
Supporting information
![]() | Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536803018233/om6160sup1.cif |
![]() | Structure factor file (CIF format) https://doi.org/10.1107/S1600536803018233/om6160Isup2.hkl |
CCDC reference: 222909
The antitubercular CH2Cl2–MeOH extract of S. brasiliensis was chromatographed on a silica gel column with increasing concentrations of EtOAc in n-hexane. The fraction eluting with 10% EtOAc in n-hexane was found to inhibit the growth of Mycobacterium tuberculosis H37Rv (ATCC 27294) by 90% at 50 µg ml−1 concentration. This fraction, when treated with ether, gave a crystalline substance which on thin-layer chronatography (TLC) showed essentially one major spot. Preparative silica gel TLC of this fraction followed by crystallization led to the isolation of fern-7-en-3α-ol, (I). Crystals were obtained by slow evaporation of n-hexane/acetone. Colorless shining transparent rectangular rods were formed after 3 d.
H-atom positions were easily visible in difference Fourier maps and all H atoms were allowed to refine freely, except for the hydroxyl H atom, which was constrained to an O—H distance of 0.84 Å and a C—O—H angle of 109.47°. Due to the absence of any heavy atoms, anomalous dispersion could not be used to define absolute configuration. In the final cycles of refinement, all Friedel pairs were merged. The enantiomer was selected based on the observed negative optical rotation of the compound in solution and the fact that this is the most common enantiomer observed in nature (Ahmad & Atta-ur-Rahman, 1994).
Data collection: SMART (Bruker, 1997); cell refinement: SMART; data reduction: SAINT (Bruker, 1997); program(s) used to solve structure: SHELXS97 (Bruker, 1997); program(s) used to refine structure: SHELXL97 (Bruker, 1997); molecular graphics: SHELXTL (Bruker, 1997); software used to prepare material for publication: SHELXTL.
C30H50O | F(000) = 476 |
Mr = 426.70 | Dx = 1.130 Mg m−3 |
Monoclinic, P21 | Melting point = 240–241 K |
Hall symbol: P 2yb | Mo Kα radiation, λ = 0.71073 Å |
a = 12.4234 (18) Å | Cell parameters from 4025 reflections |
b = 7.5526 (11) Å | θ = 2.5–23.5° |
c = 13.628 (2) Å | µ = 0.07 mm−1 |
β = 101.320 (3)° | T = 170 K |
V = 1253.8 (3) Å3 | Parallelepiped, colorless |
Z = 2 | 0.35 × 0.27 × 0.19 mm |
Bruker SMART CCD area-detector diffractometer | 3278 independent reflections |
Radiation source: fine-focus sealed tube | 2947 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.036 |
ϕ and ω scans | θmax = 28.3°, θmin = 1.5° |
Absorption correction: multi-scan (SADABS; Sheldrick, 2000) | h = −16→16 |
Tmin = 0.978, Tmax = 0.988 | k = −10→10 |
15904 measured reflections | l = −18→17 |
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)] = 0.044 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.103 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.06 | w = 1/[σ2(Fo2) + (0.0564P)2 + 0.2128P] where P = (Fo2 + 2Fc2)/3 |
3278 reflections | (Δ/σ)max = 0.001 |
427 parameters | Δρmax = 0.29 e Å−3 |
1 restraint | Δρmin = −0.21 e Å−3 |
