Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536809027998/fj2239sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S1600536809027998/fj2239Isup2.hkl |
CCDC reference: 744442
Key indicators
- Single-crystal X-ray study
- T = 173 K
- Mean (C-C) = 0.003 Å
- R factor = 0.037
- wR factor = 0.099
- Data-to-parameter ratio = 12.6
checkCIF/PLATON results
No syntax errors found
Alert level A PLAT220_ALERT_2_A Large Non-Solvent O Ueq(max)/Ueq(min) ... 4.68 Ratio
Author Response: ... Despite the use of low temperature X-ray diffraction, the furan ring C23-C24-C25-O7-C26 exhibits significant anisotropic displacement within the ring plane, with a point on the C17-C23 single bond as centroid of rotation. This is not unusual with complex compounds of natural origin. Attempts to describe this by a splitting of the furan ring in two orientations did not bring about any benefits for the present problem. The C-level Alerts PLAT220_ALERT_2_B Large Non-Solvent C Ueq(max)/Ueq(min) ... 4.42 Ratio PLAT230_ALERT_2_C Hirshfeld Test Diff for O8 - C27 .. 5.30 su stem also from the furan ring. Final remark to this problem: Compounds with this kind of natural source almost always lack sufficient material. In view of the available few milligrams of this rare compound, it was outstanding to obtain a reasonable crystal of 0.62 x 0.40 x 0.25 mm size. |
Alert level B PLAT220_ALERT_2_B Large Non-Solvent C Ueq(max)/Ueq(min) ... 4.42 Ratio
Author Response: ... Despite the use of low temperature X-ray diffraction, the furan ring C23-C24-C25-O7-C26 exhibits significant anisotropic displacement within the ring plane, with a point on the C17-C23 single bond as centroid of rotation. This is not unusual with complex compounds of natural origin. Attempts to describe this by a splitting of the furan ring in two orientations did not bring about any benefits for the present problem. The C-level Alerts PLAT220_ALERT_2_B Large Non-Solvent C Ueq(max)/Ueq(min) ... 4.42 Ratio PLAT230_ALERT_2_C Hirshfeld Test Diff for O8 - C27 .. 5.30 su stem also from the furan ring. Final remark to this problem: Compounds with this kind of natural source almost always lack sufficient material. In view of the available few milligrams of this rare compound, it was outstanding to obtain a reasonable crystal of 0.62 x 0.40 x 0.25 mm size. |
PLAT222_ALERT_3_B Large Non-Solvent H Ueq(max)/Ueq(min) ... 4.20 Ratio PLAT063_ALERT_4_B Crystal Size Likely too Large for Beam Size .... 0.62 mm
Author Response: A beam with 0.8 mm nominal diameter was used (Bruker SMART platform 3-axis diffractometer). |
Alert level C PLAT230_ALERT_2_C Hirshfeld Test Diff for O8 -- C27 .. 5.30 su PLAT241_ALERT_2_C Check High Ueq as Compared to Neighbors for O7 PLAT412_ALERT_2_C Short Intra XH3 .. XHn H9 .. H18A .. 1.86 Ang.
Author Response: CH3 groups refined in orientation with AFIX 137. These short H...H contacts are not unusual for this type of compound, they are mainly due to steric crowd. |
PLAT412_ALERT_2_C Short Intra XH3 .. XHn H19B .. H26A .. 1.88 Ang.
Author Response: CH3 groups refined in orientation with AFIX 137. These short H...H contacts are not unusual for this type of compound, they are mainly due to steric crowd. |
PLAT480_ALERT_4_C Long H...A H-Bond Reported H18C .. O1 .. 2.68 Ang. PLAT480_ALERT_4_C Long H...A H-Bond Reported H22 .. O6 .. 2.69 Ang.
Alert level G REFLT03_ALERT_4_G Please check that the estimate of the number of Friedel pairs is correct. If it is not, please give the correct count in the _publ_section_exptl_refinement section of the submitted CIF. From the CIF: _diffrn_reflns_theta_max 29.98 From the CIF: _reflns_number_total 4509 Count of symmetry unique reflns 4558 Completeness (_total/calc) 98.92% TEST3: Check Friedels for noncentro structure Estimate of Friedel pairs measured 0 Fraction of Friedel pairs measured 0.000 Are heavy atom types Z>Si present no PLAT791_ALERT_4_G The Model has Chirality at C5 (Verify) .... R PLAT791_ALERT_4_G The Model has Chirality at C6 (Verify) .... R PLAT791_ALERT_4_G The Model has Chirality at C7 (Verify) .... S PLAT791_ALERT_4_G The Model has Chirality at C8 (Verify) .... S PLAT791_ALERT_4_G The Model has Chirality at C9 (Verify) .... R PLAT791_ALERT_4_G The Model has Chirality at C10 (Verify) .... R PLAT791_ALERT_4_G The Model has Chirality at C13 (Verify) .... S PLAT791_ALERT_4_G The Model has Chirality at C14 (Verify) .... R PLAT791_ALERT_4_G The Model has Chirality at C15 (Verify) .... S PLAT791_ALERT_4_G The Model has Chirality at C17 (Verify) .... S
1 ALERT level A = In general: serious problem 3 ALERT level B = Potentially serious problem 6 ALERT level C = Check and explain 11 ALERT level G = General alerts; check 0 ALERT type 1 CIF construction/syntax error, inconsistent or missing data 6 ALERT type 2 Indicator that the structure model may be wrong or deficient 1 ALERT type 3 Indicator that the structure quality may be low 14 ALERT type 4 Improvement, methodology, query or suggestion 0 ALERT type 5 Informative message, check
Air-dried root bark of Aglaia elaeagnoidea (28 g) collected at the shore near Port Douglas, Queensland, northern Australia, was ground and extracted with MeOH at room temperature for 3 days, filtered and concentrated. The CHCl3 fraction (1.2 g) of the aqueous residue was roughly separated by column chromatography (Merck Si gel 60, 35–70 mesh) eluted initially with hexane enriched with EtOAc, followed by an increasing amount of MeOH in EtOAc and finally with MeOH. The fraction eluted with 50% EtOAc in hexane was further separated by repeated preparative MPLC (400 x 40 mm column, Merck LiChroprep silica 60, 25–40 µm, UV detection at 229 and 254 nm) using 5% 2-propanol in hexane yielding 15 mg of impure 6α-acetoxygedunin from which 3.8 mg of crystals could be obtained.
