)	0.66730 (17)	0.0291 (4)
H6	−0.0149	1.0594	0.6073	0.035*
C7	0.0785 (3)	0.7976 (2)	0.78124 (16)	0.0265 (4)
H7	0.0724	0.7073	0.8482	0.032*
C8	0.2599 (3)	0.8143 (2)	0.70802 (17)	0.0266 (4)
H8	0.2682	0.9072	0.6438	0.032*
C9	0.4478 (3)	0.7025 (2)	0.71754 (16)	0.0241 (4)
C10	0.6184 (3)	0.7319 (2)	0.62552 (16)	0.0258 (4)
H10	0.6122	0.8242	0.5605	0.031*
C11	0.7979 (3)	0.6264 (2)	0.62855 (16)	0.0257 (4)
C12	0.8084 (3)	0.4895 (2)	0.72244 (17)	0.0273 (4)
H12	0.9292	0.4163	0.7238	0.033*
C13	0.6385 (3)	0.4623 (2)	0.81404 (16)	0.0260 (4)
C14	0.4594 (3)	0.5662 (2)	0.81327 (16)	0.0257 (4)
H14	0.3454	0.5451	0.8771	0.031*
O1	−0.27079 (18)	0.75380 (14)	0.95877 (12)	0.0298 (3)
H1	−0.3888	0.7321	0.9944	0.045*
O2	−0.68101 (19)	1.17941 (15)	0.72308 (13)	0.0352 (4)
H2	−0.6634	1.2691	0.6802	0.053*
O3	0.95691 (19)	0.66150 (15)	0.53537 (12)	0.0316 (3)
H3A	1.0617	0.5971	0.5509	0.047*
O4	0.64072 (19)	0.32934 (15)	0.90904 (12)	0.0330 (4)
H4	0.7589	0.2786	0.9044	0.049*
O5	0.01297 (19)	0.14910 (15)	0.92354 (12)	0.0318 (3)
H5A	0.085 (3)	0.187 (3)	0.963 (2)	0.048*
H5B	0.095 (3)	0.148 (3)	0.8524 (14)	0.048*
O6	0.67051 (19)	0.52209 (15)	0.40983 (12)	0.0300 (3)
H6A	0.637 (4)	0.490 (3)	0.3506 (17)	0.045*
H6B	0.701 (7)	0.618 (2)	0.394 (4)	0.045*	0.50
H6C	0.565 (6)	0.513 (6)	0.472 (3)	0.045*	0.50

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
C1	0.0192 (9)	0.0256 (9)	0.0278 (9)	−0.0011 (7)	−0.0025 (7)	−0.0043 (7)
C2	0.0202 (8)	0.0243 (9)	0.0270 (9)	−0.0018 (6)	−0.0028 (7)	−0.0025 (7)
C3	0.0182 (8)	0.0268 (9)	0.0285 (9)	−0.0011 (7)	0.0012 (7)	−0.0051 (7)
C4	0.0187 (8)	0.0261 (9)	0.0322 (9)	0.0029 (7)	−0.0031 (7)	−0.0057 (7)
C5	0.0249 (9)	0.0280 (9)	0.0300 (9)	0.0003 (7)	−0.0011 (7)	0.0003 (7)
C6	0.0190 (8)	0.0307 (10)	0.0301 (9)	−0.0006 (7)	0.0017 (7)	−0.0023 (8)
C7	0.0220 (9)	0.0234 (9)	0.0295 (9)	0.0010 (7)	−0.0047 (7)	−0.0023 (7)
C8	0.0217 (9)	0.0224 (9)	0.0314 (9)	0.0006 (7)	−0.0037 (7)	−0.0034 (7)
C9	0.0204 (8)	0.0234 (9)	0.0280 (9)	−0.0009 (6)	−0.0029 (7)	−0.0080 (7)
C10	0.0211 (9)	0.0239 (9)	0.0290 (9)	−0.0010 (7)	−0.0025 (7)	−0.0042 (7)
C11	0.0195 (8)	0.0280 (9)	0.0273 (9)	−0.0042 (7)	−0.0002 (7)	−0.0056 (7)
C12	0.0182 (8)	0.0271 (9)	0.0318 (10)	0.0018 (7)	−0.0029 (7)	−0.0043 (7)
C13	0.0205 (8)	0.0266 (9)	0.0269 (9)	−0.0025 (7)	−0.0021 (7)	−0.0029 (7)
C14	0.0175 (8)	0.0303 (9)	0.0261 (9)	−0.0009 (7)	0.0003 (7)	−0.0066 (7)
O1	0.0184 (6)	0.0289 (7)	0.0309 (7)	−0.0003 (5)	−0.0007 (5)	0.0049 (5)
O2	0.0210 (7)	0.0280 (7)	0.0427 (8)	0.0060 (5)	−0.0017 (6)	0.0036 (6)
O3	0.0180 (6)	0.0314 (7)	0.0341 (7)	0.0013 (5)	0.0036 (5)	0.0003 (5)
O4	0.0189 (6)	0.0316 (7)	0.0333 (7)	0.0035 (5)	0.0022 (5)	0.0059 (6)
O5	0.0238 (7)	0.0339 (7)	0.0329 (7)	0.0019 (5)	−0.0046 (5)	−0.0050 (6)
O6	0.0239 (7)	0.0299 (7)	0.0343 (8)	−0.0026 (5)	−0.0023 (5)	−0.0078 (6)