C30H50O | V = 1253.8 (3) Å3 |
Mr = 426.70 | Z = 2 |
Monoclinic, P21 | Mo Kα radiation |
a = 12.4234 (18) Å | µ = 0.07 mm−1 |
b = 7.5526 (11) Å | T = 170 K |
c = 13.628 (2) Å | 0.35 × 0.27 × 0.19 mm |
β = 101.320 (3)° |
Bruker SMART CCD area-detector diffractometer | 3278 independent reflections |
Absorption correction: multi-scan (SADABS; Sheldrick, 2000) | 2947 reflections with I > 2σ(I) |
Tmin = 0.978, Tmax = 0.988 | Rint = 0.036 |
15904 measured reflections |
R[F2 > 2σ(F2)] = 0.044 | 1 restraint |
wR(F2) = 0.103 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.06 | Δρmax = 0.29 e Å−3 |
3278 reflections | Δρmin = −0.21 e Å−3 |
427 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 | 1.40579 (14) | 0.6237 (3) | 0.89158 (15) | 0.0510 (5) | |
H1C | 1.4412 | 0.5297 | 0.9071 | 0.076* | |
C1 | 1.19096 (19) | 0.4868 (3) | 0.90714 (18) | 0.0311 (5) | |
H1A | 1.221 (2) | 0.450 (4) | 0.847 (2) | 0.037* | |
H1B | 1.146 (2) | 0.382 (4) | 0.922 (2) | 0.037* | |
C2 | 1.2852 (2) | 0.5247 (4) | 0.99506 (19) | 0.0369 (6) | |
H2A | 1.254 (2) | 0.557 (5) | 1.058 (2) | 0.044* | |
H2B | 1.327 (2) | 0.425 (5) | 1.004 (2) | 0.044* | |
C3 | 1.35494 (19) | 0.6777 (4) | 0.97270 (18) | 0.0336 (5) | |
H3 | 1.413 (2) | 0.704 (4) | 1.029 (2) | 0.040* | |
C4 | 1.28847 (16) | 0.8509 (3) | 0.94791 (16) | 0.0258 (4) | |
C5 | 1.18708 (16) | 0.8123 (3) | 0.86352 (15) | 0.0217 (4) | |
H5 | 1.221 (2) | 0.790 (4) | 0.8061 (18) | 0.026* | |
C6 | 1.11519 (17) | 0.9759 (3) | 0.83414 (16) | 0.0255 (4) | |
H6A | 1.157 (2) | 1.067 (4) | 0.8076 (18) | 0.031* | |
H6B | 1.096 (2) | 1.034 (4) | 0.8975 (19) | 0.031* | |
C7 | 1.01005 (16) | 0.9370 (3) | 0.76111 (15) | 0.0233 (4) | |
H7 | 0.967 (2) | 1.039 (4) | 0.7398 (18) | 0.028* | |
C8 | 0.97350 (17) | 0.7761 (3) | 0.73325 (14) | 0.0197 (4) | |
C9 | 1.04349 (16) | 0.6136 (3) | 0.77089 (16) | 0.0220 (4) | |
H9 | 1.0982 (19) | 0.602 (4) | 0.7289 (18) | 0.026* | |
C10 | 1.11547 (16) | 0.6477 (3) | 0.87714 (15) | 0.0216 (4) | |
C11 | 0.9784 (2) | 0.4394 (3) | 0.76279 (18) | 0.0302 (5) | |
H11A | 0.941 (2) | 0.428 (4) | 0.818 (2) | 0.036* | |
H11B | 1.028 (2) | 0.340 (4) | 0.773 (2) | 0.036* | |
C12 | 0.89420 (19) | 0.4119 (3) | 0.66383 (17) | 0.0277 (5) | |
H12A | 0.917 (2) | 0.319 (4) | 0.625 (2) | 0.033* | |
H12B | 0.824 (2) | 0.367 (4) | 0.6792 (19) | 0.033* | |
C13 | 0.86880 (16) | 0.5793 (3) | 0.59792 (14) | 0.0207 (4) | |
C14 | 0.86016 (15) | 0.7426 (3) | 0.66738 (15) | 0.0195 (4) | |
C15 | 0.81611 (16) | 0.9046 (3) | 0.60218 (15) | 0.0211 (4) | |
H15A | 0.8088 (19) | 1.003 (4) | 0.6475 (18) | 0.025* | |
H15B | 0.871 (2) | 0.937 (4) | 0.5645 (17) | 0.025* | |
C16 | 0.70575 (17) | 0.8726 (3) | 0.52982 (16) | 0.0235 (4) | |
H16A | 0.689 (2) | 0.975 (4) | 0.492 (2) | 0.028* | |
H16B | 0.649 (2) | 0.852 (4) | 0.5701 (18) | 0.028* | |
C17 | 0.71043 (16) | 0.7145 (3) | 0.45998 (15) | 0.0203 (4) | |
C18 | 0.75713 (17) | 0.5554 (3) | 0.52701 (15) | 0.0219 (4) | |
H18 | 0.7031 (19) | 0.543 (4) | 0.5713 (18) | 0.026* | |
C19 | 0.7379 (2) | 0.3959 (3) | 0.45675 (18) | 0.0321 (5) | |
