




Supporting information
![]() | Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536808018734/fb2096sup1.cif |
![]() | Structure factor file (CIF format) https://doi.org/10.1107/S1600536808018734/fb2096Isup2.hkl |
CCDC reference: 696606
Key indicators
- Single-crystal X-ray study
- T = 293 K
- Mean
(C-C) = 0.003 Å
- R factor = 0.029
- wR factor = 0.067
- Data-to-parameter ratio = 7.6
checkCIF/PLATON results
No syntax errors found
Alert level C PLAT089_ALERT_3_C Poor Data / Parameter Ratio (Zmax .LT. 18) ..... 7.61
Alert level G REFLT03_ALERT_4_G Please check that the estimate of the number of Friedel pairs is correct. If it is not, please give the correct count in the _publ_section_exptl_refinement section of the submitted CIF. From the CIF: _diffrn_reflns_theta_max 24.99 From the CIF: _reflns_number_total 1279 Count of symmetry unique reflns 1280 Completeness (_total/calc) 99.92% TEST3: Check Friedels for noncentro structure Estimate of Friedel pairs measured 0 Fraction of Friedel pairs measured 0.000 Are heavy atom types Z>Si present no PLAT199_ALERT_1_G Check the Reported _cell_measurement_temperature 293 K PLAT200_ALERT_1_G Check the Reported _diffrn_ambient_temperature . 293 K PLAT791_ALERT_4_G Confirm the Absolute Configuration of C8 ... R
0 ALERT level A = In general: serious problem 0 ALERT level B = Potentially serious problem 1 ALERT level C = Check and explain 4 ALERT level G = General alerts; check 2 ALERT type 1 CIF construction/syntax error, inconsistent or missing data 0 ALERT type 2 Indicator that the structure model may be wrong or deficient 1 ALERT type 3 Indicator that the structure quality may be low 2 ALERT type 4 Improvement, methodology, query or suggestion 0 ALERT type 5 Informative message, check
The title compound was purified from the stems of Opuntia vulgaris according to the reported procedures (Jiang et al., 2002). Briefly, the stems of Opuntia vulgaris (1 kg) was extracted with 95% ethanol under room temperature. The extracted solution was concentrated with rotary evaporator to afford a crude extract, which was suspended in distilled water and partitioned with petroleum ether, ethyl acetate and n-butanol. Then the n-butanol fraction was subjected to silica gel column chromatography eluted with methanol-chloroform gradient solvent system to afford the title compound (16 mg). The transparent rectangular crystals of the title compound with average size of 0.50 × 0.40 × 0.30 mm were obtained by slow evaporation of the methanol solution at room temperature.
Though all the hydrogens were discernible in the difference electron density maps. Neverheless, the hydrogens were situated into the idealized position and constrained during the refinement. Hydroxyl hydrogens: O-H equalled to 0.82 Å, Uiso(H)=1.5 UeqO; Caryl-H equalled to 0.93 Å, Uiso(H)=1.2 UeqCaryl; Cmethylene-H equalled to 0.97 Å, Uiso(H)=1.2 UeqCmethylene; Cmethyl-H equalled to 0.96 Å, Uiso(H)=1.5 UeqCmethyl.
There is no heavy atom with significant anomalous dispersion contribution in the structure for the used wavelength, so the absolute configuration from the diffraction pattern itself was not determined. 836 Friedel reflections were merged before the refinement. However, the absolute configuration of the related eucomic acid has been established previously (Heller & Tamm, 1974) and therefore the title compound has been expected to share the same R configuration at the chiral center C8.
Reflection (0 0 2) was omitted.
Data collection: SMART (Bruker, 1998); cell refinement: SMART and SAINT (Bruker, 1998); data reduction: XPREP in SHELXTL (Sheldrick, 2008); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: XP (Siemens, 1998); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).
