organic compounds
4-Oxo-2-phenylchroman-6-yl propionate
aDepartment of Chemistry, Wrocław University of Environmental and Life Sciences, 25. Norwida, 50-375 Wrocław, Poland, and bFaculty of Chemistry, University of Wrocław, 14. F. Joliot-Curie, 50-383 Wrocław, Poland
*Correspondence e-mail: bialonsk@eto.wchuwr.pl
In the structure of the title compound, C18H16O4, both the S and R enantiomers appear to occupy in a random way four symmetry-equivalent sites of the in an approximately 4:1/1:4 ratio. The chiral C atom of the pyrone ring together with the phenyl ring bonded to this atom are disordered over two positions, the occupancy factor of the major component being 0.809 (5). Adjacent molecules are linked by weak C—H⋯O hydrogen bonds.
Related literature
For background to ); Harborne & Williams (2000); Di Carlo et al.,(1999); Rice-Evans (2004); Wang (2000); Halliwell (1996); Rice-Evans et al. (1996); Kostrzewa-Susłow et al. (2008). For related structures, see: Shoja et al. (1998); Białońska et al. (2007).
and their properties, see: Harborne & Baxter (1999Experimental
Crystal data
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Data collection
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Refinement
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Data collection: CrysAlis CCD, (Oxford Diffraction, 2009); cell CrysAlis RED (Oxford Diffraction, 2009); data reduction: CrysAlis RED; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: XP (Bruker, 1999); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).
Supporting information
https://doi.org/10.1107/S1600536810012298/hg2666sup1.cif
contains datablocks global, I. DOI:Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536810012298/hg2666Isup2.hkl
The title compound was obtained during esterification of 6-hydroksyflavanone using propionyl chloride (Fig.2). Crystals of 6-propionoxyflavanone were grown from a THF (tetrahydrofurane) solution under ambient conditions.
Occupancy factors for C2, C2A, C11—C16 and C11A—C16A were refined. The C11A—C16A atoms were refined using ISOR restrain. All H atoms were placed at calculated positions. H atoms attached to carbons were constrained as riding atoms, with C–H set to 0.95 - 0.99 Å. Uiso(H) values were set to 1.2Ueq of the parent atom.
Flavonoids, which are the subject of our research, are biologically active substances naturally occuring in plants. The colour of flowers and leaves and its intensity is correlated with their presence. Due to the strong UV absorption,
play protective role in plants. They are also nectar indicators. protect plants from pathogens, act as inhibitors of auxins transport and also initiate formation of root nodules in papilionaceous plants [Harborne & Baxter, 1999; Harborne & Williams, 2000].So far,