The resonances of the 1H and 13C NMR spectra of the title compound were assigned by two-dimensional NMR (H/H COSY, NOESY, HMBC, HMQC) and relevant literature for 11β-acetoxygedunin (Connolly et al., 1966) and gedunin (Taylor, 1974). 1H NMR (400 MHz, CDCl3, δ/p.p.m.): 7.41 (d, 1H, J= 1.3 Hz, 21-H), 7.41 (d, 1H, J = 1.3 Hz, 23-H), 7.07 (d, 1H, J = 10.1 Hz, 1-H), 6.33 (t, 1H, J = 1.3 Hz, 22-H), 5.94 (d, 1H, J = 10.1 Hz, 2-H), 5.61 (s, 1H, 17-H), 5.27 (dd, 1H, J = 12.4 and 2.4 Hz, 6-H), 4.89 (d, 1H, J = 2.4 Hz, 7-H), 3.61 (s, 1H, 15-H), 2.53 (m, 1H, 9-H), 2.52 (d, 1H, J = 12.4 Hz, 5-H), 2.15 (s, 3H, 7-OAc), 2.03 (s, 3H, 6-OAc), 1.60, 1.35, 1.30, and 1.10 (m, 1H each, 11-H2 and 12-H2), 1.27 (s, 3H, 26-H3), 1.26 (s, 3H, 24-H3), 1.24 (s, 3H, 18-H3), 1.21 (s, 3H, 19-H3), 1.17 (s, 3H, 25-H3). 13C NMR (CDCl3, δ/p.p.m.): 204.1 (s, C-3), 170.1 and 170.0 (s, 6- and 7-acetyl CO), 167.1 (s, C-16), 156.2 (d, C-1), 143.1 (d, C-23), 141.2 (d, C-21), 126.6 (d, C-2), 120.3 (s, C-20), 109.8 (d, C-22), 78.1 (d, C-17), 72.6 (d, C-7), 69.7 (d, C-6), 69.5 (s, C-14), 56.2 (d, C-15), 47.8 (d, C-5), 44.9 (s, C-4), 43.1 (s, C-8), 40.6 (s, C10), 48.8 (s, C-13), 38.4 (d, C-9), 31.6 (q, C-24), 25.9 (t, C-12), 21.4 (q, C-19), 21.2 (q, 6-acetyl CH3), 20.9 (q, 7-acetyl CH3), 20.2 (q, C-25), 18.1 (q, C-26), 17.9 (q, C-18), 15.0 (t, C-11).
All C-bound H atoms were placed in calculated positions (C—H = 0.95–1.00 Å) and thereafter treated as riding. A torsional parameter was refined for each methyl group. Uiso(H) = 1.2Ueq(C) and Uiso(H) = 1.5Ueq(Cmethyl) were applied. The absolute structure could not be determined from the X-ray analysis, but it is known from earlier work on related compounds (e.g. Sutherland et al., 1962). Friedel pairs were therefore merged before final refinement.
Data collection: SMART (Bruker, 2003); cell refinement: SAINT (Bruker, 2003); data reduction: SAINT, SADABS and XPREP (Bruker, 2003); 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).
C30H36O9 | F(000) = 1152 |
Mr = 540.59 | Dx = 1.295 Mg m−3 |
Orthorhombic, P212121 | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: P 2ac 2ab | Cell parameters from 852 reflections |
a = 6.475 (2) Å | θ = 2.4–29.8° |
b = 14.914 (5) Å | µ = 0.10 mm−1 |
c = 28.713 (9) Å | T = 173 K |
V = 2772.8 (15) Å3 | Prism, colourless |
Z = 4 | 0.62 × 0.40 × 0.25 mm |
Bruker SMART APEX CCD diffractometer | 4509 independent reflections |
Radiation source: fine-focus sealed tube | 4077 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.031 |
ω scans | θmax = 30.0°, θmin = 2.5° |
Absorption correction: multi-scan (SADABS; Bruker, 2003) | h = −9→9 |
Tmin = 0.89, Tmax = 0.98 | k = −20→20 |
39048 measured reflections | l = −40→40 |
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)] = 0.037 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.099 | H-atom parameters constrained |
S = 1.04 | w = 1/[σ2(Fo2) + (0.0617P)2 + 0.3403P] where P = (Fo2 + 2Fc2)/3 |
4509 reflections | (Δ/σ)max < 0.001 |
359 parameters | Δρmax = 0.26 e Å−3 |
0 restraints | Δρmin = −0.24 e Å−3 |
C30H36O9 | V = 2772.8 (15) Å3 |
Mr = 540.59 | Z = 4 |
Orthorhombic, P212121 | Mo Kα radiation |
a = 6.475 (2) Å | µ = 0.10 mm−1 |
b = 14.914 (5) Å | T = 173 K |
c = 28.713 (9) Å | 0.62 × 0.40 × 0.25 mm |
Bruker SMART APEX CCD diffractometer | 4509 independent reflections |
Absorption correction: multi-scan (SADABS; Bruker, 2003) | 4077 reflections with I > 2σ(I) |
Tmin = 0.89, Tmax = 0.98 | Rint = 0.031 |
39048 measured reflections |
R[F2 > 2σ(F2)] = 0.037 | 0 restraints |
wR(F2) = 0.099 | H-atom parameters constrained |