H19A | 0.793 (2) | 0.387 (4) | 0.418 (2) | 0.038* | |
H19B | 0.738 (2) | 0.285 (5) | 0.487 (2) | 0.038* | |
C20 | 0.6246 (2) | 0.4369 (3) | 0.39086 (17) | 0.0317 (5) | |
H20A | 0.625 (2) | 0.419 (4) | 0.322 (2) | 0.038* | |
H20B | 0.565 (2) | 0.360 (4) | 0.405 (2) | 0.038* | |
C21 | 0.59718 (16) | 0.6344 (3) | 0.40981 (15) | 0.0234 (4) | |
H21 | 0.5518 (19) | 0.639 (4) | 0.4634 (18) | 0.028* | |
C22 | 0.52988 (18) | 0.7246 (3) | 0.31581 (16) | 0.0275 (5) | |
H22 | 0.570 (2) | 0.715 (4) | 0.263 (2) | 0.033* | |
C23 | 1.2616 (2) | 0.9247 (4) | 1.04572 (17) | 0.0308 (5) | |
H23A | 1.221 (2) | 1.033 (4) | 1.034 (2) | 0.037* | |
H23B | 1.327 (2) | 0.962 (4) | 1.091 (2) | 0.037* | |
H23C | 1.220 (2) | 0.841 (4) | 1.079 (2) | 0.037* | |
C24 | 1.36140 (19) | 0.9912 (4) | 0.9116 (2) | 0.0381 (6) | |
H24A | 1.375 (2) | 0.967 (4) | 0.845 (2) | 0.046* | |
H24B | 1.324 (2) | 1.115 (5) | 0.907 (2) | 0.046* | |
H24C | 1.431 (2) | 1.000 (4) | 0.963 (2) | 0.046* | |
C25 | 1.04205 (18) | 0.6771 (3) | 0.95397 (17) | 0.0279 (5) | |
H25A | 0.990 (2) | 0.584 (4) | 0.9500 (19) | 0.034* | |
H25B | 1.084 (2) | 0.677 (4) | 1.020 (2) | 0.034* | |
H25C | 1.002 (2) | 0.785 (4) | 0.9427 (19) | 0.034* | |
C26 | 0.96283 (17) | 0.6049 (3) | 0.54017 (17) | 0.0252 (4) | |
H26A | 1.030 (2) | 0.558 (4) | 0.5769 (18) | 0.030* | |
H26B | 0.9486 (19) | 0.538 (4) | 0.4752 (19) | 0.030* | |
H26C | 0.972 (2) | 0.721 (4) | 0.5256 (19) | 0.030* | |
C27 | 0.78122 (18) | 0.7102 (3) | 0.74065 (17) | 0.0280 (5) | |
H27A | 0.708 (2) | 0.688 (4) | 0.7058 (19) | 0.034* | |
H27B | 0.779 (2) | 0.817 (4) | 0.782 (2) | 0.034* | |
H27C | 0.805 (2) | 0.611 (4) | 0.785 (2) | 0.034* | |
C28 | 0.77462 (19) | 0.7631 (3) | 0.37817 (17) | 0.0273 (5) | |
H28A | 0.787 (2) | 0.663 (4) | 0.337 (2) | 0.033* | |
H28B | 0.732 (2) | 0.853 (4) | 0.3342 (19) | 0.033* | |
H28C | 0.846 (2) | 0.810 (4) | 0.4057 (19) | 0.033* | |
C29 | 0.4211 (2) | 0.6248 (5) | 0.2819 (2) | 0.0460 (7) | |
H29A | 0.436 (3) | 0.493 (5) | 0.272 (3) | 0.055* | |
H29B | 0.377 (3) | 0.632 (5) | 0.334 (2) | 0.055* | |
H29C | 0.379 (3) | 0.678 (5) | 0.223 (2) | 0.055* | |
C30 | 0.5061 (2) | 0.9195 (4) | 0.33158 (19) | 0.0366 (6) | |
H30A | 0.457 (2) | 0.967 (4) | 0.273 (2) | 0.044* | |
H30B | 0.473 (2) | 0.941 (4) | 0.390 (2) | 0.044* | |
H30C | 0.573 (2) | 0.997 (4) | 0.348 (2) | 0.044* |
U11 | U22 | U33 | U12 | U13 | U23 | |
O1 | 0.0347 (9) | 0.0695 (14) | 0.0480 (11) | 0.0208 (10) | 0.0064 (8) | −0.0156 (10) |
C1 | 0.0330 (12) | 0.0234 (11) | 0.0322 (12) | 0.0074 (10) | −0.0049 (10) | 0.0001 (9) |
C2 | 0.0370 (13) | 0.0315 (13) | 0.0350 (13) | 0.0102 (10) | −0.0106 (11) | 0.0002 (10) |
C3 | 0.0247 (10) | 0.0443 (14) | 0.0280 (11) | 0.0076 (10) | −0.0039 (9) | −0.0055 (10) |
C4 | 0.0210 (9) | 0.0329 (12) | 0.0223 (10) | −0.0011 (9) | 0.0009 (8) | −0.0001 (9) |
C5 | 0.0201 (9) | 0.0263 (10) | 0.0184 (9) | −0.0022 (8) | 0.0031 (8) | −0.0010 (8) |
C6 | 0.0272 (10) | 0.0193 (10) | 0.0272 (10) | −0.0063 (8) | −0.0010 (9) | 0.0007 (8) |
C7 | 0.0220 (9) | 0.0194 (10) | 0.0258 (10) | 0.0011 (8) | −0.0017 (8) | 0.0029 (8) |