have not been found in organisms of animals and humans, however worldwide research proved wide range of valuable biological activities of these compounds. These include antiallergic, antiatherogenic, antidiabetic, antidiarrheic, antiinflammatory, antihepatotoxic and anticancerogenic properties [Di Carlo et al., 1999; Rice-Evans, 2004; Wang, 2000]. The wide spectrum of their pharmacological activities depends on chemical structures. Especially important is presence of carbonyl group, as well as presence, number and location of hydroxyl groups. For example, the presence of hydroxyl groups in the B ring is the main factor determining antioxidant activity of [Halliwell, 1996; Rice-Evans et al., 1996].Transformation of
by means of microorganisms is a way of modification of their structure, as well as a helpful tool for elucidation of their metabolism in mammals [Kostrzewa-Susłow et al., 2008].The
of 6-propionoxyflavanone, together with numbering scheme employed, is presented in Fig. 1. In the present analysis, atoms at position 2 in the pyrone ring [C2 and H2 (major component) and C2A and H2A (minor component)] and phenyl ring [C11—C16 (major component) and C11A—C16A (minor component)] are clearly resolved. The C11—C16 (or C11A—C16A) phenyl ring is oriented almost perpendicular to the plane of the C5—C10 arene ring. The angle between the plane of the C11—C16 (C11A—C16A) ring and the plane of the C5—C10 ring is equal to 79.79 (12) ° (89.8 (5) °). The angle between the plane of carboxylate group and the plane of the C5—C10 ring is equal to 75.62 (8) °. The O1, C3, C4 O17 atoms are situated approximately in the plane of the C5—C10 arene ring (maximum deviation is equal to 0.040 (3) Å for O1). While deviation of the C18 and C2 atoms from the plane formed by the C5—C10 arene ring are equal to 1.140 (4) and 0.676 (4) Å, respectively, deviation of the C2A atom from the plane is equal to -0.403 (13) Å. Thus, two enantiomers revealing various conformations occupy equivalent sites, however somewhat randomly, not systematically, arranged in the The ratio of the two enantiomers (R:S) in an asymmetric part of the is approximately equal to 0.8:0.2, which gives a 4:1/1:4 ratio in the overall.For background to
and their properties, see: Harborne & Baxter (1999); Harborne & Williams (2000); Di Carlo et al.,(1999); Rice-Evans (2004); Wang (2000); Halliwell (1996); Rice-Evans et al. (1996); Kostrzewa-Susłow et al. (2008). For related structures, see: Shoja et al. (1998); Białońska et al. (2007).Data collection: CrysAlis CCD, (Oxford Diffraction, 2009); cell
CrysAlis RED (Oxford Diffraction, 2009); data reduction: CrysAlis RED (Oxford Diffraction, 2009); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: XP (Bruker (1999); software used to prepare material for publication: please supply.C18H16O4 | F(000) = 624 |
Mr = 296.31 | Dx = 1.331 Mg m−3 |