S = 1.04 | Δρmax = 0.26 e Å−3 |
4509 reflections | Δρmin = −0.24 e Å−3 |
359 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 | ||
O1 | 0.0587 (3) | 0.73999 (11) | 0.23019 (6) | 0.0535 (4) | |
O2 | 0.3222 (2) | 0.68452 (7) | 0.40284 (4) | 0.0308 (3) | |
O3 | 0.21379 (17) | 0.50631 (7) | 0.42004 (3) | 0.0218 (2) | |
O4 | 0.67376 (18) | 0.33557 (9) | 0.41784 (4) | 0.0303 (3) | |
O5 | 0.3916 (2) | 0.20217 (8) | 0.45502 (4) | 0.0311 (3) | |
O6 | 0.3600 (2) | 0.29114 (9) | 0.51630 (4) | 0.0371 (3) | |
O7 | 0.3049 (7) | −0.02998 (11) | 0.35841 (9) | 0.1021 (11) | |
O8 | 0.6555 (3) | 0.70255 (12) | 0.42549 (6) | 0.0546 (4) | |
O9 | 0.3152 (3) | 0.55979 (10) | 0.49051 (4) | 0.0413 (3) | |
C1 | 0.1155 (3) | 0.51480 (13) | 0.26444 (5) | 0.0295 (3) | |
H1 | 0.0712 | 0.4558 | 0.2569 | 0.035* | |
C2 | 0.0178 (3) | 0.58569 (14) | 0.24571 (6) | 0.0342 (4) | |
H2 | −0.0937 | 0.5765 | 0.2247 | 0.041* | |
C3 | 0.0830 (3) | 0.67781 (14) | 0.25763 (6) | 0.0354 (4) | |
C4 | 0.1727 (3) | 0.69563 (11) | 0.30666 (6) | 0.0289 (3) | |
C5 | 0.2297 (2) | 0.60496 (10) | 0.33182 (5) | 0.0220 (3) | |
H5 | 0.0998 | 0.5837 | 0.3471 | 0.026* | |
C6 | 0.3893 (2) | 0.61484 (10) | 0.37098 (5) | 0.0230 (3) | |
H6 | 0.5258 | 0.6318 | 0.3573 | 0.028* | |
C7 | 0.4135 (2) | 0.52809 (10) | 0.39934 (5) | 0.0210 (3) | |
H7 | 0.5176 | 0.5376 | 0.4246 | 0.025* | |
C8 | 0.4803 (2) | 0.44830 (10) | 0.36887 (5) | 0.0198 (3) | |
C9 | 0.3279 (2) | 0.43982 (10) | 0.32698 (5) | 0.0208 (3) | |
H9 | 0.1901 | 0.4274 | 0.3413 | 0.025* | |
C10 | 0.2973 (2) | 0.52800 (10) | 0.29783 (5) | 0.0217 (3) | |
C11 | 0.3781 (3) | 0.35593 (11) | 0.29761 (5) | 0.0302 (3) | |
H11A | 0.4995 | 0.3692 | 0.2778 | 0.036* | |
H11B | 0.2600 | 0.3436 | 0.2767 | 0.036* | |
C12 | 0.4241 (3) | 0.27008 (11) | 0.32647 (6) | 0.0300 (3) | |
H12A | 0.3503 | 0.2188 | 0.3122 | 0.036* | |
H12B | 0.5739 | 0.2572 | 0.3249 | 0.036* | |
C13 | 0.3597 (2) | 0.27762 (10) | 0.37810 (5) | 0.0230 (3) | |
C14 | 0.4749 (2) | 0.35925 (10) | 0.39801 (5) | 0.0210 (3) | |
C15 | 0.5091 (2) | 0.35775 (11) | 0.44934 (5) | 0.0248 (3) | |
H15 | 0.5181 | 0.4171 | 0.4654 | 0.030* | |
C16 | 0.4171 (3) | 0.28141 (11) | 0.47670 (5) | 0.0268 (3) | |
C17 | 0.4394 (3) | 0.19354 (11) | 0.40509 (6) | 0.0325 (4) | |
H17 | 0.5926 | 0.1892 | 0.4012 | 0.039* | |
C18 | 0.1228 (2) | 0.28506 (11) | 0.38491 (5) | 0.0254 (3) | |
H18A | 0.0824 | 0.3484 | 0.3851 | 0.038* | |
H18B | 0.0840 | 0.2574 | 0.4146 | 0.038* | |
H18C | 0.0522 | 0.2541 | 0.3594 | 0.038* | |
C19 | 0.4839 (3) | 0.55432 (12) | 0.26637 (5) | 0.0286 (3) | |
H19A | 0.5308 | 0.5016 | 0.2490 | 0.043* | |
H19B | 0.5969 | 0.5767 | 0.2859 | 0.043* | |
H19C | 0.4413 | 0.6012 | 0.2445 | 0.043* | |
C20 | 0.3434 (4) | 0.10558 (12) | 0.39106 (7) | 0.0455 (5) | |
C21 | 0.4335 (7) | 0.04307 (15) | 0.36416 (10) | 0.0767 (11) | |
H21 | 0.5673 | 0.0484 | 0.3509 | 0.092* | |
C22 | 0.1459 (5) | 0.06906 (14) | 0.40432 (10) | 0.0588 (7) | |
H22 | 0.0451 | 0.0969 | 0.4235 | 0.071* | |
C23 | 0.1322 (8) | −0.01205 (18) | 0.38421 (13) | 0.0876 (13) | |
H23 | 0.0181 | −0.0516 | 0.3875 | 0.105* | |
C24 | −0.0104 (3) | 0.74131 (13) | 0.33278 (7) | 0.0399 (4) | |
H24A | −0.0409 | 0.7993 | 0.3182 | 0.060* | |
H24B | 0.0274 | 0.7507 | 0.3655 | 0.060* | |
H24C | −0.1327 | 0.7027 | 0.3311 | 0.060* | |
C25 | 0.3518 (3) | 0.76299 (12) | 0.30263 (7) | 0.0367 (4) | |
H25A | 0.3057 | 0.8158 | 0.2852 | 0.055* | |
H25B | 0.4678 | 0.7348 | 0.2863 | 0.055* | |
H25C | 0.3961 | 0.7813 | 0.3339 | 0.055* | |
C26 | 0.7086 (2) | 0.46280 (12) | 0.35367 (6) | 0.0269 (3) | |
H26A | 0.7211 | 0.5204 | 0.3375 | 0.040* | |
