Download citation
Download citation
link to html
The title compound, 5-hydroxy-4′,7-di­methoxy­isoflavone, C17H14O5, is composed of a benzo­pyran­one moiety, a phenyl moiety and two methoxy groups. The benzo­pyran­one ring is not coplanar with the phenyl ring, the dihedral angle between them being 56.28 (3)°. The two methoxy groups are nearly coplanar with their corresponding rings, having C—C—O—C torsion angles of 2.9 (2) and 5.9 (2)°. The mol­ecules are linked by C—H...O hydrogen bonds into sheets containing classical centrosymmetric R_2^2(8) rings. The sheets are further linked by aromatic π–π stacking interactions and C—H...O hydrogen bonds into a supramolecular structure.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270104009758/fr1473sup1.cif
Contains datablocks I, global

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S0108270104009758/fr1473Isup2.hkl
Contains datablock I

CCDC reference: 223440

Comment top

Hydrogen bonds and ππ stacking interactions are an important research area in supramolecular chemistry and crystal engineering (MacDonald & Whitesides, 1994). These interactions play an important role in self-assembly and recognition of aromatic compounds (Janiak, 2000; Hunter & Sanders, 1990) as an auxiliary stabilizing short contact (William et al., 1999; Luque et al., 2001; Kaafarani et al., 2001). In biomacromolecular systems, stacking interactions and hydrogen bonds are important for the double-helical DNA structure (Hunter, 1993); they can direct the intercalation of drugs into DNA (Wang et al., 1984) and they contribute to the stability of the tertiary structure of proteins (Burley & Petsko, 1985).

Genistein, a natural soy isoflavone, has potential phytoestrogen (Hua et al., 2003; Warren, 2002) and antioxidant activities (Ian et al., 1995). Studies have also found genistein effective in inhibiting cardiovascular disease (Hwang et al., 2001), tyrosine kinases (Nevala et al., 2002), and cancer cell growth (Yuan et al., 2003; W. F. Chen et al., 2003), and in accelerating the formation of bone cells (X. W. Chen et al., 2003). The title compound, 5-hydroxy-4',7-dimethoxyisoflavone, (I), is a derivative of genistein, with potential medical applications. We report here the crystal structure of (I).

The title compound is composed of a benzopyranone moiety, a phenyl moiety and two methoxy groups (Fig. 1). The geometry of the isoflavone skeleton of (I) is similar to its analogue dalspinin (Lakshmi, et al., 1996) with respect to most of the bond distances and angles. The atoms of the benzopyranone moiety, including rings A (C1–C6) and C (O1/C1/C6–C9), are almost coplanar, the dihedral angle between ring A and ring C being 1.37 (8)°. To avoid steric conflicts, the two rigid ring systems, viz. phenyl ring B (C10–C15) and the benzopyranone moiety, are rotated by 56.28 (3)° with respect to one another. The methoxy group at atom C3 is nearly coplanar with ring A, as indicated by the C16—O4—C3—C2 torsion angle [2.9 (2)°]; the methoxy group at atom C13 is also coplanar with the attached ring, the C17—O5—C13—C12 torsion angle being 5.9 (2)°.

Fig. 2 shows how a cyclic dimer is formed through a supramolecular synthon, R22(8). Methoxy atom O4 acts as a hydrogen-bond acceptor, via atom H4, to atom C4 of ring A. In this manner, a centrosymmetric R22(8) ring is formed. Hydroxy atoms O2 from the two molecules linked by the R22(8) ring act as hydrogen-bond acceptors, via atoms H14, to atoms C14 of rings B in adjacent molecules. The combination of the C14—H14···O2 interaction and the R22(8) supramolecular synthon generates a (10=1) sheet, which includes two A, two B and two C rings from four molecules, and these six rings are almost coplanar; furthermore, these dimers are also linked into (100) chains by C11—H11···O3 interactions (Fig. 3). The combination of the (10=1) sheets and the (100) chains generates a three-dimensional framework. An independent O2—H2O···O3 intramolecular hydrogen bonds generates a characteristic intramolecular S(6) motif. Details of the hydrogen bonding are given in Table 1.

