organic compounds
17βH-Periplogenin, a cardiac aglycone from the root bark of Periploca sepium Bunge
aNational Engineering Laboratory for Druggable Gene and Protein Screening, Northeast Normal University, ChangChun 130024, People's Republic of China, bInstitute of Genetics and Cytology, Northeast Normal University, ChangChun 130024, People's Republic of China, and cResearch Center of Agriculture and Medicine Gene, Engineering of Ministry of Education, Northeast Normal University, ChangChun 130024, People's Republic of China
*Correspondence e-mail: wuy705@126.com, liyuxin486@126.com
The title compound {systematic name: 4-[(3S,5S,8R,9S,10R,13R,14S,17S)-3,5,14-trihydroxy-10,13-dimethylhexadecahydro-1H-cyclopenta[a]phenanthren-17-yl]furan-2(5H)-one}, C23H34O5, was isolated from the roots of Periploca sepium Bunge, a famous Chinese traditional herbal medicine. The three six-membered rings adopt chair conformations, the cyclopentane ring displays an approximate (with the C atom bearing the methyl substituent at the flap) and the five-membered lactone ring adopts an essentially planar [maximum deviation of 0.004 (8) Å] conformation. In the crystal, molecules are linked into helical chains along [010] by O—H⋯O hydrogen bonds and weak C—H⋯O interactions. Two intramolecular O—H⋯O hydrogen bonds are also present.
Related literature
For the botanical and medicinal background to Periploca sepium Bunge, see: Li & Liu (2004); Yang et al. (2006). For the previous preparation and chemical of the title compound, see: Furuya et al. (1988); Kawaguchi et al. (1998).
Experimental
Crystal data
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Refinement
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Data collection: SMART (Bruker, 1997); cell SAINT (Bruker, 1999); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL.
Supporting information
10.1107/S1600536812018521/wn2470sup1.cif
contains datablocks I, global. DOI:Structure factors: contains datablock I. DOI: 10.1107/S1600536812018521/wn2470Isup2.hkl
Supporting information file. DOI: 10.1107/S1600536812018521/wn2470Isup3.cml
The air-dried and powdered roots of Periploca sepium Bunge (2.0 kg) were extracted with 70% EtOH (3×10 l, 3×2.0 h, 85 °C) under reflux conditions to give a crude extract, which was suspended in H2O and successively partitioned with CHCl3, EtOAc and n-butanol. A part of the CHCl3 fraction (50.0 g) was subjected to CC [SiO2, 200–300 mesh, CHCl3/MeOH (100:0, 95:5, 90:10, 80:20, 70:30, 60:40, 50:50 and 0:100(v/v)] to yield 8 fractions: Fr.1–8. Fr.3 was resubjected to CC (SiO2, 200–300 mesh, gradient of CHCl3/MeOH) and was further chromatographed on Sephadex LH-20 (CHCl3/MeOH, 1:1) to give 6 subfractions: SFr. 1–6. SFr. 4 (0.9 g) was then subjected to reverse phase preparative HPLC [Waters preparative HPLC system; XTERRA PREP MS C18 column, 5 µm, 19 mm × 150 mm; sample loading 30 - 60 mg/injection; the column was eluted with CH3OH/H2O system (52:48) at a flow rate of 16 ml/min] to provide the title compound (tR = 4.81 min, 26 mg). 1H and 13C NMR spectroscopic data of this compound were recorded on a Bruker-AV-400 spectrometer, using CD3OD as solvent and Me4Si as internal standard. The stereochemistry was established by the X-ray diffraction experiment.
In the absence of significant
effects, Friedel pairs were merged. Initially all H-atoms were located in a difference Fourier map and at the last stage these H-atoms were geometrically treated.The H-atoms were positioned geometrically (O—H = 0.82, C–H = 0.93–0.98 Å) and refined as riding with Uiso(H) = xUeq(C, O), where x = 1.5 for methyl C and O and x = 1.2 for all other H-atoms.