Geometric parameters (Å, º) top

C1—C6	1.399 (3)	C10—C11	1.396 (2)
C1—C2	1.405 (2)	C10—H10	0.9500
C1—C7	1.468 (2)	C11—O3	1.359 (2)
C2—O1	1.377 (2)	C11—C12	1.394 (3)
C2—C3	1.387 (2)	C12—C13	1.389 (2)
C3—C4	1.385 (3)	C12—H12	0.9500
C3—H3	0.9500	C13—O4	1.376 (2)
C4—O2	1.373 (2)	C13—C14	1.387 (2)
C4—C5	1.391 (3)	C14—H14	0.9500
C5—C6	1.382 (3)	O1—H1	0.8400
C5—H5	0.9500	O2—H2	0.8400
C6—H6	0.9500	O3—H3A	0.8400
C7—C8	1.335 (3)	O4—H4	0.8400
C7—H7	0.9500	O5—H5A	0.890 (10)
C8—C9	1.469 (2)	O5—H5B	0.893 (10)
C8—H8	0.9500	O6—H6A	0.897 (10)
C9—C10	1.397 (2)	O6—H6B	0.894 (10)
C9—C14	1.402 (2)	O6—H6C	0.896 (10)

C6—C1—C2	116.74 (16)	C10—C9—C8	118.39 (16)
C6—C1—C7	123.22 (15)	C14—C9—C8	122.38 (15)
C2—C1—C7	119.97 (16)	C11—C10—C9	120.38 (16)
O1—C2—C3	120.45 (15)	C11—C10—H10	119.8
O1—C2—C1	117.62 (15)	C9—C10—H10	119.8
C3—C2—C1	121.93 (16)	O3—C11—C12	122.21 (15)
C4—C3—C2	119.39 (16)	O3—C11—C10	117.25 (16)
C4—C3—H3	120.3	C12—C11—C10	120.51 (16)
C2—C3—H3	120.3	C13—C12—C11	118.52 (16)
O2—C4—C3	119.43 (15)	C13—C12—H12	120.7
O2—C4—C5	120.23 (16)	C11—C12—H12	120.7
C3—C4—C5	120.32 (16)	O4—C13—C14	117.15 (15)
C6—C5—C4	119.44 (17)	O4—C13—C12	120.98 (15)
C6—C5—H5	120.3	C14—C13—C12	121.86 (16)
C4—C5—H5	120.3	C13—C14—C9	119.49 (15)
C5—C6—C1	122.11 (16)	C13—C14—H14	120.3
C5—C6—H6	118.9	C9—C14—H14	120.3
C1—C6—H6	118.9	C2—O1—H1	109.5
C8—C7—C1	126.20 (16)	C4—O2—H2	109.5
C8—C7—H7	116.9	C11—O3—H3A	109.5
C1—C7—H7	116.9	C13—O4—H4	109.5
C7—C8—C9	126.05 (17)	H5A—O5—H5B	104 (2)
C7—C8—H8	117.0	H6A—O6—H6B	119 (4)
C9—C8—H8	117.0	H6A—O6—H6C	109 (4)
C10—C9—C14	119.21 (15)	H6B—O6—H6C	106 (5)

