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Acta Crystallogr Sect E Struct Rep Online. 2008 July 1; 64(Pt 7): o1348–o1349.
Published online 2008 June 28. doi:  10.1107/S1600536808018941
PMCID: PMC2961850

(3S,3aS,5aS,7S,8S,10aS,10bR)-7,8-Dihydr­oxy-3-isopropyl-5a,8-dimethyl-2,3,4,5,5a,6,7,8,10a,10b-deca­hydro­cyclo­hepta­[e]indene-3a(1H)-carboxylic acid

Abstract

The mol­ecule of the title compound, C20H32O4, is built up from three fused five-membered, six-membered and seven-membered rings. The five-membered ring has an envelope conformation, whereas the six- and seven-membered rings have chair conformations. The crystal structure is stabilized by strong inter­molecular O—H(...)O hydrogen bonds, forming a three-dimensional network. The absolute configuration was assigned on the basis of earlier chemical studies.

Related literature

For related literature, see: Araya et al. (2003 [triangle]); Cremer & Pople (1975 [triangle]); Fuentes et al. (2005 [triangle]); Loyola et al. (1996 [triangle], 2004 [triangle]); Wickens (1995 [triangle]).

An external file that holds a picture, illustration, etc.
Object name is e-64-o1348-scheme1.jpg

Experimental

Crystal data

  • C20H32O4
  • M r = 336.46
  • Orthorhombic, An external file that holds a picture, illustration, etc.
Object name is e-64-o1348-efi1.jpg
  • a = 11.094 (7) Å
  • b = 12.728 (10) Å
  • c = 13.8776 (11) Å
  • V = 1959.6 (19) Å3
  • Z = 4
  • Mo Kα radiation
  • μ = 0.08 mm−1
  • T = 298 (2) K
  • 0.30 × 0.20 × 0.10 mm

Data collection

  • Nonius KappaCCD area-detector diffractometer
  • Absorption correction: none
  • 9149 measured reflections
  • 1922 independent reflections
  • 1836 reflections with I > 2σ(I)
  • R int = 0.072

Refinement

  • R[F 2 > 2σ(F 2)] = 0.039
  • wR(F 2) = 0.117
  • S = 1.13
  • 1922 reflections
  • 226 parameters
  • H-atom parameters constrained
  • Δρmax = 0.21 e Å−3
  • Δρmin = −0.14 e Å−3

Data collection: COLLECT (Nonius, 2000 [triangle]); cell refinement: DENZO-SMN (Otwinowski & Minor, 1997 [triangle]); data reduction: DENZO-SMN; program(s) used to solve structure: SIR97 (Altomare et al., 1999 [triangle]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 [triangle]); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997 [triangle]) and PLATON (Spek, 2003 [triangle]); software used to prepare material for publication: WinGX (Farrugia, 1999 [triangle]).

Table 1
Hydrogen-bond geometry (Å, °)

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536808018941/bt2730sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808018941/bt2730Isup2.hkl

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

Acknowledgments

LAL thanks the Fondo Nacional de Desarrollo Científico y Tecnológico de Chile for grant 1060339. We thank the Spanish Research Council (CSIC) for providing us with a free-of-charge licence for the Cambridge Structural Database.

supplementary crystallographic information

Comment

Azorella compacta is a compact resinous cushion shrub that grows in the Andes of Peru, Bolivia, Argentina and Chile and has been used in folk medicine. The common name llareta is used for several species of the genus Azorella (Wickens, 1995). Mulinane diterpenes exhibits antiplasmodial (Loyola et al., 2004), anti-Tripanosoma cruzi (Araya et al., 2003) and antihyperglycemic (Fuentes et al., 2005) activities.We have undertaken the X-ray crystal-structure determination of the title compound in order to establish its molecular conformation and relative stereochemistry. We are not able to determine the absolute stereochemistry by X-ray methods and the configuration shown here was chosen to be in accord with that reported in previous chemical studies (Loyola et al., 1996). The structure consists of a mulinic acid skeleton and the isopropyl, methyl groups and carboxylic acid at C3, C5a, C8 and C3b are α-oriented respectively, whereas the hydroxyl groups at C8 and C7 are β-oriented. The cyclopentane (A), cyclohexane (B) and cycloheptene (C) rings are in an envelope, chair and chair conformation respectively [Q2 = 0.435 (2) Å, [var phi]2= 118.7 (3)° for rig A; QT= 0.581 (2) Å, θ = 174.4 (2)°, [var phi]=131 (2)° for ring B; QT= 0.634 (2) Å, [var phi]2=78.4 (6)°, for ring C] (Cremer & Pople, 1975). The A and B and B and C rings are trans and cis-fused respectively. The molecular conformation is stabilized by four intramolecular hydrogen bonds and the crystal structure is stabilized by three intermolecular hydrogen bonds (Table 1).