Data collection: SMART (Bruker, 1997); cell
SAINT (Bruker, 1999); data reduction: SAINT (Bruker, 1999); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).C23H34O5 | F(000) = 424 |
Mr = 390.50 | Dx = 1.254 Mg m−3 |
Monoclinic, P21 | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: P 2yb | Cell parameters from 5262 reflections |
a = 7.434 (3) Å | θ = 1.5–25.0° |
b = 10.554 (4) Å | µ = 0.09 mm−1 |
c = 13.537 (5) Å | T = 296 K |
β = 103.118 (5)° | Block, colourless |
V = 1034.4 (6) Å3 | 0.26 × 0.24 × 0.02 mm |
Z = 2 |
Bruker APEX CCD area-detector diffractometer | 1927 independent reflections |
Radiation source: fine-focus sealed tube | 1097 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.077 |
ω scans | θmax = 25.0°, θmin = 1.5° |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | h = −8→8 |
Tmin = 0.978, Tmax = 0.998 | k = −12→12 |
5262 measured reflections | l = −16→9 |
Refinement on F2 | Secondary atom site location: difference Fourier map |
Least-squares matrix: full | Hydrogen site location: inferred from neighbouring sites |
R[F2 > 2σ(F2)] = 0.053 | H-atom parameters constrained |
wR(F2) = 0.126 | w = 1/[σ2(Fo2) + (0.0536P)2] where P = (Fo2 + 2Fc2)/3 |
S = 1.01 | (Δ/σ)max < 0.001 |
1927 reflections | Δρmax = 0.17 e Å−3 |
254 parameters | Δρmin = −0.18 e Å−3 |
1 restraint | Extinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
Primary atom site location: structure-invariant direct methods | Extinction coefficient: 0.013 (3) |
C23H34O5 | V = 1034.4 (6) Å3 |
Mr = 390.50 | Z = 2 |
Monoclinic, P21 | Mo Kα radiation |
a = 7.434 (3) Å | µ = 0.09 mm−1 |
b = 10.554 (4) Å | T = 296 K |
c = 13.537 (5) Å | 0.26 × 0.24 × 0.02 mm |
β = 103.118 (5)° |
Bruker APEX CCD area-detector diffractometer | 1927 independent reflections |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | 1097 reflections with I > 2σ(I) |
Tmin = 0.978, Tmax = 0.998 | Rint = 0.077 |
5262 measured reflections |
R[F2 > 2σ(F2)] = 0.053 | 1 restraint |
wR(F2) = 0.126 | H-atom parameters constrained |
S = 1.01 | Δρmax = 0.17 e Å−3 |
1927 reflections | Δρmin = −0.18 e Å−3 |
254 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 | ||
C1 | 0.3269 (8) | 0.6136 (5) | 0.1758 (4) | 0.0561 (17) | |
H1A | 0.2076 | 0.5998 | 0.1916 | 0.067* | |
H1B | 0.3112 | 0.6777 | 0.1231 | 0.067* | |
C2 | 0.4616 (9) | 0.6639 (6) | 0.2708 (4) | 0.0639 (19) | |
H2A | 0.4156 | 0.7437 | 0.2908 | 0.077* | |
H2B | 0.4681 | 0.6042 | 0.3260 | 0.077* | |
C3 | 0.6508 (9) | 0.6834 (5) | 0.2527 (4) | 0.0555 (16) | |
H3A | 0.7350 | 0.7047 | 0.3174 | 0.067* | |
C4 | 0.7198 (7) | 0.5641 (5) | 0.2117 (4) | 0.0471 (15) | |