C6—C1—C2—O1	−177.63 (15)	C1—C7—C8—C9	−176.59 (16)
C7—C1—C2—O1	5.2 (3)	C7—C8—C9—C10	173.61 (18)
C6—C1—C2—C3	1.8 (3)	C7—C8—C9—C14	−4.5 (3)
C7—C1—C2—C3	−175.39 (16)	C14—C9—C10—C11	0.3 (3)
O1—C2—C3—C4	−179.97 (16)	C8—C9—C10—C11	−177.84 (16)
C1—C2—C3—C4	0.7 (3)	C9—C10—C11—O3	179.27 (15)
C2—C3—C4—O2	175.96 (16)	C9—C10—C11—C12	0.9 (3)
C2—C3—C4—C5	−2.6 (3)	O3—C11—C12—C13	−179.80 (16)
O2—C4—C5—C6	−176.49 (17)	C10—C11—C12—C13	−1.5 (3)
C3—C4—C5—C6	2.1 (3)	C11—C12—C13—O4	−179.83 (16)
C4—C5—C6—C1	0.5 (3)	C11—C12—C13—C14	1.0 (3)
C2—C1—C6—C5	−2.3 (3)	O4—C13—C14—C9	−179.06 (15)
C7—C1—C6—C5	174.73 (18)	C12—C13—C14—C9	0.2 (3)
C6—C1—C7—C8	6.8 (3)	C10—C9—C14—C13	−0.8 (3)
C2—C1—C7—C8	−176.28 (18)	C8—C9—C14—C13	177.25 (16)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1···O4ⁱ	0.84	1.90	2.7329 (18)	173
O2—H2···O6ⁱⁱ	0.84	1.89	2.720 (2)	171
O3—H3A···O6ⁱⁱⁱ	0.84	1.97	2.8045 (19)	169
O4—H4···O5^iv	0.84	1.89	2.7259 (19)	170
O5—H5A···O1ⁱ	0.89 (2)	1.90 (2)	2.7879 (19)	172 (2)
O5—H5B···O2^v	0.89 (2)	1.88 (2)	2.7449 (19)	161 (2)
O6—H6B···O2ⁱⁱ	0.90 (3)	1.95 (3)	2.720 (2)	143 (4)
O6—H6C···O6^vi	0.90 (4)	1.87 (4)	2.7583 (19)	172 (5)

Symmetry codes: (i) −x, −y+1, −z+2; (ii) −x, −y+2, −z+1; (iii) −x+2, −y+1, −z+1; (iv) x+1, y, z; (v) x+1, y−1, z; (vi) −x+1, −y+1, −z+1.

Experimental details

Crystal data
Chemical formula	C₁₄H₁₂O₄·2H₂O
M_r	280.27
Crystal system, space group	Triclinic, P1
Temperature (K)	293
a, b, c (Å)	6.6523 (5), 9.2005 (9), 11.5294 (8)
α, β, γ (°)	72.533 (7), 78.686 (6), 79.651 (7)
V (Å³)	654.51 (9)
Z	2
Radiation type	Cu Kα
µ (mm⁻¹)	0.95
Crystal size (mm)	0.40 × 0.30 × 0.20

