PMCCPMCCPMCC

Search tips
Search criteria 

Advanced

 
Logo of actaeInternational Union of Crystallographysearchopen accessarticle submissionjournal home pagethis article
 
Acta Crystallogr Sect E Struct Rep Online. 2009 February 1; 65(Pt 2): o317–o318.
Published online 2009 January 14. doi:  10.1107/S1600536809001123
PMCID: PMC2968310

Methyl gallate

Abstract

The crystal structure of the title compound (systematic name: methyl 3,4,5-trihydroxy­benzoate), C8H8O5, is composed of essentially planar mol­ecules [maximum departures from the mean carbon and oxygen skeleton plane of 0.0348 (10) Å]. The H atoms of the three hydroxyl groups, which function as hydrogen-bond donors and acceptors simultaneously, are oriented in the same direction around the aromatic ring. In addition to two intra­molecular hydrogen bonds, each mol­ecule is hydrogen bonded to six others, creating a three-dimensional hydrogen-bonded network.

Related literature

For natural extracts containing gallic acid methyl ester, see: Saxena et al. (1994 [triangle]); Schmidt et al. (2003 [triangle]); Hawas (2007 [triangle]). For studies concerning anti­oxidant activity, see: Aruoma et al. (1993 [triangle]); Schmidt et al. (2003 [triangle]); Hawas (2007 [triangle]). For studies concerning anti­cancer properties, see: Fiuza et al. (2004 [triangle]) and for anti­microbial properties, see: Saxena et al. (1994 [triangle]); Landete et al. (2007 [triangle]). For cocrystals containing gallic acid methyl ester, see: Sekine et al. (2003 [triangle]); Martin et al. (1986 [triangle]). Similar gallate ester conformations are found in Parkin et al. (2002 [triangle]); Okabe & Kyoyama (2002a [triangle]); Nomura et al. (2000 [triangle]); Mizuguchi et al. (2005 [triangle]). For structures with similar hydroxyl arrangements, see: Hitachi et al. (2005 [triangle]); Okabe et al. (2001 [triangle]); Okabe & Kyoyama (2002b [triangle]). For a description of the Cambridge Structural Database, see: Allen (2002 [triangle]).

An external file that holds a picture, illustration, etc.
Object name is e-65-0o317-scheme1.jpg

Experimental

Crystal data

  • C8H8O5
  • M r = 184.14
  • Monoclinic, An external file that holds a picture, illustration, etc.
Object name is e-65-0o317-efi13.jpg
  • a = 7.6963 (2) Å
  • b = 9.9111 (2) Å
  • c = 10.5625 (2) Å
  • β = 95.9930 (10)°
  • V = 801.29 (3) Å3
  • Z = 4
  • Cu Kα radiation
  • μ = 1.12 mm−1
  • T = 100 (2) K
  • 0.31 × 0.23 × 0.21 mm

Data collection

  • Bruker SMART APEXII CCD diffractometer
  • Absorption correction: numerical (SADABS; Sheldrick, 2004 [triangle]) T min = 0.723, T max = 0.799
  • 8192 measured reflections
  • 1352 independent reflections
  • 1311 reflections with I > 2σ(I)
  • R int = 0.034

Refinement

  • R[F 2 > 2σ(F 2)] = 0.033
  • wR(F 2) = 0.093
  • S = 0.69
  • 1352 reflections
  • 121 parameters
  • All H-atom parameters refined
  • Δρmax = 0.23 e Å−3
  • Δρmin = −0.20 e Å−3

Data collection: APEX2 (Bruker , 2004 [triangle]); cell refinement: SAINT-Plus (Bruker, 2004 [triangle]); data reduction: SAINT-Plus; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 [triangle]); program(s) used to refine structure: WinGX (Farrugia, 1999 [triangle]); molecular graphics: ORTEP-3 (Farrugia, 1997 [triangle]) and Mercury (Macrae et al., 2006 [triangle]); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008 [triangle]).