Intermolecular stacking via aromatic ππ interactions is also present (Fig. 3), the two molecules being offset by partial overlap of rings B (π rich) and C (π deficient). Ring B of one molecule and ring C of a neighbouring molecule are almost parallel, with a dihedral angle between them of 8.02 (7)°. The perpendicular plane-to-plane distance between the rings is 3.311 Å, and the corresponding Cg···Cgi distance is 3.693 Å [Cg represents the centroids of rings A and C; symmetry code: (i) 0.5 − x, 0.5 + y, 1.5 − z], indicating that a strong ππ stacking interaction exists in the title compound. Hydrogen bonds and aromatic ππ stacking interactions play a key role in assembling the supramolecular structure.

Experimental top

Genistein (1.0 g) was dissolved in Na2CO3 (20 ml, 5%) and dimethyl sulfate (0.5 ml) was added dropwise to the solution with stirring. The mixture was stirred for 4 h at room temperature and a colorless precipitate began to appear. The precipitate was filtered off and washed with water until the pH of the filtrate was 8. After recrystallization from ethyl acetate, the product had a melting point of 428 K. Crystals of (I) suitable for X-ray analysis were obtained by slow evaporation from ethyl acetate after 7 d at room temperature.

Refinement top

H atoms were placed at calculated positions and treated as riding, with C—H distances in the range 0.93–0.96 Å and Uiso(H) values of 1.2Ueq of the attached C atom [1.5Ueq(C) for methyl H atoms].

Computing details top

Data collection: XSCANS (Siemens, 1996); cell refinement: XSCANS; data reduction: SHELXTL (Siemens, 1997); program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.

