Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S160053680703838X/hb2498sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S160053680703838X/hb2498Isup2.hkl |
CCDC reference: 662415
Crushed and dried Garcinia cambogia fruit rinds (200 g) were immersed in 250 ml hot water for 10 h. Water was decanted and the process was repeated three times. The combined water extracts were concentrated to get a thick syrupy mass to which acetone was added. The precipitated mass was filtered off and washed with acetone. On evaporation, the acetone layer gave a gummy mass which was extracted with ethyl acetate. The ethyl acetate was charcolized, dried over anhydrous sodium sulfate, which on concentration gave crude garcinia lactone. This material was recrystallized using ethyl acetate and n-hexane to yield the title compound (29.0 g) in high purity. Colourless plates of (I) were grown from ethyl acetate and n-hexane (1:1 v/v) for data collection.
In the absence of significant anomalous dispersion effects, Friedel pairs were merged. Therefore the absolute structure of (I) is indeterminate from this experiment (in the arbitrarily chosen model used here, C3 and C4 have S conformation). All the H atoms were positioned geometrically (C—H = 0.97–0.98 Å, O—H = 0.82 Å) and refined as riding, with Uiso(H) = 1.5Ueq(C) or 1.5Ueq(O).
The main active ingredient of Garcinia cambogia fruit rind is (-)hydroxycitric acid (HCA) along with Garcinia lactone and citric acid (Clouatre & Robenbaum, 1994). In India the fruit is known as kokum, the extract of which is used as a souring agent in cooking. In Indian medicine, Garcinia is considered to be one of the prime herbs that is beneficial for heart. Garcinia has also received worldwide attention as a nutraceutical for effective obesity control (Sullivan et al., 1974; Clouatre & Robenbaum, 1994). The title compound, (I), (Fig. 1) was extracted by a novel procedure (Balasubramanyam et al.,2000).
The five membered C1/C2/C3/C4/O2 lactone ring in (I) adopts an envelope conformation with C3 deviating by 0.539 (1) Å from the plane of the other four atoms. Selected torsion angles for O2/C4/C5/C6 and C2/C3/C6/O5 are -20.88 (1)° and -154.45 (1)°, respectively.
The crystal structure of (I) is stabilized by intermolecular O—H···O and intra- and intermolecular C—H···O hydrogen bonds (Table 1, Fig. 2).
For background literature, see: Sullivan et al. (1974); Clouatre & Robenbaum (1994). For the extraction procedure, see: Balasubramanyam et al., (2000).
Data collection: SMART (Bruker, 2004); cell refinement: SAINT (Bruker, 2004); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Bruker, 2000); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 (Farrugia, 1997) and CAMERON (Watkin et al., 1993); software used to prepare material for publication: PLATON (Spek, 2003).
C6H6O7 | Dx = 1.723 Mg m−3 |
