3,5,3'-Trihy-droxy-4'-meth-oxy-7-(3-methyl-but-2-en-yloxy)flavone.

The title compound pteleifolosin C, C(21)H(20)O(7), was isolated from the petroleum ether-soluble fraction of an indigenous Chinese tree Melicope pteleifolia (Rutaceae). The dihedral angle between the benzene rings is 2.7 (2)°. Intra-molecular O-H⋯O hydrogen bonds occur. In the crystal, mol-ecules are linked by inter-molecular O-H-O hydrogen bonds.

Related literature

For the medicinal usage of M. pteleifolia in China, see: Chinese Pharmacopoeia (1977 ▶) and for folk use of M. pteleifolia in South East Asia, see: Gunawardana et al. (1987 ▶); Shaari et al. (2006 ▶). For related structures and background to pteleifolosin C, see: Smith et al. (2001 ▶); Sultana et al. (1999 ▶).

Experimental

Crystal data

C21H20O7

M = 384.37

Triclinic,

a = 8.4073 (18) Å

b = 9.0343 (19) Å

c = 12.489 (3) Å

α = 79.371 (2)°

β = 83.519 (3)°

γ = 78.806 (3)°

V = 911.7 (3) Å3

Z = 2

Mo Kα radiation

μ = 0.11 mm−1

T = 296 K

0.60 × 0.50 × 0.45 mm

Data collection

Bruker APEXII CCD diffractometer

Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ▶) T min = 0.939, T max = 0.954

8186 measured reflections

4103 independent reflections

3126 reflections with I > 2σ(I)

R int = 0.019

Refinement

R[F 2 > 2σ(F 2)] = 0.046

wR(F 2) = 0.114

S = 0.98

4103 reflections

259 parameters

H-atom parameters constrained

Δρmax = 0.21 e Å−3

Δρmin = −0.22 e Å−3

Data collection: APEX2 (Bruker, 2004 ▶); 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.

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536811005393/jh2258sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536811005393/jh2258Isup2.hkl

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

C21H20O7	Z = 2
Mr = 384.37	F(000) = 404
Triclinic, P1	Dx = 1.400 Mg m−3
a = 8.4073 (18) Å	Mo Kα radiation, λ = 0.71073 Å
b = 9.0343 (19) Å	Cell parameters from 3191 reflections
c = 12.489 (3) Å	θ = 0.0–0.0°
α = 79.371 (2)°	µ = 0.11 mm−1
β = 83.519 (3)°	T = 296 K
γ = 78.806 (3)°	Block, colourless
V = 911.7 (3) Å3	0.60 × 0.50 × 0.45 mm

Bruker APEXII CCD diffractometer	4103 independent reflections
Radiation source: fine-focus sealed tube	3126 reflections with I > 2σ(I)
graphite	Rint = 0.019
φ and ω scans	θmax = 27.5°, θmin = 2.3°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −10→10
Tmin = 0.939, Tmax = 0.954	k = −11→11
8186 measured reflections	l = −16→16

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)] = 0.046	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.114	H-atom parameters constrained
S = 0.98	w = 1/[σ2(Fo2) + (0.0437P)2 + 0.4019P] where P = (Fo2 + 2Fc2)/3
4103 reflections	(Δ/σ)max = 0.001
259 parameters	Δρmax = 0.21 e Å−3
0 restraints	Δρmin = −0.22 e Å−3

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.