Data collection
Diffractometer	Agilent Xcalibur Onyx Nova diffractometer
Absorption correction	Multi-scan (CrysAlis PRO; Agilent, 2010)
T_min, T_max	0.704, 0.834
No. of measured, independent and observed [I > 2σ(I)] reflections	4145, 2297, 2002
R_int	0.022
(sin θ/λ)_max (Å⁻¹)	0.595

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.042, 0.141, 1.13
No. of reflections	2297
No. of parameters	197
No. of restraints	5
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρ_max, Δρ_min (e Å⁻³)	0.50, −0.44

Computer programs: CrysAlis PRO (Agilent, 2010), SHELXTL (Sheldrick, 2008), publCIF (Westrip, 2010).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1···O4ⁱ	0.84	1.90	2.7329 (18)	173
O2—H2···O6ⁱⁱ	0.84	1.89	2.720 (2)	171
O3—H3A···O6ⁱⁱⁱ	0.84	1.97	2.8045 (19)	169
O4—H4···O5^iv	0.84	1.89	2.7259 (19)	170
O5—H5A···O1ⁱ	0.89 (2)	1.90 (2)	2.7879 (19)	172 (2)
O5—H5B···O2^v	0.893 (17)	1.884 (18)	2.7449 (19)	161 (2)
O6—H6B···O2ⁱⁱ	0.90 (3)	1.95 (3)	2.720 (2)	143 (4)
O6—H6C···O6^vi	0.90 (4)	1.87 (4)	2.7583 (19)	172 (5)

Symmetry codes: (i) −x, −y+1, −z+2; (ii) −x, −y+2, −z+1; (iii) −x+2, −y+1, −z+1; (iv) x+1, y, z; (v) x+1, y−1, z; (vi) −x+1, −y+1, −z+1.

Acknowledgements

The authors gratefully thank the Scientific Research Foundation for Returned Overseas Chinese Scholars (X. He), the State Education Ministry, the National Natural Science Foundation of China, (30800169, X. Hu) and the Research Fund for the Doctoral Program of Higher Education of China (200805581146, X. Hu).

