Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270109033083/sq3212sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270109033083/sq3212Isup2.hkl |
CCDC reference: 755985
Nonactin anhydride was isolated as an amorphous powder from the culture broth of Streptomyces sp. by ethyl acetate extraction, followed by silica gel chromatography and reverse phase preparation HPLC [high-pressure liquid chromatography/]. Its antimicrobial activities were monitored by agar diffusion assays during purification steps. A crystalline sample was isolated after being re-crystallized thrice from acetone.
All H-atoms were placed in geometrically idealized locations with C—H distances 0.98 Å to the primary, 0.99 Å to the secondary, and 1.00 Å to the tertiary C atoms. The H atoms were refined as riding with isotropic displacement coefficients Uiso(H) = 1.5*Ueq(Cmethyl) or 1.2*Ueq(Cother).
Data collection: APEX2 (Bruker, 2009); cell refinement: SAINT-Plus (Bruker, 2009); data reduction: SAINT-Plus (Bruker, 2009); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008) and OLEX2 (Dolomanov et al., 2009); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).
C40H64O12 | F(000) = 1600 |
Mr = 736.91 | Dx = 1.197 Mg m−3 |
Monoclinic, P2/n | Cu Kα radiation, λ = 1.54178 Å |
Hall symbol: -P 2yac | Cell parameters from 9798 reflections |
a = 28.252 (10) Å | θ = 6.3–68.8° |
b = 5.569 (2) Å | µ = 0.71 mm−1 |
c = 28.270 (11) Å | T = 100 K |
β = 113.120 (19)° | Needle, colourless |
V = 4090 (3) Å3 | 0.55 × 0.20 × 0.12 mm |
Z = 4 |
Bruker SMART APEXII area-detector diffractometer | 7460 independent reflections |
Radiation source: fine-focus sealed tube | 7285 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.024 |
0.70° ω and 0.7° ϕ scans | θmax = 69.5°, θmin = 1.7° |
Absorption correction: multi-scan (SADABS; Bruker, 2009) | h = −33→33 |
Tmin = 0.694, Tmax = 0.918 | k = −6→6 |
51667 measured reflections | l = −33→33 |
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)] = 0.043 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.110 | H-atom parameters constrained |
S = 1.05 | w = 1/[σ2(Fo2) + (0.0784P)2 + 1.1388P] where P = (Fo2 + 2Fc2)/3 |
7460 reflections | (Δ/σ)max = 0.001 |
478 parameters | Δρmax = 0.55 e Å−3 |
0 restraints | Δρmin = −0.20 e Å−3 |
C40H64O12 | V = 4090 (3) Å3 |
Mr = 736.91 | Z = 4 |
Monoclinic, P2/n | Cu Kα radiation |
a = 28.252 (10) Å | µ = 0.71 mm−1 |
