PMCCPMCCPMCC

Search tips
Search criteria 

Advanced

 
Logo of actaeInternational Union of Crystallographysearchopen accessarticle submissionjournal home pagethis article
 
Acta Crystallogr Sect E Struct Rep Online. 2010 June 1; 66(Pt 6): o1366.
Published online 2010 May 15. doi:  10.1107/S1600536810017502
PMCID: PMC2979420

Alternariol

Abstract

In the title compound (systematic name: 3,7,9-trihydr­oxy-1-methyl-6H-benzo[c]chromen-6-one), C14H10O5, the methyl group is shifted out of the molecular plane due to a steric collision, thus causing a slight twist of the benzene rings. The mol­ecular structure is stabilized by an intra­molecular O—H(...)O hydrogen bond, generating an S(6) ring. In the crystal, mol­ecules are connected by inter­molecular O—H(...)O hydrogen bonds into a three-dimensional network.

Related literature

Alternariol is a mycotoxin (toxic secondary fungal metabolite) produced by ubiquitous Alternaria moulds. For information on occurence and toxicity, see: Weidenbörner (2001 [triangle]); Brugger et al. (2006 [triangle]); Wollenhaupt et al. (2008 [triangle]); Fehr et al. (2009 [triangle]). For crystallization, alternariol was obtained by total synthesis according to Koch et al. (2005 [triangle]). For a comparable structure, (2-chloro-7-hydr­oxy-8-methyl-6H-benzo[c]chromen-6-one), see: Appel et al. (2006 [triangle]).

An external file that holds a picture, illustration, etc.
Object name is e-66-o1366-scheme1.jpg

Experimental

Crystal data

  • C14H10O5
  • M r = 258.22
  • Orthorhombic, An external file that holds a picture, illustration, etc.
Object name is e-66-o1366-efi1.jpg
  • a = 18.969 (3) Å
  • b = 3.7244 (6) Å
  • c = 15.235 (3) Å
  • V = 1076.3 (3) Å3
  • Z = 4
  • Mo Kα radiation
  • μ = 0.12 mm−1
  • T = 150 K
  • 0.40 × 0.10 × 0.02 mm

Data collection

  • Stoe IPDS diffractometer
  • 6072 measured reflections
  • 1338 independent reflections
  • 1053 reflections with I > 2σ(I)
  • R int = 0.067

Refinement

  • R[F 2 > 2σ(F 2)] = 0.035
  • wR(F 2) = 0.069
  • S = 0.99
  • 1338 reflections
  • 191 parameters
  • 1 restraint
  • H atoms treated by a mixture of independent and constrained refinement
  • Δρmax = 0.16 e Å−3
  • Δρmin = −0.23 e Å−3

Data collection: X-AREA (Stoe & Cie, 2006 [triangle]); cell refinement: X-AREA; data reduction: X-AREA; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 [triangle]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 [triangle]); molecular graphics: DIAMOND (Brandenburg, 2010 [triangle]) and ORTEPIII (Burnett & Johnson, 1996 [triangle]); software used to prepare material for publication: SHELXTL (Sheldrick, 2008 [triangle]).

Table 1
Hydrogen-bond geometry (Å, °)

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536810017502/bt5266sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810017502/bt5266Isup2.hkl

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

supplementary crystallographic information

Comment

Alternariol is a cytotoxic, fetotoxic, teratogenic (Weidenbörner, 2001), mutagenic (Brugger et al., 2006, Wollenhaupt et al., 2008) and genotoxic (Fehr et al., 2009) mycotoxin produced by ubiquitous Alternaria fungi. It naturally occurs on fruits, vegetables and cereals like apples, tomatoes or wheat (Weidenbörner, 2001) and has also been obtained by total synthesis (Koch et al., 2005). The molecular structure of the title compound and the atom-labeling scheme are shown in Fig. 1. It is noteworthy that the benzene rings are not fully coplanar. This phenomenon is not observed for the benzo[c]chromen-6-one analogue 2-chloro-7-hydroxy-8-methyl-6H-benzo[c]chromen-6-one (Appel et al., 2006). Hence, the lacking planarity of the alternariol molecule may be attributed to a steric effect caused by the proximity of the H6A hydrogen to the C14 methyl group, which is not present in the planar analogue. This explanation is corroborated by the fact that the C8—C13—C14 angle is increased to 124.93 (17)°. The absolute configuration cannot be derived confidently since the molecule is a weak anomalous scatterer, which is documented by a large s.u. value for the Flack X parameter. Besides the intramolecular hydrogen bonds between O3—H3 and O2 (see dashed blue bonds in fig. 2), each molecule is connected to four adjacent molecules via intermolecular hydrogen bonds (see dashed green bonds in fig. 2). As a result undulated layers in the the ac plane are formed.

