Tectorigenin monohydrate: an isoflavone from Belamcanda chinensis

Liu, B.; Ma, Y.; Gao, H.; Wu, Q.

doi:10.1107/S1600536808030833

organic compounds

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ISSN: 2056-9890

Volume 64| Part 11| November 2008| Page o2056

doi:10.1107/S1600536808030833

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Tectorigenin monohydrate: an isoflavone from Belamcanda chinensis

Benguo Liu,^a ^* Yuxiang Ma,^b Han Gao ^a and Qiong Wu ^c

^aSchool of Food Science, Henan Institute of Science and Technology, Xinxiang 453003, People's Republic of China, ^bCollege of Grain and Food, Henan University of Technology, Zhengzhou 450052, People's Republic of China, and ^cJilin Key Laboratory for Biotechnology of Agricultural Products Processing, Changchun University, Changchun 130022, People's Republic of China
^*Correspondence e-mail: benguoliu2008@yahoo.com.cn

(Received 20 September 2008; accepted 24 September 2008; online 4 October 2008)

The title compound [systematic name: 5,7-dihydroxy-3-(4-hydroxyphenyl)-6-methoxy-4H-chromen-4-one monohydrate], C₁₆H₁₂O₆·H₂O, is isolated from Belamcanda chinensis and is said to have antimicrobiotic and anti-inflammatory effects. The chromen-4-one system and the benzene ring are inclined at a dihedral angle of 36.79 (6)°. Molecules are linked by inter- and intramolecular O—H⋯O hydrogen bonds.

Related literature

For general background, see: Oh et al. (2001 ). For a related structure, see: Gao et al. (2008 ).

Experimental

Crystal data

C₁₆H₁₂O₆·H₂O
M_r = 318.27
Monoclinic, P 2₁ /c
a = 12.971 (3) Å
b = 14.652 (3) Å
c = 7.2930 (15) Å
β = 103.81 (3)°
V = 1346.0 (5) Å³
Z = 4
Mo Kα radiation
μ = 0.13 mm⁻¹
T = 113 (2) K
0.14 × 0.04 × 0.02 mm

Data collection

Rigaku Saturn CCD area-detector diffractometer
Absorption correction: multi-scan (CrystalClear; Rigaku/MSC, 2005 ) T_min = 0.973, T_max = 0.998
9180 measured reflections
2967 independent reflections
2069 reflections with I > 2σ(I)
R_int = 0.085

Refinement

R[F² > 2σ(F²)] = 0.044
wR(F²) = 0.117
S = 1.00
2967 reflections
224 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.33 e Å⁻³
Δρ_min = −0.27 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O7—H7B⋯O2ⁱ	0.77 (3)	2.57 (2)	2.971 (2)	114 (2)
O7—H7A⋯O6ⁱⁱ	0.95 (3)	1.95 (3)	2.884 (2)	167 (2)
O6—H6⋯O1ⁱⁱⁱ	0.88 (2)	1.88 (2)	2.7368 (17)	167 (2)
O3—H3⋯O5	0.90 (2)	1.71 (2)	2.5658 (16)	159.6 (18)
O1—H1⋯O7^iv	0.87 (2)	1.83 (2)	2.6630 (17)	160.4 (19)
Symmetry codes: (i) x, y, z+1; (ii) $[x-1, -y+{\script{3\over 2}}, z-{\script{1\over 2}}]$ ; (iii) x+1, y, z+1; (iv) x, y, z-1.

Data collection: CrystalClear (Rigaku/MSC, 2005); cell refinement: CrystalClear; data reduction: CrystalClear; 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.

Supporting information

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536808030833/bt2795sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536808030833/bt2795Isup2.hkl

checkCIF report

Comment top

The title compound [systematic name: 5,7-dihydroxy-3-(4-hydroxyphenyl)-6-methoxy-4H-chromen-4-one] was isolated from Belamcanda chinensis and is said to have antimicrobiotic and anti-inflammatory effects. We report here the crystal structure of its monohydrate. The two aromatic ring systems rings are inclined at a dihedral angle of 36.79 (6)°. The molecules are linked by intermolecular O—H···O hydrogen bonds (Table 1).