H4A | 0.7423 | 0.5004 | 0.2647 | 0.057* | |
H4B | 0.8368 | 0.5824 | 0.1944 | 0.057* | |
C5 | 0.5873 (7) | 0.5090 (5) | 0.1180 (4) | 0.0386 (13) | |
C6 | 0.6653 (7) | 0.3883 (5) | 0.0839 (4) | 0.0433 (14) | |
H6A | 0.7914 | 0.4036 | 0.0785 | 0.052* | |
H6B | 0.5937 | 0.3655 | 0.0170 | 0.052* | |
C7 | 0.6629 (7) | 0.2779 (5) | 0.1564 (4) | 0.0414 (14) | |
H7A | 0.7462 | 0.2959 | 0.2212 | 0.050* | |
H7B | 0.7058 | 0.2017 | 0.1290 | 0.050* | |
C8 | 0.4684 (7) | 0.2562 (5) | 0.1723 (4) | 0.0361 (13) | |
H8A | 0.3901 | 0.2376 | 0.1053 | 0.043* | |
C9 | 0.3906 (7) | 0.3778 (5) | 0.2096 (4) | 0.0373 (13) | |
H9A | 0.4724 | 0.4013 | 0.2745 | 0.045* | |
C10 | 0.3898 (7) | 0.4900 (5) | 0.1345 (4) | 0.0389 (13) | |
C11 | 0.1987 (7) | 0.3499 (5) | 0.2297 (4) | 0.0469 (15) | |
H11A | 0.1527 | 0.4252 | 0.2570 | 0.056* | |
H11B | 0.1136 | 0.3289 | 0.1663 | 0.056* | |
C12 | 0.2059 (7) | 0.2412 (5) | 0.3039 (4) | 0.0447 (15) | |
H12A | 0.0842 | 0.2290 | 0.3171 | 0.054* | |
H12B | 0.2899 | 0.2630 | 0.3675 | 0.054* | |
C13 | 0.2699 (7) | 0.1166 (5) | 0.2639 (3) | 0.0408 (14) | |
C14 | 0.4603 (7) | 0.1395 (5) | 0.2376 (4) | 0.0390 (13) | |
C15 | 0.5971 (7) | 0.1384 (5) | 0.3422 (4) | 0.0485 (15) | |
H15A | 0.7128 | 0.0996 | 0.3371 | 0.058* | |
H15B | 0.6219 | 0.2243 | 0.3673 | 0.058* | |
C16 | 0.5062 (7) | 0.0614 (7) | 0.4146 (4) | 0.069 (2) | |
H16A | 0.5827 | −0.0105 | 0.4421 | 0.082* | |
H16B | 0.4876 | 0.1138 | 0.4703 | 0.082* | |
C17 | 0.3218 (7) | 0.0170 (6) | 0.3500 (4) | 0.0486 (15) | |
H17A | 0.3448 | −0.0630 | 0.3182 | 0.058* | |
C18 | 0.1250 (8) | 0.0656 (6) | 0.1759 (4) | 0.0617 (18) | |
H18A | 0.0945 | 0.1293 | 0.1241 | 0.093* | |
H18B | 0.0163 | 0.0431 | 0.1990 | 0.093* | |
H18C | 0.1723 | −0.0080 | 0.1487 | 0.093* | |
C19 | 0.2521 (7) | 0.4643 (6) | 0.0324 (4) | 0.0511 (16) | |
H19A | 0.2542 | 0.5339 | −0.0129 | 0.077* | |
H19B | 0.1299 | 0.4551 | 0.0438 | 0.077* | |
H19C | 0.2866 | 0.3878 | 0.0030 | 0.077* | |
C20 | 0.1787 (7) | −0.0093 (6) | 0.4098 (4) | 0.0473 (15) | |
C22 | 0.1329 (8) | 0.0576 (7) | 0.4823 (4) | 0.0612 (18) | |
H22A | 0.1868 | 0.1340 | 0.5074 | 0.073* | |
C23 | −0.0140 (9) | −0.0056 (7) | 0.5170 (5) | 0.0648 (19) | |
C21 | 0.0617 (10) | −0.1253 (7) | 0.3915 (6) | 0.091 (2) | |
H21A | −0.0109 | −0.1279 | 0.3222 | 0.110* | |
H21B | 0.1366 | −0.2014 | 0.4048 | 0.110* | |
O5 | −0.0980 (6) | 0.0251 (6) | 0.5800 (3) | 0.0923 (17) | |
O1 | 0.6546 (6) | 0.7847 (4) | 0.1820 (3) | 0.0702 (13) | |
H1C | 0.6349 | 0.7560 | 0.1242 | 0.105* | |
O2 | 0.5832 (5) | 0.5977 (3) | 0.0338 (2) | 0.0470 (10) | |
H2C | 0.6038 | 0.6697 | 0.0563 | 0.071* | |
O3 | 0.5070 (5) | 0.0290 (3) | 0.1852 (3) | 0.0538 (11) | |