b = 5.569 (2) Å | T = 100 K |
c = 28.270 (11) Å | 0.55 × 0.20 × 0.12 mm |
β = 113.120 (19)° |
Bruker SMART APEXII area-detector diffractometer | 7460 independent reflections |
Absorption correction: multi-scan (SADABS; Bruker, 2009) | 7285 reflections with I > 2σ(I) |
Tmin = 0.694, Tmax = 0.918 | Rint = 0.024 |
51667 measured reflections |
R[F2 > 2σ(F2)] = 0.043 | 0 restraints |
wR(F2) = 0.110 | H-atom parameters constrained |
S = 1.05 | Δρmax = 0.55 e Å−3 |
7460 reflections | Δρmin = −0.20 e Å−3 |
478 parameters |
Experimental. The structure is pseudo-merohedrally twinned in a monoclinic unit cell (space group P2/n, a = 28.252 (10) Å, b = 5.569 (2) Å, c = 28.270 (11) Å, b = 113.12°, V = 4090.3 Å3). The a and c lengths are approximately equal, thus the twin law is (0 0 - 1 0 - 1 0 - 1 0 0) with the minor component contribution of 45.08 (11)%. The tightest wrapping box was calculated in the following way. The best, intermediate, and worst least square planes based on the coordinates of all atoms were calculated [Schomaker, V., Waser, J., Marsh, R. E. & Bergman, G. (1959). Acta Cryst. 12, 600–604] with unit weights. Then the six distances between each plane and the outermost point of the molecular van der Waals sphere from either side of each plane were found. The pairwise sum of the distances from each plane represent dimensions of the box reported in this paper. |
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 | 0.91863 (5) | 0.1503 (2) | 0.28283 (5) | 0.0212 (3) | |
O2 | 0.92528 (5) | 0.1093 (2) | 0.41695 (5) | 0.0157 (3) | |
O3 | 0.95057 (5) | 0.4845 (2) | 0.44662 (5) | 0.0201 (3) | |
O4 | 0.78146 (5) | 0.3410 (2) | 0.41400 (5) | 0.0224 (3) | |
O5 | 0.64137 (4) | 0.3756 (2) | 0.36927 (4) | 0.0171 (3) | |
O6 | 0.61674 (5) | 0.0159 (2) | 0.38889 (5) | 0.0235 (3) | |
C1 | 0.88622 (7) | 0.1343 (3) | 0.22891 (7) | 0.0187 (4) | |
H1 | 0.8607 | 0.2686 | 0.2194 | 0.022* | |
C2 | 0.85763 (8) | −0.1066 (4) | 0.22133 (7) | 0.0248 (4) | |
H2A | 0.8210 | −0.0815 | 0.2153 | 0.030* | |
H2B | 0.8595 | −0.1961 | 0.1919 | 0.030* | |
C3 | 0.88576 (8) | −0.2402 (3) | 0.27151 (7) | 0.0234 (4) | |
H3B | 0.9148 | −0.3356 | 0.2702 | 0.028* | |
H3A | 0.8622 | −0.3477 | 0.2799 | 0.028* | |
C4 | 0.90483 (7) | −0.0358 (3) | 0.31008 (7) | 0.0185 (4) | |
H4 | 0.8764 | 0.0210 | 0.3200 | 0.022* | |
C5 | 0.95173 (7) | −0.0989 (3) | 0.35795 (7) | 0.0182 (4) | |
H5B | 0.9810 | −0.1304 | 0.3478 | 0.022* | |