Experimental

Dried and finely powdered whole plant of Azorella compacta (3,0 kg) were extracted with petroleum ether at room temperature. After filtration, the solvent was evaporated in vacuum yielding a gum (220 g). The concentrated petrol ether extract was adsorbed on silica gel (300 g) and slurried onto the top of a column containing silica gel (2.0 kg) in petroleum ether, and eluted with a petroleum ether/ethyl acetate gradient with increasing amounts of ethyl acetate to produce six fractions. Fraction 2 (100 g) eluted with petroleum ether/ethyl acetate(18:2) was further separated and purified by silica gel column chromatography(petroleum ether/ethyl acetate), 19:1) to give 600 mg of the title compound. The structure were elucidated by analysis of their spectroscopic data. Recrystallization from hexane-ethyl acetate (7:3) at room temperature afforded colourless crystals suitable for X-ray diffraction analysis.

Refinement

All H atoms were located on a difference Fourier map and then treated as riding atoms, with C - H bond lengths in the range 0.96 - 0.98 Å and O - H distances of 0.82 Å. For methyl atoms, Uiso(H) = 1.5Ueq(C), while for other H atoms, Uiso(H) = 1.2Ueq(C, O). In the absence of significant anomalous scattering effects, Friedel pairs were averaged. The absolute configuration shown here was chosen to be in accord with that reported in previous chemical studies (Loyola et al., 1996).

Figures

Fig. 1.
The molecule of compound (I), showing the atom-labelling scheme. Displacement ellipsoids are drawn at the 30% probability level and H atoms are shown as small spheres of arbitrary radii.

Crystal data

C20H32O4F000 = 736
Mr = 336.46Dx = 1.14 Mg m3
Orthorhombic, P212121Mo Kα radiation λ = 0.71073 Å
Hall symbol: P 2ac 2abCell parameters from 5686 reflections
a = 11.094 (7) Åθ = 2.3–25.2º
b = 12.728 (10) ŵ = 0.08 mm1
c = 13.8776 (11) ÅT = 298 (2) K
V = 1959.6 (19) Å3Block, colorless
Z = 40.30 × 0.20 × 0.10 mm

Data collection

Nonius KappaCCD area-detector diffractometer1836 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tubeRint = 0.072
Monochromator: graphiteθmax = 25.2º
[var phi] scans, and ω scans with κ offsetsθmin = 2.4º
Absorption correction: noneh = −9→13
9149 measured reflectionsk = −11→15
1922 independent reflectionsl = −15→16

Refinement

Refinement on F2H-atom parameters constrained
Least-squares matrix: full  w = 1/[σ2(Fo2) + (0.0775P)2 + 0.1473P] where P = (Fo2 + 2Fc2)/3
R[F2 > 2σ(F2)] = 0.039(Δ/σ)max = 0.005
wR(F2) = 0.117Δρmax = 0.21 e Å3
S = 1.13Δρmin = −0.14 e Å3
1922 reflectionsExtinction correction: none
226 parameters

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.
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)