C12H14O6 | F(000) = 536 |
Mr = 254.23 | Dx = 1.395 Mg m−3 |
Orthorhombic, P212121 | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: P 2ac 2ab | Cell parameters from 6709 reflections |
a = 5.9109 (6) Å | θ = 1.4–25.0° |
b = 7.0348 (7) Å | µ = 0.11 mm−1 |
c = 29.109 (3) Å | T = 293 K |
V = 1210.4 (2) Å3 | Rectangular, colourless |
Z = 4 | 0.40 × 0.32 × 0.25 mm |
Bruker SMART/CCD diffractometer | 1047 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.046 |
Graphite monochromator | θmax = 25.0°, θmin = 1.4° |
ω scans | h = −6→7 |
6709 measured reflections | k = −8→7 |
1279 independent reflections | l = −27→34 |
Refinement on F2 | Secondary atom site location: difference Fourier map |
Least-squares matrix: full | Hydrogen site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.029 | H-atom parameters constrained |
wR(F2) = 0.066 | w = 1/[σ2(Fo2) + (0.0328P)2] where P = (Fo2 + 2Fc2)/3 |
S = 1.05 | (Δ/σ)max < 0.001 |
1278 reflections | Δρmax = 0.14 e Å−3 |
168 parameters | Δρmin = −0.12 e Å−3 |
0 restraints | Extinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
42 constraints | Extinction coefficient: 0.0070 (19) |
Primary atom site location: structure-invariant direct methods |
C12H14O6 | V = 1210.4 (2) Å3 |
Mr = 254.23 | Z = 4 |
Orthorhombic, P212121 | Mo Kα radiation |
a = 5.9109 (6) Å | µ = 0.11 mm−1 |
b = 7.0348 (7) Å | T = 293 K |
c = 29.109 (3) Å | 0.40 × 0.32 × 0.25 mm |
Bruker SMART/CCD diffractometer | 1047 reflections with I > 2σ(I) |
6709 measured reflections | Rint = 0.046 |
1279 independent reflections |
R[F2 > 2σ(F2)] = 0.029 | 0 restraints |
wR(F2) = 0.066 | H-atom parameters constrained |
S = 1.05 | Δρmax = 0.14 e Å−3 |
1278 reflections | Δρmin = −0.12 e Å−3 |
168 parameters |
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 | ||
O1 | 0.2505 (3) | 0.2830 (2) | 0.32392 (5) | 0.0466 (5) | |
H1 | 0.1313 | 0.2346 | 0.3323 | 0.070* | |
O2 | 0.5510 (2) | 0.5081 (2) | 0.11441 (5) | 0.0400 (4) | |
H2 | 0.5099 | 0.5865 | 0.1335 | 0.060* | |
O3 | 0.1405 (3) | 0.6278 (2) | 0.13901 (5) | 0.0425 (4) | |
O4 | −0.0301 (3) | 0.3948 (3) | 0.09911 (6) | 0.0499 (5) | |
H4 | −0.1460 | 0.4500 | 0.1070 | 0.075* | |
O5 | 0.2745 (4) | 0.6569 (3) | 0.03265 (6) | 0.0640 (6) | |
O6 | 0.3709 (3) | 0.4543 (2) | −0.02286 (5) | 0.0543 (5) | |
C1 | 0.2722 (4) | 0.2631 (3) | 0.27718 (8) | 0.0344 (6) | |
C2 | 0.4773 (4) | 0.3133 (3) | 0.25799 (8) | 0.0367 (6) | |
H2B | 0.5932 | 0.3598 | 0.2764 | 0.044* | |
C3 | 0.5089 (4) | 0.2940 (3) | 0.21133 (8) | 0.0370 (6) | |
H3A | 0.6475 | 0.3286 | 0.1987 | 0.044* | |
C4 | 0.3420 (4) | 0.2253 (3) | 0.18265 (8) | 0.0346 (6) | |