	x	y	z	Uiso*/Ueq
C5	0.0698 (2)	0.01370 (19)	0.72012 (14)	0.0408 (4)
H5A	0.1690	−0.0115	0.6744	0.049*
H5B	−0.0105	0.0810	0.6751	0.049*
C2	−0.0595 (2)	−0.21729 (19)	0.72655 (15)	0.0416 (4)
C4	0.0075 (2)	−0.12862 (19)	0.77422 (14)	0.0428 (4)
H4	0.0170	−0.1574	0.8490	0.051*
C3	−0.1194 (3)	−0.3565 (2)	0.79063 (18)	0.0584 (5)
H3A	−0.0962	−0.3684	0.8656	0.088*
H3B	−0.0656	−0.4454	0.7606	0.088*
H3C	−0.2347	−0.3445	0.7866	0.088*
C1	−0.0815 (3)	−0.1880 (2)	0.60687 (17)	0.0596 (5)
H1A	−0.0403	−0.0973	0.5729	0.089*
H1B	−0.1951	−0.1745	0.5962	0.089*
H1C	−0.0234	−0.2736	0.5747	0.089*
O1	0.10023 (15)	0.08534 (13)	0.80716 (9)	0.0457 (3)
C9	0.30637 (18)	0.47465 (17)	0.75333 (12)	0.0334 (3)
C7	0.18620 (19)	0.29532 (17)	0.67786 (13)	0.0351 (3)
H7	0.1540	0.2639	0.6181	0.042*
C8	0.25584 (17)	0.42543 (17)	0.66575 (12)	0.0308 (3)
C11	0.2147 (2)	0.2601 (2)	0.87334 (13)	0.0433 (4)
H11	0.1990	0.2042	0.9429	0.052*
C6	0.16667 (19)	0.21424 (18)	0.78258 (13)	0.0368 (4)
C10	0.2850 (2)	0.38769 (19)	0.85908 (13)	0.0404 (4)
O2	0.3353 (2)	0.43126 (16)	0.94546 (10)	0.0612 (4)
H2	0.3772	0.5074	0.9245	0.092*
C14	0.33864 (17)	0.63647 (16)	0.54058 (12)	0.0296 (3)
C12	0.37894 (18)	0.60914 (17)	0.73464 (12)	0.0337 (3)
C13	0.39232 (18)	0.68726 (17)	0.62346 (12)	0.0327 (3)
O3	0.27254 (13)	0.50474 (12)	0.56215 (8)	0.0341 (3)
O4	0.42931 (16)	0.66001 (14)	0.80866 (9)	0.0477 (3)
C19	0.2782 (2)	0.69577 (18)	0.24055 (13)	0.0383 (4)
H19	0.2381	0.6470	0.1927	0.046*
C15	0.33922 (17)	0.70364 (17)	0.42430 (12)	0.0304 (3)
C18	0.33616 (19)	0.83015 (18)	0.20187 (12)	0.0348 (3)
C16	0.39856 (19)	0.83993 (17)	0.38400 (12)	0.0343 (3)
H16	0.4396	0.8888	0.4313	0.041*
C17	0.39621 (19)	0.90123 (17)	0.27506 (13)	0.0348 (3)
C20	0.27958 (19)	0.63340 (18)	0.35041 (13)	0.0356 (3)
H20	0.2400	0.5429	0.3755	0.043*
O7	0.34083 (16)	0.90551 (14)	0.09652 (9)	0.0479 (3)
O6	0.45551 (17)	1.03420 (14)	0.23818 (10)	0.0501 (3)
H6	0.4399	1.0631	0.1734	0.075*
C21	0.2862 (3)	0.8369 (2)	0.01710 (15)	0.0635 (6)
H21A	0.3524	0.7381	0.0141	0.095*
H21B	0.2944	0.9006	−0.0532	0.095*
H21C	0.1749	0.8255	0.0367	0.095*
O5	0.46006 (16)	0.81540 (14)	0.60612 (9)	0.0478 (3)
H5	0.4836	0.8311	0.6645	0.072*