Related literature top

For general background, see: Oh et al. (2001). For related structures, see: Gao et al. (2008).

Experimental top

The title compound was isolated from Belamcanda chinensis.

Computing details top

Data collection: CrystalClear (Rigaku/MSC, 2005); cell refinement: CrystalClear (Rigaku/MSC, 2005); data reduction: CrystalClear (Rigaku/MSC, 2005); 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 (Sheldrick, 2008).

Figures top

Fig. 1. A view of the title compound. Displacement ellopsoids are drawn at the 30% probability level and H atoms are shown as small spheres of arbitrary radii.

5,7-dihydroxy-3-(4-hydroxyphenyl)-6-methoxy-4H-chromen-4-one monohydrate top

Crystal data top

C₁₆H₁₂O₆·H₂O	F(000) = 664
M_r = 318.27	D_x = 1.571 Mg m⁻³
Monoclinic, P2₁/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 2562 reflections
a = 12.971 (3) Å	θ = 1.6–27.1°
b = 14.652 (3) Å	µ = 0.13 mm⁻¹
c = 7.2930 (15) Å	T = 113 K
β = 103.81 (3)°	Block, colorless
V = 1346.0 (5) Å³	0.14 × 0.04 × 0.02 mm
Z = 4

Data collection top

Rigaku Saturn CCD area-detector diffractometer	2967 independent reflections
Radiation source: rotating anode	2069 reflections with I > 2σ(I)
Confocal monochromator	R_int = 0.085
Detector resolution: 7.31 pixels mm^-1	θ_max = 27.1°, θ_min = 1.6°
ω and ϕ scans	h = −16→16
Absorption correction: multi-scan (CrystalClear; Rigaku/MSC, 2005)	k = −15→18
T_min = 0.973, T_max = 0.998	l = −9→7
9180 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)] = 0.045	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.117	H atoms treated by a mixture of independent and constrained refinement
S = 1.00	w = 1/[σ²(F_o²) + (0.0629P)²] where P = (F_o² + 2F_c²)/3
2967 reflections	(Δ/σ)_max = 0.001
224 parameters	Δρ_max = 0.33 e Å⁻³
0 restraints	Δρ_min = −0.27 e Å⁻³

Crystal data top

C₁₆H₁₂O₆·H₂O	V = 1346.0 (5) Å³
M_r = 318.27	Z = 4
Monoclinic, P2₁/c	Mo Kα radiation
a = 12.971 (3) Å	µ = 0.13 mm⁻¹
b = 14.652 (3) Å	T = 113 K
c = 7.2930 (15) Å	0.14 × 0.04 × 0.02 mm
β = 103.81 (3)°