H5A | 0.9446 | −0.2495 | 0.3725 | 0.022* | |
C6 | 0.96790 (6) | 0.0922 (3) | 0.39968 (7) | 0.0165 (4) | |
H6 | 0.9727 | 0.2495 | 0.3851 | 0.020* | |
C7 | 1.01712 (7) | 0.0223 (4) | 0.44479 (7) | 0.0210 (4) | |
H7B | 1.0254 | 0.1451 | 0.4717 | 0.031* | |
H7C | 1.0454 | 0.0096 | 0.4331 | 0.031* | |
H7A | 1.0122 | −0.1327 | 0.4586 | 0.031* | |
C8 | 0.92139 (6) | 0.3170 (3) | 0.43956 (6) | 0.0151 (3) | |
C9 | 0.87431 (7) | 0.3154 (3) | 0.45280 (7) | 0.0180 (4) | |
H9 | 0.8712 | 0.1527 | 0.4662 | 0.022* | |
C10 | 0.87958 (8) | 0.5005 (4) | 0.49439 (8) | 0.0238 (4) | |
H10B | 0.8841 | 0.6606 | 0.4824 | 0.036* | |
H10C | 0.9096 | 0.4611 | 0.5257 | 0.036* | |
H10A | 0.8485 | 0.4986 | 0.5018 | 0.036* | |
C11 | 0.82678 (7) | 0.3585 (3) | 0.40234 (7) | 0.0194 (4) | |
H11 | 0.8254 | 0.2304 | 0.3770 | 0.023* | |
C12 | 0.82469 (7) | 0.6053 (3) | 0.37733 (8) | 0.0239 (4) | |
H12B | 0.8581 | 0.6896 | 0.3932 | 0.029* | |
H12A | 0.8158 | 0.5891 | 0.3399 | 0.029* | |
C13 | 0.78249 (7) | 0.7391 (3) | 0.38769 (8) | 0.0241 (4) | |
H13B | 0.7968 | 0.8277 | 0.4207 | 0.029* | |
H13A | 0.7640 | 0.8529 | 0.3596 | 0.029* | |
C14 | 0.74738 (7) | 0.5364 (3) | 0.38995 (7) | 0.0192 (4) | |
H14 | 0.7239 | 0.4896 | 0.3542 | 0.023* | |
C15 | 0.71592 (7) | 0.5946 (3) | 0.42108 (7) | 0.0198 (4) | |
H15A | 0.6960 | 0.7427 | 0.4070 | 0.024* | |
H15B | 0.7398 | 0.6293 | 0.4569 | 0.024* | |
C16 | 0.67895 (7) | 0.4004 (3) | 0.42231 (7) | 0.0186 (4) | |
H16 | 0.6979 | 0.2457 | 0.4343 | 0.022* | |
C17 | 0.65115 (7) | 0.4687 (4) | 0.45664 (7) | 0.0224 (4) | |
H17B | 0.6350 | 0.6265 | 0.4464 | 0.034* | |
H17C | 0.6759 | 0.4750 | 0.4925 | 0.034* | |
H17A | 0.6246 | 0.3487 | 0.4532 | 0.034* | |
C18 | 0.61346 (6) | 0.1723 (3) | 0.35814 (7) | 0.0174 (4) | |
C19 | 0.57883 (7) | 0.1604 (3) | 0.30121 (7) | 0.0181 (4) | |
H19 | 0.5600 | 0.3165 | 0.2912 | 0.022* | |
C20 | 0.53906 (7) | −0.0397 (4) | 0.29040 (7) | 0.0235 (4) | |
H20C | 0.5567 | −0.1938 | 0.3015 | 0.035* | |
H20A | 0.5178 | −0.0457 | 0.2535 | 0.035* | |
H20B | 0.5171 | −0.0082 | 0.3093 | 0.035* | |
O1A | 0.91541 (5) | 0.3740 (2) | 0.78040 (5) | 0.0227 (3) | |
O2A | 0.86769 (4) | 0.4332 (2) | 0.64024 (5) | 0.0165 (2) | |
O3A | 0.88767 (5) | 0.0839 (2) | 0.61238 (6) | 0.0259 (3) | |
O4A | 0.71629 (5) | 0.1861 (2) | 0.58421 (5) | 0.0221 (3) | |
O5A | 0.58226 (5) | 0.1216 (2) | 0.57723 (5) | 0.0161 (3) | |
O6A | 0.55184 (5) | 0.4938 (2) | 0.55089 (5) | 0.0203 (3) | |