Monoclinic, P21/n | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2yn | Cell parameters from 2758 reflections |
a = 7.863 (2) Å | θ = 2.9–36.8° |
b = 17.876 (4) Å | µ = 0.09 mm−1 |
c = 10.731 (2) Å | T = 100 K |
β = 101.28 (3)° | Plate, colorless |
V = 1479.2 (6) Å3 | 0.32 × 0.15 × 0.09 mm |
Z = 4 |
Kuma KM4 CCD diffractometer | 1906 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.126 |
Graphite monochromator | θmax = 33.0°, θmin = 2.9° |
ω scan | h = −9→12 |
23501 measured reflections | k = −27→27 |
5512 independent reflections | l = −16→16 |
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)] = 0.063 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.140 | H-atom parameters constrained |
S = 0.86 | w = 1/[σ2(Fo2) + (0.0501P)2] where P = (Fo2 + 2Fc2)/3 |
5512 reflections | (Δ/σ)max < 0.001 |
263 parameters | Δρmax = 0.26 e Å−3 |
186 restraints | Δρmin = −0.20 e Å−3 |
C18H16O4 | V = 1479.2 (6) Å3 |
Mr = 296.31 | Z = 4 |
Monoclinic, P21/n | Mo Kα radiation |
a = 7.863 (2) Å | µ = 0.09 mm−1 |
b = 17.876 (4) Å | T = 100 K |
c = 10.731 (2) Å | 0.32 × 0.15 × 0.09 mm |
β = 101.28 (3)° |
Kuma KM4 CCD diffractometer | 1906 reflections with I > 2σ(I) |
23501 measured reflections | Rint = 0.126 |
5512 independent reflections |
R[F2 > 2σ(F2)] = 0.063 | 186 restraints |
wR(F2) = 0.140 | H-atom parameters constrained |
S = 0.86 | Δρmax = 0.26 e Å−3 |
5512 reflections | Δρmin = −0.20 e Å−3 |
263 parameters |
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. |
x | y | z | Uiso*/Ueq | Occ. (<1) | |
O1 | 0.08199 (17) | 0.09868 (7) | 0.26522 (11) | 0.0360 (3) | |
C3 | −0.2206 (2) | 0.11679 (11) | 0.28343 (16) | 0.0333 (5) | |
H3C | −0.2405 | 0.1702 | 0.2607 | 0.040* | 0.191 (5) |
H3D | −0.3312 | 0.0899 | 0.2539 | 0.040* | 0.191 (5) |
H3A | −0.3199 | 0.1516 | 0.2612 | 0.040* | 0.809 (5) |
H3B | −0.2583 | 0.0672 | 0.2469 | 0.040* | 0.809 (5) |
C2 | −0.0717 (3) | 0.14510 (17) | 0.2248 (2) | 0.0291 (7) | 0.809 (5) |
H2 | −0.0437 | 0.1975 | 0.2544 | 0.035* | 0.809 (5) |
C2A | −0.0799 (12) | 0.0847 (7) | 0.2107 (8) | 0.029 (3) | 0.191 (5) |
H2A | −0.0935 | 0.0290 | 0.2091 | 0.034* | 0.191 (5) |
O4 | −0.27867 (17) | 0.11284 (9) | 0.49357 (12) | 0.0510 (4) | |
C4 | −0.1720 (3) | 0.11027 (12) | 0.42566 (17) | 0.0367 (5) | |
C5 | 0.0761 (3) | 0.09439 (11) | 0.60752 (17) | 0.0354 (5) | |
H5 | −0.0024 | 0.0986 | 0.6641 | 0.042* | |
C6 | 0.2489 (2) | 0.08326 (10) | 0.65442 (16) | 0.0325 (5) | |
C7 | 0.3650 (3) | 0.07588 (11) | 0.57403 (18) | 0.0378 (5) | |
H7 | 0.4845 | 0.0680 | 0.6080 | 0.045* | |
C8 | 0.3072 (2) | 0.07993 (11) | 0.44393 (17) | 0.0375 (5) | |
H8 | 0.3865 | 0.0740 | 0.3883 | 0.045* | |
C9 | 0.1325 (2) | 0.09266 (10) | 0.39496 (16) | 0.0300 (4) | |
C10 | 0.0149 (2) | 0.09958 (10) | 0.47656 (16) | 0.0310 (4) | |
C11 | −0.1170 (4) | 0.1450 (3) | 0.0831 (3) | 0.0303 (7) | 0.809 (5) |