Data collection top

Rigaku Saturn CCD area-detector diffractometer	2967 independent reflections
Absorption correction: multi-scan (CrystalClear; Rigaku/MSC, 2005)	2069 reflections with I > 2σ(I)
T_min = 0.973, T_max = 0.998	R_int = 0.085
9180 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.045	0 restraints
wR(F²) = 0.117	H atoms treated by a mixture of independent and constrained refinement
S = 1.00	Δρ_max = 0.33 e Å⁻³
2967 reflections	Δρ_min = −0.27 e Å⁻³
224 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
O1	0.15492 (10)	0.72865 (7)	−0.00354 (17)	0.0204 (3)
H1	0.1297 (17)	0.6740 (14)	−0.033 (3)	0.031*
O2	0.26095 (9)	0.56579 (7)	0.09198 (16)	0.0191 (3)
O3	0.45733 (10)	0.56828 (7)	0.34259 (17)	0.0193 (3)
H3	0.5174 (18)	0.5889 (13)	0.420 (3)	0.029*
O4	0.45077 (9)	0.89559 (7)	0.32487 (17)	0.0173 (3)
O5	0.61065 (9)	0.66388 (7)	0.53713 (16)	0.0188 (3)
O6	1.02531 (10)	0.87836 (8)	0.95714 (18)	0.0221 (3)
H6	1.0680 (18)	0.8325 (15)	0.952 (3)	0.033*
C1	0.25505 (13)	0.72879 (10)	0.1088 (2)	0.0159 (4)
C2	0.30232 (13)	0.81198 (9)	0.1645 (2)	0.0161 (4)
H2	0.2660	0.8676	0.1254	0.019*
C3	0.40402 (13)	0.81206 (9)	0.2788 (2)	0.0142 (4)
C4	0.55224 (13)	0.89830 (10)	0.4301 (2)	0.0157 (4)
H4	0.5850	0.9566	0.4520	0.019*
C5	0.61050 (13)	0.82575 (10)	0.5063 (2)	0.0141 (4)
C6	0.56447 (13)	0.73485 (10)	0.4688 (2)	0.0142 (4)
C7	0.45876 (13)	0.73227 (10)	0.3443 (2)	0.0141 (4)
C8	0.40834 (13)	0.64784 (9)	0.2855 (2)	0.0148 (4)
C9	0.30772 (14)	0.64647 (9)	0.1659 (2)	0.0155 (4)
C10	0.22428 (15)	0.50987 (11)	0.2257 (3)	0.0243 (5)
H10A	0.1689	0.5425	0.2702	0.036*
H10B	0.2838	0.4963	0.3332	0.036*
H10C	0.1952	0.4527	0.1648	0.036*
C11	0.71993 (13)	0.83905 (9)	0.6228 (2)	0.0153 (4)
C12	0.74392 (14)	0.91262 (9)	0.7482 (2)	0.0157 (4)
H12	0.6895	0.9541	0.7595	0.019*
C13	0.84645 (14)	0.92549 (9)	0.8561 (2)	0.0172 (4)
H13	0.8622	0.9759	0.9401	0.021*
C14	0.92533 (13)	0.86514 (10)	0.8412 (2)	0.0165 (4)
C15	0.90422 (14)	0.79282 (10)	0.7145 (2)	0.0197 (4)
H15	0.9594	0.7526	0.7010	0.024*
C16	0.80091 (14)	0.78018 (10)	0.6076 (2)	0.0185 (4)
H16	0.7857	0.7302	0.5225	0.022*
O7	0.04211 (12)	0.58284 (9)	0.8508 (2)	0.0333 (4)
H7A	0.033 (2)	0.5862 (15)	0.718 (4)	0.050*
H7B	0.076 (2)	0.5390 (18)	0.876 (4)	0.050*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
O1	0.0144 (7)	0.0182 (6)	0.0251 (7)	0.0000 (4)	−0.0024 (5)	−0.0017 (4)
O2	0.0203 (7)	0.0157 (5)	0.0204 (6)	−0.0030 (4)	0.0031 (5)	−0.0024 (4)
O3	0.0178 (7)	0.0122 (5)	0.0247 (7)	0.0012 (4)	−0.0012 (5)	0.0003 (4)
O4	0.0142 (6)	0.0122 (5)	0.0233 (6)	0.0001 (4)	0.0001 (5)	0.0003 (4)
O5	0.0170 (6)	0.0151 (5)	0.0228 (6)	0.0026 (4)	0.0018 (5)	0.0022 (4)
O6	0.0142 (7)	0.0193 (6)	0.0287 (7)	0.0001 (5)	−0.0033 (5)	−0.0036 (4)
C1	0.0118 (8)	0.0211 (8)	0.0142 (8)	0.0007 (6)	0.0023 (7)	−0.0008 (5)
C2	0.0150 (9)	0.0167 (7)	0.0167 (8)	0.0031 (6)	0.0039 (7)	0.0011 (5)
C3	0.0144 (8)	0.0137 (7)	0.0156 (8)	−0.0020 (6)	0.0060 (7)	−0.0013 (5)
C4	0.0135 (8)	0.0167 (7)	0.0169 (8)	−0.0019 (6)	0.0038 (7)	−0.0018 (5)
C5	0.0129 (8)	0.0162 (7)	0.0144 (8)	0.0003 (6)	0.0054 (7)	−0.0015 (5)
C6	0.0142 (9)	0.0158 (7)	0.0135 (8)	0.0009 (6)	0.0052 (7)	0.0000 (5)
C7	0.0118 (8)	0.0161 (7)	0.0149 (8)	0.0013 (6)	0.0043 (7)	0.0006 (5)
C8	0.0165 (9)	0.0141 (7)	0.0146 (8)	0.0008 (6)	0.0053 (7)	0.0006 (5)
C9	0.0182 (9)	0.0141 (7)	0.0149 (8)	−0.0021 (6)	0.0054 (7)	−0.0012 (5)
C10	0.0250 (10)	0.0205 (8)	0.0285 (10)	−0.0043 (7)	0.0090 (8)	0.0021 (6)
C11	0.0152 (9)	0.0140 (7)	0.0159 (8)	−0.0019 (6)	0.0023 (7)	0.0016 (5)
C12	0.0162 (9)	0.0136 (7)	0.0181 (8)	0.0019 (6)	0.0056 (7)	0.0015 (5)
C13	0.0199 (10)	0.0125 (7)	0.0186 (8)	−0.0029 (6)	0.0033 (7)	−0.0018 (5)
C14	0.0132 (8)	0.0169 (7)	0.0181 (8)	−0.0018 (6)	0.0013 (7)	0.0022 (5)
C15	0.0153 (9)	0.0183 (7)	0.0253 (9)	0.0030 (6)	0.0045 (7)	−0.0031 (6)
C16	0.0177 (9)	0.0179 (7)	0.0192 (9)	−0.0006 (6)	0.0030 (7)	−0.0047 (5)
O7	0.0329 (9)	0.0253 (6)	0.0358 (9)	0.0005 (6)	−0.0037 (7)	−0.0060 (5)