C1A | 0.90376 (7) | 0.3781 (3) | 0.82568 (7) | 0.0194 (4) | |
H1A | 0.8787 | 0.2471 | 0.8232 | 0.023* | |
C2A | 0.87834 (8) | 0.6229 (3) | 0.82567 (7) | 0.0245 (4) | |
H2AA | 0.8412 | 0.6035 | 0.8179 | 0.029* | |
H2AB | 0.8950 | 0.7038 | 0.8594 | 0.029* | |
C3A | 0.88651 (7) | 0.7646 (3) | 0.78358 (7) | 0.0228 (4) | |
H3AB | 0.9188 | 0.8588 | 0.7976 | 0.027* | |
H3AA | 0.8573 | 0.8746 | 0.7660 | 0.027* | |
C4A | 0.88956 (7) | 0.5692 (3) | 0.74732 (7) | 0.0188 (4) | |
H4A | 0.8541 | 0.5187 | 0.7239 | 0.023* | |
C5A | 0.92012 (7) | 0.6434 (3) | 0.71600 (7) | 0.0190 (4) | |
H5AA | 0.9055 | 0.7951 | 0.6979 | 0.023* | |
H5AB | 0.9559 | 0.6772 | 0.7400 | 0.023* | |
C6A | 0.92160 (6) | 0.4630 (3) | 0.67665 (7) | 0.0172 (4) | |
H6A | 0.9355 | 0.3064 | 0.6938 | 0.021* | |
C7A | 0.95391 (7) | 0.5527 (4) | 0.64827 (8) | 0.0219 (4) | |
H7AB | 0.9540 | 0.4321 | 0.6231 | 0.033* | |
H7AC | 0.9892 | 0.5808 | 0.6729 | 0.033* | |
H7AA | 0.9393 | 0.7031 | 0.6305 | 0.033* | |
C8A | 0.85651 (7) | 0.2350 (3) | 0.61117 (6) | 0.0176 (4) | |
C9A | 0.79892 (7) | 0.2188 (3) | 0.57855 (7) | 0.0192 (4) | |
H9A | 0.7875 | 0.3769 | 0.5610 | 0.023* | |
C10A | 0.78742 (8) | 0.0264 (4) | 0.53726 (8) | 0.0265 (4) | |
H10F | 0.8016 | −0.1275 | 0.5534 | 0.040* | |
H10E | 0.8031 | 0.0716 | 0.5132 | 0.040* | |
H10D | 0.7501 | 0.0115 | 0.5186 | 0.040* | |
C11A | 0.77060 (7) | 0.1788 (3) | 0.61467 (7) | 0.0193 (4) | |
H11A | 0.7797 | 0.3122 | 0.6404 | 0.023* | |
C12A | 0.78186 (7) | −0.0625 (4) | 0.64343 (8) | 0.0242 (4) | |
H12C | 0.8113 | −0.1452 | 0.6398 | 0.029* | |
H12D | 0.7895 | −0.0396 | 0.6804 | 0.029* | |
C13A | 0.73172 (7) | −0.2048 (3) | 0.61685 (8) | 0.0244 (4) | |
H13C | 0.7326 | −0.2992 | 0.5875 | 0.029* | |
H13D | 0.7254 | −0.3145 | 0.6413 | 0.029* | |
C14A | 0.69111 (7) | −0.0075 (3) | 0.59860 (7) | 0.0179 (4) | |
H14A | 0.6814 | 0.0439 | 0.6275 | 0.022* | |
C15A | 0.64347 (7) | −0.0792 (3) | 0.55253 (7) | 0.0194 (4) | |
H15D | 0.6300 | −0.2307 | 0.5608 | 0.023* | |
H15C | 0.6536 | −0.1124 | 0.5234 | 0.023* | |
C16A | 0.60043 (7) | 0.1045 (3) | 0.53535 (7) | 0.0175 (4) | |
H16A | 0.6140 | 0.2637 | 0.5300 | 0.021* | |
C17A | 0.55628 (7) | 0.0271 (4) | 0.48618 (7) | 0.0215 (4) | |
H17E | 0.5430 | −0.1284 | 0.4917 | 0.032* | |
H17F | 0.5686 | 0.0126 | 0.4584 | 0.032* | |
H17D | 0.5287 | 0.1472 | 0.4768 | 0.032* | |
C18A | 0.55914 (6) | 0.3282 (3) | 0.58030 (7) | 0.0163 (4) | |