C5 | 0.1367 (4) | 0.1752 (3) | 0.20275 (8) | 0.0389 (6) | |
H5A | 0.0209 | 0.1285 | 0.1843 | 0.047* | |
C6 | 0.1010 (4) | 0.1933 (3) | 0.24947 (9) | 0.0387 (6) | |
H6A | −0.0373 | 0.1588 | 0.2622 | 0.046* | |
C7 | 0.3804 (4) | 0.2011 (3) | 0.13179 (8) | 0.0400 (6) | |
H7A | 0.2693 | 0.1119 | 0.1201 | 0.048* | |
H7B | 0.5286 | 0.1451 | 0.1272 | 0.048* | |
C8 | 0.3660 (4) | 0.3855 (3) | 0.10324 (7) | 0.0336 (5) | |
C9 | 0.3831 (4) | 0.3384 (3) | 0.05217 (8) | 0.0403 (6) | |
H9A | 0.5339 | 0.2904 | 0.0459 | 0.048* | |
H9B | 0.2767 | 0.2375 | 0.0452 | 0.048* | |
C10 | 0.3374 (4) | 0.5023 (4) | 0.02090 (8) | 0.0424 (6) | |
C11 | 0.1476 (4) | 0.4865 (4) | 0.11534 (7) | 0.0347 (5) | |
C12 | 0.3196 (5) | 0.5985 (4) | −0.05667 (9) | 0.0681 (9) | |
H12A | 0.3552 | 0.5515 | −0.0868 | 0.102* | |
H12B | 0.4079 | 0.7102 | −0.0505 | 0.102* | |
H12C | 0.1617 | 0.6297 | −0.0552 | 0.102* |
U11 | U22 | U33 | U12 | U13 | U23 | |
O1 | 0.0418 (10) | 0.0604 (11) | 0.0377 (10) | −0.0079 (10) | 0.0050 (8) | 0.0063 (9) |
O2 | 0.0255 (9) | 0.0527 (11) | 0.0418 (11) | −0.0021 (8) | 0.0013 (7) | −0.0105 (9) |
O3 | 0.0368 (9) | 0.0474 (10) | 0.0432 (10) | 0.0061 (9) | 0.0051 (8) | −0.0103 (8) |
O4 | 0.0229 (9) | 0.0617 (12) | 0.0651 (12) | 0.0047 (9) | −0.0011 (9) | −0.0157 (11) |
O5 | 0.0819 (15) | 0.0646 (12) | 0.0454 (11) | 0.0208 (12) | 0.0057 (11) | −0.0017 (10) |
O6 | 0.0678 (12) | 0.0652 (11) | 0.0298 (9) | −0.0045 (11) | 0.0042 (10) | −0.0054 (9) |
C1 | 0.0334 (13) | 0.0335 (13) | 0.0363 (14) | 0.0024 (11) | 0.0021 (11) | 0.0060 (11) |
C2 | 0.0315 (12) | 0.0395 (14) | 0.0391 (15) | −0.0086 (12) | −0.0029 (11) | 0.0020 (12) |
C3 | 0.0277 (12) | 0.0404 (13) | 0.0429 (15) | −0.0040 (12) | 0.0035 (11) | 0.0041 (12) |
C4 | 0.0294 (12) | 0.0326 (12) | 0.0417 (14) | 0.0046 (11) | −0.0010 (11) | 0.0021 (11) |
C5 | 0.0293 (12) | 0.0412 (13) | 0.0463 (15) | −0.0009 (12) | −0.0045 (12) | 0.0000 (12) |
C6 | 0.0263 (12) | 0.0430 (13) | 0.0470 (15) | −0.0029 (11) | 0.0030 (11) | 0.0068 (13) |
C7 | 0.0336 (12) | 0.0431 (13) | 0.0431 (14) | 0.0062 (12) | −0.0021 (12) | −0.0074 (12) |
C8 | 0.0223 (11) | 0.0441 (14) | 0.0344 (13) | 0.0009 (12) | −0.0012 (11) | −0.0054 (12) |
C9 | 0.0334 (13) | 0.0521 (14) | 0.0356 (14) | 0.0060 (12) | 0.0028 (11) | −0.0071 (12) |
C10 | 0.0315 (13) | 0.0572 (16) | 0.0385 (14) | −0.0011 (15) | 0.0029 (12) | −0.0075 (14) |
C11 | 0.0277 (12) | 0.0460 (14) | 0.0303 (12) | 0.0012 (13) | −0.0001 (11) | 0.0007 (12) |
C12 | 0.085 (2) | 0.080 (2) | 0.0393 (15) | −0.023 (2) | −0.0078 (16) | 0.0111 (16) |
O1—C1 | 1.374 (3) | C4—C5 | 1.392 (3) |
O1—H1 | 0.8200 | C4—C7 | 1.507 (3) |
O2—C8 | 1.430 (3) | C5—C6 | 1.382 (3) |
O2—H2 | 0.8200 | C5—H5A | 0.9300 |