H26B | 0.7507 | 0.4142 | 0.3327 | 0.040* | |
H26C | 0.7978 | 0.4629 | 0.3813 | 0.040* | |
C27 | 0.4760 (4) | 0.72270 (14) | 0.42919 (7) | 0.0419 (5) | |
C28 | 0.3892 (6) | 0.79118 (17) | 0.46226 (9) | 0.0655 (8) | |
H28A | 0.4966 | 0.8349 | 0.4702 | 0.098* | |
H28B | 0.3415 | 0.7612 | 0.4907 | 0.098* | |
H28C | 0.2729 | 0.8221 | 0.4475 | 0.098* | |
C29 | 0.1864 (3) | 0.52448 (11) | 0.46639 (5) | 0.0268 (3) | |
C30 | −0.0241 (3) | 0.49403 (14) | 0.48189 (6) | 0.0382 (4) | |
H30A | −0.0316 | 0.4956 | 0.5160 | 0.057* | |
H30B | −0.0485 | 0.4327 | 0.4710 | 0.057* | |
H30C | −0.1294 | 0.5340 | 0.4688 | 0.057* |
U11 | U22 | U33 | U12 | U13 | U23 | |
O1 | 0.0596 (10) | 0.0553 (9) | 0.0454 (8) | 0.0088 (8) | −0.0091 (7) | 0.0263 (7) |
O2 | 0.0402 (7) | 0.0240 (5) | 0.0281 (5) | −0.0007 (5) | 0.0018 (5) | −0.0018 (4) |
O3 | 0.0219 (5) | 0.0257 (5) | 0.0177 (4) | −0.0016 (4) | 0.0032 (4) | 0.0006 (4) |
O4 | 0.0194 (5) | 0.0432 (6) | 0.0284 (5) | 0.0036 (5) | 0.0000 (4) | 0.0133 (5) |
O5 | 0.0357 (6) | 0.0287 (6) | 0.0289 (6) | −0.0005 (5) | −0.0027 (5) | 0.0088 (5) |
O6 | 0.0407 (7) | 0.0463 (7) | 0.0242 (5) | −0.0066 (6) | 0.0035 (5) | 0.0092 (5) |
O7 | 0.200 (3) | 0.0281 (8) | 0.0781 (14) | 0.0038 (15) | −0.016 (2) | −0.0129 (8) |
O8 | 0.0467 (9) | 0.0676 (10) | 0.0496 (8) | −0.0210 (8) | −0.0039 (7) | −0.0149 (8) |
O9 | 0.0463 (8) | 0.0528 (8) | 0.0247 (5) | −0.0105 (7) | 0.0018 (6) | −0.0083 (6) |
C1 | 0.0263 (8) | 0.0408 (9) | 0.0213 (6) | −0.0019 (7) | −0.0024 (6) | 0.0031 (6) |
C2 | 0.0247 (8) | 0.0528 (10) | 0.0251 (7) | 0.0013 (8) | −0.0037 (6) | 0.0097 (7) |
C3 | 0.0259 (8) | 0.0483 (10) | 0.0319 (8) | 0.0067 (8) | 0.0012 (7) | 0.0147 (7) |
C4 | 0.0283 (8) | 0.0298 (7) | 0.0285 (7) | 0.0048 (7) | 0.0039 (6) | 0.0101 (6) |
C5 | 0.0198 (6) | 0.0259 (7) | 0.0202 (6) | 0.0005 (5) | 0.0021 (5) | 0.0052 (5) |
C6 | 0.0242 (7) | 0.0232 (7) | 0.0215 (6) | −0.0016 (6) | 0.0023 (6) | 0.0006 (5) |
C7 | 0.0198 (6) | 0.0250 (7) | 0.0182 (6) | −0.0022 (5) | 0.0004 (5) | 0.0015 (5) |
C8 | 0.0178 (6) | 0.0238 (6) | 0.0179 (6) | 0.0006 (5) | 0.0002 (5) | 0.0035 (5) |
C9 | 0.0211 (6) | 0.0248 (6) | 0.0166 (6) | −0.0007 (6) | 0.0007 (5) | 0.0023 (5) |
C10 | 0.0205 (6) | 0.0278 (7) | 0.0169 (6) | 0.0005 (6) | 0.0011 (5) | 0.0037 (5) |
C11 | 0.0451 (10) | 0.0276 (7) | 0.0178 (6) | 0.0009 (7) | 0.0028 (7) | −0.0010 (6) |
C12 | 0.0372 (9) | 0.0284 (7) | 0.0244 (7) | 0.0084 (7) | 0.0042 (6) | −0.0021 (6) |
C13 | 0.0253 (7) | 0.0213 (6) | 0.0224 (6) | 0.0049 (6) | 0.0016 (5) | 0.0015 (5) |
C14 | 0.0184 (6) | 0.0259 (7) | 0.0187 (6) | 0.0027 (5) | 0.0010 (5) | 0.0037 (5) |
C15 | 0.0224 (7) | 0.0308 (7) | 0.0212 (6) | −0.0018 (6) | −0.0020 (6) | 0.0065 (5) |
C16 | 0.0229 (7) | 0.0325 (8) | 0.0249 (7) | −0.0006 (6) | −0.0026 (6) | 0.0093 (6) |
C17 | 0.0406 (9) | 0.0257 (7) | 0.0311 (8) | 0.0103 (7) | 0.0012 (7) | 0.0049 (6) |
C18 | 0.0242 (7) | 0.0258 (7) | 0.0262 (7) | −0.0016 (6) | −0.0013 (6) | 0.0031 (6) |
C19 | 0.0257 (7) | 0.0383 (8) | 0.0217 (6) | 0.0022 (7) | 0.0056 (6) | 0.0082 (6) |
C20 | 0.0767 (16) | 0.0233 (8) | 0.0365 (9) | 0.0091 (10) | −0.0058 (10) | 0.0034 (7) |
C21 | 0.138 (3) | 0.0313 (10) | 0.0610 (15) | 0.0238 (15) | 0.0115 (19) | −0.0033 (10) |
C22 | 0.0819 (18) | 0.0284 (9) | 0.0661 (14) | −0.0109 (11) | −0.0189 (14) | 0.0047 (9) |
C23 | 0.142 (4) | 0.0335 (12) | 0.087 (2) | −0.0168 (18) | −0.032 (3) | −0.0012 (13) |
C24 | 0.0366 (9) | 0.0372 (9) | 0.0458 (10) | 0.0111 (8) | 0.0102 (8) | 0.0104 (8) |
C25 | 0.0387 (9) | 0.0318 (8) | 0.0397 (9) | −0.0024 (7) | 0.0049 (8) | 0.0140 (7) |