C8 | 0.0205 (9) | 0.0184 (9) | 0.0198 (9) | 0.0017 (7) | 0.0031 (7) | 0.0015 (8) |
C9 | 0.0215 (9) | 0.0178 (9) | 0.0249 (10) | 0.0013 (8) | 0.0004 (8) | −0.0005 (8) |
C10 | 0.0212 (9) | 0.0192 (10) | 0.0224 (9) | 0.0019 (8) | −0.0004 (7) | 0.0010 (8) |
C11 | 0.0340 (12) | 0.0190 (11) | 0.0324 (11) | −0.0015 (9) | −0.0064 (9) | 0.0065 (9) |
C12 | 0.0327 (11) | 0.0163 (10) | 0.0307 (11) | −0.0023 (9) | −0.0021 (9) | 0.0016 (9) |
C13 | 0.0226 (9) | 0.0163 (9) | 0.0219 (9) | −0.0004 (7) | 0.0011 (8) | −0.0004 (7) |
C14 | 0.0182 (9) | 0.0169 (9) | 0.0225 (9) | −0.0016 (7) | 0.0020 (7) | −0.0010 (7) |
C15 | 0.0213 (9) | 0.0149 (10) | 0.0256 (10) | −0.0003 (7) | 0.0012 (8) | −0.0011 (8) |
C16 | 0.0227 (10) | 0.0204 (10) | 0.0254 (11) | 0.0026 (8) | 0.0001 (8) | −0.0029 (8) |
C17 | 0.0188 (9) | 0.0207 (10) | 0.0215 (9) | −0.0024 (7) | 0.0046 (7) | −0.0007 (8) |
C18 | 0.0241 (10) | 0.0184 (9) | 0.0228 (10) | −0.0034 (8) | 0.0039 (8) | −0.0014 (8) |
C19 | 0.0378 (12) | 0.0197 (11) | 0.0337 (12) | −0.0025 (9) | −0.0053 (10) | −0.0045 (9) |
C20 | 0.0366 (12) | 0.0281 (12) | 0.0265 (11) | −0.0093 (10) | −0.0039 (9) | −0.0026 (10) |
C21 | 0.0220 (9) | 0.0268 (11) | 0.0206 (9) | −0.0047 (8) | 0.0021 (8) | 0.0000 (8) |
C22 | 0.0256 (10) | 0.0339 (12) | 0.0216 (10) | −0.0037 (9) | 0.0014 (8) | 0.0013 (9) |
C23 | 0.0314 (11) | 0.0362 (13) | 0.0222 (10) | 0.0003 (10) | −0.0013 (9) | −0.0032 (10) |
C24 | 0.0256 (11) | 0.0539 (17) | 0.0330 (12) | −0.0134 (12) | 0.0011 (10) | −0.0003 (12) |
C25 | 0.0290 (11) | 0.0289 (12) | 0.0264 (10) | −0.0033 (9) | 0.0067 (9) | 0.0037 (9) |
C26 | 0.0219 (10) | 0.0255 (11) | 0.0278 (10) | 0.0044 (8) | 0.0041 (8) | −0.0031 (9) |
C27 | 0.0239 (10) | 0.0347 (12) | 0.0257 (10) | −0.0025 (9) | 0.0055 (9) | −0.0012 (10) |
C28 | 0.0269 (10) | 0.0301 (12) | 0.0260 (10) | −0.0028 (9) | 0.0082 (9) | 0.0020 (9) |
C29 | 0.0352 (13) | 0.0601 (19) | 0.0351 (13) | −0.0152 (13) | −0.0118 (11) | 0.0150 (14) |
C30 | 0.0336 (12) | 0.0429 (14) | 0.0299 (12) | 0.0111 (11) | −0.0022 (10) | 0.0005 (11) |
O1—C3 | 1.436 (3) | C16—H16A | 0.93 (3) |
O1—H1C | 0.8400 | C16—H16B | 0.99 (3) |
C1—C2 | 1.529 (3) | C17—C28 | 1.537 (3) |
C1—C10 | 1.541 (3) | C17—C18 | 1.551 (3) |
C1—H1A | 1.00 (3) | C17—C21 | 1.560 (3) |
C1—H1B | 1.01 (3) | C18—C19 | 1.528 (3) |
C2—C3 | 1.510 (4) | C18—H18 | 0.99 (2) |
C2—H2A | 1.03 (3) | C19—C20 | 1.545 (3) |
C2—H2B | 0.91 (3) | C19—H19A | 0.95 (3) |
C3—C4 | 1.549 (3) | C19—H19B | 0.93 (3) |
C3—H3 | 0.97 (3) | C20—C21 | 1.563 (3) |
C4—C24 | 1.538 (3) | C20—H20A | 0.94 (3) |
C4—C23 | 1.541 (3) | C20—H20B | 0.98 (3) |
C4—C5 | 1.557 (3) | C21—C22 | 1.544 (3) |
C5—C6 | 1.531 (3) | C21—H21 | 1.01 (2) |
C5—C10 | 1.561 (3) | C22—C30 | 1.526 (4) |
C5—H5 | 0.98 (2) | C22—C29 | 1.537 (3) |
C6—C7 | 1.508 (3) | C22—H22 | 0.96 (3) |
C6—H6A | 0.97 (3) | C23—H23A | 0.96 (3) |
C6—H6B | 1.04 (3) | C23—H23B | 0.96 (3) |
C7—C8 | 1.326 (3) | C23—H23C | 0.98 (3) |
C7—H7 | 0.95 (3) | C24—H24A | 0.98 (3) |
C8—C9 | 1.533 (3) | C24—H24B | 1.04 (4) |