C12 | −0.1411 (5) | 0.0793 (2) | 0.0138 (4) | 0.0366 (9) | 0.809 (5) |
H12 | −0.1219 | 0.0327 | 0.0570 | 0.044* | 0.809 (5) |
C13 | −0.1934 (7) | 0.0798 (3) | −0.1190 (4) | 0.0397 (10) | 0.809 (5) |
H13 | −0.2060 | 0.0342 | −0.1652 | 0.048* | 0.809 (5) |
C14 | −0.2265 (7) | 0.1475 (3) | −0.1823 (5) | 0.0382 (11) | 0.809 (5) |
H14 | −0.2649 | 0.1483 | −0.2719 | 0.046* | 0.809 (5) |
C15 | −0.2034 (5) | 0.2140 (2) | −0.1141 (3) | 0.0417 (8) | 0.809 (5) |
H15 | −0.2251 | 0.2605 | −0.1572 | 0.050* | 0.809 (5) |
C16 | −0.1478 (4) | 0.2128 (2) | 0.0186 (3) | 0.0376 (7) | 0.809 (5) |
H16 | −0.1311 | 0.2585 | 0.0646 | 0.045* | 0.809 (5) |
C11A | −0.119 (2) | 0.1114 (11) | 0.0698 (17) | 0.034 (3) | 0.191 (5) |
C12A | −0.172 (2) | 0.0636 (11) | −0.0273 (17) | 0.037 (3) | 0.191 (5) |
H12A | −0.1752 | 0.0112 | −0.0136 | 0.045* | 0.191 (5) |
C13A | −0.220 (3) | 0.0935 (16) | −0.147 (2) | 0.040 (3) | 0.191 (5) |
H13A | −0.2685 | 0.0616 | −0.2153 | 0.048* | 0.191 (5) |
C14A | −0.201 (3) | 0.1676 (14) | −0.170 (2) | 0.035 (2) | 0.191 (5) |
H14A | −0.2292 | 0.1866 | −0.2541 | 0.042* | 0.191 (5) |
C15A | −0.142 (2) | 0.2133 (9) | −0.0714 (15) | 0.038 (2) | 0.191 (5) |
H15A | −0.1262 | 0.2652 | −0.0847 | 0.046* | 0.191 (5) |
C16A | −0.1042 (19) | 0.1832 (10) | 0.0494 (14) | 0.033 (2) | 0.191 (5) |
H16A | −0.0662 | 0.2154 | 0.1197 | 0.040* | 0.191 (5) |
O17 | 0.30900 (16) | 0.07682 (7) | 0.78730 (11) | 0.0366 (3) | |
O18 | 0.28558 (19) | 0.20177 (8) | 0.80597 (12) | 0.0481 (4) | |
C18 | 0.3155 (2) | 0.14193 (13) | 0.85498 (18) | 0.0368 (5) | |
C19 | 0.3615 (3) | 0.12719 (12) | 0.99504 (17) | 0.0429 (5) | |
H19A | 0.4743 | 0.1008 | 1.0143 | 0.051* | |
H19B | 0.2729 | 0.0937 | 1.0192 | 0.051* | |
C20 | 0.3734 (3) | 0.19745 (13) | 1.07435 (19) | 0.0525 (6) | |
H20A | 0.4030 | 0.1842 | 1.1646 | 0.079* | |
H20B | 0.2615 | 0.2234 | 1.0570 | 0.079* | |
H20C | 0.4632 | 0.2303 | 1.0529 | 0.079* |
U11 | U22 | U33 | U12 | U13 | U23 | |
O1 | 0.0336 (8) | 0.0530 (9) | 0.0217 (7) | 0.0076 (6) | 0.0058 (6) | 0.0035 (6) |
C3 | 0.0309 (10) | 0.0463 (12) | 0.0221 (9) | −0.0009 (9) | 0.0037 (8) | 0.0026 (8) |
C2 | 0.0281 (13) | 0.0357 (18) | 0.0218 (11) | 0.0042 (12) | 0.0009 (9) | 0.0039 (11) |
C2A | 0.029 (6) | 0.044 (8) | 0.015 (4) | −0.001 (5) | 0.009 (4) | 0.006 (4) |
O4 | 0.0312 (8) | 0.0941 (12) | 0.0288 (7) | −0.0055 (8) | 0.0086 (6) | 0.0014 (8) |
C4 | 0.0309 (10) | 0.0531 (13) | 0.0255 (10) | −0.0048 (10) | 0.0045 (9) | −0.0011 (9) |
C5 | 0.0328 (11) | 0.0499 (14) | 0.0244 (10) | −0.0013 (9) | 0.0081 (8) | 0.0012 (9) |
C6 | 0.0368 (11) | 0.0385 (12) | 0.0220 (9) | 0.0016 (9) | 0.0050 (8) | 0.0033 (8) |
C7 | 0.0312 (11) | 0.0504 (13) | 0.0309 (10) | 0.0068 (10) | 0.0037 (8) | 0.0064 (9) |
C8 | 0.0321 (11) | 0.0543 (14) | 0.0264 (10) | 0.0089 (10) | 0.0062 (8) | 0.0044 (9) |
C9 | 0.0351 (11) | 0.0333 (11) | 0.0207 (9) | 0.0024 (9) | 0.0030 (8) | 0.0024 (8) |