Figures top
[Figure 1] Fig. 1. A view of the molecule of (I), showing the atom-numbering scheme and 50% probability displacement ellipsoids. All H atoms have been omitted for clarity.
[Figure 2] Fig. 2. Part of the crystal structure of (I), showing the formation of the (10=1) sheets via hydrogen bonds. Atoms marked with an asterisk (*), hash (#) or ampersand (&) are at the symmetry positions (1 − x, 1 − y, 1 − z), (x − 0.5, 0.5 − y, z − 0.5) and (1.5 − x, 0.5 + y, 1.5 − z), respectively. For clarity, some H atoms have been omitted.
[Figure 3] Fig. 3. Part of the crystal structure of (I), showing the formation of the (100) chains via hydrogen bonds and ππ stacking interactions. Labels Cg represent the centroids of rings A and C. Atoms marked with an asterisk (*), hash (#) or ampersand (&) are at the symmetry positions (1 − x, y, z), (0.5 − x, 0.5 + y, 1.5 − z) and (1 + x, y, z), respectively. For clarity, some H atoms have been omitted.
5-hydroxy-4',7-dimethoxyisoflavone top
Crystal data top
C17H14O5F(000) = 624
Mr = 298.28Dx = 1.441 Mg m3
Monoclinic, P21/nMelting point: 428 K
Hall symbol: -P 2ynMo Kα radiation, λ = 0.71073 Å
a = 5.7754 (8) ÅCell parameters from 34 reflections
b = 7.9446 (12) Åθ = 2.7–15.9°
c = 30.044 (5) ŵ = 0.11 mm1
β = 93.807 (12)°T = 296 K
V = 1375.4 (4) Å3Prism, colorless
Z = 40.58 × 0.54 × 0.50 mm
Data collection top
Siemens P4
diffractometer
Rint = 0.010
Radiation source: normal-focus sealed tubeθmax = 25.3°, θmin = 1.4°
Graphite monochromatorh = 06
ω scansk = 09
3089 measured reflectionsl = 3636
2485 independent reflections3 standard reflections every 97 reflections
1673 reflections with I > 2σ(I) intensity decay: 0.4%
Refinement top
Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.035H-atom parameters constrained
wR(F2) = 0.087 w = 1/[σ2(Fo2) + (0.0522P)2]
where P = (Fo2 + 2Fc2)/3
S = 0.90(Δ/σ)max = 0.001
2485 reflectionsΔρmax = 0.19 e Å3
203 parametersΔρmin = 0.15 e Å3
0 restraintsExtinction correction: SHELXL97, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: structure-invariant direct methodsExtinction coefficient: 0.0233 (18)
Crystal data top
C17H14O5V = 1375.4 (4) Å3
Mr = 298.28Z = 4
Monoclinic, P21/nMo Kα radiation
a = 5.7754 (8) ŵ = 0.11 mm1
b = 7.9446 (12) ÅT = 296 K
c = 30.044 (5) Å0.58 × 0.54 × 0.50 mm
β = 93.807 (12)°
Data collection top
Siemens P4
diffractometer
Rint = 0.010
3089 measured reflections3 standard reflections every 97 reflections
2485 independent reflections intensity decay: 0.4%
1673 reflections with I > 2σ(I)
Refinement top
R[F2 > 2σ(F2)] = 0.0350 restraints
wR(F2) = 0.087H-atom parameters constrained
S = 0.90Δρmax = 0.19 e Å3
2485 reflectionsΔρmin = 0.15 e Å3
203 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
xyzUiso*/Ueq
O10.01497 (17)0.23550 (14)0.65150 (3)0.0479 (3)
O20.67377 (18)0.55119 (15)0.62862 (4)0.0529 (3)
H2O0.68100.55060.65600.064*
O30.54957 (17)0.48501 (15)0.70802 (3)0.0501 (3)
O40.2227 (2)0.34532 (17)0.50583 (4)0.0652 (4)
O50.2007 (2)0.38703 (16)0.90489 (3)0.0589 (3)
C10.1410 (3)0.30694 (19)0.62475 (5)0.0407 (4)
C20.0933 (3)0.2862 (2)0.57932 (5)0.0470 (4)
H20.03760.22790.56810.056*
C30.2472 (3)0.3554 (2)0.55126 (5)0.0476 (4)
C40.4436 (3)0.4439 (2)0.56772 (5)0.0484 (4)
H40.54490.48970.54820.058*
C50.4862 (2)0.46291 (19)0.61293 (5)0.0411 (4)
C60.3343 (2)0.39272 (18)0.64309 (5)0.0377 (4)
C70.3740 (2)0.41124 (19)0.69099 (5)0.0388 (4)
C80.1961 (2)0.34029 (19)0.71724 (5)0.0392 (4)
C90.0199 (3)0.2566 (2)0.69617 (5)0.0460 (4)
H90.08870.20850.71390.055*
C100.2007 (2)0.35938 (19)0.76658 (5)0.0399 (4)
C110.0120 (3)0.4273 (2)0.78600 (5)0.0446 (4)
H110.11370.46520.76780.054*
C120.0040 (3)0.4406 (2)0.83202 (5)0.0455 (4)
H120.12450.48760.84440.055*
C130.1896 (3)0.3833 (2)0.85900 (5)0.0430 (4)
C140.3817 (3)0.3153 (2)0.84024 (5)0.0474 (4)
H140.50650.27620.85850.057*
C150.3877 (3)0.3056 (2)0.79459 (5)0.0447 (4)
H150.51880.26240.78230.054*
C160.0224 (3)0.2657 (2)0.48580 (6)0.0693 (6)
H16A0.02710.14780.49270.083*
H16B0.01830.28050.45400.083*
H16C0.11380.31490.49710.083*
C170.0006 (3)0.4395 (3)0.92563 (6)0.0701 (6)
H17A0.03290.55510.91830.084*
H17B0.02460.42780.95740.084*
H17C0.13000.37100.91520.084*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.0451 (6)0.0544 (7)0.0445 (6)0.0130 (5)0.0053 (5)0.0019 (5)
O20.0459 (6)0.0624 (8)0.0509 (7)0.0150 (6)0.0062 (5)0.0014 (6)