	U11	U22	U33	U12	U13	U23
C5	0.0505 (9)	0.0343 (9)	0.0406 (9)	−0.0176 (7)	−0.0023 (7)	−0.0040 (7)
C2	0.0397 (9)	0.0351 (9)	0.0512 (10)	−0.0108 (7)	0.0002 (7)	−0.0085 (8)
C4	0.0513 (10)	0.0358 (9)	0.0427 (9)	−0.0165 (7)	−0.0038 (7)	−0.0007 (7)
C3	0.0605 (12)	0.0405 (11)	0.0785 (14)	−0.0238 (9)	0.0020 (10)	−0.0096 (10)
C1	0.0662 (13)	0.0615 (13)	0.0584 (12)	−0.0201 (10)	−0.0063 (10)	−0.0191 (10)
O1	0.0668 (8)	0.0371 (7)	0.0382 (6)	−0.0282 (6)	−0.0063 (5)	0.0019 (5)
C9	0.0385 (8)	0.0312 (8)	0.0319 (8)	−0.0106 (6)	−0.0025 (6)	−0.0043 (6)
C7	0.0423 (8)	0.0333 (8)	0.0335 (8)	−0.0147 (7)	−0.0058 (6)	−0.0048 (6)
C8	0.0346 (7)	0.0284 (8)	0.0297 (7)	−0.0097 (6)	−0.0020 (6)	−0.0015 (6)
C11	0.0612 (11)	0.0411 (10)	0.0297 (8)	−0.0210 (8)	−0.0037 (7)	0.0015 (7)
C6	0.0427 (9)	0.0304 (8)	0.0386 (9)	−0.0149 (7)	−0.0032 (7)	−0.0006 (7)
C10	0.0543 (10)	0.0397 (9)	0.0311 (8)	−0.0171 (8)	−0.0049 (7)	−0.0054 (7)
O2	0.1038 (11)	0.0607 (9)	0.0313 (6)	−0.0451 (8)	−0.0121 (7)	−0.0029 (6)
C14	0.0325 (7)	0.0243 (7)	0.0332 (8)	−0.0095 (6)	−0.0021 (6)	−0.0034 (6)
C12	0.0394 (8)	0.0322 (8)	0.0326 (8)	−0.0116 (6)	−0.0038 (6)	−0.0070 (6)
C13	0.0376 (8)	0.0279 (8)	0.0350 (8)	−0.0132 (6)	−0.0029 (6)	−0.0040 (6)
O3	0.0468 (6)	0.0302 (6)	0.0292 (5)	−0.0178 (5)	−0.0057 (4)	−0.0016 (4)
O4	0.0714 (8)	0.0457 (7)	0.0350 (6)	−0.0294 (6)	−0.0104 (6)	−0.0065 (5)
C19	0.0528 (10)	0.0331 (8)	0.0344 (8)	−0.0169 (7)	−0.0096 (7)	−0.0060 (7)
C15	0.0322 (7)	0.0280 (8)	0.0316 (7)	−0.0068 (6)	−0.0032 (6)	−0.0045 (6)
C18	0.0436 (8)	0.0326 (8)	0.0283 (8)	−0.0092 (7)	−0.0039 (6)	−0.0025 (6)
C16	0.0432 (8)	0.0319 (8)	0.0320 (8)	−0.0147 (6)	−0.0046 (6)	−0.0065 (6)
C17	0.0418 (8)	0.0279 (8)	0.0367 (8)	−0.0137 (6)	−0.0026 (6)	−0.0031 (6)
C20	0.0451 (9)	0.0290 (8)	0.0357 (8)	−0.0151 (7)	−0.0054 (7)	−0.0029 (6)
O7	0.0756 (9)	0.0419 (7)	0.0299 (6)	−0.0223 (6)	−0.0089 (6)	0.0000 (5)
O6	0.0808 (9)	0.0405 (7)	0.0363 (6)	−0.0356 (6)	−0.0079 (6)	0.0029 (5)
C21	0.1061 (17)	0.0570 (13)	0.0328 (9)	−0.0242 (12)	−0.0198 (10)	−0.0021 (9)
O5	0.0753 (8)	0.0424 (7)	0.0364 (6)	−0.0362 (6)	−0.0113 (6)	−0.0028 (5)