Geometric parameters (Å, º) top

O1—C1	1.3602 (18)	C5—C11	1.483 (2)
O1—H1	0.87 (2)	C6—C7	1.453 (2)
O2—C9	1.3784 (16)	C7—C8	1.4171 (19)
O2—C10	1.439 (2)	C8—C9	1.386 (2)
O3—C8	1.3453 (17)	C10—H10A	0.9800
O3—H3	0.90 (2)	C10—H10B	0.9800
O4—C4	1.3568 (18)	C10—H10C	0.9800
O4—C3	1.3717 (16)	C11—C16	1.384 (2)
O5—C6	1.2434 (17)	C11—C12	1.400 (2)
O6—C14	1.3823 (18)	C12—C13	1.387 (2)
O6—H6	0.88 (2)	C12—H12	0.9500
C1—C2	1.381 (2)	C13—C14	1.376 (2)
C1—C9	1.400 (2)	C13—H13	0.9500
C2—C3	1.382 (2)	C14—C15	1.390 (2)
C2—H2	0.9500	C15—C16	1.393 (2)
C3—C7	1.3917 (19)	C15—H15	0.9500
C4—C5	1.345 (2)	C16—H16	0.9500
C4—H4	0.9500	O7—H7A	0.95 (3)
C5—C6	1.458 (2)	O7—H7B	0.77 (3)