C26 | 0.0180 (6) | 0.0364 (8) | 0.0263 (7) | 0.0001 (6) | 0.0030 (6) | 0.0083 (6) |
C27 | 0.0607 (13) | 0.0341 (9) | 0.0309 (8) | −0.0134 (9) | −0.0003 (9) | −0.0065 (7) |
C28 | 0.095 (2) | 0.0476 (13) | 0.0538 (13) | −0.0037 (15) | −0.0014 (14) | −0.0251 (11) |
C29 | 0.0343 (8) | 0.0266 (7) | 0.0195 (6) | −0.0010 (7) | 0.0055 (6) | −0.0014 (5) |
C30 | 0.0412 (10) | 0.0434 (10) | 0.0299 (8) | −0.0086 (8) | 0.0164 (7) | −0.0055 (7) |
O1—C3 | 1.227 (2) | C12—C13 | 1.544 (2) |
O2—C27 | 1.374 (3) | C12—H12A | 0.9900 |
O2—C6 | 1.4510 (18) | C12—H12B | 0.9900 |
O3—C29 | 1.3697 (18) | C13—C14 | 1.538 (2) |
O3—C7 | 1.4600 (18) | C13—C18 | 1.551 (2) |
O4—C15 | 1.436 (2) | C13—C17 | 1.562 (2) |
O4—C14 | 1.4517 (18) | C14—C15 | 1.491 (2) |
O5—C16 | 1.346 (2) | C15—C16 | 1.506 (2) |
O5—C17 | 1.472 (2) | C15—H15 | 1.0000 |
O6—C16 | 1.204 (2) | C17—C20 | 1.507 (3) |
O7—C23 | 1.368 (6) | C17—H17 | 1.0000 |
O7—C21 | 1.381 (5) | C18—H18A | 0.9800 |
O8—C27 | 1.205 (3) | C18—H18B | 0.9800 |
O9—C29 | 1.205 (2) | C18—H18C | 0.9800 |
C1—C2 | 1.344 (2) | C19—H19A | 0.9800 |
C1—C10 | 1.531 (2) | C19—H19B | 0.9800 |
C1—H1 | 0.9500 | C19—H19C | 0.9800 |
C2—C3 | 1.478 (3) | C20—C21 | 1.344 (3) |
C2—H2 | 0.9500 | C20—C22 | 1.441 (4) |
C3—C4 | 1.546 (3) | C21—H21 | 0.9500 |
C4—C25 | 1.539 (3) | C22—C23 | 1.343 (4) |
C4—C24 | 1.560 (3) | C22—H22 | 0.9500 |
C4—C5 | 1.577 (2) | C23—H23 | 0.9500 |
C5—C6 | 1.534 (2) | C24—H24A | 0.9800 |
C5—C10 | 1.569 (2) | C24—H24B | 0.9800 |
C5—H5 | 1.0000 | C24—H24C | 0.9800 |
C6—C7 | 1.537 (2) | C25—H25A | 0.9800 |
C6—H6 | 1.0000 | C25—H25B | 0.9800 |
C7—C8 | 1.539 (2) | C25—H25C | 0.9800 |
C7—H7 | 1.0000 | C26—H26A | 0.9800 |
C8—C26 | 1.557 (2) | C26—H26B | 0.9800 |
C8—C9 | 1.561 (2) | C26—H26C | 0.9800 |
C8—C14 | 1.570 (2) | C27—C28 | 1.504 (3) |
C9—C11 | 1.544 (2) | C28—H28A | 0.9800 |
C9—C10 | 1.571 (2) | C28—H28B | 0.9800 |
C9—H9 | 1.0000 | C28—H28C | 0.9800 |
C10—C19 | 1.559 (2) | C29—C30 | 1.504 (3) |
C11—C12 | 1.554 (2) | C30—H30A | 0.9800 |
C11—H11A | 0.9900 | C30—H30B | 0.9800 |
C11—H11B | 0.9900 | C30—H30C | 0.9800 |
C27—O2—C6 | 115.28 (15) | C15—C14—C8 | 122.44 (13) |
C29—O3—C7 | 117.80 (12) | C13—C14—C8 | 118.83 (12) |
C15—O4—C14 | 62.14 (9) | O4—C15—C14 | 59.43 (9) |
C16—O5—C17 | 120.09 (12) | O4—C15—C16 | 116.61 (14) |
C23—O7—C21 | 105.9 (2) | C14—C15—C16 | 117.91 (14) |
C2—C1—C10 | 120.74 (16) | O4—C15—H15 | 116.8 |
C2—C1—H1 | 119.6 | C14—C15—H15 | 116.8 |
C10—C1—H1 | 119.6 | C16—C15—H15 | 116.8 |
C1—C2—C3 | 120.26 (16) | O6—C16—O5 | 120.32 (15) |
C1—C2—H2 | 119.9 | O6—C16—C15 | 121.52 (16) |
C3—C2—H2 | 119.9 | O5—C16—C15 | 118.11 (14) |
O1—C3—C2 | 121.14 (18) | O5—C17—C20 | 104.45 (14) |
O1—C3—C4 | 120.21 (19) | O5—C17—C13 | 110.09 (13) |
C2—C3—C4 | 118.58 (14) | C20—C17—C13 | 115.47 (15) |
C25—C4—C3 | 109.08 (14) | O5—C17—H17 | 108.9 |
C25—C4—C24 | 108.90 (16) | C20—C17—H17 | 108.9 |
C3—C4—C24 | 103.16 (15) | C13—C17—H17 | 108.9 |
C25—C4—C5 | 114.70 (14) | C13—C18—H18A | 109.5 |
C3—C4—C5 | 110.96 (14) | C13—C18—H18B | 109.5 |
C24—C4—C5 | 109.39 (13) | H18A—C18—H18B | 109.5 |
C6—C5—C10 | 109.77 (12) | C13—C18—H18C | 109.5 |
C6—C5—C4 | 114.27 (13) | H18A—C18—H18C | 109.5 |
C10—C5—C4 | 114.05 (12) | H18B—C18—H18C | 109.5 |
C6—C5—H5 | 106.0 | C10—C19—H19A | 109.5 |
C10—C5—H5 | 106.0 | C10—C19—H19B | 109.5 |
C4—C5—H5 | 106.0 | H19A—C19—H19B | 109.5 |
O2—C6—C5 | 109.22 (12) | C10—C19—H19C | 109.5 |
O2—C6—C7 | 107.43 (12) | H19A—C19—H19C | 109.5 |
C5—C6—C7 | 112.10 (12) | H19B—C19—H19C | 109.5 |
O2—C6—H6 | 109.3 | C21—C20—C22 | 106.0 (3) |
C5—C6—H6 | 109.3 | C21—C20—C17 | 125.3 (3) |
C7—C6—H6 | 109.3 | C22—C20—C17 | 128.7 (2) |