C10 | 0.0297 (10) | 0.0398 (12) | 0.0235 (10) | −0.0008 (8) | 0.0051 (8) | 0.0019 (8) |
C11 | 0.0287 (13) | 0.039 (2) | 0.0252 (14) | 0.0019 (18) | 0.0085 (10) | −0.0011 (15) |
C12 | 0.0418 (19) | 0.041 (2) | 0.0261 (19) | 0.0011 (16) | 0.0045 (16) | 0.0034 (16) |
C13 | 0.042 (2) | 0.050 (2) | 0.027 (2) | 0.0019 (17) | 0.0054 (16) | 0.0004 (16) |
C14 | 0.036 (2) | 0.057 (3) | 0.0211 (15) | 0.0063 (19) | 0.0045 (13) | −0.0009 (18) |
C15 | 0.049 (2) | 0.0538 (18) | 0.0220 (16) | 0.0168 (16) | 0.0050 (13) | 0.0067 (15) |
C16 | 0.0494 (18) | 0.0398 (18) | 0.0238 (15) | 0.0082 (14) | 0.0077 (12) | 0.0030 (13) |
C11A | 0.038 (4) | 0.036 (5) | 0.028 (4) | 0.003 (4) | 0.004 (4) | −0.004 (4) |
C12A | 0.040 (4) | 0.045 (4) | 0.026 (5) | 0.003 (4) | 0.004 (4) | −0.004 (4) |
C13A | 0.038 (4) | 0.052 (5) | 0.029 (5) | 0.006 (4) | 0.005 (4) | 0.004 (4) |
C14A | 0.037 (4) | 0.047 (4) | 0.023 (4) | 0.006 (4) | 0.011 (4) | 0.005 (4) |
C15A | 0.043 (4) | 0.041 (4) | 0.028 (4) | 0.008 (4) | 0.001 (4) | 0.003 (4) |
C16A | 0.041 (4) | 0.032 (5) | 0.025 (4) | 0.012 (4) | 0.003 (4) | −0.001 (4) |
O17 | 0.0386 (8) | 0.0457 (9) | 0.0231 (7) | 0.0039 (7) | −0.0001 (6) | 0.0015 (6) |
O18 | 0.0642 (10) | 0.0454 (9) | 0.0318 (8) | −0.0007 (8) | 0.0023 (7) | 0.0045 (7) |
C18 | 0.0311 (11) | 0.0506 (14) | 0.0284 (10) | 0.0003 (10) | 0.0047 (8) | 0.0015 (10) |
C19 | 0.0454 (12) | 0.0564 (14) | 0.0252 (10) | 0.0072 (11) | 0.0027 (9) | 0.0026 (9) |
C20 | 0.0544 (14) | 0.0722 (17) | 0.0289 (11) | 0.0118 (12) | 0.0032 (10) | −0.0057 (11) |
O1—C2A | 1.317 (10) | C12—C13 | 1.404 (5) |
O1—C9 | 1.375 (2) | C12—H12 | 0.9500 |
O1—C2 | 1.460 (3) | C13—C14 | 1.386 (6) |
C3—C4 | 1.504 (2) | C13—H13 | 0.9500 |
C3—C2 | 1.520 (3) | C14—C15 | 1.390 (6) |
C3—C2A | 1.581 (10) | C14—H14 | 0.9500 |
C3—H3C | 0.9900 | C15—C16 | 1.405 (4) |
C3—H3D | 0.9900 | C15—H15 | 0.9500 |
C3—H3A | 0.9899 | C16—H16 | 0.9500 |
C3—H3B | 0.9901 | C11A—C16A | 1.31 (2) |
C2—C11 | 1.492 (4) | C11A—C12A | 1.35 (2) |
C2—H2 | 1.0000 | C12A—C13A | 1.37 (2) |
C2A—C11A | 1.558 (19) | C12A—H12A | 0.9500 |
C2A—H3B | 1.5579 | C13A—C14A | 1.36 (3) |
C2A—H2A | 1.0000 | C13A—H13A | 0.9500 |
O4—C4 | 1.215 (2) | C14A—C15A | 1.35 (3) |
C4—C10 | 1.476 (3) | C14A—H14A | 0.9500 |
C5—C6 | 1.368 (3) | C15A—C16A | 1.381 (19) |
C5—C10 | 1.397 (2) | C15A—H15A | 0.9500 |
C5—H5 | 0.9500 | C16A—H16A | 0.9500 |
C6—C7 | 1.379 (3) | O17—C18 | 1.367 (2) |
C6—O17 | 1.416 (2) | O18—C18 | 1.195 (2) |
C7—C8 | 1.383 (3) | C18—C19 | 1.499 (3) |
C7—H7 | 0.9500 | C19—C20 | 1.510 (3) |
C8—C9 | 1.390 (3) | C19—H19A | 0.9900 |
C8—H8 | 0.9500 | C19—H19B | 0.9900 |
C9—C10 | 1.398 (2) | C20—H20A | 0.9800 |
C11—C12 | 1.383 (4) | C20—H20B | 0.9800 |
C11—C16 | 1.394 (4) | C20—H20C | 0.9800 |
C2A—O1—C9 | 119.8 (4) | C8—C9—C10 | 120.23 (16) |
C2A—O1—C2 | 45.9 (5) | C5—C10—C9 | 118.98 (18) |