O3—C11 | 1.210 (3) | C6—H6A | 0.9300 |
O4—C11 | 1.320 (3) | C7—C8 | 1.543 (3) |
O4—H4 | 0.8200 | C7—H7A | 0.9700 |
O5—C10 | 1.200 (3) | C7—H7B | 0.9700 |
O6—C10 | 1.333 (3) | C8—C11 | 1.515 (3) |
O6—C12 | 1.446 (3) | C8—C9 | 1.526 (3) |
C1—C2 | 1.380 (3) | C9—C10 | 1.494 (3) |
C1—C6 | 1.384 (3) | C9—H9A | 0.9700 |
C2—C3 | 1.378 (3) | C9—H9B | 0.9700 |
C2—H2B | 0.9300 | C12—H12A | 0.9600 |
C3—C4 | 1.380 (3) | C12—H12B | 0.9600 |
C3—H3A | 0.9300 | C12—H12C | 0.9600 |
C1—O1—H1 | 109.5 | C8—C7—H7B | 108.5 |
C8—O2—H2 | 109.5 | H7A—C7—H7B | 107.5 |
C11—O4—H4 | 109.5 | O2—C8—C11 | 108.40 (17) |
C10—O6—C12 | 116.2 (2) | O2—C8—C9 | 107.55 (19) |
O1—C1—C2 | 117.2 (2) | C11—C8—C9 | 112.63 (19) |
O1—C1—C6 | 123.0 (2) | O2—C8—C7 | 110.03 (18) |
C2—C1—C6 | 119.8 (2) | C11—C8—C7 | 108.44 (18) |
C3—C2—C1 | 119.5 (2) | C9—C8—C7 | 109.77 (19) |
C3—C2—H2B | 120.2 | C10—C9—C8 | 114.4 (2) |
C1—C2—H2B | 120.2 | C10—C9—H9A | 108.6 |
C2—C3—C4 | 122.3 (2) | C8—C9—H9A | 108.6 |
C2—C3—H3A | 118.9 | C10—C9—H9B | 108.6 |
C4—C3—H3A | 118.9 | C8—C9—H9B | 108.6 |
C3—C4—C5 | 117.2 (2) | H9A—C9—H9B | 107.6 |
C3—C4—C7 | 121.8 (2) | O5—C10—O6 | 123.3 (2) |
C5—C4—C7 | 121.0 (2) | O5—C10—C9 | 125.6 (2) |
C6—C5—C4 | 121.5 (2) | O6—C10—C9 | 111.1 (2) |
C6—C5—H5A | 119.2 | O3—C11—O4 | 125.3 (2) |
C4—C5—H5A | 119.2 | O3—C11—C8 | 123.2 (2) |
C5—C6—C1 | 119.6 (2) | O4—C11—C8 | 111.43 (19) |
C5—C6—H6A | 120.2 | O6—C12—H12A | 109.5 |
C1—C6—H6A | 120.2 | O6—C12—H12B | 109.5 |
C4—C7—C8 | 115.19 (19) | H12A—C12—H12B | 109.5 |
C4—C7—H7A | 108.5 | O6—C12—H12C | 109.5 |
C8—C7—H7A | 108.5 | H12A—C12—H12C | 109.5 |
C4—C7—H7B | 108.5 | H12B—C12—H12C | 109.5 |
O1—C1—C2—C3 | 179.3 (2) | C4—C7—C8—C9 | −174.1 (2) |
C6—C1—C2—C3 | 0.3 (4) | O2—C8—C9—C10 | −68.8 (2) |
C1—C2—C3—C4 | −0.2 (4) | C11—C8—C9—C10 | 50.5 (3) |
C2—C3—C4—C5 | 0.1 (3) | C7—C8—C9—C10 | 171.5 (2) |
C2—C3—C4—C7 | −178.7 (2) | C12—O6—C10—O5 | −2.1 (4) |
C3—C4—C5—C6 | 0.0 (3) | C12—O6—C10—C9 | 176.6 (2) |
C7—C4—C5—C6 | 178.7 (2) | C8—C9—C10—O5 | −5.7 (4) |
C4—C5—C6—C1 | 0.1 (4) | C8—C9—C10—O6 | 175.6 (2) |
O1—C1—C6—C5 | −179.2 (2) | O2—C8—C11—O3 | −13.9 (3) |
C2—C1—C6—C5 | −0.2 (4) | C9—C8—C11—O3 | −132.8 (2) |
C3—C4—C7—C8 | −78.5 (3) | C7—C8—C11—O3 | 105.5 (2) |
C5—C4—C7—C8 | 102.8 (3) | O2—C8—C11—O4 | 169.74 (19) |
C4—C7—C8—O2 | 67.7 (3) | C9—C8—C11—O4 | 50.9 (3) |
C4—C7—C8—C11 | −50.7 (3) | C7—C8—C11—O4 | −70.8 (2) |
D—H···A | D—H | H···A | D···A | D—H···A |
O1—H1···O3i | 0.82 | 1.96 | 2.775 (2) | 172 |
O2—H2···O1ii | 0.82 | 2.34 | 2.888 (2) | 125 |
O4—H4···O2iii | 0.82 | 1.85 | 2.639 (2) | 161 |
C12—H12B···O5iv | 0.96 | 2.42 | 3.268 (4) | 148 |