O3—C7—C6 | 108.21 (12) | C20—C21—O7 | 110.8 (4) |
O3—C7—C8 | 107.95 (11) | C20—C21—H21 | 124.6 |
C6—C7—C8 | 112.24 (12) | O7—C21—H21 | 124.6 |
O3—C7—H7 | 109.5 | C23—C22—C20 | 106.6 (3) |
C6—C7—H7 | 109.5 | C23—C22—H22 | 126.7 |
C8—C7—H7 | 109.5 | C20—C22—H22 | 126.7 |
C7—C8—C26 | 108.58 (13) | C22—C23—O7 | 110.8 (4) |
C7—C8—C9 | 108.85 (12) | C22—C23—H23 | 124.6 |
C26—C8—C9 | 113.32 (11) | O7—C23—H23 | 124.6 |
C7—C8—C14 | 110.18 (11) | C4—C24—H24A | 109.5 |
C26—C8—C14 | 106.74 (12) | C4—C24—H24B | 109.5 |
C9—C8—C14 | 109.15 (12) | H24A—C24—H24B | 109.5 |
C11—C9—C8 | 110.69 (12) | C4—C24—H24C | 109.5 |
C11—C9—C10 | 114.45 (11) | H24A—C24—H24C | 109.5 |
C8—C9—C10 | 114.98 (12) | H24B—C24—H24C | 109.5 |
C11—C9—H9 | 105.2 | C4—C25—H25A | 109.5 |
C8—C9—H9 | 105.2 | C4—C25—H25B | 109.5 |
C10—C9—H9 | 105.2 | H25A—C25—H25B | 109.5 |
C1—C10—C19 | 105.40 (12) | C4—C25—H25C | 109.5 |
C1—C10—C5 | 105.61 (13) | H25A—C25—H25C | 109.5 |
C19—C10—C5 | 113.12 (13) | H25B—C25—H25C | 109.5 |
C1—C10—C9 | 108.83 (13) | C8—C26—H26A | 109.5 |
C19—C10—C9 | 114.95 (13) | C8—C26—H26B | 109.5 |
C5—C10—C9 | 108.42 (11) | H26A—C26—H26B | 109.5 |
C9—C11—C12 | 114.64 (12) | C8—C26—H26C | 109.5 |
C9—C11—H11A | 108.6 | H26A—C26—H26C | 109.5 |
C12—C11—H11A | 108.6 | H26B—C26—H26C | 109.5 |
C9—C11—H11B | 108.6 | O8—C27—O2 | 123.16 (18) |
C12—C11—H11B | 108.6 | O8—C27—C28 | 125.8 (2) |
H11A—C11—H11B | 107.6 | O2—C27—C28 | 111.0 (2) |
C13—C12—C11 | 113.60 (13) | C27—C28—H28A | 109.5 |
C13—C12—H12A | 108.8 | C27—C28—H28B | 109.5 |
C11—C12—H12A | 108.8 | H28A—C28—H28B | 109.5 |
C13—C12—H12B | 108.8 | C27—C28—H28C | 109.5 |
C11—C12—H12B | 108.8 | H28A—C28—H28C | 109.5 |
H12A—C12—H12B | 107.7 | H28B—C28—H28C | 109.5 |
C14—C13—C12 | 106.49 (13) | O9—C29—O3 | 123.71 (16) |
C14—C13—C18 | 112.10 (13) | O9—C29—C30 | 126.10 (15) |
C12—C13—C18 | 113.16 (13) | O3—C29—C30 | 110.19 (14) |
C14—C13—C17 | 106.91 (13) | C29—C30—H30A | 109.5 |
C12—C13—C17 | 109.19 (13) | C29—C30—H30B | 109.5 |
C18—C13—C17 | 108.77 (14) | H30A—C30—H30B | 109.5 |
O4—C14—C15 | 58.43 (9) | C29—C30—H30C | 109.5 |
O4—C14—C13 | 112.54 (12) | H30A—C30—H30C | 109.5 |
C15—C14—C13 | 115.33 (12) | H30B—C30—H30C | 109.5 |
O4—C14—C8 | 113.27 (12) | ||
C10—C1—C2—C3 | −0.8 (3) | C11—C12—C13—C18 | 66.3 (2) |
C1—C2—C3—O1 | 151.7 (2) | C11—C12—C13—C17 | −172.40 (15) |
C1—C2—C3—C4 | −31.5 (3) | C15—O4—C14—C13 | −106.78 (14) |
O1—C3—C4—C25 | −41.8 (2) | C15—O4—C14—C8 | 114.90 (14) |
C2—C3—C4—C25 | 141.42 (17) | C12—C13—C14—O4 | −90.70 (14) |
O1—C3—C4—C24 | 73.9 (2) | C18—C13—C14—O4 | 145.05 (12) |
C2—C3—C4—C24 | −102.93 (18) | C17—C13—C14—O4 | 25.94 (16) |
O1—C3—C4—C5 | −169.06 (17) | C12—C13—C14—C15 | −155.18 (13) |
C2—C3—C4—C5 | 14.1 (2) | C18—C13—C14—C15 | 80.56 (16) |
C25—C4—C5—C6 | 33.94 (19) | C17—C13—C14—C15 | −38.54 (18) |
C3—C4—C5—C6 | 158.10 (13) | C12—C13—C14—C8 | 45.10 (17) |
C24—C4—C5—C6 | −88.73 (17) | C18—C13—C14—C8 | −79.16 (16) |
C25—C4—C5—C10 | −93.47 (17) | C17—C13—C14—C8 | 161.74 (13) |
C3—C4—C5—C10 | 30.69 (18) | C7—C8—C14—O4 | −95.19 (14) |
C24—C4—C5—C10 | 143.86 (15) | C26—C8—C14—O4 | 22.52 (16) |
C27—O2—C6—C5 | −157.85 (14) | C9—C8—C14—O4 | 145.34 (12) |
C27—O2—C6—C7 | 80.34 (16) | C7—C8—C14—C15 | −28.89 (19) |
C10—C5—C6—O2 | −178.48 (11) | C26—C8—C14—C15 | 88.82 (16) |
C4—C5—C6—O2 | 51.94 (16) | C9—C8—C14—C15 | −148.36 (14) |
C10—C5—C6—C7 | −59.54 (15) | C7—C8—C14—C13 | 129.32 (13) |
C4—C5—C6—C7 | 170.89 (12) | C26—C8—C14—C13 | −112.97 (14) |
C29—O3—C7—C6 | −103.01 (14) | C9—C8—C14—C13 | 9.85 (17) |
C29—O3—C7—C8 | 135.29 (13) | C14—O4—C15—C16 | 108.19 (15) |