Mr = 190.11 | Melting point = 449–451 K |
Orthorhombic, P212121 | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: P 2ac 2ab | Cell parameters from 545 reflections |
a = 6.2657 (10) Å | θ = 1.0–28.0° |
b = 8.6591 (14) Å | µ = 0.16 mm−1 |
c = 13.504 (2) Å | T = 292 K |
V = 732.7 (2) Å3 | Plate, colourless |
Z = 4 | 0.30 × 0.20 × 0.10 mm |
F(000) = 392 |
Bruker SMART APEX CCD diffractometer | 836 independent reflections |
Radiation source: fine-focus sealed tube | 810 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.022 |
φ and ω scans | θmax = 25.7°, θmin = 2.8° |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | h = −7→7 |
Tmin = 0.935, Tmax = 0.984 | k = −10→10 |
5568 measured reflections | l = −16→15 |
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)] = 0.027 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.066 | H-atom parameters constrained |
S = 1.10 | w = 1/[σ2(Fo2) + (0.0319P)2 + 0.2219P] where P = (Fo2 + 2Fc2)/3 |
836 reflections | (Δ/σ)max < 0.001 |
118 parameters | Δρmax = 0.21 e Å−3 |
0 restraints | Δρmin = −0.17 e Å−3 |
C6H6O7 | V = 732.7 (2) Å3 |
Mr = 190.11 | Z = 4 |
Orthorhombic, P212121 | Mo Kα radiation |
a = 6.2657 (10) Å | µ = 0.16 mm−1 |
b = 8.6591 (14) Å | T = 292 K |
c = 13.504 (2) Å | 0.30 × 0.20 × 0.10 mm |
Bruker SMART APEX CCD diffractometer | 836 independent reflections |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | 810 reflections with I > 2σ(I) |
Tmin = 0.935, Tmax = 0.984 | Rint = 0.022 |
5568 measured reflections |
R[F2 > 2σ(F2)] = 0.027 | 0 restraints |
wR(F2) = 0.066 | H-atom parameters constrained |
S = 1.10 | Δρmax = 0.21 e Å−3 |
836 reflections | Δρmin = −0.17 e Å−3 |
118 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 | ||
O5 | 1.0046 (2) | −0.15092 (19) | 0.14395 (13) | 0.0390 (4) | |
O6 | 0.4251 (2) | 0.00593 (19) | −0.05515 (12) | 0.0350 (4) | |
O3 | 0.7966 (2) | 0.09450 (18) | 0.23129 (10) | 0.0281 (4) | |
H3 | 0.9172 | 0.1169 | 0.2126 | 0.042* | |
O2 | 0.4978 (2) | 0.21068 (16) | 0.08633 (10) | 0.0259 (3) | |
O7 | 0.7760 (3) | −0.03680 (19) | −0.07537 (11) | 0.0336 (4) | |
H7 | 0.7377 | −0.0840 | −0.1249 | 0.050* | |
O4 | 0.6882 (2) | −0.25433 (17) | 0.10495 (12) | 0.0339 (4) | |
H4 | 0.7592 | −0.3321 | 0.0942 | 0.051* | |
O1 | 0.1911 (2) | 0.19661 (19) | 0.16734 (13) | 0.0371 (4) | |
C6 | 0.8148 (3) | −0.1423 (2) | 0.13577 (15) | 0.0254 (5) | |
C2 | 0.4591 (3) | −0.0075 (2) | 0.18784 (15) | 0.0250 (5) | |
H2A | 0.3931 | −0.0972 | 0.1576 | 0.030* | |
H2B | 0.4451 | −0.0149 | 0.2592 | 0.030* | |
C1 | 0.3614 (3) | 0.1399 (2) | 0.14948 (15) | 0.0252 (4) | |
C3 | 0.6927 (3) | 0.0069 (2) | 0.15732 (14) | 0.0213 (4) | |
C4 | 0.6711 (3) | 0.1092 (2) | 0.06284 (14) | 0.0216 (4) | |
H4A | 0.8023 | 0.1681 | 0.0515 | 0.026* | |
C5 | 0.6089 (3) | 0.0196 (2) | −0.03010 (14) | 0.0243 (5) |
U11 | U22 | U33 | U12 | U13 | U23 | |