Experimental

Alternariol was supplied by the workgroup of Prof. R. Faust (University of Kassel, Germany) by total synthesis according to a literature procedure (Koch et al., 2005). Alternariol crystals were grown by sublimation in argon atmosphere. To do so, 100 mg of crude alternariol were heated to 380 °C for 2.5 h under a slow argon flow (atmospheric pressure). After cooling to room temperature, colourless needles could be collected from the water cooled compartment of the reaction vessel.

Refinement

In the absence of anomalous scatterers, the absolute structure cannot be determined therefore Friedel pairs were merged prior to refinement. The hydrogen atoms were located in difference maps and refined with Uiso(H) set to 1.2 Ueq of the parent atom (1.5 for methyl groups).

Figures

Fig. 1.
: ORTEP representation of the title compound with atomic labeling shown with 30% probability displacement ellipsoids.
Fig. 2.
: View of the unit cell of the title compound along [010], showing the hydrogen-bonded layers.

Crystal data

C14H10O5F(000) = 536
Mr = 258.22Dx = 1.594 Mg m3
Orthorhombic, Pca21Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2c -2acCell parameters from 1894 reflections
a = 18.969 (3) Åθ = 5–26°
b = 3.7244 (6) ŵ = 0.12 mm1
c = 15.235 (3) ÅT = 150 K
V = 1076.3 (3) Å3Needle, colourless
Z = 40.40 × 0.10 × 0.02 mm

Data collection

Stoe IPDS diffractometer1053 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tubeRint = 0.067
graphiteθmax = 28.1°, θmin = 2.5°
rotation method scansh = −24→22
6072 measured reflectionsk = −4→4
1338 independent reflectionsl = −20→20

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)] = 0.035Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.069H atoms treated by a mixture of independent and constrained refinement
S = 0.99w = 1/[σ2(Fo2) + (0.0314P)2] where P = (Fo2 + 2Fc2)/3
1338 reflections(Δ/σ)max < 0.001
191 parametersΔρmax = 0.16 e Å3
1 restraintΔρmin = −0.23 e Å3

Special details

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds 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
O10.54295 (9)0.3728 (6)0.78417 (11)0.0213 (4)
O20.44464 (9)0.1215 (6)0.74006 (11)0.0272 (5)
O30.42666 (9)−0.0612 (6)0.57652 (13)0.0277 (5)
H30.4192 (17)−0.038 (10)0.632 (2)0.033*
O40.61983 (10)0.1209 (7)0.38531 (11)0.0275 (5)
H40.5946 (18)0.002 (10)0.344 (2)0.033*
O50.74389 (10)0.8553 (6)0.91670 (10)0.0260 (5)
H50.78430.93070.90380.031*
C10.50516 (13)0.2203 (8)0.71956 (16)0.0193 (6)
C20.53589 (13)0.1856 (8)0.63425 (15)0.0167 (6)
C30.49365 (13)0.0493 (8)0.56447 (16)0.0192 (6)
C40.52045 (14)0.0246 (8)0.48049 (17)0.0194 (6)
H4A0.4917 (15)−0.072 (8)0.4295 (19)0.023*
C50.58935 (13)0.1357 (9)0.46651 (15)0.0183 (6)
C60.63205 (15)0.2688 (8)0.53304 (15)0.0178 (6)
H6A0.6788 (15)0.341 (8)0.5183 (18)0.021*
C70.60688 (12)0.2911 (7)0.61830 (15)0.0135 (5)
C80.64850 (13)0.4228 (7)0.69286 (14)0.0141 (5)
C90.61339 (12)0.4710 (8)0.77287 (16)0.0166 (6)
C100.64335 (14)0.6136 (8)0.84775 (16)0.0194 (6)
H100.6189 (14)0.644 (8)0.9006 (18)0.023*
C110.71326 (13)0.7093 (8)0.84418 (16)0.0186 (6)
C120.75199 (13)0.6479 (8)0.76803 (16)0.0159 (5)
H120.7968 (16)0.696 (8)0.7685 (17)0.019*
C130.72187 (13)0.5072 (7)0.69300 (15)0.0146 (5)
C140.77182 (13)0.4380 (8)0.61791 (16)0.0198 (6)
H14A0.82050.46830.63820.030*
H14B0.76220.60830.57040.030*
H14C0.76520.19230.59640.030*

Atomic displacement parameters (Å2)