Symmetry codes: (i) −x, y−1/2, −z+1/2; (ii) −x+1, y+1/2, −z+1/2; (iii) x−1, y, z; (iv) x+1/2, −y+3/2, −z. |
Experimental details
Crystal data | |
Chemical formula | C12H14O6 |
Mr | 254.23 |
Crystal system, space group | Orthorhombic, P212121 |
Temperature (K) | 293 |
a, b, c (Å) | 5.9109 (6), 7.0348 (7), 29.109 (3) |
V (Å3) | 1210.4 (2) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.11 |
Crystal size (mm) | 0.40 × 0.32 × 0.25 |
Data collection | |
Diffractometer | Bruker SMART/CCD diffractometer |
Absorption correction | – |
No. of measured, independent and observed [I > 2σ(I)] reflections | 6709, 1279, 1047 |
Rint | 0.046 |
(sin θ/λ)max (Å−1) | 0.594 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.029, 0.066, 1.05 |
No. of reflections | 1278 |
No. of parameters | 168 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.14, −0.12 |
Computer programs: SMART (Bruker, 1998), SMART and SAINT (Bruker, 1998), XPREP in SHELXTL (Sheldrick, 2008), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), XP (Siemens, 1998), SHELXTL (Sheldrick, 2008).
D—H···A | D—H | H···A | D···A | D—H···A |
O1—H1···O3i | 0.820 | 1.960 | 2.775 (2) | 172.1 |
O2—H2···O1ii | 0.820 | 2.335 | 2.888 (2) | 125.3 |
O4—H4···O2iii | 0.820 | 1.850 | 2.639 (2) | 161.1 |
C12—H12B···O5iv | 0.960 | 2.420 | 3.268 (4) | 147.6 |
Symmetry codes: (i) −x, y−1/2, −z+1/2; (ii) −x+1, y+1/2, −z+1/2; (iii) x−1, y, z; (iv) x+1/2, −y+3/2, −z. |
Methyl eucomate is the methyl ester of the eucomic acid. The title compound has been isolated from several edible plants, e. g. Opuntia dillenii (Jiang et al., 2006) or Opuntia vulgaris (Jiang et al., 2002). However, the stereochemistry of the ester has not been established yet. In the present paper, we report its crystal structure.
The molecule contains phenol, carboxyl, ester and hydroxyl functional groups (Fig. 1). The mean deviation of the benzene ring from planarity is 0.0004 Å and its dihedral angle with the plane of the carboxylic group at C8 is 50.3 (3)°, while it is roughly perpendicular to the ester group at C10 with a dihedral angle of 87.3 (3)°.
The intermolecular hydrogen bonds O1—H···O3, O2—H···O1 and O4—H···O2 (Tab. 1) link the molecules into layers that are parallel to (001) (Fig. 2).
There is no heavy atom with a significant anomalous dispersion contribution, so the absolute configuration from the diffraction pattern itself could not be determined. However, the absolute configuration of the eucomic acid has been established by synthesis (Heller & Tamm, 1974) though its crystal structure has not been determined. Therefore the title compound is expected to share the same R configuration at the chiral centre C8.