O5 | 0.0218 (8) | 0.0381 (9) | 0.0570 (10) | 0.0038 (7) | −0.0013 (8) | 0.0039 (9) |
O6 | 0.0283 (9) | 0.0377 (9) | 0.0389 (9) | −0.0021 (8) | −0.0084 (7) | −0.0072 (7) |
O3 | 0.0240 (7) | 0.0391 (9) | 0.0212 (7) | −0.0047 (7) | −0.0007 (6) | −0.0034 (6) |
O2 | 0.0271 (8) | 0.0240 (7) | 0.0265 (7) | 0.0046 (6) | 0.0039 (7) | 0.0023 (6) |
O7 | 0.0336 (9) | 0.0420 (9) | 0.0253 (7) | 0.0052 (7) | 0.0015 (7) | −0.0095 (7) |
O4 | 0.0287 (8) | 0.0251 (7) | 0.0480 (10) | 0.0020 (7) | −0.0003 (7) | −0.0072 (7) |
O1 | 0.0246 (8) | 0.0359 (9) | 0.0510 (10) | 0.0055 (8) | 0.0084 (8) | −0.0037 (8) |
C6 | 0.0244 (10) | 0.0287 (11) | 0.0230 (10) | 0.0010 (9) | 0.0000 (9) | 0.0061 (9) |
C2 | 0.0221 (10) | 0.0274 (10) | 0.0254 (10) | 0.0003 (9) | 0.0036 (8) | 0.0016 (9) |
C1 | 0.0228 (10) | 0.0264 (10) | 0.0263 (10) | −0.0015 (9) | −0.0008 (9) | −0.0039 (9) |
C3 | 0.0207 (10) | 0.0260 (10) | 0.0173 (9) | −0.0030 (10) | −0.0003 (8) | 0.0010 (8) |
C4 | 0.0199 (9) | 0.0239 (9) | 0.0209 (10) | −0.0009 (9) | 0.0016 (8) | 0.0006 (8) |
C5 | 0.0279 (11) | 0.0233 (10) | 0.0215 (10) | 0.0005 (9) | 0.0002 (8) | 0.0019 (8) |
O5—C6 | 1.197 (2) | O1—C1 | 1.199 (3) |
O6—C5 | 1.206 (3) | C6—C3 | 1.530 (3) |
O3—C3 | 1.413 (2) | C2—C1 | 1.507 (3) |
O3—H3 | 0.8200 | C2—C3 | 1.526 (3) |
O2—C1 | 1.354 (2) | C2—H2A | 0.9700 |
O2—C4 | 1.433 (2) | C2—H2B | 0.9700 |
O7—C5 | 1.307 (3) | C3—C4 | 1.559 (3) |
O7—H7 | 0.8200 | C4—C5 | 1.526 (3) |
O4—C6 | 1.320 (3) | C4—H4A | 0.9800 |
O4—H4 | 0.8200 | ||
C3—O3—H3 | 109.5 | O3—C3—C2 | 107.16 (16) |
C1—O2—C4 | 109.88 (15) | O3—C3—C6 | 110.94 (16) |
C5—O7—H7 | 109.5 | C2—C3—C6 | 117.51 (17) |
C6—O4—H4 | 109.5 | O3—C3—C4 | 108.30 (16) |
O5—C6—O4 | 125.5 (2) | C2—C3—C4 | 100.64 (15) |
O5—C6—C3 | 122.1 (2) | C6—C3—C4 | 111.56 (15) |
O4—C6—C3 | 112.34 (16) | O2—C4—C5 | 107.47 (15) |
C1—C2—C3 | 103.13 (17) | O2—C4—C3 | 103.47 (15) |
C1—C2—H2A | 111.1 | C5—C4—C3 | 114.01 (16) |
C3—C2—H2A | 111.1 | O2—C4—H4A | 110.5 |
C1—C2—H2B | 111.1 | C5—C4—H4A | 110.5 |
C3—C2—H2B | 111.1 | C3—C4—H4A | 110.5 |
H2A—C2—H2B | 109.1 | O6—C5—O7 | 126.6 (2) |
O1—C1—O2 | 120.2 (2) | O6—C5—C4 | 121.64 (18) |
O1—C1—C2 | 129.7 (2) | O7—C5—C4 | 111.72 (18) |
O2—C1—C2 | 110.10 (17) | ||
C4—O2—C1—O1 | −169.51 (18) | C1—O2—C4—C5 | 91.59 (18) |
C4—O2—C1—C2 | 10.6 (2) | C1—O2—C4—C3 | −29.35 (19) |
C3—C2—C1—O1 | −166.8 (2) | O3—C3—C4—O2 | −76.88 (18) |
C3—C2—C1—O2 | 13.1 (2) | C2—C3—C4—O2 | 35.34 (19) |
C1—C2—C3—O3 | 84.37 (18) | C6—C3—C4—O2 | 160.76 (15) |
C1—C2—C3—C6 | −150.01 (17) | O3—C3—C4—C5 | 166.72 (15) |
C1—C2—C3—C4 | −28.73 (19) | C2—C3—C4—C5 | −81.1 (2) |
O5—C6—C3—O3 | −30.7 (3) | C6—C3—C4—C5 | 44.4 (2) |
O4—C6—C3—O3 | 151.34 (16) | O2—C4—C5—O6 | −20.9 (3) |
O5—C6—C3—C2 | −154.5 (2) | C3—C4—C5—O6 | 93.2 (2) |
O4—C6—C3—C2 | 27.6 (2) | O2—C4—C5—O7 | 159.30 (16) |
O5—C6—C3—C4 | 90.1 (3) | C3—C4—C5—O7 | −86.7 (2) |
O4—C6—C3—C4 | −87.8 (2) |
D—H···A | D—H | H···A | D···A | D—H···A |