xyzUiso*/Ueq
O10.22790 (18)0.80481 (16)0.67764 (12)0.0550 (5)
H10.23710.79690.61950.066 (2)*
O20.39658 (15)0.89409 (15)0.66282 (11)0.0497 (5)
O30.01429 (13)1.24195 (13)1.01859 (10)0.0361 (4)
H30.04081.19861.05680.066 (2)*
O40.27135 (13)1.21546 (12)0.99028 (10)0.0352 (4)
H40.34221.23210.98350.066 (2)*
C10.44994 (19)1.03680 (17)0.81893 (16)0.0368 (5)
H1A0.47781.09710.85540.046 (2)*
H1B0.47451.04460.75220.046 (2)*
C20.4986 (2)0.93369 (19)0.86208 (19)0.0431 (6)
H2A0.53960.94770.92240.046 (2)*
H2B0.55540.90140.8180.046 (2)*
C30.3898 (2)0.85939 (16)0.87930 (14)0.0338 (5)
H3A0.36420.86990.94620.041*
C3A0.28837 (18)0.90550 (15)0.81408 (13)0.0278 (4)
C40.15886 (19)0.88598 (16)0.84672 (15)0.0330 (4)
H4A0.15240.89940.91530.046 (2)*
H4B0.13810.8130.83550.046 (2)*
C50.0704 (2)0.95643 (19)0.79272 (17)0.0407 (5)
H5A−0.00970.94390.81820.046 (2)*
H5B0.06980.93540.72550.046 (2)*
C5A0.09599 (19)1.07500 (17)0.79757 (15)0.0343 (5)
C60.06692 (18)1.11212 (16)0.90075 (14)0.0329 (4)
H6A−0.01361.08750.91590.046 (2)*
H6B0.12171.07580.94380.046 (2)*
C70.07182 (19)1.22815 (17)0.92647 (14)0.0322 (4)
H70.02321.26580.87870.039*
C80.1969 (2)1.27901 (16)0.92731 (15)0.0332 (5)
C90.2535 (2)1.28268 (17)0.82860 (15)0.0377 (5)
H90.28271.34810.80990.045*
C100.2678 (2)1.20670 (18)0.76493 (15)0.0390 (5)
H100.30861.22650.70930.047*
C10A0.22889 (19)1.09300 (16)0.76724 (13)0.0319 (4)
H10A0.23541.06750.70080.038*
C10B0.31312 (18)1.02422 (15)0.82710 (13)0.0286 (4)
H10B0.29361.03970.89450.034*
C110.4236 (2)0.74293 (17)0.86931 (15)0.0398 (5)
H110.46060.73350.80580.048*
C120.5173 (3)0.7132 (3)0.9447 (2)0.0599 (8)
H12A0.58440.76070.94080.066 (2)*
H12B0.54480.64270.93310.066 (2)*
H12C0.4820.71731.00770.066 (2)*
C130.3176 (3)0.6675 (2)0.8759 (3)0.0675 (9)
H13A0.27660.67770.93620.066 (2)*
H13B0.34630.59650.87210.066 (2)*
H13C0.26280.68080.82380.066 (2)*
C140.31036 (18)0.86941 (16)0.71064 (13)0.0301 (4)
C150.0128 (3)1.1305 (2)0.72577 (19)0.0545 (7)
H15A0.02561.10220.66250.066 (2)*
H15B0.03031.20440.72540.066 (2)*
H15C−0.06961.11980.74440.066 (2)*
C160.1909 (3)1.39039 (18)0.9685 (2)0.0525 (6)
H16A0.15861.3881.03260.066 (2)*
H16B0.13991.4330.92850.066 (2)*
H16C0.27041.420.97020.066 (2)*

Atomic displacement parameters (Å2)