H3B | 0.4851 | 0.0431 | 0.1241 | 0.081* | |
O4 | −0.0578 (6) | −0.1125 (5) | 0.4641 (4) | 0.0856 (15) |
U11 | U22 | U33 | U12 | U13 | U23 | |
C1 | 0.057 (4) | 0.052 (4) | 0.067 (4) | 0.022 (3) | 0.028 (3) | 0.015 (4) |
C2 | 0.109 (6) | 0.034 (3) | 0.056 (4) | 0.007 (3) | 0.034 (4) | −0.007 (3) |
C3 | 0.085 (5) | 0.038 (3) | 0.043 (4) | −0.013 (3) | 0.013 (3) | 0.004 (3) |
C4 | 0.053 (4) | 0.042 (4) | 0.043 (3) | −0.011 (3) | 0.005 (3) | 0.006 (3) |
C5 | 0.051 (3) | 0.034 (3) | 0.035 (3) | 0.004 (3) | 0.016 (3) | 0.005 (3) |
C6 | 0.041 (3) | 0.051 (4) | 0.042 (4) | 0.002 (3) | 0.019 (3) | 0.006 (3) |
C7 | 0.044 (3) | 0.044 (3) | 0.039 (3) | 0.008 (3) | 0.014 (3) | 0.012 (3) |
C8 | 0.042 (3) | 0.039 (3) | 0.029 (3) | 0.001 (3) | 0.011 (2) | 0.002 (3) |
C9 | 0.039 (3) | 0.038 (3) | 0.036 (3) | 0.009 (3) | 0.011 (2) | −0.001 (3) |
C10 | 0.045 (3) | 0.038 (3) | 0.033 (3) | 0.013 (3) | 0.008 (2) | 0.002 (3) |
C11 | 0.052 (4) | 0.039 (3) | 0.058 (4) | 0.008 (3) | 0.030 (3) | 0.005 (3) |
C12 | 0.047 (4) | 0.048 (4) | 0.043 (3) | 0.000 (3) | 0.020 (3) | 0.005 (3) |
C13 | 0.045 (3) | 0.049 (4) | 0.028 (3) | 0.000 (3) | 0.006 (3) | 0.003 (3) |
C14 | 0.048 (3) | 0.037 (3) | 0.038 (3) | 0.005 (3) | 0.022 (3) | −0.001 (3) |
C15 | 0.042 (3) | 0.058 (4) | 0.045 (3) | 0.005 (3) | 0.011 (3) | 0.008 (3) |
C16 | 0.043 (4) | 0.099 (5) | 0.062 (4) | −0.004 (4) | 0.008 (3) | 0.031 (4) |
C17 | 0.046 (3) | 0.056 (4) | 0.046 (3) | 0.000 (3) | 0.014 (3) | 0.010 (3) |
C18 | 0.066 (4) | 0.070 (4) | 0.046 (3) | −0.020 (4) | 0.007 (3) | −0.004 (3) |
C19 | 0.043 (3) | 0.067 (4) | 0.040 (3) | 0.001 (3) | 0.003 (3) | 0.017 (3) |
C20 | 0.041 (3) | 0.053 (4) | 0.047 (4) | −0.001 (3) | 0.011 (3) | 0.012 (3) |
C22 | 0.059 (4) | 0.084 (5) | 0.045 (3) | −0.020 (4) | 0.021 (3) | 0.004 (4) |
C23 | 0.053 (4) | 0.089 (6) | 0.054 (4) | −0.007 (4) | 0.017 (3) | 0.013 (5) |
C21 | 0.106 (6) | 0.074 (5) | 0.111 (6) | −0.025 (5) | 0.060 (5) | 0.006 (5) |
O5 | 0.071 (3) | 0.150 (5) | 0.060 (3) | −0.008 (3) | 0.025 (2) | 0.018 (4) |
O1 | 0.116 (4) | 0.046 (2) | 0.052 (3) | −0.013 (2) | 0.025 (3) | 0.002 (2) |
O2 | 0.063 (2) | 0.043 (2) | 0.037 (2) | −0.0012 (19) | 0.0163 (18) | 0.0047 (19) |
O3 | 0.083 (3) | 0.038 (2) | 0.051 (2) | 0.014 (2) | 0.036 (2) | 0.003 (2) |
O4 | 0.088 (4) | 0.072 (3) | 0.107 (4) | −0.024 (3) | 0.044 (3) | 0.006 (3) |
C1—C10 | 1.533 (7) | C12—H12A | 0.9700 |
C1—C2 | 1.534 (8) | C12—H12B | 0.9700 |
C1—H1A | 0.9700 | C13—C18 | 1.512 (7) |
C1—H1B | 0.9700 | C13—C17 | 1.552 (7) |
C2—C3 | 1.496 (8) | C13—C14 | 1.555 (6) |
C2—H2A | 0.9700 | C14—O3 | 1.448 (6) |
C2—H2B | 0.9700 | C14—C15 | 1.545 (7) |