U11U22U33U12U13U23
O10.0154 (8)0.0343 (13)0.0141 (8)−0.0028 (8)0.0031 (6)−0.0013 (9)
O20.0164 (9)0.0475 (14)0.0177 (8)−0.0068 (9)0.0028 (7)0.0060 (9)
O30.0125 (9)0.0439 (14)0.0268 (10)−0.0096 (9)0.0011 (8)−0.0021 (11)
O40.0164 (9)0.0518 (15)0.0143 (9)−0.0034 (10)−0.0002 (7)−0.0092 (9)
O50.0244 (10)0.0405 (13)0.0131 (8)−0.0053 (9)−0.0034 (7)−0.0063 (9)
C10.0152 (13)0.0243 (18)0.0183 (13)−0.0006 (11)−0.0013 (9)0.0027 (11)
C20.0139 (12)0.0187 (16)0.0176 (12)0.0002 (10)0.0010 (9)0.0038 (11)
C30.0113 (12)0.0239 (17)0.0222 (13)−0.0027 (11)−0.0021 (10)0.0012 (12)
C40.0166 (13)0.0218 (17)0.0200 (12)0.0027 (11)−0.0052 (10)−0.0022 (11)
C50.0149 (13)0.0277 (17)0.0123 (11)0.0025 (12)0.0021 (9)−0.0019 (12)
C60.0134 (12)0.0226 (17)0.0175 (12)0.0001 (10)0.0012 (9)−0.0003 (11)
C70.0124 (11)0.0153 (15)0.0127 (11)0.0024 (9)0.0007 (9)0.0026 (11)
C80.0170 (12)0.0150 (14)0.0102 (10)0.0036 (10)−0.0006 (9)−0.0001 (10)
C90.0129 (11)0.0216 (17)0.0153 (10)0.0008 (10)−0.0006 (10)0.0035 (11)
C100.0207 (14)0.0257 (17)0.0117 (11)0.0037 (11)0.0030 (9)0.0001 (11)
C110.0205 (13)0.0227 (17)0.0125 (11)0.0014 (11)−0.0061 (10)−0.0013 (11)
C120.0124 (11)0.0191 (15)0.0163 (11)0.0014 (10)−0.0020 (9)0.0014 (11)
C130.0166 (12)0.0139 (15)0.0133 (10)0.0023 (10)0.0015 (9)0.0030 (10)
C140.0130 (12)0.0279 (17)0.0184 (11)−0.0009 (10)0.0004 (9)−0.0038 (12)

Geometric parameters (Å, °)