C8—C14 | 1.535 (3) | C24—H24C | 0.99 (3) |
C9—C11 | 1.537 (3) | C25—H25A | 0.95 (3) |
C9—C10 | 1.567 (3) | C25—H25B | 0.95 (3) |
C9—H9 | 0.98 (2) | C25—H25C | 0.95 (3) |
C10—C25 | 1.534 (3) | C26—H26A | 0.96 (3) |
C11—C12 | 1.550 (3) | C26—H26B | 1.00 (3) |
C11—H11A | 0.96 (3) | C26—H26C | 0.91 (3) |
C11—H11B | 0.97 (3) | C27—H27A | 0.96 (3) |
C12—C13 | 1.547 (3) | C27—H27B | 0.99 (3) |
C12—H12A | 0.95 (3) | C27—H27C | 0.97 (3) |
C12—H12B | 1.00 (3) | C28—H28A | 0.97 (3) |
C13—C18 | 1.538 (3) | C28—H28B | 0.99 (3) |
C13—C26 | 1.543 (3) | C28—H28C | 0.96 (3) |
C13—C14 | 1.571 (3) | C29—H29A | 1.03 (4) |
C14—C15 | 1.548 (3) | C29—H29B | 0.98 (3) |
C14—C27 | 1.550 (3) | C29—H29C | 0.96 (3) |
C15—C16 | 1.543 (3) | C30—H30A | 0.97 (3) |
C15—H15A | 0.98 (3) | C30—H30B | 0.98 (3) |
C15—H15B | 0.96 (2) | C30—H30C | 1.00 (3) |
C16—C17 | 1.535 (3) | ||
C3—O1—H1C | 109.5 | C17—C16—H16B | 109.8 (16) |
C2—C1—C10 | 113.1 (2) | C15—C16—H16B | 108.3 (14) |
C2—C1—H1A | 110.1 (15) | H16A—C16—H16B | 109 (2) |
C10—C1—H1A | 107.7 (17) | C16—C17—C28 | 110.60 (18) |
C2—C1—H1B | 111.3 (15) | C16—C17—C18 | 107.02 (16) |
C10—C1—H1B | 109.5 (16) | C28—C17—C18 | 115.14 (18) |
H1A—C1—H1B | 105 (2) | C16—C17—C21 | 115.63 (17) |
C3—C2—C1 | 111.5 (2) | C28—C17—C21 | 109.04 (17) |
C3—C2—H2A | 108.2 (19) | C18—C17—C21 | 99.13 (16) |
C1—C2—H2A | 109.7 (16) | C19—C18—C13 | 119.81 (18) |
C3—C2—H2B | 109 (2) | C19—C18—C17 | 104.31 (16) |
C1—C2—H2B | 106.2 (19) | C13—C18—C17 | 117.79 (16) |
H2A—C2—H2B | 112 (3) | C19—C18—H18 | 105.3 (15) |
O1—C3—C2 | 107.1 (2) | C13—C18—H18 | 105.3 (13) |
O1—C3—C4 | 111.6 (2) | C17—C18—H18 | 102.3 (15) |
C2—C3—C4 | 112.82 (18) | C18—C19—C20 | 102.65 (19) |
O1—C3—H3 | 107.4 (17) | C18—C19—H19A | 111.4 (18) |
C2—C3—H3 | 111.2 (18) | C20—C19—H19A | 111.7 (17) |
C4—C3—H3 | 106.5 (19) | C18—C19—H19B | 116.1 (18) |
C24—C4—C23 | 105.7 (2) | C20—C19—H19B | 110.8 (18) |
C24—C4—C3 | 109.24 (19) | H19A—C19—H19B | 104 (2) |
C23—C4—C3 | 108.29 (18) | C19—C20—C21 | 107.34 (18) |
C24—C4—C5 | 109.46 (18) | C19—C20—H20A | 111.5 (17) |
C23—C4—C5 | 115.19 (17) | C21—C20—H20A | 110.2 (19) |
C3—C4—C5 | 108.81 (18) | C19—C20—H20B | 113.6 (16) |
C6—C5—C4 | 112.83 (18) | C21—C20—H20B | 109.7 (18) |
C6—C5—C10 | 110.92 (16) | H20A—C20—H20B | 104 (2) |
C4—C5—C10 | 117.29 (17) | C22—C21—C17 | 119.18 (18) |
C6—C5—H5 | 104.7 (15) | C22—C21—C20 | 112.57 (18) |
C4—C5—H5 | 101.9 (14) | C17—C21—C20 | 103.63 (17) |
C10—C5—H5 | 107.9 (16) | C22—C21—H21 | 107.3 (14) |
C7—C6—C5 | 113.62 (18) | C17—C21—H21 | 104.6 (14) |
C7—C6—H6A | 110.4 (15) | C20—C21—H21 | 109.0 (16) |
C5—C6—H6A | 109.9 (16) | C30—C22—C29 | 109.4 (2) |
C7—C6—H6B | 108.5 (14) | C30—C22—C21 | 113.40 (19) |
C5—C6—H6B | 110.1 (15) | C29—C22—C21 | 109.5 (2) |
H6A—C6—H6B | 104 (2) | C30—C22—H22 | 108.9 (18) |
C8—C7—C6 | 124.83 (19) | C29—C22—H22 | 107.3 (16) |
C8—C7—H7 | 121.1 (16) | C21—C22—H22 | 108.1 (16) |
C6—C7—H7 | 113.9 (16) | C4—C23—H23A | 111.5 (16) |
C7—C8—C9 | 119.87 (18) | C4—C23—H23B | 111.2 (16) |
C7—C8—C14 | 122.80 (18) | H23A—C23—H23B | 102 (2) |