C19A | 0.54583 (7) | 0.3310 (3) | 0.62747 (7) | 0.0180 (4) | |
H19A | 0.5329 | 0.1681 | 0.6314 | 0.022* | |
C20A | 0.50345 (7) | 0.5138 (4) | 0.62136 (8) | 0.0250 (4) | |
H20E | 0.5162 | 0.6760 | 0.6198 | 0.037* | |
H20F | 0.4935 | 0.5021 | 0.6508 | 0.037* | |
H20D | 0.4735 | 0.4805 | 0.5896 | 0.037* |
U11 | U22 | U33 | U12 | U13 | U23 | |
O1 | 0.0277 (7) | 0.0183 (6) | 0.0124 (6) | −0.0041 (5) | 0.0023 (5) | −0.0001 (5) |
O2 | 0.0164 (6) | 0.0164 (6) | 0.0169 (6) | −0.0002 (5) | 0.0095 (5) | −0.0004 (5) |
O3 | 0.0200 (7) | 0.0167 (6) | 0.0242 (7) | −0.0017 (5) | 0.0095 (5) | 0.0008 (5) |
O4 | 0.0182 (6) | 0.0181 (6) | 0.0360 (8) | 0.0020 (5) | 0.0162 (6) | 0.0042 (6) |
O5 | 0.0162 (6) | 0.0190 (6) | 0.0144 (6) | −0.0004 (5) | 0.0042 (5) | −0.0010 (5) |
O6 | 0.0262 (7) | 0.0238 (6) | 0.0209 (7) | 0.0012 (5) | 0.0096 (5) | 0.0051 (5) |
C1 | 0.0202 (9) | 0.0220 (9) | 0.0122 (8) | 0.0025 (7) | 0.0044 (7) | −0.0001 (7) |
C2 | 0.0240 (10) | 0.0320 (10) | 0.0171 (9) | −0.0084 (8) | 0.0067 (7) | −0.0047 (8) |
C3 | 0.0311 (10) | 0.0210 (9) | 0.0200 (9) | −0.0062 (8) | 0.0122 (8) | −0.0011 (7) |
C4 | 0.0220 (9) | 0.0194 (8) | 0.0166 (9) | −0.0001 (7) | 0.0103 (7) | −0.0005 (7) |
C5 | 0.0225 (9) | 0.0184 (8) | 0.0157 (9) | 0.0043 (7) | 0.0096 (7) | 0.0036 (7) |
C6 | 0.0158 (8) | 0.0208 (9) | 0.0157 (8) | 0.0004 (7) | 0.0093 (7) | 0.0040 (7) |
C7 | 0.0171 (9) | 0.0303 (10) | 0.0170 (9) | 0.0018 (7) | 0.0083 (7) | 0.0050 (8) |
C8 | 0.0144 (8) | 0.0161 (8) | 0.0130 (8) | 0.0016 (7) | 0.0034 (6) | 0.0031 (6) |
C9 | 0.0198 (9) | 0.0169 (8) | 0.0194 (9) | 0.0004 (7) | 0.0100 (7) | −0.0002 (7) |
C10 | 0.0232 (10) | 0.0284 (10) | 0.0217 (10) | 0.0034 (8) | 0.0110 (8) | −0.0045 (8) |
C11 | 0.0134 (8) | 0.0212 (9) | 0.0249 (9) | 0.0001 (7) | 0.0088 (7) | −0.0020 (7) |
C12 | 0.0165 (9) | 0.0285 (10) | 0.0258 (10) | −0.0008 (7) | 0.0075 (8) | 0.0061 (8) |
C13 | 0.0163 (9) | 0.0208 (9) | 0.0315 (10) | 0.0000 (7) | 0.0055 (8) | 0.0048 (8) |
C14 | 0.0147 (9) | 0.0215 (9) | 0.0195 (9) | −0.0003 (7) | 0.0045 (7) | −0.0009 (7) |
C15 | 0.0163 (8) | 0.0205 (9) | 0.0188 (8) | 0.0010 (7) | 0.0028 (7) | −0.0039 (7) |
C16 | 0.0160 (8) | 0.0234 (9) | 0.0134 (8) | 0.0034 (7) | 0.0025 (7) | −0.0002 (7) |
C17 | 0.0235 (9) | 0.0293 (10) | 0.0155 (9) | 0.0016 (8) | 0.0091 (7) | −0.0017 (7) |
C18 | 0.0161 (8) | 0.0181 (8) | 0.0206 (9) | 0.0023 (7) | 0.0099 (7) | −0.0009 (7) |