O1—C11.343 (3)C6—C71.386 (3)
O1—C91.396 (3)C6—H6A0.95 (3)
O2—C11.245 (3)C7—C81.468 (3)
O3—C31.348 (3)C8—C91.401 (3)
O3—H30.86 (3)C8—C131.427 (4)
O4—C51.367 (3)C9—C101.381 (4)
O4—H40.91 (4)C10—C111.374 (4)
O5—C111.362 (3)C10—H100.94 (3)
O5—H50.8400C11—C121.392 (4)
C1—C21.430 (3)C12—C131.381 (4)
C2—C71.424 (3)C12—H120.87 (3)
C2—C31.425 (4)C13—C141.508 (3)
C3—C41.380 (3)C14—H14A0.9800
C4—C51.387 (4)C14—H14B0.9800
C4—H4A1.01 (3)C14—H14C0.9800
C5—C61.389 (4)
C1—O1—C9122.07 (19)C9—C8—C13115.7 (2)
C3—O3—H3105 (2)C9—C8—C7117.4 (2)
C5—O4—H4115 (2)C13—C8—C7126.8 (2)
C11—O5—H5109.5C10—C9—O1113.1 (2)
O2—C1—O1115.6 (2)C10—C9—C8124.9 (2)
O2—C1—C2125.2 (2)O1—C9—C8121.9 (2)
O1—C1—C2119.1 (2)C11—C10—C9117.7 (2)
C7—C2—C3120.2 (2)C11—C10—H10118.7 (17)
C7—C2—C1121.0 (2)C9—C10—H10123.6 (17)
C3—C2—C1118.8 (2)O5—C11—C10118.9 (2)
O3—C3—C4116.9 (2)O5—C11—C12121.1 (2)
O3—C3—C2122.5 (2)C10—C11—C12120.0 (2)
C4—C3—C2120.6 (2)C13—C12—C11122.2 (2)
C3—C4—C5118.0 (2)C13—C12—H12119.3 (18)
C3—C4—H4A122.4 (16)C11—C12—H12118.4 (18)
C5—C4—H4A119.6 (16)C12—C13—C8119.2 (2)
O4—C5—C4121.7 (2)C12—C13—C14115.6 (2)
O4—C5—C6115.4 (2)C8—C13—C14125.1 (2)
C4—C5—C6122.9 (2)C13—C14—H14A109.5
C7—C6—C5120.3 (2)C13—C14—H14B109.5
C7—C6—H6A121.6 (17)H14A—C14—H14B109.5
C5—C6—H6A118.1 (17)C13—C14—H14C109.5
C6—C7—C2118.0 (2)H14A—C14—H14C109.5
C6—C7—C8124.1 (2)H14B—C14—H14C109.5
C2—C7—C8118.0 (2)
C9—O1—C1—O2174.9 (2)C6—C7—C8—C9172.4 (3)
C9—O1—C1—C2−5.6 (4)C2—C7—C8—C9−6.5 (4)
O2—C1—C2—C7−176.9 (3)C6—C7—C8—C13−7.9 (4)
O1—C1—C2—C73.6 (4)C2—C7—C8—C13173.3 (3)
O2—C1—C2—C34.3 (4)C1—O1—C9—C10−178.2 (3)
O1—C1—C2—C3−175.2 (3)C1—O1—C9—C81.3 (4)
C7—C2—C3—O3178.6 (3)C13—C8—C9—C104.5 (4)
C1—C2—C3—O3−2.6 (4)C7—C8—C9—C10−175.7 (3)
C7—C2—C3—C4−1.3 (4)C13—C8—C9—O1−174.9 (2)
C1—C2—C3—C4177.5 (3)C7—C8—C9—O14.8 (4)
O3—C3—C4—C5−179.8 (3)O1—C9—C10—C11178.2 (3)
C2—C3—C4—C50.1 (4)C8—C9—C10—C11−1.3 (4)
C3—C4—C5—O4−179.9 (3)C9—C10—C11—O5179.1 (2)
C3—C4—C5—C60.1 (5)C9—C10—C11—C12−2.6 (4)
O4—C5—C6—C7−179.1 (3)O5—C11—C12—C13−178.6 (3)
C4—C5—C6—C70.9 (5)C10—C11—C12—C133.1 (4)
C5—C6—C7—C2−2.1 (4)C11—C12—C13—C80.3 (4)
C5—C6—C7—C8179.1 (3)C11—C12—C13—C14−176.7 (3)
C3—C2—C7—C62.3 (4)C9—C8—C13—C12−3.9 (4)
C1—C2—C7—C6−176.5 (3)C7—C8—C13—C12176.4 (3)
C3—C2—C7—C8−178.8 (3)C9—C8—C13—C14172.9 (3)
C1—C2—C7—C82.5 (4)C7—C8—C13—C14−6.8 (4)

Hydrogen-bond geometry (Å, °)

D—H···AD—HH···AD···AD—H···A
O3—H3···O20.86 (3)1.82 (3)2.605 (3)152 (3)
O4—H4···O2i0.91 (3)1.81 (3)2.685 (3)162 (3)
O5—H5···O4ii0.841.972.809 (2)175

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

Footnotes

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: BT5266).

References

  • Appel, B., Saleh, N. N. R. & Langer, P. (2006). Chem. Eur. J.12, 1221–1236. [PubMed]
  • Brandenburg, K. (2010). DIAMOND Crystal Impact GbR, Bonn, Germany.
  • Brugger, E. M., Wagner, J., Schumacher, D. M., Koch, K., Podlech, J., Metzler, M. & Lehmann, L. (2006). Toxicol. Lett.164, 221–230. [PubMed]
  • Burnett, M. N. & Johnson, C. K. (1996). ORTEPIII Report ORNL-6895. Oak Ridge National Laboratory, Tennessee, USA.
  • Fehr, M., Pahlke, G., Fritz, J., Christensen, M. O., Boege, F., Altemoller, M., Podlech, J. & Marko, D. (2009). Mol. Nutr. Food Res.53, 441–451. [PubMed]
  • Koch, K., Podlech, J., Pfeiffer, E. & Metzler, M. (2005). J. Org. Chem.70, 3275–3276. [PubMed]
  • Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. [PubMed]
  • Stoe & Cie (2006). X-AREA Stoe & Cie, Darmstadt, Germany.
  • Weidenbörner, M. (2001). Encyclopedia of Food Mycotoxins, 1st ed. Berlin: Springer.
  • Wollenhaupt, K., Schneider, F. & Tiemann, U. (2008). Toxicol. Lett.182, 57–62. [PubMed]

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