U11U22U33U12U13U23
O10.0571 (10)0.0727 (11)0.0351 (9)−0.0269 (10)0.0080 (8)−0.0216 (8)
O20.0426 (9)0.0711 (12)0.0353 (8)−0.0131 (8)0.0105 (7)−0.0178 (8)
O30.0291 (7)0.0475 (9)0.0318 (8)0.0110 (6)0.0051 (6)−0.0001 (6)
O40.0272 (7)0.0449 (8)0.0335 (7)−0.0028 (7)0.0012 (6)0.0082 (6)
C10.0314 (11)0.0364 (10)0.0427 (11)−0.0054 (9)0.0010 (9)−0.0081 (9)
C20.0300 (10)0.0459 (12)0.0534 (14)0.0010 (10)−0.0109 (10)−0.0080 (10)
C30.0382 (11)0.0376 (10)0.0255 (9)0.0046 (9)−0.0058 (8)−0.0040 (8)
C3A0.0273 (9)0.0316 (9)0.0245 (9)−0.0005 (8)0.0013 (8)−0.0027 (7)
C40.0304 (9)0.0366 (10)0.0320 (9)−0.0052 (8)0.0054 (8)−0.0059 (8)
C50.0281 (10)0.0482 (12)0.0457 (12)−0.0008 (9)−0.0036 (9)−0.0128 (10)
C5A0.0308 (10)0.0420 (11)0.0302 (10)0.0071 (9)−0.0045 (8)−0.0040 (8)
C60.0252 (9)0.0400 (10)0.0337 (10)0.0016 (8)0.0015 (8)−0.0007 (8)
C70.0290 (9)0.0411 (10)0.0264 (9)0.0112 (9)0.0033 (8)0.0017 (8)
C80.0369 (10)0.0317 (9)0.0310 (10)0.0064 (9)0.0034 (8)0.0015 (8)
C90.0434 (12)0.0321 (9)0.0377 (11)0.0021 (9)0.0084 (9)0.0100 (8)
C100.0462 (12)0.0413 (11)0.0294 (10)0.0074 (10)0.0113 (9)0.0084 (8)
C10A0.0372 (10)0.0383 (10)0.0201 (8)0.0061 (9)0.0026 (8)−0.0012 (7)
C10B0.0285 (10)0.0310 (9)0.0263 (9)−0.0004 (8)0.0019 (7)−0.0029 (7)
C110.0444 (12)0.0388 (11)0.0362 (11)0.0101 (10)−0.0013 (10)0.0028 (8)
C120.0706 (18)0.0638 (16)0.0454 (13)0.0282 (15)−0.0104 (13)0.0082 (11)
C130.0611 (18)0.0407 (13)0.101 (2)0.0003 (13)0.0004 (17)0.0144 (14)
C140.0301 (9)0.0331 (9)0.0272 (9)0.0010 (8)−0.0024 (8)−0.0027 (7)
C150.0484 (13)0.0693 (16)0.0458 (13)0.0188 (13)−0.0178 (12)−0.0044 (13)
C160.0619 (15)0.0367 (12)0.0588 (15)−0.0006 (11)0.0168 (13)−0.0067 (11)

Geometric parameters (Å, °)