C19 | 0.0180 (8) | 0.0174 (8) | 0.0174 (8) | 0.0008 (7) | 0.0054 (7) | −0.0009 (7) |
C20 | 0.0180 (9) | 0.0265 (10) | 0.0262 (10) | −0.0048 (8) | 0.0089 (8) | −0.0025 (8) |
O1A | 0.0363 (8) | 0.0196 (6) | 0.0187 (7) | 0.0043 (5) | 0.0177 (6) | 0.0021 (5) |
O2A | 0.0127 (6) | 0.0193 (6) | 0.0164 (6) | −0.0004 (5) | 0.0045 (5) | −0.0019 (5) |
O3A | 0.0229 (7) | 0.0243 (7) | 0.0317 (8) | 0.0041 (6) | 0.0121 (6) | −0.0042 (6) |
O4A | 0.0143 (6) | 0.0182 (6) | 0.0283 (7) | 0.0008 (5) | 0.0024 (5) | 0.0039 (5) |
O5A | 0.0183 (6) | 0.0171 (6) | 0.0156 (6) | 0.0007 (5) | 0.0096 (5) | 0.0003 (5) |
O6A | 0.0251 (7) | 0.0167 (6) | 0.0191 (7) | 0.0011 (5) | 0.0089 (5) | 0.0026 (5) |
C1A | 0.0244 (9) | 0.0215 (9) | 0.0155 (9) | −0.0022 (7) | 0.0113 (7) | −0.0009 (7) |
C2A | 0.0283 (10) | 0.0263 (10) | 0.0200 (9) | 0.0058 (8) | 0.0106 (8) | −0.0013 (8) |
C3A | 0.0269 (10) | 0.0224 (9) | 0.0180 (9) | 0.0048 (8) | 0.0076 (8) | −0.0016 (8) |
C4A | 0.0180 (9) | 0.0212 (9) | 0.0154 (9) | −0.0002 (7) | 0.0046 (7) | −0.0012 (7) |
C5A | 0.0177 (8) | 0.0198 (9) | 0.0177 (8) | −0.0028 (7) | 0.0051 (7) | 0.0005 (7) |
C6A | 0.0099 (8) | 0.0224 (9) | 0.0157 (8) | 0.0004 (7) | 0.0011 (6) | 0.0030 (7) |
C7A | 0.0195 (9) | 0.0249 (9) | 0.0230 (9) | 0.0009 (7) | 0.0101 (7) | 0.0030 (8) |
C8A | 0.0177 (8) | 0.0207 (9) | 0.0163 (8) | −0.0011 (7) | 0.0086 (7) | 0.0005 (7) |
C9A | 0.0201 (9) | 0.0172 (8) | 0.0180 (8) | −0.0012 (7) | 0.0049 (7) | −0.0001 (7) |
C10A | 0.0303 (11) | 0.0284 (10) | 0.0220 (10) | −0.0078 (8) | 0.0115 (8) | −0.0078 (8) |
C11A | 0.0143 (8) | 0.0216 (9) | 0.0193 (9) | 0.0010 (7) | 0.0036 (7) | −0.0009 (7) |
C12A | 0.0192 (9) | 0.0289 (10) | 0.0246 (10) | 0.0055 (8) | 0.0088 (8) | 0.0070 (8) |
C13A | 0.0207 (9) | 0.0227 (9) | 0.0330 (11) | 0.0032 (8) | 0.0138 (8) | 0.0066 (8) |
C14A | 0.0172 (9) | 0.0180 (8) | 0.0210 (9) | 0.0012 (7) | 0.0100 (8) | −0.0012 (7) |
C15A | 0.0199 (9) | 0.0190 (8) | 0.0234 (9) | −0.0015 (7) | 0.0129 (7) | −0.0051 (7) |
C16A | 0.0183 (8) | 0.0201 (8) | 0.0177 (9) | −0.0022 (7) | 0.0112 (7) | −0.0012 (7) |
C17A | 0.0199 (10) | 0.0298 (10) | 0.0173 (9) | −0.0038 (7) | 0.0100 (8) | −0.0014 (7) |
C18A | 0.0140 (8) | 0.0167 (8) | 0.0170 (8) | −0.0023 (6) | 0.0050 (7) | −0.0007 (7) |
C19A | 0.0197 (9) | 0.0169 (8) | 0.0203 (9) | −0.0006 (7) | 0.0109 (7) | −0.0008 (7) |
C20A | 0.0194 (10) | 0.0303 (10) | 0.0265 (11) | 0.0060 (8) | 0.0104 (8) | −0.0003 (8) |