C3—O1 | 1.440 (6) | C15—C16 | 1.542 (7) |
C3—C4 | 1.512 (8) | C15—H15A | 0.9700 |
C3—H3A | 0.9800 | C15—H15B | 0.9700 |
C4—C5 | 1.532 (7) | C16—C17 | 1.523 (7) |
C4—H4A | 0.9700 | C16—H16A | 0.9700 |
C4—H4B | 0.9700 | C16—H16B | 0.9700 |
C5—O2 | 1.469 (6) | C17—C20 | 1.502 (7) |
C5—C6 | 1.515 (7) | C17—H17A | 0.9800 |
C5—C10 | 1.548 (7) | C18—H18A | 0.9600 |
C6—C7 | 1.527 (7) | C18—H18B | 0.9600 |
C6—H6A | 0.9700 | C18—H18C | 0.9600 |
C6—H6B | 0.9700 | C19—H19A | 0.9600 |
C7—C8 | 1.527 (7) | C19—H19B | 0.9600 |
C7—H7A | 0.9700 | C19—H19C | 0.9600 |
C7—H7B | 0.9700 | C20—C22 | 1.315 (7) |
C8—C14 | 1.525 (7) | C20—C21 | 1.490 (8) |
C8—C9 | 1.539 (6) | C22—C23 | 1.447 (8) |
C8—H8A | 0.9800 | C22—H22A | 0.9300 |
C9—C11 | 1.540 (6) | C23—O5 | 1.210 (7) |
C9—C10 | 1.560 (6) | C23—O4 | 1.335 (8) |
C9—H9A | 0.9800 | C21—O4 | 1.474 (8) |
C10—C19 | 1.546 (7) | C21—H21A | 0.9700 |
C11—C12 | 1.517 (7) | C21—H21B | 0.9700 |
C11—H11A | 0.9700 | O1—H1C | 0.8200 |
C11—H11B | 0.9700 | O2—H2C | 0.8200 |
C12—C13 | 1.538 (7) | O3—H3B | 0.8200 |
C10—C1—C2 | 113.9 (4) | C11—C12—H12A | 109.1 |
C10—C1—H1A | 108.8 | C13—C12—H12A | 109.1 |
C2—C1—H1A | 108.8 | C11—C12—H12B | 109.1 |
C10—C1—H1B | 108.8 | C13—C12—H12B | 109.1 |
C2—C1—H1B | 108.8 | H12A—C12—H12B | 107.9 |
H1A—C1—H1B | 107.7 | C18—C13—C12 | 111.1 (5) |
C3—C2—C1 | 111.7 (5) | C18—C13—C17 | 111.2 (4) |
C3—C2—H2A | 109.3 | C12—C13—C17 | 111.1 (4) |
C1—C2—H2A | 109.3 | C18—C13—C14 | 113.4 (4) |
C3—C2—H2B | 109.3 | C12—C13—C14 | 108.6 (4) |
C1—C2—H2B | 109.3 | C17—C13—C14 | 101.1 (4) |
H2A—C2—H2B | 107.9 | O3—C14—C8 | 108.7 (3) |
O1—C3—C2 | 111.8 (5) | O3—C14—C15 | 105.2 (4) |
O1—C3—C4 | 108.3 (4) | C8—C14—C15 | 115.7 (4) |
C2—C3—C4 | 110.8 (5) | O3—C14—C13 | 108.6 (4) |
O1—C3—H3A | 108.6 | C8—C14—C13 | 114.5 (4) |
C2—C3—H3A | 108.6 | C15—C14—C13 | 103.5 (4) |
C4—C3—H3A | 108.6 | C16—C15—C14 | 107.1 (4) |
C3—C4—C5 | 114.3 (5) | C16—C15—H15A | 110.3 |
C3—C4—H4A | 108.7 | C14—C15—H15A | 110.3 |
C5—C4—H4A | 108.7 | C16—C15—H15B | 110.3 |
C3—C4—H4B | 108.7 | C14—C15—H15B | 110.3 |
C5—C4—H4B | 108.7 | H15A—C15—H15B | 108.5 |
H4A—C4—H4B | 107.6 | C17—C16—C15 | 105.3 (4) |
O2—C5—C6 | 103.9 (4) | C17—C16—H16A | 110.7 |
O2—C5—C4 | 107.2 (4) | C15—C16—H16A | 110.7 |
C6—C5—C4 | 110.6 (4) | C17—C16—H16B | 110.7 |
O2—C5—C10 | 110.0 (4) | C15—C16—H16B | 110.7 |
C6—C5—C10 | 112.1 (4) | H16A—C16—H16B | 108.8 |
C4—C5—C10 | 112.5 (4) | C20—C17—C16 | 113.7 (4) |
C5—C6—C7 | 112.6 (4) | C20—C17—C13 | 116.4 (4) |
C5—C6—H6A | 109.1 | C16—C17—C13 | 105.1 (4) |
C7—C6—H6A | 109.1 | C20—C17—H17A | 107.0 |
C5—C6—H6B | 109.1 | C16—C17—H17A | 107.0 |
C7—C6—H6B | 109.1 | C13—C17—H17A | 107.0 |