C9—C8—C14 | 117.28 (17) | C4—C23—H23C | 112.9 (17) |
C8—C9—C11 | 113.94 (16) | H23A—C23—H23C | 108 (2) |
C8—C9—C10 | 111.15 (17) | H23B—C23—H23C | 110 (2) |
C11—C9—C10 | 113.84 (17) | C4—C24—H24A | 113.2 (19) |
C8—C9—H9 | 106.8 (16) | C4—C24—H24B | 110.6 (17) |
C11—C9—H9 | 107.4 (16) | H24A—C24—H24B | 106 (2) |
C10—C9—H9 | 102.7 (14) | C4—C24—H24C | 107.6 (18) |
C25—C10—C1 | 110.20 (18) | H24A—C24—H24C | 112 (2) |
C25—C10—C5 | 113.29 (18) | H24B—C24—H24C | 107 (3) |
C1—C10—C5 | 109.18 (17) | C10—C25—H25A | 110.1 (16) |
C25—C10—C9 | 110.28 (17) | C10—C25—H25B | 111.2 (16) |
C1—C10—C9 | 108.83 (17) | H25A—C25—H25B | 107 (2) |
C5—C10—C9 | 104.86 (16) | C10—C25—H25C | 112.2 (16) |
C9—C11—C12 | 115.65 (18) | H25A—C25—H25C | 107 (2) |
C9—C11—H11A | 110.2 (18) | H25B—C25—H25C | 109 (2) |
C12—C11—H11A | 108.8 (16) | C13—C26—H26A | 111.2 (15) |
C9—C11—H11B | 110.3 (17) | C13—C26—H26B | 111.6 (14) |
C12—C11—H11B | 108.8 (17) | H26A—C26—H26B | 105 (2) |
H11A—C11—H11B | 102 (2) | C13—C26—H26C | 111.8 (16) |
C13—C12—C11 | 114.94 (18) | H26A—C26—H26C | 110 (2) |
C13—C12—H12A | 109.4 (17) | H26B—C26—H26C | 107 (2) |
C11—C12—H12A | 110.7 (16) | C14—C27—H27A | 111.7 (15) |
C13—C12—H12B | 108.3 (16) | C14—C27—H27B | 109.6 (16) |
C11—C12—H12B | 109.4 (15) | H27A—C27—H27B | 107 (2) |
H12A—C12—H12B | 103 (2) | C14—C27—H27C | 111.4 (15) |
C18—C13—C26 | 111.96 (16) | H27A—C27—H27C | 109 (2) |
C18—C13—C12 | 108.97 (16) | H27B—C27—H27C | 108 (2) |
C26—C13—C12 | 108.06 (17) | C17—C28—H28A | 113.3 (16) |
C18—C13—C14 | 108.10 (16) | C17—C28—H28B | 107.9 (15) |
C26—C13—C14 | 110.91 (16) | H28A—C28—H28B | 108 (2) |
C12—C13—C14 | 108.78 (16) | C17—C28—H28C | 112.0 (15) |
C8—C14—C15 | 112.69 (16) | H28A—C28—H28C | 106 (2) |
C8—C14—C27 | 105.85 (16) | H28B—C28—H28C | 109 (2) |
C15—C14—C27 | 107.30 (17) | C22—C29—H29A | 110.2 (18) |
C8—C14—C13 | 108.57 (15) | C22—C29—H29B | 109.8 (19) |
C15—C14—C13 | 109.45 (16) | H29A—C29—H29B | 107 (3) |
C27—C14—C13 | 113.01 (17) | C22—C29—H29C | 111 (2) |
C16—C15—C14 | 114.39 (17) | H29A—C29—H29C | 112 (3) |
C16—C15—H15A | 109.9 (14) | H29B—C29—H29C | 107 (3) |
C14—C15—H15A | 107.6 (15) | C22—C30—H30A | 110.2 (19) |
C16—C15—H15B | 109.4 (14) | C22—C30—H30B | 113.7 (19) |
C14—C15—H15B | 107.3 (15) | H30A—C30—H30B | 108 (2) |
H15A—C15—H15B | 108 (2) | C22—C30—H30C | 114.8 (18) |
C17—C16—C15 | 112.40 (17) | H30A—C30—H30C | 109 (3) |
C17—C16—H16A | 109.7 (17) | H30B—C30—H30C | 100 (2) |
C15—C16—H16A | 107.3 (16) | ||
C10—C1—C2—C3 | −57.7 (3) | C7—C8—C14—C27 | −92.6 (2) |
C1—C2—C3—O1 | −64.7 (2) | C9—C8—C14—C27 | 84.8 (2) |
C1—C2—C3—C4 | 58.5 (3) | C7—C8—C14—C13 | 145.8 (2) |
O1—C3—C4—C24 | −51.2 (2) | C9—C8—C14—C13 | −36.8 (2) |
C2—C3—C4—C24 | −171.90 (19) | C18—C13—C14—C8 | −175.90 (16) |
O1—C3—C4—C23 | −165.9 (2) | C26—C13—C14—C8 | −52.8 (2) |
C2—C3—C4—C23 | 73.4 (2) | C12—C13—C14—C8 | 65.9 (2) |
O1—C3—C4—C5 | 68.2 (2) | C18—C13—C14—C15 | −52.5 (2) |
C2—C3—C4—C5 | −52.4 (2) | C26—C13—C14—C15 | 70.6 (2) |
C24—C4—C5—C6 | −61.2 (2) | C12—C13—C14—C15 | −170.71 (16) |
C23—C4—C5—C6 | 57.7 (3) | C18—C13—C14—C27 | 67.0 (2) |