O30.0384 (6)0.0637 (8)0.0478 (6)0.0080 (6)0.0006 (5)0.0031 (6)
O40.0744 (8)0.0792 (9)0.0421 (7)0.0131 (7)0.0041 (6)0.0062 (6)
O50.0617 (7)0.0739 (9)0.0410 (6)0.0041 (7)0.0022 (6)0.0013 (6)
C10.0385 (8)0.0380 (9)0.0462 (9)0.0022 (7)0.0068 (7)0.0040 (7)
C20.0459 (9)0.0469 (10)0.0479 (9)0.0066 (8)0.0002 (7)0.0031 (8)
C30.0550 (10)0.0488 (10)0.0395 (9)0.0025 (9)0.0058 (8)0.0005 (7)
C40.0485 (10)0.0514 (10)0.0465 (10)0.0047 (8)0.0119 (8)0.0052 (8)
C50.0361 (8)0.0397 (9)0.0482 (9)0.0004 (7)0.0068 (7)0.0016 (7)
C60.0351 (8)0.0362 (8)0.0420 (9)0.0024 (7)0.0048 (6)0.0036 (7)
C70.0327 (8)0.0383 (9)0.0452 (9)0.0037 (7)0.0011 (7)0.0035 (7)
C80.0344 (8)0.0392 (9)0.0440 (8)0.0023 (7)0.0034 (7)0.0059 (7)
C90.0426 (9)0.0497 (10)0.0465 (9)0.0048 (8)0.0094 (7)0.0063 (8)
C100.0359 (8)0.0404 (9)0.0435 (9)0.0013 (7)0.0046 (7)0.0059 (7)
C110.0362 (8)0.0520 (10)0.0456 (9)0.0035 (7)0.0020 (7)0.0100 (8)
C120.0385 (8)0.0524 (10)0.0463 (9)0.0053 (8)0.0085 (7)0.0052 (8)
C130.0442 (9)0.0450 (9)0.0398 (9)0.0045 (8)0.0022 (7)0.0034 (7)
C140.0395 (9)0.0529 (10)0.0485 (10)0.0051 (8)0.0060 (7)0.0055 (8)
C150.0362 (8)0.0493 (10)0.0488 (10)0.0040 (7)0.0045 (7)0.0033 (8)
C160.0804 (13)0.0746 (14)0.0512 (11)0.0036 (12)0.0076 (10)0.0113 (10)
C170.0696 (12)0.0936 (16)0.0482 (10)0.0055 (11)0.0125 (9)0.0068 (10)
Geometric parameters (Å, º) top
O1—C91.3542 (17)C8—C91.339 (2)
O1—C11.3697 (17)C8—C101.489 (2)
O2—C51.3489 (17)C9—H90.9300
O2—H2O0.8200C10—C111.380 (2)
O3—C71.2508 (17)C10—C151.3913 (19)
O4—C31.3653 (18)C11—C121.390 (2)
O4—C161.4167 (19)C11—H110.9300
O5—C131.3762 (18)C12—C131.378 (2)
O5—C171.418 (2)C12—H120.9300
C1—C21.384 (2)C13—C141.387 (2)
C1—C61.390 (2)C14—C151.377 (2)
C2—C31.379 (2)C14—H140.9300
C2—H20.9300C15—H150.9300
C3—C41.397 (2)C16—H16A0.9600
C4—C51.373 (2)C16—H16B0.9600
C4—H40.9300C16—H16C0.9600
C5—C61.417 (2)C17—H17A0.9600
C6—C71.4497 (19)C17—H17B0.9600
C7—C81.450 (2)C17—H17C0.9600
C9—O1—C1118.05 (12)C11—C10—C15117.87 (13)
C5—O2—H2O109.5C11—C10—C8119.89 (13)
C3—O4—C16118.58 (13)C15—C10—C8122.20 (13)
C13—O5—C17117.49 (13)C10—C11—C12121.97 (14)
O1—C1—C2115.71 (13)C10—C11—H11119.0
O1—C1—C6120.83 (13)C12—C11—H11119.0
C2—C1—C6123.46 (14)C13—C12—C11118.95 (15)
C3—C2—C1117.46 (15)C13—C12—H12120.5
C3—C2—H2121.3C11—C12—H12120.5
C1—C2—H2121.3O5—C13—C12124.41 (14)
O4—C3—C2124.01 (15)O5—C13—C14115.48 (13)
O4—C3—C4114.29 (14)C12—C13—C14120.11 (14)
C2—C3—C4121.70 (14)C15—C14—C13120.04 (14)
C5—C4—C3119.58 (15)C15—C14—H14120.0
C5—C4—H4120.2C13—C14—H14120.0
C3—C4—H4120.2C14—C15—C10121.03 (14)
O2—C5—C4119.34 (14)C14—C15—H15119.5
O2—C5—C6119.88 (13)C10—C15—H15119.5
C4—C5—C6120.78 (14)O4—C16—H16A109.5
C1—C6—C5117.03 (13)O4—C16—H16B109.5
C1—C6—C7120.89 (13)H16A—C16—H16B109.5
C5—C6—C7122.08 (13)O4—C16—H16C109.5
O3—C7—C6121.61 (14)H16A—C16—H16C109.5
O3—C7—C8122.96 (14)H16B—C16—H16C109.5
C6—C7—C8115.42 (13)O5—C17—H17A109.5
C9—C8—C7118.66 (14)O5—C17—H17B109.5
C9—C8—C10118.96 (13)H17A—C17—H17B109.5
C7—C8—C10122.37 (13)O5—C17—H17C109.5
C8—C9—O1126.03 (14)H17A—C17—H17C109.5
C8—C9—H9117.0H17B—C17—H17C109.5
O1—C9—H9117.0
C9—O1—C1—C2177.98 (14)O3—C7—C8—C9176.87 (14)
C9—O1—C1—C62.5 (2)C6—C7—C8—C93.7 (2)
O1—C1—C2—C3179.58 (14)O3—C7—C8—C104.0 (2)
C6—C1—C2—C30.1 (2)C6—C7—C8—C10175.34 (13)
C16—O4—C3—C22.9 (2)C7—C8—C9—O12.5 (2)
C16—O4—C3—C4176.73 (15)C10—C8—C9—O1176.65 (14)
C1—C2—C3—O4179.93 (15)C1—O1—C9—C80.8 (2)
C1—C2—C3—C40.3 (2)C9—C8—C10—C1154.1 (2)
O4—C3—C4—C5179.78 (14)C7—C8—C10—C11124.94 (16)
C2—C3—C4—C50.1 (2)C9—C8—C10—C15123.66 (17)
C3—C4—C5—O2178.75 (14)C7—C8—C10—C1557.3 (2)
C3—C4—C5—C60.5 (2)C15—C10—C11—C120.8 (2)
O1—C1—C6—C5179.89 (13)C8—C10—C11—C12177.07 (15)
C2—C1—C6—C50.7 (2)C10—C11—C12—C130.5 (2)
O1—C1—C6—C71.0 (2)C17—O5—C13—C125.9 (2)
C2—C1—C6—C7179.56 (14)C17—O5—C13—C14173.76 (16)
O2—C5—C6—C1178.37 (13)C11—C12—C13—O5178.89 (14)
C4—C5—C6—C10.9 (2)C11—C12—C13—C140.8 (2)
O2—C5—C6—C70.5 (2)O5—C13—C14—C15179.94 (15)
C4—C5—C6—C7179.72 (14)C12—C13—C14—C150.2 (2)
C1—C6—C7—O3178.48 (14)C13—C14—C15—C101.6 (2)
C5—C6—C7—O32.7 (2)C11—C10—C15—C141.9 (2)
C1—C6—C7—C82.1 (2)C8—C10—C15—C14175.98 (15)
C5—C6—C7—C8176.70 (14)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O2—H2O···O30.821.862.590 (2)148
C4—H4···O4i0.932.543.459 (2)171
C11—H11···O3ii0.932.563.464 (2)164
C14—H14···O2iii0.932.583.399 (2)147
Symmetry codes: (i) x+1, y+1, z+1; (ii) x1, y, z; (iii) x+3/2, y1/2, z+3/2.