Table 1
Hydrogen-bond geometry (Å, °)

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536809001123/rz2286sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809001123/rz2286Isup2.hkl

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

Acknowledgments

We are indebted to the NSF (CHE-0443345) and The College of William and Mary for the purchase of X-ray equipment. This work was supported in part by the US National Science Foundation (CHE-0315934). Any opinions, findings and conclusions or recommendations expressed in this material are those of the author and do not necessarily reflect the views of the National Science Foundation. SP gratefully acknowledges the Physics Department of the College of William and Mary for funding and ICDD GIA 08–04.

supplementary crystallographic information

Comment

Gallic acid methyl ester (I) is a polyphenolic compound present in grape seeds and other natural substrates (Saxena et al., 1994; Schmidt et al., 2003; Hawas, 2007). Like other polyphenols, I shows antioxidant activity (Aruoma et al., 1993; Schmidt et al., 2003; Hawas, 2007). Formerly used as an astringent and in opthalmology, its anticancer (Fiuza et al., 2004) and antimicrobial properties (Saxena et al., 1994; Landete et al., 2007) have also been studied. The molecular structure of I is shown below.

The molecular geometry is as expected from chemical bond rules (Figure 1) and it shows an almost planar conformation, with maximum departures from the mean carbon and oxygen skeleton plane of 0.0343 (9) and 0.0348 (10) Å for O4 and C8, respectively. The relative positions of the carbonyl and the three hydroxyls were also observed in a cocrystal of I and 5-chloro-2-methyl-4-isothiazoline-3-one (Sekine et al., 2003). Four other compounds containing a gallic acid ester moiety have crystallized in an analogous conformation (Parkin et al., 2002; Okabe & Kyoyama, 2002a; Nomura et al., 2000; Mizuguchi et al., 2005). Three other planar conformations of gallic acid esters are found in the Cambridge Structural Database (Allen, 2002). I has one of these other conformations in a cocrystal with caffeine (Martin et al., 1986).

Crystallized I has intra- and intermolecular hydrogen bonding. The hydroxyl H atoms bound to O3 and O4 (donors) form intramolecular hydrogen bonds to O4 and O5 (acceptors), respectively. This is shown in Figure 1. Similar hydroxyl arrangements have been reported in other gallic acid derivatives, such as gallate ester solvates (Hitachi et al., 2005), a gallic acid monohydrate polymorph (Okabe et al., 2001) and 2,3,4-trihydroxybenzophenone monohydrate (Okabe & Kyoyama, 2002b).

Gallic acid methyl ester forms a three-dimensional H-bonded network lacking significant aromatic ring stacking interactions. There is one molecule of I in the asymmetric unit. The H-bonded network is shown in Figure 2. Using the carbonyl ester oxygen O1 (acceptor) and the hydroxyl O3 and O4 (donors), each molecule is linked to another four through two O1···H3—O3, and two O1···H4—O4 H-bonds. These H-bonds are likely relatively weak due to the spacial orientation of the H atoms with respect to the lone electron pairs of O1. In addition, there are two other O5—H5···O3 H-bonds. The three hydroxyl sites are used as hydrogen bond donors and acceptors simultaneously. In the ester group, only the carbonyl oxygen is used as an H-bond acceptor.

Experimental

Gallic acid methyl ester was commercially obtained from Sigma-Aldrich (98% purity) and used as received. The crystal structure determination was carried out from a crystal with rhombic prismatic habit selected from the powder.

Refinement

All hydrogen atoms were observed in the Fourier difference map. However, the torsion angle for the hydroxyl H was refined from the electron density and the methyl H was positioned in idealized staggered geometry. The H atoms were refined constrained to ride on their parent C or O atoms, with Uiso(H)=1.2 Ueq(C) for aromatic H, and Uiso(H)=1.5 Ueq(C or O) for methyl and hydroxyl H, respectively.