References

Agilent (2010). CrysAlis PRO. Agilent Technologies, Yarnton, England. Google Scholar
Andrabi, S. A., Spina, M. G., Lorenz, P., Ebmeyer, U., Wolf, G. & Horn, T. F. (2004). Brain Res. 1017, 98–107. Web of Science CrossRef PubMed CAS Google Scholar
Ban, J. Y., Cho, S. O., Choi, S. H., Ju, H. S., Kim, J. Y., Bae, K., Song, K. S. & Seong, Y. H. (2008). J. Pharmacol. Sci. 106, 68–77. Web of Science CrossRef PubMed CAS Google Scholar
Ban, J. Y., Jeon, S. Y., Nguyen, T. T., Bae, K., Song, K. S. & Seong, Y. H. (2006). Biol. Pharm. Bull. 29, 2419–2424. Web of Science CrossRef PubMed CAS Google Scholar
Breuer, C., Wolf, G., Andrabi, S. A., Lorenz, P. & Horn, T. F. (2006). Neurosci. Lett. 393, 113–118. Web of Science CrossRef PubMed CAS Google Scholar
Chao, J., Yu, M. S., Ho, Y. S., Wang, M. & Chang, R. C. (2008). Free Radical Biol. Med. 45, 1019–1026. Web of Science CrossRef CAS Google Scholar
Charoenlarp, P., Radomyos, P. & Bunnag, D. (1989). J. Med. Assoc. Thai. 72, 71–73. CAS PubMed Google Scholar
Charoenlarp, P., Radomyos, P. & Harinasuta, T. (1981). Southeast Asian J. Trop. Med. Public Health, 12, 568–570. CAS PubMed Google Scholar
Chuanasa, T., Phromjai, J., Lipipun, V., Likhitwitayawuid, K., Suzuki, M., Pramyothin, P., Hattori, M. & Shiraki, K. (2008). Antiviral Res. 80, 62–70. Web of Science CrossRef PubMed CAS Google Scholar
Chung, K. O., Kim, B. Y., Lee, M. H., Kim, Y. R., Chung, H. Y., Park, J. H. & Moon, J. O. (2003). J. Pharm. Pharmacol. 55, 1695–1700. Web of Science CrossRef PubMed CAS Google Scholar
Galindo, I., Hernaez, B., Berna, J., Fenoll, J., Cenis, J. L., Escribano, J. M. & Alonso, C. (2011). Antiviral Res. 91, 57–63. Web of Science CrossRef CAS PubMed Google Scholar
Hano, Y., Tsubura, H. & Nomura, T. (1986). Heterocycles, 24, 2603–2610. CAS Google Scholar
Kim, D. H., Kim, J. H., Baek, S. H., Seo, J. H., Kho, Y. H., Oh, T. K. & Lee, C. H. (2004). Biotechnol. Bioeng. 87, 849–854. Web of Science CrossRef PubMed CAS Google Scholar
Kim, Y. M., Yun, J., Lee, C. K., Lee, H., Min, K. R. & Kim, Y. (2002). J. Biol. Chem. 277, 16340–16344. Web of Science CrossRef PubMed CAS Google Scholar
Likhitwitayawuid, K. (2008). Curr. Sci. 94, 44–52. CAS Google Scholar
Likhitwitayawuid, K., Chaiwiriya, S., Sritularak, B. & Lipipun, V. (2006). Chem. Biodivers. 3, 1138–1143. Web of Science CrossRef PubMed CAS Google Scholar
Likhitwitayawuid, K., Sritularak, B., Benchanak, K., Lipipun, V., Mathew, J. & Schinazi, R. F. (2005). Nat. Prod. Res. 19, 177–182. Web of Science CrossRef PubMed CAS Google Scholar
Lipipun, V., Sasivimolphan, P., Yoshida, Y., Daikoku, T., Sritularak, B., Ritthidej, G., Likhitwitayawuid, K., Pramyothin, P., Hattori, M. & Shiraki, K. (2011). Antiviral Res. 91, 154–160. Web of Science CrossRef CAS PubMed Google Scholar
Liu, D., Kim, D. H., Park, J. M., Na, H. K. & Surh, Y. J. (2009). Nutr. Cancer, 61, 855–863. Web of Science CrossRef CAS PubMed Google Scholar
Mongolsuk, S., Robertson, A. & Towers, R. (1957). J. Chem. Soc. pp. 2231–2233. CrossRef Web of Science Google Scholar
Piao, S.-J., Qiu, F., Chen, L.-X., Pan, Y. & Dou, D.-Q. (2009). Helv. Chim. Acta, 92, 579–587. CrossRef CAS Google Scholar
Qiu, F., Komatsu, K., Kawasaki, K., Saito, K., Yao, X. & Kano, Y. (1996). Planta Med. 62, 559–561. CrossRef PubMed CAS Web of Science Google Scholar
Sasivimolphan, P., Lipipun, V., Likhitwitayawuid, K., Takemoto, M., Pramyothin, P., Hattori, M. & Shiraki, K. (2009). Antiviral Res. 84, 95–97. Web of Science CrossRef PubMed CAS Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Shin, N. H., Ryu, S. Y., Choi, E. J., Kang, S. H., Chang, I. M., Min, K. R. & Kim, Y. (1998). Biochem. Biophys. Res. Commun. 243, 801–803. Web of Science CrossRef CAS PubMed Google Scholar
Westrip, S. P. (2010). J. Appl. Cryst. 43, 920–925. Web of Science CrossRef CAS IUCr Journals Google Scholar
Zheng, Z. P., Cheng, K. W., Zhu, Q., Wang, X. C., Lin, Z. X. & Wang, M. (2010). J. Agric. Food Chem. 58, 5368–5373. Web of Science CrossRef CAS PubMed Google Scholar
Zheng, Z. P., Zhu, Q., Fan, C. L., Tan, H. Y. & Wang, M. (2011). Food Funct. 2, 259–264. Web of Science CrossRef CAS PubMed Google Scholar