H6A—C6—H6B | 107.8 | C13—C18—H18A | 109.5 |
C6—C7—C8 | 110.8 (4) | C13—C18—H18B | 109.5 |
C6—C7—H7A | 109.5 | H18A—C18—H18B | 109.5 |
C8—C7—H7A | 109.5 | C13—C18—H18C | 109.5 |
C6—C7—H7B | 109.5 | H18A—C18—H18C | 109.5 |
C8—C7—H7B | 109.5 | H18B—C18—H18C | 109.5 |
H7A—C7—H7B | 108.1 | C10—C19—H19A | 109.5 |
C14—C8—C7 | 111.5 (4) | C10—C19—H19B | 109.5 |
C14—C8—C9 | 114.6 (4) | H19A—C19—H19B | 109.5 |
C7—C8—C9 | 111.1 (4) | C10—C19—H19C | 109.5 |
C14—C8—H8A | 106.4 | H19A—C19—H19C | 109.5 |
C7—C8—H8A | 106.4 | H19B—C19—H19C | 109.5 |
C9—C8—H8A | 106.4 | C22—C20—C21 | 109.0 (5) |
C8—C9—C11 | 109.3 (4) | C22—C20—C17 | 129.6 (6) |
C8—C9—C10 | 111.4 (4) | C21—C20—C17 | 121.3 (6) |
C11—C9—C10 | 113.2 (4) | C20—C22—C23 | 109.7 (6) |
C8—C9—H9A | 107.5 | C20—C22—H22A | 125.2 |
C11—C9—H9A | 107.5 | C23—C22—H22A | 125.2 |
C10—C9—H9A | 107.5 | O5—C23—O4 | 120.1 (7) |
C1—C10—C19 | 106.3 (4) | O5—C23—C22 | 130.8 (8) |
C1—C10—C5 | 108.6 (4) | O4—C23—C22 | 109.0 (6) |
C19—C10—C5 | 110.6 (4) | O4—C21—C20 | 103.3 (6) |
C1—C10—C9 | 111.4 (4) | O4—C21—H21A | 111.1 |
C19—C10—C9 | 110.7 (4) | C20—C21—H21A | 111.1 |
C5—C10—C9 | 109.2 (4) | O4—C21—H21B | 111.1 |
C12—C11—C9 | 111.5 (4) | C20—C21—H21B | 111.1 |
C12—C11—H11A | 109.3 | H21A—C21—H21B | 109.1 |
C9—C11—H11A | 109.3 | C3—O1—H1C | 109.5 |
C12—C11—H11B | 109.3 | C5—O2—H2C | 109.5 |
C9—C11—H11B | 109.3 | C14—O3—H3B | 109.5 |
H11A—C11—H11B | 108.0 | C23—O4—C21 | 108.9 (5) |
C11—C12—C13 | 112.4 (4) |
D—H···A | D—H | H···A | D···A | D—H···A |
O1—H1C···O2 | 0.82 | 2.06 | 2.778 (5) | 147 |
O2—H2C···O1 | 0.82 | 2.05 | 2.778 (5) | 147 |
O3—H3B···O2i | 0.82 | 2.16 | 2.977 (5) | 175 |
C11—H11A···O5ii | 0.97 | 2.57 | 3.393 (7) | 143 |
Symmetry codes: (i) −x+1, y−1/2, −z; (ii) −x, y+1/2, −z+1. |
Experimental details
Crystal data | |
Chemical formula | C23H34O5 |
Mr | 390.50 |
Crystal system, space group | Monoclinic, P21 |
Temperature (K) | 296 |
a, b, c (Å) | 7.434 (3), 10.554 (4), 13.537 (5) |
β (°) | 103.118 (5) |
V (Å3) | 1034.4 (6) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 0.09 |
Crystal size (mm) | 0.26 × 0.24 × 0.02 |
Data collection | |
Diffractometer | Bruker APEX CCD area-detector diffractometer |
Absorption correction | Multi-scan (SADABS; Sheldrick, 1996) |
Tmin, Tmax | 0.978, 0.998 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 5262, 1927, 1097 |
Rint | 0.077 |
(sin θ/λ)max (Å−1) | 0.595 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.053, 0.126, 1.01 |
No. of reflections | 1927 |
No. of parameters | 254 |
No. of restraints | 1 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.17, −0.18 |