C9—O1—C2 | 113.80 (15) | C5—C10—C4 | 120.20 (17) |
C4—C3—C2 | 112.49 (16) | C9—C10—C4 | 120.80 (16) |
C4—C3—C2A | 114.1 (4) | C12—C11—C16 | 118.7 (3) |
C2—C3—C2A | 41.1 (4) | C12—C11—C2 | 122.0 (4) |
C4—C3—H3C | 108.7 | C16—C11—C2 | 119.2 (3) |
C2—C3—H3C | 71.0 | C11—C12—C13 | 121.4 (4) |
C2A—C3—H3C | 108.7 | C11—C12—H12 | 119.3 |
C4—C3—H3D | 108.7 | C13—C12—H12 | 119.3 |
C2—C3—H3D | 136.7 | C14—C13—C12 | 119.6 (5) |
C2A—C3—H3D | 108.7 | C14—C13—H13 | 120.2 |
H3C—C3—H3D | 107.6 | C12—C13—H13 | 120.2 |
C4—C3—H3A | 109.0 | C13—C14—C15 | 119.7 (5) |
C2—C3—H3A | 109.0 | C13—C14—H14 | 120.1 |
C2A—C3—H3A | 134.8 | C15—C14—H14 | 120.1 |
H3C—C3—H3A | 41.9 | C14—C15—C16 | 120.2 (4) |
H3D—C3—H3A | 68.1 | C14—C15—H15 | 119.9 |
C4—C3—H3B | 109.3 | C16—C15—H15 | 119.9 |
C2—C3—H3B | 109.2 | C11—C16—C15 | 120.4 (3) |
C2A—C3—H3B | 70.3 | C11—C16—H16 | 119.8 |
H3C—C3—H3B | 138.1 | C15—C16—H16 | 119.8 |
H3D—C3—H3B | 42.5 | C16A—C11A—C12A | 121.0 (17) |
H3A—C3—H3B | 107.8 | C16A—C11A—C2A | 117.1 (16) |
O1—C2—C11 | 108.7 (2) | C12A—C11A—C2A | 121.9 (17) |
O1—C2—C3 | 110.33 (18) | C11A—C12A—C13A | 118 (2) |
C11—C2—C3 | 111.8 (2) | C11A—C12A—H12A | 121.2 |
O1—C2—H2 | 108.6 | C13A—C12A—H12A | 121.2 |
C11—C2—H2 | 108.6 | C14A—C13A—C12A | 122 (2) |
C3—C2—H2 | 108.6 | C14A—C13A—H13A | 119.0 |
O1—C2A—C11A | 111.4 (9) | C12A—C13A—H13A | 119.0 |
O1—C2A—C3 | 114.9 (7) | C15A—C14A—C13A | 119 (2) |
C11A—C2A—C3 | 109.9 (9) | C15A—C14A—H14A | 120.6 |
O1—C2A—H3B | 140.0 | C13A—C14A—H14A | 120.6 |
C11A—C2A—H3B | 106.5 | C14A—C15A—C16A | 118.6 (16) |
C3—C2A—H3B | 36.8 | C14A—C15A—H15A | 120.7 |
O1—C2A—H2A | 106.7 | C16A—C15A—H15A | 120.7 |
C11A—C2A—H2A | 106.7 | C11A—C16A—C15A | 121.9 (14) |
C3—C2A—H2A | 106.7 | C11A—C16A—H16A | 119.0 |
H3B—C2A—H2A | 73.0 | C15A—C16A—H16A | 119.0 |
O4—C4—C10 | 122.48 (16) | C18—O17—C6 | 115.85 (15) |
O4—C4—C3 | 122.51 (18) | O18—C18—O17 | 122.98 (18) |
C10—C4—C3 | 115.01 (16) | O18—C18—C19 | 125.9 (2) |
C6—C5—C10 | 120.12 (18) | O17—C18—C19 | 111.08 (18) |
C6—C5—H5 | 119.9 | C18—C19—C20 | 113.28 (19) |
C10—C5—H5 | 119.9 | C18—C19—H19A | 108.9 |
C5—C6—C7 | 120.98 (17) | C20—C19—H19A | 108.9 |
C5—C6—O17 | 119.59 (17) | C18—C19—H19B | 108.9 |
C7—C6—O17 | 119.39 (17) | C20—C19—H19B | 108.9 |
C6—C7—C8 | 119.97 (19) | H19A—C19—H19B | 107.7 |
C6—C7—H7 | 120.0 | C19—C20—H20A | 109.5 |
C8—C7—H7 | 120.0 | C19—C20—H20B | 109.5 |
C7—C8—C9 | 119.70 (18) | H20A—C20—H20B | 109.5 |
C7—C8—H8 | 120.1 | C19—C20—H20C | 109.5 |
C9—C8—H8 | 120.1 | H20A—C20—H20C | 109.5 |
O1—C9—C8 | 117.62 (17) | H20B—C20—H20C | 109.5 |
O1—C9—C10 | 122.15 (17) | ||
C2A—O1—C2—C11 | −68.7 (5) | C8—C9—C10—C4 | −177.69 (18) |
C9—O1—C2—C11 | −177.9 (2) | O4—C4—C10—C5 | −2.1 (3) |
C2A—O1—C2—C3 | 54.2 (5) | C3—C4—C10—C5 | 178.64 (18) |
C9—O1—C2—C3 | −55.0 (2) | O4—C4—C10—C9 | 176.33 (19) |
C4—C3—C2—O1 | 53.9 (3) | C3—C4—C10—C9 | −2.9 (3) |