C1—O1—H1	113.5 (13)	O2—C9—C8	121.26 (13)
C9—O2—C10	114.16 (13)	O2—C9—C1	118.99 (13)
C8—O3—H3	100.2 (12)	C8—C9—C1	119.62 (13)
C4—O4—C3	118.50 (11)	O2—C10—H10A	109.5
C14—O6—H6	112.1 (13)	O2—C10—H10B	109.5
O1—C1—C2	118.13 (13)	H10A—C10—H10B	109.5
O1—C1—C9	120.40 (13)	O2—C10—H10C	109.5
C2—C1—C9	121.47 (13)	H10A—C10—H10C	109.5
C1—C2—C3	118.09 (13)	H10B—C10—H10C	109.5
C1—C2—H2	121.0	C16—C11—C12	118.55 (14)
C3—C2—H2	121.0	C16—C11—C5	120.86 (13)
O4—C3—C2	116.81 (12)	C12—C11—C5	120.58 (15)
O4—C3—C7	120.39 (13)	C13—C12—C11	120.59 (15)
C2—C3—C7	122.80 (13)	C13—C12—H12	119.7
C5—C4—O4	125.74 (13)	C11—C12—H12	119.7
C5—C4—H4	117.1	C14—C13—C12	119.88 (14)
O4—C4—H4	117.1	C14—C13—H13	120.1
C4—C5—C6	118.67 (14)	C12—C13—H13	120.1
C4—C5—C11	119.95 (13)	C13—C14—O6	117.93 (14)
C6—C5—C11	121.36 (13)	C13—C14—C15	120.68 (14)
O5—C6—C7	121.41 (13)	O6—C14—C15	121.39 (15)
O5—C6—C5	123.52 (14)	C14—C15—C16	118.98 (16)
C7—C6—C5	115.08 (12)	C14—C15—H15	120.5
C3—C7—C8	117.94 (13)	C16—C15—H15	120.5
C3—C7—C6	121.37 (13)	C11—C16—C15	121.29 (14)
C8—C7—C6	120.69 (13)	C11—C16—H16	119.4
O3—C8—C9	119.11 (12)	C15—C16—H16	119.4
O3—C8—C7	120.86 (13)	H7A—O7—H7B	102 (2)
C9—C8—C7	120.03 (13)

O1—C1—C2—C3	179.92 (17)	C10—O2—C9—C8	73.9 (2)
C9—C1—C2—C3	0.2 (3)	C10—O2—C9—C1	−110.33 (18)
C4—O4—C3—C2	−177.22 (16)	O3—C8—C9—O2	−5.6 (3)
C4—O4—C3—C7	2.1 (3)	C7—C8—C9—O2	173.72 (17)
C1—C2—C3—O4	177.11 (17)	O3—C8—C9—C1	178.63 (17)
C1—C2—C3—C7	−2.2 (3)	C7—C8—C9—C1	−2.1 (3)
C3—O4—C4—C5	−4.9 (3)	O1—C1—C9—O2	6.3 (3)
O4—C4—C5—C6	2.7 (3)	C2—C1—C9—O2	−173.97 (17)
O4—C4—C5—C11	−178.42 (17)	O1—C1—C9—C8	−177.84 (17)
C4—C5—C6—O5	−177.81 (18)	C2—C1—C9—C8	1.9 (3)
C11—C5—C6—O5	3.3 (3)	C4—C5—C11—C16	−139.51 (19)
C4—C5—C6—C7	2.0 (3)	C6—C5—C11—C16	39.4 (3)
C11—C5—C6—C7	−176.86 (16)	C4—C5—C11—C12	39.3 (3)
O4—C3—C7—C8	−177.26 (17)	C6—C5—C11—C12	−141.85 (18)
C2—C3—C7—C8	2.0 (3)	C16—C11—C12—C13	−0.7 (3)
O4—C3—C7—C6	2.6 (3)	C5—C11—C12—C13	−179.49 (16)
C2—C3—C7—C6	−178.17 (18)	C11—C12—C13—C14	−0.5 (3)
O5—C6—C7—C3	175.31 (19)	C12—C13—C14—O6	−177.31 (16)
C5—C6—C7—C3	−4.5 (3)	C12—C13—C14—C15	2.1 (3)
O5—C6—C7—C8	−4.8 (3)	C13—C14—C15—C16	−2.4 (3)
C5—C6—C7—C8	175.30 (17)	O6—C14—C15—C16	176.94 (16)
C3—C7—C8—O3	179.49 (17)	C12—C11—C16—C15	0.3 (3)
C6—C7—C8—O3	−0.4 (3)	C5—C11—C16—C15	179.12 (17)
C3—C7—C8—C9	0.2 (3)	C14—C15—C16—C11	1.2 (3)
C6—C7—C8—C9	−179.67 (17)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O7—H7B···O2ⁱ	0.77 (3)	2.57 (2)	2.971 (2)	114 (2)
O7—H7A···O6ⁱⁱ	0.95 (3)	1.95 (3)	2.884 (2)	167 (2)
O6—H6···O1ⁱⁱⁱ	0.88 (2)	1.88 (2)	2.7368 (17)	167 (2)
O3—H3···O5	0.90 (2)	1.71 (2)	2.5658 (16)	159.6 (18)
O1—H1···O7^iv	0.87 (2)	1.83 (2)	2.6630 (17)	160.4 (19)