O2—C6—C7—O3 | 59.79 (15) | C13—C14—C15—O4 | 101.94 (14) |
C5—C6—C7—O3 | −60.21 (15) | C8—C14—C15—O4 | −99.15 (15) |
O2—C6—C7—C8 | 178.81 (12) | O4—C14—C15—C16 | −106.01 (16) |
C5—C6—C7—C8 | 58.81 (16) | C13—C14—C15—C16 | −4.1 (2) |
O3—C7—C8—C26 | −170.06 (11) | C8—C14—C15—C16 | 154.85 (14) |
C6—C7—C8—C26 | 70.76 (15) | C17—O5—C16—O6 | 172.96 (16) |
O3—C7—C8—C9 | 66.16 (14) | C17—O5—C16—C15 | −4.3 (2) |
C6—C7—C8—C9 | −53.01 (16) | O4—C15—C16—O6 | 143.88 (16) |
O3—C7—C8—C14 | −53.49 (14) | C14—C15—C16—O6 | −148.35 (16) |
C6—C7—C8—C14 | −172.67 (12) | O4—C15—C16—O5 | −38.9 (2) |
C7—C8—C9—C11 | −175.38 (12) | C14—C15—C16—O5 | 28.8 (2) |
C26—C8—C9—C11 | 63.71 (16) | C16—O5—C17—C20 | −166.21 (16) |
C14—C8—C9—C11 | −55.09 (15) | C16—O5—C17—C13 | −41.7 (2) |
C7—C8—C9—C10 | 53.01 (15) | C14—C13—C17—O5 | 61.47 (17) |
C26—C8—C9—C10 | −67.90 (16) | C12—C13—C17—O5 | 176.30 (14) |
C14—C8—C9—C10 | 173.30 (12) | C18—C13—C17—O5 | −59.77 (18) |
C2—C1—C10—C19 | −75.97 (19) | C14—C13—C17—C20 | 179.41 (16) |
C2—C1—C10—C5 | 44.02 (19) | C12—C13—C17—C20 | −65.8 (2) |
C2—C1—C10—C9 | 160.24 (15) | C18—C13—C17—C20 | 58.2 (2) |
C6—C5—C10—C1 | 172.32 (12) | O5—C17—C20—C21 | −135.9 (2) |
C4—C5—C10—C1 | −57.99 (16) | C13—C17—C20—C21 | 103.1 (3) |
C6—C5—C10—C19 | −72.91 (15) | O5—C17—C20—C22 | 41.4 (3) |
C4—C5—C10—C19 | 56.78 (17) | C13—C17—C20—C22 | −79.6 (2) |
C6—C5—C10—C9 | 55.81 (15) | C22—C20—C21—O7 | 1.5 (3) |
C4—C5—C10—C9 | −174.49 (12) | C17—C20—C21—O7 | 179.3 (2) |
C11—C9—C10—C1 | 61.00 (17) | C23—O7—C21—C20 | −2.0 (3) |
C8—C9—C10—C1 | −169.21 (12) | C21—C20—C22—C23 | −0.3 (3) |
C11—C9—C10—C19 | −56.92 (18) | C17—C20—C22—C23 | −178.1 (2) |
C8—C9—C10—C19 | 72.88 (16) | C20—C22—C23—O7 | −0.9 (3) |
C11—C9—C10—C5 | 175.40 (13) | C21—O7—C23—C22 | 1.8 (4) |
C8—C9—C10—C5 | −54.81 (16) | C6—O2—C27—O8 | 2.3 (3) |
C8—C9—C11—C12 | 43.91 (19) | C6—O2—C27—C28 | −177.72 (17) |
C10—C9—C11—C12 | 175.79 (14) | C7—O3—C29—O9 | 2.3 (2) |
C9—C11—C12—C13 | 14.2 (2) | C7—O3—C29—C30 | −177.55 (13) |
C11—C12—C13—C14 | −57.29 (18) |
D—H···A | D—H | H···A | D···A | D—H···A |
C11—H11B···O1i | 0.99 | 2.59 | 3.410 (3) | 141 |
C18—H18C···O1i | 0.98 | 2.68 | 3.571 (2) | 152 |
C18—H18B···O6ii | 0.98 | 2.56 | 3.497 (2) | 160 |
C22—H22···O6ii | 0.95 | 2.69 | 3.601 (3) | 162 |
C24—H24B···O2 | 0.98 | 2.40 | 3.066 (3) | 125 |
C25—H25C···O2 | 0.98 | 2.50 | 3.112 (2) | 121 |
C5—H5···O3 | 1.00 | 2.50 | 2.931 (2) | 105 |
C9—H9···O3 | 1.00 | 2.55 | 2.944 (2) | 103 |
C18—H18B···O5 | 0.98 | 2.45 | 2.934 (2) | 110 |
C7—H7···O9 | 1.00 | 2.33 | 2.735 (2) | 103 |
Symmetry codes: (i) −x, y−1/2, −z+1/2; (ii) x−1/2, −y+1/2, −z+1. |
Experimental details
Crystal data | |
Chemical formula | C30H36O9 |
Mr | 540.59 |
Crystal system, space group | Orthorhombic, P212121 |
Temperature (K) | 173 |
a, b, c (Å) | 6.475 (2), 14.914 (5), 28.713 (9) |
V (Å3) | 2772.8 (15) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.10 |
Crystal size (mm) | 0.62 × 0.40 × 0.25 |
Data collection | |
Diffractometer | Bruker SMART APEX CCD diffractometer |
Absorption correction | Multi-scan (SADABS; Bruker, 2003) |
Tmin, Tmax | 0.89, 0.98 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 39048, 4509, 4077 |
Rint | 0.031 |
(sin θ/λ)max (Å−1) | 0.703 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.037, 0.099, 1.04 |
No. of reflections | 4509 |
No. of parameters | 359 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.26, −0.24 |
Computer programs: SMART (Bruker, 2003), SAINT (Bruker, 2003), SAINT, SADABS and XPREP (Bruker, 2003), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008).