Computer programs: SMART (Bruker, 1997), SAINT (Bruker, 1999), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008).
D—H···A | D—H | H···A | D···A | D—H···A |
O1—H1C···O2 | 0.82 | 2.06 | 2.778 (5) | 146.8 |
O2—H2C···O1 | 0.82 | 2.05 | 2.778 (5) | 147.0 |
O3—H3B···O2i | 0.82 | 2.16 | 2.977 (5) | 174.5 |
C11—H11A···O5ii | 0.97 | 2.57 | 3.393 (7) | 143 |
Symmetry codes: (i) −x+1, y−1/2, −z; (ii) −x, y+1/2, −z+1. |
Acknowledgements
This research was supported by the National Natural Science Foundation of China (Nos. 31170324 and 31070318), the Fundamental Research Funds for the Central Universities, grants from the Jilin Province Science & Technology Committee, China (Nos. 20100911, 20102203, 20110938 and 20110711), as well as the Scientific and Technical Project of the Administration of Traditional Chinese Medicine of Jilin Province (No. 2010pt069).
References
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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.
Periploca sepium Bunge (Asclepiadaceae) is native and widespread in the Loess hilly regions of northwest China (Li and Liu, 2004; Yang et al., 2006). Its root bark, which is officially listed in the Chinese Pharmacopoeia under the name Cortex Periploca (Xiangjiapi in Chinese), has been frequently used to treat rheumatism and strengthen tendons and bones. The title compound, 17βH-periplogenin, which has been previously obtained as a biotransformation product of digitoxigenin (Furuya et al., 1988; Kawaguchi et al., 1998), was isolated from the root bark of Periploca sepium Bunge in our recent investigation. To the best of our knowledge, this is its first isolation from plant material. The isolated compound was identified by NMR spectra, which were compared with the previous report (Furuya et al., 1988).
The crystal structure of 17βH-periplogenin has not yet been reported. In view of this, the crystal structure determination of the title compound was carried out and the results are presented here.
As shown in Fig. 1, the molecule consists of three six-membered rings (A, B and C), one cyclopentane ring (D) and one five-membered lactone ring. Rings A:B, B:C and C:D are cis-, trans- and cis- fused, respectively. The three six-membered rings adopt chair conformations, the cyclopentane ring displays an approximate envelope conformation with C13 as the flap atom, and the five-membered lactone ring adopts a planar conformation.
In the crystal structure, molecules are linked into helical chains along [010] through O3—H3B···O2 hydrogen bonds and C11—H11A···O5 weak interactions (Fig. 2 and Table 1). Two intramolecular O—H···O hydrogen bonds are also present (Table 1).