O3—H3···O1i | 0.82 | 1.95 | 2.764 (2) | 173 |
O4—H4···O6ii | 0.82 | 1.90 | 2.721 (2) | 174 |
O7—H7···O3iii | 0.82 | 1.96 | 2.697 (2) | 150 |
C4—H4A···O2iv | 0.98 | 2.46 | 3.268 (2) | 139 |
C2—H2A···O4 | 0.97 | 2.40 | 2.808 (3) | 104 |
C2—H2A···O5v | 0.97 | 2.49 | 3.163 (2) | 127 |
Symmetry codes: (i) x+1, y, z; (ii) x+1/2, −y−1/2, −z; (iii) −x+3/2, −y, z−1/2; (iv) x+1/2, −y+1/2, −z; (v) x−1, y, z. |
Experimental details
Crystal data | |
Chemical formula | C6H6O7 |
Mr | 190.11 |
Crystal system, space group | Orthorhombic, P212121 |
Temperature (K) | 292 |
a, b, c (Å) | 6.2657 (10), 8.6591 (14), 13.504 (2) |
V (Å3) | 732.7 (2) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.16 |
Crystal size (mm) | 0.30 × 0.20 × 0.10 |
Data collection | |
Diffractometer | Bruker SMART APEX CCD |
Absorption correction | Multi-scan (SADABS; Sheldrick, 1996) |
Tmin, Tmax | 0.935, 0.984 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 5568, 836, 810 |
Rint | 0.022 |
(sin θ/λ)max (Å−1) | 0.609 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.027, 0.066, 1.10 |
No. of reflections | 836 |
No. of parameters | 118 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.21, −0.17 |
Computer programs: SMART (Bruker, 2004), SAINT (Bruker, 2004), SAINT, SHELXTL (Bruker, 2000), SHELXL97 (Sheldrick, 1997), ORTEP-3 (Farrugia, 1997) and CAMERON (Watkin et al., 1993), PLATON (Spek, 2003).
D—H···A | D—H | H···A | D···A | D—H···A |
O3—H3···O1i | 0.82 | 1.95 | 2.764 (2) | 173 |
O4—H4···O6ii | 0.82 | 1.90 | 2.721 (2) | 174 |
O7—H7···O3iii | 0.82 | 1.96 | 2.697 (2) | 150 |
C4—H4A···O2iv | 0.98 | 2.46 | 3.268 (2) | 139 |
C2—H2A···O4 | 0.97 | 2.40 | 2.808 (3) | 104 |
C2—H2A···O5v | 0.97 | 2.49 | 3.163 (2) | 127 |
Symmetry codes: (i) x+1, y, z; (ii) x+1/2, −y−1/2, −z; (iii) −x+3/2, −y, z−1/2; (iv) x+1/2, −y+1/2, −z; (v) x−1, y, z. |
The main active ingredient of Garcinia cambogia fruit rind is (-)hydroxycitric acid (HCA) along with Garcinia lactone and citric acid (Clouatre & Robenbaum, 1994). In India the fruit is known as kokum, the extract of which is used as a souring agent in cooking. In Indian medicine, Garcinia is considered to be one of the prime herbs that is beneficial for heart. Garcinia has also received worldwide attention as a nutraceutical for effective obesity control (Sullivan et al., 1974; Clouatre & Robenbaum, 1994). The title compound, (I), (Fig. 1) was extracted by a novel procedure (Balasubramanyam et al.,2000).
The five membered C1/C2/C3/C4/O2 lactone ring in (I) adopts an envelope conformation with C3 deviating by 0.539 (1) Å from the plane of the other four atoms. Selected torsion angles for O2/C4/C5/C6 and C2/C3/C6/O5 are -20.88 (1)° and -154.45 (1)°, respectively.
The crystal structure of (I) is stabilized by intermolecular O—H···O and intra- and intermolecular C—H···O hydrogen bonds (Table 1, Fig. 2).