D—H···A | D—H | H···A | D···A | D—H···A |
C11—H11B···O1i | 0.99 | 2.59 | 3.410 (3) | 141 |
C18—H18C···O1i | 0.98 | 2.68 | 3.571 (2) | 152 |
C18—H18B···O6ii | 0.98 | 2.56 | 3.497 (2) | 160 |
C22—H22···O6ii | 0.95 | 2.69 | 3.601 (3) | 162 |
C24—H24B···O2 | 0.98 | 2.40 | 3.066 (3) | 125 |
C25—H25C···O2 | 0.98 | 2.50 | 3.112 (2) | 121 |
C5—H5···O3 | 1.00 | 2.50 | 2.931 (2) | 105 |
C9—H9···O3 | 1.00 | 2.55 | 2.944 (2) | 103 |
C18—H18B···O5 | 0.98 | 2.45 | 2.934 (2) | 110 |
C7—H7···O9 | 1.00 | 2.33 | 2.735 (2) | 103 |
Symmetry codes: (i) −x, y−1/2, −z+1/2; (ii) x−1/2, −y+1/2, −z+1. |
The genus Aglaia of the family Meliaceae has received scientific attention due to its bioactivity potential. Besides its unique chemical capacity to produce flavaglines with pronounced insecticidal, antifungal, and anticancer activities (Greger et al., 2001; Engelmeier et al., 2000; Hausott et al., 2004), Aglaia is also characterized by the accumulation of bisamides, lignans, and triterpenes (Greger et al., 2000). However, in contrast to other genera of that family the highly active triterpenoid limonoids appear to be rare in Aglaia only known so far from Aglaia elaeagnoidea collected in Sempu Island, Java, Indonesia (6α,11β-diacetoxygedunin; Fuzzati et al., 1996), but not from samples collected in India and Thailand (Brader et al., 1998). Our investigation of the root bark of Aglaia elaeagnoidea originating from northern Australia led now to the second isolation of a limonoid from this genus, namely the title compound 6α-acetoxygedunin. This compound was previously isolated from several other genera of the Meliaceae family, such as Guarea grandiflora Decne.ex Steud. (Jimenez et al., 1998) or Carapa guianensis Aubl. (Lavie et al., 1972), but its crystal structure has not been determined as yet.
6α-Acetoxygedunin contains the gedunin skeleton with four six-membered rings (A, B, C, D), which are all trans-fused and adopt screw-boat, chair, twist-boat, and twisted half-chair conformation, respectively (Fig. 1). The D-ring, a lactone, is stiffened by fusion with an oxiran ring and bears in equatorial position a furan ring in approximately perpendicular orientation to the main plane of the molecule. Bond length and angles are normal (cf. geometric parameters) and compare well with the parent compound gedunin (Toscano et al., 1996), which is devoid of the 6-acetoxy group O2—(C27O8)—C28H3, and with three more gedunin derivatives, 11α-hydroxygedunin (Mitsui et al., 2006), 11β-hydroxygedunin (Mitsui et al., 2006), and 7-oxogedunin (Waratchareeyakul et al., 2004; 7-acetoxy group replaced by a carbonyl oxygen with concomitant change of C7 from sp3 to sp2 hybridization). However, the torsion angles within the A/B/C/D rings of these five compounds show in part considerable variations and consequently the molecular conformations as well. This is visualized by three superposition plots of 6α-acetoxygedunin and its congeners shown in Figures 2 to 4. Fig. 2 demonstrates that 6α-acetoxygedunin and 11α-hydroxygedunin (Mitsui et al. 2006; it contains two independent molecules) have relatively closely matching conformations of their A/B/C/D rings. Fig. 3 compares 6α-acetoxygedunin and gedunin showing that their B, C, and D rings match very well, but that the A-rings display a significant mismatch. The torsion angle T1 = C3—C4—C5—C10 may be used as a qualitative measure for this match/mismatch: It is 30.7 (2)° in 6α-acetoxygedunin and 51.2° in gedunin, while the remaining three gedunin-type compounds have T1 angles between 32.2° (11α-hydroxygedunin) and 45.3° (7-oxogedunin). Fig. 4 demonstrates that the most outstanding difference in conformation exists between 6α-acetoxygedunin and 7-oxogedunin. This difference does not arise from the unlike hybridization of C7 (sp3 in title compound and sp2 in 7-oxogedunin), but is clearly provoked by ring C, which switches from a twist-boat conformation in 6α-acetoxygedunin via a virtual boat-intermediate into a twist-boat conformation of opposite twist in 7-oxogedunin. This can be tracked by the torsion angle T2 = C9—C11—C12—C13, which is +14.2 (2)° in 6α-acetoxygedunin (+21.6° in gedunin; +9.5° and +14.5° for the two independent molecules in 11α-hydroxygedunin), while it is -38.9° in 7-oxogedunin and -20.7° in 11β-hydroxygedunin. The described variations come essentially from the fact that B– and D-rings behave hard (B-ring in a relaxed and essentially invariant chair-conformation, D-ring in a twisted half-chair conformation fixed by oxiran ring and lacton group) while A-rings (screw-boat) and C-rings (between boat and twist-boat) behave soft and labile in conformation. The soft parts of the molecules are certainly controlled by the steric requirements of the ring substituents and by the crystal packing with its interplay of intra- and intermolecular forces. In the title compound 6α-acetoxygedunin such forces involve only several quite weak intra- and inter-molecular C—H···O interactions, which are listed in Table 1. For a packing diagram of 6α-acetoxygedunin, see Fig. 5.