C2A—C3—C2—O1 | −47.5 (5) | O1—C2—C11—C12 | 53.9 (4) |
C4—C3—C2—C11 | 175.0 (2) | C3—C2—C11—C12 | −68.2 (4) |
C2A—C3—C2—C11 | 73.6 (5) | O1—C2—C11—C16 | −130.7 (3) |
C9—O1—C2A—C11A | 167.4 (8) | C3—C2—C11—C16 | 107.3 (3) |
C2—O1—C2A—C11A | 72.1 (9) | C16—C11—C12—C13 | 0.8 (5) |
C9—O1—C2A—C3 | 41.6 (10) | C2—C11—C12—C13 | 176.3 (4) |
C2—O1—C2A—C3 | −53.7 (7) | C11—C12—C13—C14 | −1.9 (7) |
C4—C3—C2A—O1 | −39.4 (10) | C12—C13—C14—C15 | 1.7 (8) |
C2—C3—C2A—O1 | 57.7 (7) | C13—C14—C15—C16 | −0.5 (7) |
C4—C3—C2A—C11A | −165.9 (8) | C12—C11—C16—C15 | 0.4 (5) |
C2—C3—C2A—C11A | −68.8 (9) | C2—C11—C16—C15 | −175.2 (3) |
C2—C3—C4—O4 | 155.4 (2) | C14—C15—C16—C11 | −0.6 (5) |
C2A—C3—C4—O4 | −159.7 (5) | O1—C2A—C11A—C16A | −61.9 (18) |
C2—C3—C4—C10 | −25.4 (3) | C3—C2A—C11A—C16A | 66.6 (17) |
C2A—C3—C4—C10 | 19.6 (6) | O1—C2A—C11A—C12A | 119.9 (17) |
C10—C5—C6—C7 | −1.0 (3) | C3—C2A—C11A—C12A | −111.6 (17) |
C10—C5—C6—O17 | −178.93 (17) | C16A—C11A—C12A—C13A | −5 (3) |
C5—C6—C7—C8 | 0.2 (3) | C2A—C11A—C12A—C13A | 173.6 (17) |
O17—C6—C7—C8 | 178.17 (18) | C11A—C12A—C13A—C14A | 6 (4) |
C6—C7—C8—C9 | 1.0 (3) | C12A—C13A—C14A—C15A | −4 (4) |
C2A—O1—C9—C8 | 156.3 (7) | C13A—C14A—C15A—C16A | −1 (3) |
C2—O1—C9—C8 | −152.26 (19) | C12A—C11A—C16A—C15A | 0 (3) |
C2A—O1—C9—C10 | −24.2 (7) | C2A—C11A—C16A—C15A | −177.7 (12) |
C2—O1—C9—C10 | 27.2 (3) | C14A—C15A—C16A—C11A | 2 (3) |
C7—C8—C9—O1 | 177.93 (18) | C5—C6—O17—C18 | −74.2 (2) |
C7—C8—C9—C10 | −1.5 (3) | C7—C6—O17—C18 | 107.8 (2) |
C6—C5—C10—C9 | 0.5 (3) | C6—O17—C18—O18 | −5.5 (3) |
C6—C5—C10—C4 | 178.93 (18) | C6—O17—C18—C19 | 173.63 (16) |
O1—C9—C10—C5 | −178.66 (17) | O18—C18—C19—C20 | −1.8 (3) |
C8—C9—C10—C5 | 0.8 (3) | O17—C18—C19—C20 | 179.05 (17) |
O1—C9—C10—C4 | 2.9 (3) |
D—H···A | D—H | H···A | D···A | D—H···A |
C2—H2···O18i | 1.00 | 2.37 | 3.145 (3) | 133 |
Symmetry code: (i) x−1/2, −y+1/2, z−1/2. |
Experimental details
Crystal data | |
Chemical formula | C18H16O4 |
Mr | 296.31 |
Crystal system, space group | Monoclinic, P21/n |
Temperature (K) | 100 |
a, b, c (Å) | 7.863 (2), 17.876 (4), 10.731 (2) |
β (°) | 101.28 (3) |
V (Å3) | 1479.2 (6) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.09 |
Crystal size (mm) | 0.32 × 0.15 × 0.09 |
Data collection | |
Diffractometer | Kuma KM4 CCD |
Absorption correction | – |
No. of measured, independent and observed [I > 2σ(I)] reflections | 23501, 5512, 1906 |
Rint | 0.126 |
(sin θ/λ)max (Å−1) | 0.766 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.063, 0.140, 0.86 |
No. of reflections | 5512 |
No. of parameters | 263 |
No. of restraints | 186 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.26, −0.20 |
Computer programs: CrysAlis CCD, (Oxford Diffraction, 2009), CrysAlis RED (Oxford Diffraction, 2009), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), XP (Bruker (1999), please supply.
