3-Hy­droxy-1,2-dimeth­oxyxanthone

Abstract

The title compound (systematic name: 3-hy­droxy-1,2-dimeth­oxy-9H-xanthen-9-one), C₁₅H₁₂O₅, was isolated from Polygala arillata. The tricyclic unit is essentially planar (r.m.s. deviation = 0.039 Å). In the crystal, the mol­ecules form stacks along the a axis. Inter­molecular O—H⋯O hydrogen bonds link the mol­ecules into chains parallel to [010].

Related literature

For general background to the title compound and the plant Polygala arillata, see: Corrêa et al. (1970 ▶); De Oliveira et al. (1968 ▶); Dominguez et al. (1990 ▶); Gottlieb et al. (1970 ▶); Jiangshu New Medicinal College (1977 ▶); Li et al. (1999 ▶); Lin et al. (2005 ▶); Miao et al. (1996 ▶, 1997 ▶).

Experimental

Crystal data

• C₁₅H₁₂O₅

• M _r = 272.25

• Triclinic,

• a = 7.338 (2) Å

• b = 7.824 (3) Å

• c = 11.964 (4) Å

• α = 94.634 (4)°

• β = 93.561 (4)°

• γ = 115.027 (4)°

• V = 616.8 (3) ų

• Z = 2

• Mo Kα radiation

• μ = 0.11 mm⁻¹

• T = 293 K

• 0.15 × 0.12 × 0.10 mm

Data collection

• Bruker SMART APEX CCD area-detector diffractometer

• Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ▶) T _min = 0.984, T _max = 0.989

• 2562 measured reflections

• 2126 independent reflections

• 1697 reflections with I > 2σ(I)

• R _int = 0.037

Refinement

• R[F ² > 2σ(F ²)] = 0.063

• wR(F ²) = 0.190

• S = 1.07

• 2126 reflections

• 184 parameters

• H-atom parameters constrained

• Δρ_max = 0.23 e Å⁻³

• Δρ_min = −0.32 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

Supplementary material file. DOI: 10.1107/S160053681102160X/yk2009Isup3.cml

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
O5—H5⋯O2i	0.82	1.90	2.713 (3)	169

Symmetry code: (i) .

supplementary crystallographic information

Comment

Polygala arillata Buch-Ham is mainly distributed in south-west of China. The roots of Polygala arillata has been used in Chinese folk medicine to treat expectorant, hepatitis, pneumonia and rheumatism (Jiangshu New Medicinal College, 1977). Some chemical constituents of this plant have been reported previously (Miao et al., 1996, 1997; Li et al., 1999). Our chemical investigation of this plant for bioactive components resulted in the isolation of the title compound, which was previously obtained from Kielmeyera rupestris (Corrêa et al., 1970), Kielmeyera speciosa (De Oliveira et al., 1968, Gottlieb et al., 1970), Polygala nitida (Dominguez et al., 1990) and Polygala fallax (Lin et al., 2005). Herein we report the crystal structure determination of the title compound.

Experimental

Three 5 kg portions of dry powdered stem bark of Polygala arillata were refluxed for 1 h with 95% ethanol (50L). After removal of ethanol under reduced pressure, the extract was suspended in water and then partitioned with chloroform, ethyl acetate and n-butanol. The chloroform soluble fraction (50 g) was subjected to silica gel column chromatography using gradient elution (petroleum ether/acetone, 10:1 to 2:1, v/v). 3-hydroxy-1,2-dimethoxyxanthone was obtained from the fraction eluted by 3:1 petroleum ether/acetone ratio. Single crystals suitable for X-ray diffraction analysis were grown by slow evaporation of acetone solution at room temperature.

Refinement

The hydroxyl H atoms attached to O5 was located by a difference Fourier map and refined isotropically with a restrained O–H distance 0.82 Å. The remaining H atoms were placed in calculated positions with C—H distances in the range 0.93–0.98 Å. The Uĩso~ values were set equal to 1.2Ueq (C,O) for methyl and hydroxyl H atoms and 1.5Ueq(C) for the remaining H atoms.

Figures

Fig. 1.

The molecular structure of the title compound, showing the atom-labelling scheme and displacement ellipsoids drawn at the 30% probability level.