C3—C4—C5—C6 | 179.52 (18) | C26—C13—C14—C27 | −169.91 (17) |
C24—C4—C5—C10 | 168.07 (19) | C12—C13—C14—C27 | −51.2 (2) |
C23—C4—C5—C10 | −73.0 (3) | C8—C14—C15—C16 | 176.26 (17) |
C3—C4—C5—C10 | 48.8 (2) | C27—C14—C15—C16 | −67.6 (2) |
C4—C5—C6—C7 | −173.43 (17) | C13—C14—C15—C16 | 55.3 (2) |
C10—C5—C6—C7 | −39.5 (2) | C14—C15—C16—C17 | −56.2 (2) |
C5—C6—C7—C8 | 8.4 (3) | C15—C16—C17—C28 | −74.6 (2) |
C6—C7—C8—C9 | −4.0 (3) | C15—C16—C17—C18 | 51.6 (2) |
C6—C7—C8—C14 | 173.30 (19) | C15—C16—C17—C21 | 160.91 (18) |
C7—C8—C9—C11 | 160.8 (2) | C26—C13—C18—C19 | 63.0 (2) |
C14—C8—C9—C11 | −16.6 (3) | C12—C13—C18—C19 | −56.5 (3) |
C7—C8—C9—C10 | 30.6 (3) | C14—C13—C18—C19 | −174.56 (19) |
C14—C8—C9—C10 | −146.84 (17) | C26—C13—C18—C17 | −65.6 (2) |
C2—C1—C10—C25 | −74.5 (3) | C12—C13—C18—C17 | 174.90 (18) |
C2—C1—C10—C5 | 50.6 (3) | C14—C13—C18—C17 | 56.8 (2) |
C2—C1—C10—C9 | 164.5 (2) | C16—C17—C18—C19 | 168.81 (17) |
C6—C5—C10—C25 | −56.5 (2) | C28—C17—C18—C19 | −67.8 (2) |
C4—C5—C10—C25 | 75.2 (2) | C21—C17—C18—C19 | 48.3 (2) |
C6—C5—C10—C1 | −179.70 (17) | C16—C17—C18—C13 | −55.6 (2) |
C4—C5—C10—C1 | −48.1 (2) | C28—C17—C18—C13 | 67.8 (2) |
C6—C5—C10—C9 | 63.8 (2) | C21—C17—C18—C13 | −176.08 (17) |
C4—C5—C10—C9 | −164.54 (17) | C13—C18—C19—C20 | −172.57 (19) |
C8—C9—C10—C25 | 63.8 (2) | C17—C18—C19—C20 | −38.1 (2) |
C11—C9—C10—C25 | −66.5 (2) | C18—C19—C20—C21 | 12.6 (2) |
C8—C9—C10—C1 | −175.22 (17) | C16—C17—C21—C22 | 81.3 (2) |
C11—C9—C10—C1 | 54.5 (2) | C28—C17—C21—C22 | −44.1 (3) |
C8—C9—C10—C5 | −58.5 (2) | C18—C17—C21—C22 | −164.80 (19) |
C11—C9—C10—C5 | 171.22 (18) | C16—C17—C21—C20 | −152.75 (18) |
C8—C9—C11—C12 | 43.2 (3) | C28—C17—C21—C20 | 81.9 (2) |
C10—C9—C11—C12 | 172.0 (2) | C18—C17—C21—C20 | −38.80 (19) |
C9—C11—C12—C13 | −13.2 (3) | C19—C20—C21—C22 | 147.0 (2) |
C11—C12—C13—C18 | −158.3 (2) | C19—C20—C21—C17 | 16.9 (2) |
C11—C12—C13—C26 | 79.8 (2) | C17—C21—C22—C30 | −56.2 (3) |
C11—C12—C13—C14 | −40.7 (3) | C20—C21—C22—C30 | −177.8 (2) |
C7—C8—C14—C15 | 24.4 (3) | C17—C21—C22—C29 | −178.7 (2) |
C9—C8—C14—C15 | −158.26 (17) | C20—C21—C22—C29 | 59.7 (3) |
D—H···A | D—H | H···A | D···A | D—H···A |
C24—H24C···O1i | 0.99 (3) | 2.72 (3) | 3.677 (3) | 162 (3) |
Symmetry code: (i) −x+3, y+1/2, −z+2. |
Experimental details
Crystal data | |
Chemical formula | C30H50O |
Mr | 426.70 |
Crystal system, space group | Monoclinic, P21 |
Temperature (K) | 170 |
a, b, c (Å) | 12.4234 (18), 7.5526 (11), 13.628 (2) |
β (°) | 101.320 (3) |
V (Å3) | 1253.8 (3) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 0.07 |
Crystal size (mm) | 0.35 × 0.27 × 0.19 |
Data collection | |
Diffractometer | Bruker SMART CCD area-detector diffractometer |
Absorption correction | Multi-scan (SADABS; Sheldrick, 2000) |
Tmin, Tmax | 0.978, 0.988 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 15904, 3278, 2947 |
Rint | 0.036 |
(sin θ/λ)max (Å−1) | 0.667 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.044, 0.103, 1.06 |
No. of reflections | 3278 |
No. of parameters | 427 |