C5—O1	1.4328 (19)	C10—O2	1.3501 (19)
C5—C4	1.498 (2)	O2—H2	0.8200
C5—H5A	0.9700	C14—C13	1.359 (2)
C5—H5B	0.9700	C14—O3	1.3793 (16)
C2—C4	1.319 (2)	C14—C15	1.467 (2)
C2—C1	1.495 (3)	C12—O4	1.2513 (17)
C2—C3	1.503 (2)	C12—C13	1.440 (2)
C4—H4	0.9300	C13—O5	1.3590 (17)
C3—H3A	0.9600	C19—C18	1.380 (2)
C3—H3B	0.9600	C19—C20	1.384 (2)
C3—H3C	0.9600	C19—H19	0.9300
C1—H1A	0.9600	C15—C20	1.396 (2)
C1—H1B	0.9600	C15—C16	1.404 (2)
C1—H1C	0.9600	C18—O7	1.3655 (19)
O1—C6	1.3581 (18)	C18—C17	1.396 (2)
C9—C8	1.390 (2)	C16—C17	1.372 (2)
C9—C10	1.419 (2)	C16—H16	0.9300
C9—C12	1.433 (2)	C17—O6	1.3713 (18)
C7—C6	1.385 (2)	C20—H20	0.9300
C7—C8	1.389 (2)	O7—C21	1.421 (2)
C7—H7	0.9300	O6—H6	0.8200
C8—O3	1.3650 (18)	C21—H21A	0.9600
C11—C10	1.369 (2)	C21—H21B	0.9600
C11—C6	1.400 (2)	C21—H21C	0.9600
C11—H11	0.9300	O5—H5	0.8200
O1—C5—C4	105.77 (13)	O2—C10—C9	119.45 (14)
O1—C5—H5A	110.6	C11—C10—C9	120.28 (14)
C4—C5—H5A	110.6	C10—O2—H2	109.5
O1—C5—H5B	110.6	C13—C14—O3	119.66 (13)
C4—C5—H5B	110.6	C13—C14—C15	128.81 (13)
H5A—C5—H5B	108.7	O3—C14—C15	111.53 (12)
C4—C2—C1	123.26 (17)	O4—C12—C9	123.70 (14)
C4—C2—C3	121.40 (17)	O4—C12—C13	119.81 (14)
C1—C2—C3	115.33 (16)	C9—C12—C13	116.49 (13)
C2—C4—C5	126.59 (16)	C14—C13—O5	121.85 (14)
C2—C4—H4	116.7	C14—C13—C12	121.80 (13)
C5—C4—H4	116.7	O5—C13—C12	116.35 (13)
C2—C3—H3A	109.5	C8—O3—C14	121.51 (11)
C2—C3—H3B	109.5	C18—C19—C20	120.15 (14)
H3A—C3—H3B	109.5	C18—C19—H19	119.9
C2—C3—H3C	109.5	C20—C19—H19	119.9
H3A—C3—H3C	109.5	C20—C15—C16	118.06 (14)
H3B—C3—H3C	109.5	C20—C15—C14	120.56 (13)
C2—C1—H1A	109.5	C16—C15—C14	121.38 (13)
C2—C1—H1B	109.5	O7—C18—C19	126.65 (13)
H1A—C1—H1B	109.5	O7—C18—C17	114.35 (14)
C2—C1—H1C	109.5	C19—C18—C17	118.99 (14)
H1A—C1—H1C	109.5	C17—C16—C15	120.24 (13)
H1B—C1—H1C	109.5	C17—C16—H16	119.9
C6—O1—C5	119.15 (12)	C15—C16—H16	119.9
C8—C9—C10	118.12 (14)	C16—C17—O6	118.83 (13)
C8—C9—C12	119.70 (14)	C16—C17—C18	121.24 (14)
C10—C9—C12	122.18 (14)	O6—C17—C18	119.93 (14)
C6—C7—C8	117.30 (14)	C19—C20—C15	121.31 (14)
C6—C7—H7	121.3	C19—C20—H20	119.3
C8—C7—H7	121.3	C15—C20—H20	119.3
O3—C8—C7	116.47 (13)	C18—O7—C21	117.28 (13)
O3—C8—C9	120.82 (13)	C17—O6—H6	109.5