O1—C141.312 (3)C6—C71.520 (3)
O1—H10.82C6—H6A0.97
O2—C141.206 (3)C6—H6B0.97
O3—C71.440 (2)C7—C81.531 (3)
O3—H30.82C7—H70.98
O4—C81.449 (3)C8—C91.508 (3)
O4—H40.82C8—C161.530 (3)
C1—C10B1.531 (3)C9—C101.319 (3)
C1—C21.540 (3)C9—H90.93
C1—H1A0.97C10—C10A1.510 (3)
C1—H1B0.97C10—H100.93
C2—C31.551 (3)C10A—C10B1.526 (3)
C2—H2A0.97C10A—H10A0.98
C2—H2B0.97C10B—H10B0.98
C3—C111.535 (3)C11—C121.523 (3)
C3—C3A1.559 (3)C11—C131.521 (4)
C3—H3A0.98C11—H110.98
C3A—C41.527 (3)C12—H12A0.96
C3A—C141.527 (3)C12—H12B0.96
C3A—C10B1.546 (3)C12—H12C0.96
C4—C51.526 (3)C13—H13A0.96
C4—H4A0.97C13—H13B0.96
C4—H4B0.97C13—H13C0.96
C5—C5A1.537 (3)C15—H15A0.96
C5—H5A0.97C15—H15B0.96
C5—H5B0.97C15—H15C0.96
C5A—C151.531 (3)C16—H16A0.96
C5A—C61.542 (3)C16—H16B0.96
C5A—C10A1.550 (3)C16—H16C0.96
C14—O1—H1109.5O4—C8—C9109.10 (16)
C7—O3—H3109.5O4—C8—C16108.5 (2)
C8—O4—H4109.5C9—C8—C16109.20 (18)
C10B—C1—C2103.26 (18)O4—C8—C7106.57 (16)
C10B—C1—H1A111.1C9—C8—C7112.58 (18)
C2—C1—H1A111.1C16—C8—C7110.82 (19)
C10B—C1—H1B111.1C10—C9—C8129.5 (2)
C2—C1—H1B111.1C10—C9—H9115.3
H1A—C1—H1B109.1C8—C9—H9115.3
C1—C2—C3107.89 (18)C9—C10—C10A130.8 (2)
C1—C2—H2A110.1C9—C10—H10114.6
C3—C2—H2A110.1C10A—C10—H10114.6
C1—C2—H2B110.1C10—C10A—C10B112.72 (18)
C3—C2—H2B110.1C10—C10A—C5A114.76 (18)
H2A—C2—H2B108.4C10B—C10A—C5A110.47 (16)
C11—C3—C2112.66 (19)C10—C10A—H10A106.1
C11—C3—C3A119.15 (17)C10B—C10A—H10A106.1
C2—C3—C3A104.03 (17)C5A—C10A—H10A106.1
C11—C3—H3A106.8C10A—C10B—C1120.45 (18)
C2—C3—H3A106.8C10A—C10B—C3A112.84 (16)
C3A—C3—H3A106.8C1—C10B—C3A105.65 (16)
C4—C3A—C14112.35 (16)C10A—C10B—H10B105.6
C4—C3A—C10B106.94 (16)C1—C10B—H10B105.6
C14—C3A—C10B112.05 (16)C3A—C10B—H10B105.6
C4—C3A—C3116.49 (17)C12—C11—C13109.3 (2)
C14—C3A—C3108.49 (16)C12—C11—C3110.2 (2)
C10B—C3A—C399.89 (15)C13—C11—C3114.5 (2)
C3A—C4—C5111.34 (17)C12—C11—H11107.5
C3A—C4—H4A109.4C13—C11—H11107.5
C5—C4—H4A109.4C3—C11—H11107.5
C3A—C4—H4B109.4C11—C12—H12A109.5
C5—C4—H4B109.4C11—C12—H12B109.5
H4A—C4—H4B108H12A—C12—H12B109.5
C4—C5—C5A115.89 (18)C11—C12—H12C109.5
C4—C5—H5A108.3H12A—C12—H12C109.5
C5A—C5—H5A108.3H12B—C12—H12C109.5
C4—C5—H5B108.3C11—C13—H13A109.5
C5A—C5—H5B108.3C11—C13—H13B109.5
H5A—C5—H5B107.4H13A—C13—H13B109.5
C15—C5A—C5108.27 (19)C11—C13—H13C109.5
C15—C5A—C6109.69 (18)H13A—C13—H13C109.5
C5—C5A—C6107.63 (18)H13B—C13—H13C109.5
C15—C5A—C10A109.16 (19)O2—C14—O1121.61 (18)
C5—C5A—C10A107.99 (17)O2—C14—C3A124.46 (18)
C6—C5A—C10A113.94 (17)O1—C14—C3A113.90 (17)
C7—C6—C5A120.54 (18)C5A—C15—H15A109.5
C7—C6—H6A107.2C5A—C15—H15B109.5
C5A—C6—H6A107.2H15A—C15—H15B109.5
C7—C6—H6B107.2C5A—C15—H15C109.5
C5A—C6—H6B107.2H15A—C15—H15C109.5
H6A—C6—H6B106.8H15B—C15—H15C109.5
O3—C7—C6108.13 (17)C8—C16—H16A109.5
O3—C7—C8110.08 (17)C8—C16—H16B109.5
C6—C7—C8116.42 (17)H16A—C16—H16B109.5
O3—C7—H7107.3C8—C16—H16C109.5
C6—C7—H7107.3H16A—C16—H16C109.5
C8—C7—H7107.3H16B—C16—H16C109.5
C10B—C1—C2—C38.2 (2)C9—C10—C10A—C10B−79.8 (3)
C1—C2—C3—C11149.26 (18)C9—C10—C10A—C5A47.8 (3)
C1—C2—C3—C3A18.8 (2)C15—C5A—C10A—C1060.6 (2)
C11—C3—C3A—C481.3 (2)C5—C5A—C10A—C10178.06 (18)
C2—C3—C3A—C4−152.25 (18)C6—C5A—C10A—C10−62.4 (2)
C11—C3—C3A—C14−46.6 (2)C15—C5A—C10A—C10B−170.67 (17)
C2—C3—C3A—C1479.8 (2)C5—C5A—C10A—C10B−53.2 (2)
C11—C3—C3A—C10B−164.02 (18)C6—C5A—C10A—C10B66.3 (2)
C2—C3—C3A—C10B−37.57 (19)C10—C10A—C10B—C1−43.1 (2)
C14—C3A—C4—C5−68.2 (2)C5A—C10A—C10B—C1−172.95 (17)
C10B—C3A—C4—C555.2 (2)C10—C10A—C10B—C3A−169.03 (16)
C3—C3A—C4—C5165.83 (16)C5A—C10A—C10B—C3A61.1 (2)
C3A—C4—C5—C5A−55.1 (2)C2—C1—C10B—C10A−162.12 (17)
C4—C5—C5A—C15170.12 (19)C2—C1—C10B—C3A−32.9 (2)
C4—C5—C5A—C6−71.4 (2)C4—C3A—C10B—C10A−60.5 (2)
C4—C5—C5A—C10A52.0 (2)C14—C3A—C10B—C10A63.1 (2)
C15—C5A—C6—C7−56.7 (3)C3—C3A—C10B—C10A177.76 (15)
C5—C5A—C6—C7−174.27 (18)C4—C3A—C10B—C1165.97 (16)
C10A—C5A—C6—C766.0 (2)C14—C3A—C10B—C1−70.5 (2)
C5A—C6—C7—O3166.72 (16)C3—C3A—C10B—C144.2 (2)
C5A—C6—C7—C8−68.8 (2)C2—C3—C11—C1262.0 (3)
O3—C7—C8—O469.69 (19)C3A—C3—C11—C12−175.7 (2)
C6—C7—C8—O4−53.8 (2)C2—C3—C11—C13−174.3 (2)
O3—C7—C8—C9−170.74 (16)C3A—C3—C11—C13−52.1 (3)
C6—C7—C8—C965.8 (2)C4—C3A—C14—O2165.1 (2)
O3—C7—C8—C16−48.1 (2)C10B—C3A—C14—O244.7 (3)
C6—C7—C8—C16−171.59 (18)C3—C3A—C14—O2−64.7 (3)
O4—C8—C9—C1067.3 (3)C4—C3A—C14—O1−17.0 (2)
C16—C8—C9—C10−174.3 (3)C10B—C3A—C14—O1−137.48 (19)
C7—C8—C9—C10−50.8 (3)C3—C3A—C14—O1113.2 (2)
C8—C9—C10—C10A2.5 (4)