No. of restraints | 1 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.29, −0.21 |
Computer programs: SMART (Bruker, 1997), SMART, SAINT (Bruker, 1997), SHELXS97 (Bruker, 1997), SHELXL97 (Bruker, 1997), SHELXTL (Bruker, 1997), SHELXTL.
D—H···A | D—H | H···A | D···A | D—H···A |
C24—H24C···O1i | 0.99 (3) | 2.72 (3) | 3.677 (3) | 162 (3) |
Symmetry code: (i) −x+3, y+1/2, −z+2. |
The growing number of deaths due to tuberculosis (TB) and the existence of strains of TB resistant to existing drugs has created an urgent need for the identification of leads for new antimycobacterial drugs. There are 8 million new cases of tuberculosis each year (Dye et al., 1999) and it is estimated that this number will increase to 10 million cases per year. There are an estimated 3 million deaths due to TB every year. Strains of TB resistant to existing drugs are found in nearly every country (Cohn et al., 1997), and a percentage of these are resistant to multiple drugs making effective treatment extremely expensive and in many cases impossible. Most patients in developing countries, where TB is an even bigger problem than elsewhere in the world, can not afford expensive drug treatments. There have been no new drugs developed for TB in over 30 years. Current activity in new drug development has centered around the rifamycins, rifabutin, rifapentine and KRM-1648, some of which exhibit cross-resistance with rifampin. It is in this regard that the bioassay guided fractionation of the antitubercular methanol extract of S. brasiliensis Spreng. (Euphorbiaceae), found active against the H37Rv strain (ATCC 27294) of Mycobacterium tuberculosis, was initiated, leading to the isolation of the title compound, (I).
X-ray crystallographic analysis of (I) was undertaken to unequivocally establish the structure and to assign the relative stereochemistry at C3. Although (I) has previously been reported in the literature (Nakane et al., 1999), this is the first report of its isolation from S. brasiliensis and of its crystal structure. The X-ray structure of (I) can now serve as a standard for comparison of related fernanes. With reference to the Scheme, the absolute configuration at all chiral centers is 3R, 5S, 9R, 10S, 13S, 14S, 17R, 18R, 21R.
As shown in Fig. 1, rings A and D assume a chair conformation, while rings B and C adopt a twist-boat conformation. The A/B, C/D, and D/E ring junctions are trans fused about the C5—C10, C13—C14 and C17—C18 bonds, respectively. The relative orientation of the hydroxyl group at C3, and that of the isopropyl group at C21 is α. No hydrogen bonds were detected between the hydroxyl groups of screw-related molecules; however, the molecules pack such that the hydroxyls of adjacent molecules are as close to each other as possible [5.075 (2) Å]. The distance between hydroxyls related by unit translation along the b axis is 7.5526 (11) Å. Hydrogen bonding was observed between the C24 methyl H and the hydroxyl oxygen of screw-related molecule with a bond length 2.72 (3) Å and a bond angle of 162 (2)°.