Experimental details

Crystal data
Chemical formulaC17H14O5
Mr298.28
Crystal system, space groupMonoclinic, P21/n
Temperature (K)296
a, b, c (Å)5.7754 (8), 7.9446 (12), 30.044 (5)
β (°) 93.807 (12)
V3)1375.4 (4)
Z4
Radiation typeMo Kα
µ (mm1)0.11
Crystal size (mm)0.58 × 0.54 × 0.50
Data collection
DiffractometerSiemens P4
diffractometer
Absorption correction
No. of measured, independent and
observed [I > 2σ(I)] reflections
3089, 2485, 1673
Rint0.010
(sin θ/λ)max1)0.600
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.035, 0.087, 0.90
No. of reflections2485
No. of parameters203
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.19, 0.15

Computer programs: XSCANS (Siemens, 1996), XSCANS, SHELXTL (Siemens, 1997), SHELXS97 (Sheldrick, 1990), SHELXL97 (Sheldrick, 1997), SHELXTL.

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O2—H2O···O30.821.862.590 (2)148
C4—H4···O4i0.932.543.459 (2)171
C11—H11···O3ii0.932.563.464 (2)164
C14—H14···O2iii0.932.583.399 (2)147
Symmetry codes: (i) x+1, y+1, z+1; (ii) x1, y, z; (iii) x+3/2, y1/2, z+3/2.
 

Follow Acta Cryst. C
Sign up for e-alerts
Follow Acta Cryst. on Twitter
Follow us on facebook
Sign up for RSS feeds