Figures

Fig. 1.
Thermal ellipsoid plot of gallic acid methyl ester with the atomic numbering scheme. Non-H atoms are represented at 50% probability level. Intramolecular hydrogen bonds are shown with dashed lines.
Fig. 2.
The packing of gallic acid methyl ester molecules along the a-axis showing the unit cell and the hydrogen bonded network formed (dashed lines). Symmetry codes: (i) x,y,z; (ii) 1/2 + x, 1.5 - y, -1/2 + z; (iii) -1/2 + x, 1.5 - y, 1/2 + z; (iv) -1/2 + x,1.5 ...

Crystal data

C8H8O5F(000) = 384
Mr = 184.14Dx = 1.526 Mg m3
Monoclinic, P21/nMelting point: 474 K
Hall symbol: -P 2ynCu Kα radiation, λ = 1.54178 Å
a = 7.6963 (2) ÅCell parameters from 1352 reflections
b = 9.9111 (2) Åθ = 6.1–67.0°
c = 10.5625 (2) ŵ = 1.12 mm1
β = 95.993 (1)°T = 100 K
V = 801.29 (3) Å3Rhombic prism, colourless
Z = 40.31 × 0.23 × 0.21 mm

Data collection

Bruker SMART APEXII CCD diffractometer1352 independent reflections
Radiation source: fine-focus sealed tube1311 reflections with I > 2σ(I)
graphiteRint = 0.034
ω and ψ scansθmax = 67.0°, θmin = 6.1°
Absorption correction: numerical (SADABS; Sheldrick, 2004)h = −8→9
Tmin = 0.723, Tmax = 0.799k = −11→11
8192 measured reflectionsl = −12→12

Refinement

Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.033Hydrogen site location: difference Fourier map
wR(F2) = 0.093All H-atom parameters refined
S = 0.69w = 1/[σ2(Fo2) + (0.0834P)2 + 0.9466P] where P = (Fo2 + 2Fc2)/3
1352 reflections(Δ/σ)max = 0.004
121 parametersΔρmax = 0.23 e Å3
0 restraintsΔρmin = −0.20 e Å3
32 constraints

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.

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

xyzUiso*/Ueq
O10.14003 (11)1.05605 (9)0.77633 (8)0.0145 (2)
O20.29090 (12)0.99023 (9)0.61631 (8)0.0156 (3)
O3−0.38148 (12)0.74067 (10)0.72722 (9)0.0189 (3)
H3−0.43890.67420.69630.028*
O4−0.33530 (12)0.58249 (9)0.52444 (9)0.0167 (2)
H4−0.3140.54620.45590.025*
O5−0.05442 (13)0.61740 (10)0.39075 (9)0.0185 (3)
H50.01270.65240.34220.028*
C70.15489 (17)0.98352 (13)0.68447 (12)0.0121 (3)
C10.02736 (17)0.87858 (13)0.63777 (12)0.0126 (3)
C2−0.11958 (17)0.85957 (13)0.70290 (12)0.0126 (3)
H2−0.13780.91450.7740.015*
C3−0.23803 (17)0.75983 (13)0.66260 (12)0.0129 (3)
C4−0.21306 (17)0.67861 (13)0.55808 (12)0.0129 (3)
C5−0.06683 (17)0.69987 (13)0.49284 (12)0.0134 (3)
C60.05370 (16)0.79838 (13)0.53249 (12)0.0134 (3)
H60.15390.81160.48850.016*
C80.42258 (18)1.09026 (14)0.65644 (13)0.0182 (3)
H8A0.51611.08670.60030.027*
H8B0.47121.07150.74410.027*
H8C0.36951.18020.65210.027*

Atomic displacement parameters (Å2)