Symmetry codes: (i) x, y, z+1; (ii) x−1, −y+3/2, z−1/2; (iii) x+1, y, z+1; (iv) x, y, z−1.

Experimental details

Crystal data
Chemical formula	C₁₆H₁₂O₆·H₂O
M_r	318.27
Crystal system, space group	Monoclinic, P2₁/c
Temperature (K)	113
a, b, c (Å)	12.971 (3), 14.652 (3), 7.2930 (15)
β (°)	103.81 (3)
V (Å³)	1346.0 (5)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	0.13
Crystal size (mm)	0.14 × 0.04 × 0.02

Data collection
Diffractometer	Rigaku Saturn CCD area-detector diffractometer
Absorption correction	Multi-scan (CrystalClear; Rigaku/MSC, 2005)
T_min, T_max	0.973, 0.998
No. of measured, independent and observed [I > 2σ(I)] reflections	9180, 2967, 2069
R_int	0.085
(sin θ/λ)_max (Å⁻¹)	0.642

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.045, 0.117, 1.00
No. of reflections	2967
No. of parameters	224
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρ_max, Δρ_min (e Å⁻³)	0.33, −0.27

Computer programs: CrystalClear (Rigaku/MSC, 2005), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O7—H7B···O2ⁱ	0.77 (3)	2.57 (2)	2.971 (2)	114 (2)
O7—H7A···O6ⁱⁱ	0.95 (3)	1.95 (3)	2.884 (2)	167 (2)
O6—H6···O1ⁱⁱⁱ	0.88 (2)	1.88 (2)	2.7368 (17)	167 (2)
O3—H3···O5	0.90 (2)	1.71 (2)	2.5658 (16)	159.6 (18)
O1—H1···O7^iv	0.87 (2)	1.83 (2)	2.6630 (17)	160.4 (19)

Symmetry codes: (i) x, y, z+1; (ii) x−1, −y+3/2, z−1/2; (iii) x+1, y, z+1; (iv) x, y, z−1.

References

Gao, H., Li, G., Zhang, J. & Zeng, J. (2008). Acta Cryst. E64, o1538. Web of Science CSD CrossRef IUCr Journals Google Scholar
Oh, K. B., Kang, H. & Matsuoka, H. (2001). Biosci. Biotechnol. Biochem. 65, 939–942. Web of Science CrossRef PubMed CAS Google Scholar
Rigaku/MSC (2005). CrystalClear. Rigaku/MSC, The Woodlands, Texas, USA. Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar

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Volume 64| Part 11| November 2008| Page o2056

doi:10.1107/S1600536808030833

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