C7—C8—C9	122.71 (14)	O7—C21—H21A	109.5
C10—C11—C6	119.59 (15)	O7—C21—H21B	109.5
C10—C11—H11	120.2	H21A—C21—H21B	109.5
C6—C11—H11	120.2	O7—C21—H21C	109.5
O1—C6—C7	124.01 (14)	H21A—C21—H21C	109.5
O1—C6—C11	114.00 (14)	H21B—C21—H21C	109.5
C7—C6—C11	121.99 (14)	C13—O5—H5	109.5
O2—C10—C11	120.26 (15)
C1—C2—C4—C5	0.8 (3)	C15—C14—C13—C12	178.36 (14)
C3—C2—C4—C5	−179.14 (17)	O4—C12—C13—C14	−179.72 (15)
O1—C5—C4—C2	168.75 (17)	C9—C12—C13—C14	0.2 (2)
C4—C5—O1—C6	176.45 (14)	O4—C12—C13—O5	−0.4 (2)
C6—C7—C8—O3	−179.33 (14)	C9—C12—C13—O5	179.51 (14)
C6—C7—C8—C9	0.5 (2)	C7—C8—O3—C14	179.37 (13)
C10—C9—C8—O3	179.69 (14)	C9—C8—O3—C14	−0.5 (2)
C12—C9—C8—O3	−0.8 (2)	C13—C14—O3—C8	1.6 (2)
C10—C9—C8—C7	−0.2 (2)	C15—C14—O3—C8	−178.21 (12)
C12—C9—C8—C7	179.31 (14)	C13—C14—C15—C20	179.39 (15)
C5—O1—C6—C7	9.8 (2)	O3—C14—C15—C20	−0.8 (2)
C5—O1—C6—C11	−170.35 (15)	C13—C14—C15—C16	−0.9 (2)
C8—C7—C6—O1	179.81 (14)	O3—C14—C15—C16	178.91 (13)
C8—C7—C6—C11	−0.1 (2)	C20—C19—C18—O7	−179.26 (16)
C10—C11—C6—O1	179.35 (15)	C20—C19—C18—C17	0.2 (2)
C10—C11—C6—C7	−0.8 (3)	C20—C15—C16—C17	0.4 (2)
C6—C11—C10—O2	−178.46 (17)	C14—C15—C16—C17	−179.33 (14)
C6—C11—C10—C9	1.1 (3)	C15—C16—C17—O6	−179.80 (14)
C8—C9—C10—O2	178.91 (15)	C15—C16—C17—C18	−0.3 (2)
C12—C9—C10—O2	−0.5 (3)	O7—C18—C17—C16	179.55 (15)
C8—C9—C10—C11	−0.7 (2)	C19—C18—C17—C16	0.0 (2)
C12—C9—C10—C11	179.86 (16)	O7—C18—C17—O6	−1.0 (2)
C8—C9—C12—O4	−179.14 (15)	C19—C18—C17—O6	179.51 (15)
C10—C9—C12—O4	0.3 (3)	C18—C19—C20—C15	−0.1 (3)
C8—C9—C12—C13	1.0 (2)	C16—C15—C20—C19	−0.2 (2)
C10—C9—C12—C13	−179.57 (15)	C14—C15—C20—C19	179.55 (15)
O3—C14—C13—O5	179.23 (13)	C19—C18—O7—C21	−2.5 (3)
C15—C14—C13—O5	−1.0 (3)	C17—C18—O7—C21	178.09 (16)
O3—C14—C13—C12	−1.5 (2)

D—H···A	D—H	H···A	D···A	D—H···A
O5—H5···O4	0.82	2.21	2.6682 (17)	115
O5—H5···O6i	0.82	2.04	2.7914 (16)	153
O6—H6···O7	0.82	2.19	2.6440 (16)	115
O2—H2···O4	0.82	1.88	2.6155 (17)	148

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O5—H5⋯O4	0.82	2.21	2.6682 (17)	115
O5—H5⋯O6i	0.82	2.04	2.7914 (16)	153
O6—H6⋯O7	0.82	2.19	2.6440 (16)	115
O2—H2⋯O4	0.82	1.88	2.6155 (17)	148

Symmetry code: (i) .