Crystal data

C15H12O5	Z = 2
Mr = 272.25	F(000) = 284
Triclinic, P1	Dx = 1.466 Mg m−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 7.338 (2) Å	Cell parameters from 804 reflections
b = 7.824 (3) Å	θ = 2.9–27.3°
c = 11.964 (4) Å	µ = 0.11 mm−1
α = 94.634 (4)°	T = 293 K
β = 93.561 (4)°	Block, colourless
γ = 115.027 (4)°	0.15 × 0.12 × 0.10 mm
V = 616.8 (3) Å3

Data collection

Bruker SMART APEX CCD area-detector diffractometer	2126 independent reflections
Radiation source: fine-focus sealed tube	1697 reflections with I > 2σ(I)
graphite	Rint = 0.037
φ and ω scans	θmax = 25.0°, θmin = 1.7°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −6→8
Tmin = 0.984, Tmax = 0.989	k = −9→5
2562 measured reflections	l = −13→14

Refinement

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)] = 0.063	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.190	H-atom parameters constrained
S = 1.07	w = 1/[σ2(Fo2) + (0.1114P)2 + 0.1836P] where P = (Fo2 + 2Fc2)/3
2126 reflections	(Δ/σ)max < 0.001
184 parameters	Δρmax = 0.23 e Å−3
0 restraints	Δρmin = −0.32 e Å−3

Special details

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 > 2σ(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 (Ų)

	x	y	z	Uiso*/Ueq
O1	0.2867 (3)	0.6977 (2)	0.52398 (13)	0.0473 (5)
O2	0.2172 (3)	0.1946 (2)	0.35370 (16)	0.0603 (6)
O3	0.2629 (2)	0.3673 (2)	0.15973 (14)	0.0498 (5)
O4	0.2920 (3)	0.6826 (2)	0.06394 (14)	0.0544 (5)
O5	0.3176 (3)	0.9927 (2)	0.19396 (15)	0.0592 (6)
H5	0.2921	1.0654	0.2365	0.089*
C1	0.2721 (3)	0.5208 (3)	0.22752 (19)	0.0396 (5)
C2	0.2933 (3)	0.6818 (3)	0.17897 (19)	0.0434 (6)
C3	0.3077 (3)	0.8442 (3)	0.2474 (2)	0.0446 (6)
C4	0.3094 (3)	0.8437 (3)	0.3620 (2)	0.0444 (6)
H4	0.3253	0.9520	0.4077	0.053*
C5	0.2517 (4)	0.5696 (4)	0.6956 (2)	0.0534 (6)
H5A	0.2708	0.6866	0.7317	0.064*
C6	0.2189 (4)	0.4191 (4)	0.7557 (2)	0.0599 (7)
H6	0.2148	0.4343	0.8333	0.072*
C7	0.1919 (4)	0.2451 (4)	0.7025 (2)	0.0599 (7)
H7	0.1689	0.1442	0.7444	0.072*
C8	0.1988 (4)	0.2210 (4)	0.5886 (2)	0.0522 (6)
H8	0.1827	0.1041	0.5537	0.063*
C9	0.2376 (3)	0.3482 (3)	0.4018 (2)	0.0417 (6)
C10	0.2654 (3)	0.5149 (3)	0.34488 (19)	0.0376 (5)
C11	0.2873 (3)	0.6818 (3)	0.4091 (2)	0.0397 (5)
C12	0.2559 (3)	0.5436 (3)	0.5796 (2)	0.0437 (6)
C13	0.2302 (3)	0.3713 (3)	0.5240 (2)	0.0422 (6)
C14	0.0691 (5)	0.2530 (4)	0.0989 (3)	0.0700 (8)
H14A	−0.0279	0.1977	0.1511	0.105*
H14B	0.0770	0.1539	0.0496	0.105*
H14C	0.0278	0.3306	0.0551	0.105*
C15	0.4879 (5)	0.7613 (5)	0.0279 (3)	0.0741 (9)
H15A	0.5620	0.8891	0.0637	0.111*
H15B	0.4772	0.7615	−0.0524	0.111*
H15C	0.5575	0.6865	0.0481	0.111*

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
O1	0.0617 (10)	0.0392 (9)	0.0448 (9)	0.0267 (8)	0.0019 (8)	0.0002 (7)
O2	0.0869 (14)	0.0343 (9)	0.0675 (12)	0.0328 (9)	0.0145 (10)	0.0052 (8)
O3	0.0571 (10)	0.0413 (9)	0.0539 (10)	0.0275 (8)	−0.0010 (8)	−0.0093 (7)
O4	0.0648 (11)	0.0587 (11)	0.0442 (10)	0.0317 (9)	−0.0002 (8)	0.0053 (8)
O5	0.0896 (14)	0.0429 (10)	0.0591 (11)	0.0397 (10)	0.0147 (10)	0.0137 (8)
C1	0.0373 (11)	0.0346 (11)	0.0480 (13)	0.0186 (9)	0.0005 (9)	−0.0032 (9)
C2	0.0447 (12)	0.0424 (13)	0.0455 (13)	0.0220 (10)	0.0022 (10)	0.0017 (10)
C3	0.0487 (13)	0.0353 (12)	0.0548 (14)	0.0226 (10)	0.0049 (10)	0.0077 (10)
C4	0.0525 (13)	0.0335 (12)	0.0525 (14)	0.0248 (10)	0.0037 (11)	0.0005 (10)
C5	0.0511 (14)	0.0574 (15)	0.0497 (14)	0.0230 (12)	0.0003 (11)	0.0013 (11)
C6	0.0504 (14)	0.0740 (19)	0.0502 (15)	0.0208 (13)	0.0029 (11)	0.0154 (13)
C7	0.0504 (14)	0.0602 (17)	0.0641 (17)	0.0164 (12)	0.0021 (12)	0.0250 (13)
C8	0.0459 (13)	0.0433 (13)	0.0665 (16)	0.0172 (11)	0.0046 (11)	0.0136 (11)
C9	0.0378 (11)	0.0332 (11)	0.0577 (14)	0.0190 (9)	0.0048 (10)	0.0034 (10)
C10	0.0335 (11)	0.0307 (11)	0.0503 (13)	0.0161 (8)	0.0026 (9)	0.0027 (9)
C11	0.0399 (11)	0.0364 (12)	0.0457 (12)	0.0202 (9)	0.0018 (9)	0.0008 (9)
C12	0.0380 (11)	0.0439 (13)	0.0506 (13)	0.0188 (10)	0.0032 (9)	0.0077 (10)
C13	0.0327 (11)	0.0404 (13)	0.0543 (14)	0.0163 (9)	0.0034 (10)	0.0086 (10)
C14	0.0711 (18)	0.0511 (16)	0.078 (2)	0.0234 (13)	−0.0121 (15)	−0.0171 (14)
C15	0.085 (2)	0.083 (2)	0.0597 (17)	0.0379 (17)	0.0243 (16)	0.0156 (15)