U11U22U33U12U13U23
O10.0147 (5)0.0147 (5)0.0141 (5)0.0011 (4)0.0010 (4)−0.0023 (4)
O20.0135 (5)0.0186 (5)0.0153 (5)−0.0048 (4)0.0040 (4)−0.0030 (4)
O30.0171 (5)0.0206 (5)0.0209 (5)−0.0067 (4)0.0108 (4)−0.0070 (4)
O40.0188 (5)0.0180 (5)0.0141 (5)−0.0071 (4)0.0058 (4)−0.0043 (4)
O50.0237 (5)0.0196 (5)0.0140 (5)−0.0080 (4)0.0103 (4)−0.0057 (4)
C10.0135 (6)0.0127 (6)0.0114 (6)0.0019 (5)0.0004 (5)0.0028 (5)
C20.0147 (7)0.0130 (6)0.0104 (6)0.0023 (5)0.0021 (5)−0.0002 (5)
C30.0127 (6)0.0147 (6)0.0120 (6)0.0012 (5)0.0041 (5)0.0025 (5)
C40.0137 (6)0.0123 (6)0.0124 (6)−0.0012 (5)0.0000 (5)0.0022 (5)
C50.0176 (7)0.0129 (6)0.0100 (6)0.0012 (5)0.0032 (5)0.0002 (5)
C60.0127 (6)0.0159 (7)0.0121 (6)0.0004 (5)0.0040 (5)0.0024 (5)
C70.0129 (7)0.0122 (6)0.0111 (6)0.0037 (5)0.0006 (5)0.0030 (5)
C80.0157 (7)0.0203 (7)0.0185 (7)−0.0071 (5)0.0015 (6)−0.0010 (5)

Geometric parameters (Å, °)

O1—C71.2225 (16)C1—C61.3988 (19)
O2—C71.3327 (15)C2—C31.3815 (18)
O2—C81.4491 (16)C2—H20.95
O3—C31.3705 (15)C3—C41.3957 (18)
O3—H30.84C4—C51.3956 (18)
O4—C41.3598 (16)C5—C61.3813 (18)
O4—H40.84C6—H60.95
O5—C51.3644 (16)C8—H8A0.98
O5—H50.84C8—H8B0.98
C7—C11.4790 (19)C8—H8C0.98
C1—C21.3965 (17)
C7—O2—C8116.16 (10)O4—C4—C5123.25 (11)
C3—O3—H3109.5O4—C4—C3117.52 (11)
C4—O4—H4109.5C5—C4—C3119.22 (12)
C5—O5—H5109.5O5—C5—C6124.25 (11)
O1—C7—O2122.91 (12)O5—C5—C4115.24 (12)
O1—C7—C1124.36 (11)C6—C5—C4120.51 (11)
O2—C7—C1112.72 (11)C5—C6—C1119.62 (12)
C2—C1—C6120.47 (12)C5—C6—H6120.2
C2—C1—C7118.29 (11)C1—C6—H6120.2
C6—C1—C7121.24 (12)O2—C8—H8A109.5
C3—C2—C1119.15 (12)O2—C8—H8B109.5
C3—C2—H2120.4H8A—C8—H8B109.5
C1—C2—H2120.4O2—C8—H8C109.5
O3—C3—C2119.06 (11)H8A—C8—H8C109.5
O3—C3—C4119.91 (12)H8B—C8—H8C109.5
C2—C3—C4121.03 (12)
C8—O2—C7—O1−0.42 (18)C2—C3—C4—O4179.88 (11)
C8—O2—C7—C1−179.68 (10)O3—C3—C4—C5179.65 (11)
O1—C7—C1—C2−0.53 (19)C2—C3—C4—C5−0.7 (2)
O2—C7—C1—C2178.71 (11)O4—C4—C5—O50.45 (19)
O1—C7—C1—C6−179.44 (12)C3—C4—C5—O5−178.97 (11)
O2—C7—C1—C6−0.19 (17)O4—C4—C5—C6−179.37 (11)
C6—C1—C2—C30.47 (19)C3—C4—C5—C61.21 (19)
C7—C1—C2—C3−178.44 (11)O5—C5—C6—C1179.28 (12)
C1—C2—C3—O3179.52 (11)C4—C5—C6—C1−0.92 (19)
C1—C2—C3—C4−0.17 (19)C2—C1—C6—C50.07 (19)
O3—C3—C4—O40.19 (18)C7—C1—C6—C5178.95 (11)