Hydrogen-bond geometry (Å, °)

D—H···AD—HH···AD···AD—H···A
O1—H1···O4i0.821.802.613 (3)170
O3—H3···O2ii0.822.012.825 (3)173
O4—H4···O3iii0.821.942.752 (3)172
C1—H1B···O20.972.442.889 (4)108
C5—H5B···O10.972.513.054 (4)116
C6—H6B···O40.972.522.901 (3)104
C16—H16A···O30.962.462.809 (4)101

Symmetry codes: (i) −x+1/2, −y+2, z−1/2; (ii) −x+1/2, −y+2, z+1/2; (iii) x+1/2, −y+5/2, −z+2.

Footnotes

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: BT2730).

References

  • Altomare, A., Burla, M. C., Camalli, M., Cascarano, G. L., Giacovazzo, C., Guagliardi, A., Moliterni, A. G. G., Polidori, G. & Spagna, R. (1999). J. Appl. Cryst.32, 115–119.
  • Araya, J. E., Neira, I., Da Silva, S., Mortara, R. A., Manque, P., Cordero, E., Sagua, H., Loyola, A., Bórquez, J., Morales, G. & González, J. (2003). Mem. Inst. Oswaldo Cruz, Rio de Janeiro, 98, 413–418. [PubMed]
  • Cremer, D. & Pople, J. A. (1975). J. Am. Chem. Soc.97, 1354–1358.
  • Farrugia, L. J. (1997). J. Appl. Cryst.30, 565.
  • Farrugia, L. J. (1999). J. Appl. Cryst.32, 837–838.
  • Fuentes, N. L., Sagua, H., Morales, G., Bórquez, J., San-Martín, A., Soto, J. & Loyola, L. A. (2005). Phytother. Res.19, 713–716. [PubMed]
  • Loyola, L., Bórquez, J., Morales, B. & San Martín, A. (1996). Phytochemistry, 43, 165–168.
  • Loyola, L. A., Bórquez, J., Morales, G., San-Martín, A., Darias, J., Flores, N. & Giménez, A. (2004). Phytochemistry, 65, 1931–1935. [PubMed]
  • Nonius (2000). COLLECT Nonius BV, Delft, The Netherlands.
  • Otwinowski, Z. & Minor, W. (1997). Methods in Enzymology, Vol. 276, Macromolecular Crystallography, Part A, edited by C. W. Carter Jr & R. M. Sweet, pp. 307–326. New York; Academic Press.
  • Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. [PubMed]
  • Spek, A. L. (2003). J. Appl. Cryst.36, 7–13.
  • Wickens, G. E. (1995). Econ. Bot.49, 207–212.

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