Geometric parameters (Å, °)

O1—C12	1.366 (3)	C5—H5A	0.9300
O1—C11	1.370 (3)	C6—C7	1.383 (4)
O2—C9	1.234 (3)	C6—H6	0.9300
O3—C1	1.368 (3)	C7—C8	1.367 (4)
O3—C14	1.430 (3)	C7—H7	0.9300
O4—C2	1.376 (3)	C8—C13	1.405 (3)
O4—C15	1.415 (3)	C8—H8	0.9300
O5—C3	1.349 (3)	C9—C10	1.463 (3)
O5—H5	0.8200	C9—C13	1.466 (3)
C1—C2	1.383 (3)	C10—C11	1.402 (3)
C1—C10	1.412 (3)	C12—C13	1.386 (3)
C2—C3	1.415 (3)	C14—H14A	0.9600
C3—C4	1.370 (3)	C14—H14B	0.9600
C4—C11	1.379 (3)	C14—H14C	0.9600
C4—H4	0.9300	C15—H15A	0.9600
C5—C6	1.370 (4)	C15—H15B	0.9600
C5—C12	1.391 (4)	C15—H15C	0.9600
C12—O1—C11	119.52 (18)	O2—C9—C10	124.6 (2)
C1—O3—C14	114.41 (19)	O2—C9—C13	120.0 (2)
C2—O4—C15	113.4 (2)	C10—C9—C13	115.45 (19)
C3—O5—H5	109.5	C11—C10—C1	116.5 (2)
O3—C1—C2	118.6 (2)	C11—C10—C9	119.1 (2)
O3—C1—C10	120.1 (2)	C1—C10—C9	124.3 (2)
C2—C1—C10	121.2 (2)	O1—C11—C4	114.15 (19)
O4—C2—C1	120.4 (2)	O1—C11—C10	123.0 (2)
O4—C2—C3	119.7 (2)	C4—C11—C10	122.9 (2)
C1—C2—C3	119.8 (2)	O1—C12—C13	122.1 (2)
O5—C3—C4	123.5 (2)	O1—C12—C5	116.1 (2)
O5—C3—C2	116.7 (2)	C13—C12—C5	121.8 (2)
C4—C3—C2	119.7 (2)	C12—C13—C8	117.8 (2)
C3—C4—C11	119.7 (2)	C12—C13—C9	120.7 (2)
C3—C4—H4	120.2	C8—C13—C9	121.4 (2)
C11—C4—H4	120.2	O3—C14—H14A	109.5
C6—C5—C12	118.6 (3)	O3—C14—H14B	109.5
C6—C5—H5A	120.7	H14A—C14—H14B	109.5
C12—C5—H5A	120.7	O3—C14—H14C	109.5
C5—C6—C7	120.9 (3)	H14A—C14—H14C	109.5
C5—C6—H6	119.6	H14B—C14—H14C	109.5
C7—C6—H6	119.6	O4—C15—H15A	109.5
C8—C7—C6	120.3 (2)	O4—C15—H15B	109.5
C8—C7—H7	119.9	H15A—C15—H15B	109.5
C6—C7—H7	119.9	O4—C15—H15C	109.5
C7—C8—C13	120.5 (3)	H15A—C15—H15C	109.5
C7—C8—H8	119.7	H15B—C15—H15C	109.5
C13—C8—H8	119.7

Hydrogen-bond geometry (Å, °)

D—H···A	D—H	H···A	D···A	D—H···A
O5—H5···O2i	0.82	1.90	2.713 (3)	169

Symmetry codes: (i) x, y+1, z.