Hydrogen-bond geometry (Å, °)

D—H···AD—HH···AD···AD—H···A
O3—H3···O40.842.252.7075 (13)115
O4—H4···O50.842.292.7247 (12)112
O4—H4···O1i0.842.152.9470 (13)159
O3—H3···O1ii0.841.992.7007 (12)142
O5—H5···O3iii0.841.862.6859 (12)166

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

Footnotes

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: RZ2286).

References

  • Allen, F. H. (2002). Acta Cryst. B58, 380–388. [PubMed]
  • Aruoma, O. I., Murcia, A., Butler, J. & Halliwell, B. (1993). J. Agric. Food Chem.41, 1880–1885.
  • Bruker (2004). APEX2 and SAINT-Plus Bruker AXS Inc., Madison Wisconsin, U. S. A..
  • Farrugia, L. J. (1997). J. Appl. Cryst.30, 565.
  • Farrugia, L. J. (1999). J. Appl. Cryst.32, 837–838.
  • Fiuza, S. M., Gomes, C., Teixeira, L. J., Girao da Cruz, M. T., Cordeiro, M. N. D. S., Milhazes, N., Borges, F. & Marques, M. P. M. (2004). Bioorg. Med. Chem.12, 3581–3589. [PubMed]
  • Hawas, U. W. (2007). Nat. Prod. Res.21, 632–640. [PubMed]
  • Hitachi, A., Makino, T., Iwata, S. & Mizuguchi, J. (2005). Acta Cryst. E61, o2590–o2592.
  • Landete, J. M., Rodriguez, H., De las Rivas, B. & Munoz, R. (2007). J. Food. Prot., 70, 2670–2675. [PubMed]
  • Macrae, C. F., Edgington, P. R., McCabe, P., Pidcock, E., Shields, G. P., Taylor, R., Towler, M. & van de Streek, J. (2006). J. Appl. Cryst.39, 453–457.
  • Martin, R., Lilley, T. H., Bailey, N. A., Falshaw, C. P., Haslam, E., Magnolato, D. & Begley, M. J. (1986). Chem. Commun. pp. 105–106.
  • Mizuguchi, J., Hitachi, A., Iwata, S. & Makino, T. (2005). Acta Cryst. E61, o2593–o2595.
  • Nomura, E., Hosoda, A. & Taniguchi, H. (2000). Org. Lett.2, 779–781. [PubMed]
  • Okabe, N. & Kyoyama, H. (2002a). Acta Cryst. E58, o245–o247.
  • Okabe, N. & Kyoyama, H. (2002b). Acta Cryst. E58, o565–o567.
  • Okabe, N., Kyoyama, H. & Suzuki, M. (2001). Acta Cryst. E57, o764–o766.
  • Parkin, A., Parsons, S., Robertson, J. H. & Tasker, P. A. (2002). Acta Cryst. E58, o1348–o1350.
  • Saxena, G., McCutcheon, A. R., Farmer, S., Towers, G. H. N. & Hancock, R. (1994). J. Ethnopharm.42, 95–99. [PubMed]
  • Schmidt, S., Niklova, I., Pokorny, J., Farkas, P. & Sekretar, S. (2003). Eur. J. Lipid Sci. Technol.105, 427–435.
  • Sekine, A., Mitsumori, T., Uekusa, H., Ohashi, Y. & Yagi, M. (2003) Anal. Sci. X-Ray Struct. Anal. Online, 19, x47–x48.
  • Sheldrick, G. M. (2004). SADABS University of Göttingen, Germany.
  • Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. [PubMed]

Articles from Acta Crystallographica Section E: Structure Reports Online are provided here courtesy of International Union of Crystallography