D—H···A | D—H | H···A | D···A | D—H···A |
C2—H2···O18i | 1.00 | 2.37 | 3.145 (3) | 133.2 |
Symmetry code: (i) x−1/2, −y+1/2, z−1/2. |
Acknowledgements
Publication/Project "Biotransformations for pharmaceutical and cosmetics industry" No. POIG.01.03.01-00-158/09-00 was part-financed by the European Union within the European Regional Development Fund.
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This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.
Flavonoids, which are the subject of our research, are biologically active substances naturally occuring in plants. The colour of flowers and leaves and its intensity is correlated with their presence. Due to the strong UV absorption, flavonoids play protective role in plants. They are also nectar indicators. Flavonoids protect plants from pathogens, act as inhibitors of auxins transport and also initiate formation of root nodules in papilionaceous plants [Harborne & Baxter, 1999; Harborne & Williams, 2000].
So far, flavonoids have not been found in organisms of animals and humans, however worldwide research proved wide range of valuable biological activities of these compounds. These include antiallergic, antiatherogenic, antidiabetic, antidiarrheic, antiinflammatory, antihepatotoxic and anticancerogenic properties [Di Carlo et al., 1999; Rice-Evans, 2004; Wang, 2000]. The wide spectrum of their pharmacological activities depends on chemical structures. Especially important is presence of carbonyl group, as well as presence, number and location of hydroxyl groups. For example, the presence of hydroxyl groups in the B ring is the main factor determining antioxidant activity of flavonoids [Halliwell, 1996; Rice-Evans et al., 1996].
Transformation of flavonoids by means of microorganisms is a way of modification of their structure, as well as a helpful tool for elucidation of their metabolism in mammals [Kostrzewa-Susłow et al., 2008].
The crystal structure of 6-propionoxyflavanone, together with numbering scheme employed, is presented in Fig. 1. In the present analysis, atoms at position 2 in the pyrone ring [C2 and H2 (major component) and C2A and H2A (minor component)] and phenyl ring [C11—C16 (major component) and C11A—C16A (minor component)] are clearly resolved. The C11—C16 (or C11A—C16A) phenyl ring is oriented almost perpendicular to the plane of the C5—C10 arene ring. The angle between the plane of the C11—C16 (C11A—C16A) ring and the plane of the C5—C10 ring is equal to 79.79 (12) ° (89.8 (5) °). The angle between the plane of carboxylate group and the plane of the C5—C10 ring is equal to 75.62 (8) °. The O1, C3, C4 O17 atoms are situated approximately in the plane of the C5—C10 arene ring (maximum deviation is equal to 0.040 (3) Å for O1). While deviation of the C18 and C2 atoms from the plane formed by the C5—C10 arene ring are equal to 1.140 (4) and 0.676 (4) Å, respectively, deviation of the C2A atom from the plane is equal to -0.403 (13) Å. Thus, two enantiomers revealing various conformations occupy equivalent sites, however somewhat randomly, not systematically, arranged in the unit cell. The ratio of the two enantiomers (R:S) in an asymmetric part of the unit cell is approximately equal to 0.8:0.2, which gives a 4:1/1:4 ratio in the crystal structure overall.