O1—C4 | 1.433 (2) | O1A—C4A | 1.433 (2) |
O1—C1 | 1.440 (2) | O1A—C1A | 1.442 (2) |
O2—C8 | 1.347 (2) | O2A—C8A | 1.338 (2) |
O2—C6 | 1.469 (2) | O2A—C6A | 1.475 (2) |
O3—C8 | 1.209 (2) | O3A—C8A | 1.208 (2) |
O4—C14 | 1.435 (2) | O4A—C11A | 1.435 (2) |
O4—C11 | 1.445 (2) | O4A—C14A | 1.436 (2) |
O5—C18 | 1.344 (2) | O5A—C18A | 1.343 (2) |
O5—C16 | 1.464 (2) | O5A—C16A | 1.467 (2) |
O6—C18 | 1.208 (2) | O6A—C18A | 1.204 (2) |
C1—C2 | 1.537 (3) | C1A—C19Aii | 1.539 (3) |
C1—C19i | 1.543 (2) | C1A—C2A | 1.541 (3) |
C1—H1 | 1.0000 | C1A—H1A | 1.0000 |
C2—C3 | 1.520 (3) | C2A—C3A | 1.519 (3) |
C2—H2A | 0.9900 | C2A—H2AA | 0.9900 |
C2—H2B | 0.9900 | C2A—H2AB | 0.9900 |
C3—C4 | 1.521 (3) | C3A—C4A | 1.521 (2) |
C3—H3B | 0.9900 | C3A—H3AB | 0.9900 |
C3—H3A | 0.9900 | C3A—H3AA | 0.9900 |
C4—C5 | 1.518 (3) | C4A—C5A | 1.517 (2) |
C4—H4 | 1.0000 | C4A—H4A | 1.0000 |
C5—C6 | 1.520 (2) | C5A—C6A | 1.511 (2) |
C5—H5B | 0.9900 | C5A—H5AA | 0.9900 |
C5—H5A | 0.9900 | C5A—H5AB | 0.9900 |
C6—C7 | 1.523 (3) | C6A—C7A | 1.517 (2) |
C6—H6 | 1.0000 | C6A—H6A | 1.0000 |
C7—H7B | 0.9800 | C7A—H7AB | 0.9800 |
C7—H7C | 0.9800 | C7A—H7AC | 0.9800 |
C7—H7A | 0.9800 | C7A—H7AA | 0.9800 |
C8—C9 | 1.516 (2) | C8A—C9A | 1.526 (2) |
C9—C10 | 1.526 (3) | C9A—C10A | 1.523 (3) |
C9—C11 | 1.546 (3) | C9A—C11A | 1.541 (2) |
C9—H9 | 1.0000 | C9A—H9A | 1.0000 |
C10—H10B | 0.9800 | C10A—H10F | 0.9800 |
C10—H10C | 0.9800 | C10A—H10E | 0.9800 |
C10—H10A | 0.9800 | C10A—H10D | 0.9800 |
C11—C12 | 1.536 (3) | C11A—C12A | 1.538 (3) |
C11—H11 | 1.0000 | C11A—H11A | 1.0000 |
C12—C13 | 1.528 (3) | C12A—C13A | 1.537 (3) |
C12—H12B | 0.9900 | C12A—H12C | 0.9900 |
C12—H12A | 0.9900 | C12A—H12D | 0.9900 |
C13—C14 | 1.520 (3) | C13A—C14A | 1.524 (3) |
C13—H13B | 0.9900 | C13A—H13C | 0.9900 |
C13—H13A | 0.9900 | C13A—H13D | 0.9900 |
C14—C15 | 1.511 (2) | C14A—C15A | 1.513 (3) |
C14—H14 | 1.0000 | C14A—H14A | 1.0000 |
C15—C16 | 1.513 (3) | C15A—C16A | 1.516 (3) |
C15—H15A | 0.9900 | C15A—H15D | 0.9900 |
C15—H15B | 0.9900 | C15A—H15C | 0.9900 |
C16—C17 | 1.517 (2) | C16A—C17A | 1.520 (3) |
C16—H16 | 1.0000 | C16A—H16A | 1.0000 |
C17—H17B | 0.9800 | C17A—H17E | 0.9800 |
C17—H17C | 0.9800 | C17A—H17F | 0.9800 |
C17—H17A | 0.9800 | C17A—H17D | 0.9800 |
C18—C19 | 1.522 (2) | C18A—C19A | 1.521 (2) |
C19—C20 | 1.526 (2) | C19A—C20A | 1.529 (2) |
C19—C1i | 1.543 (2) | C19A—C1Aii | 1.539 (3) |
C19—H19 | 1.0000 | C19A—H19A | 1.0000 |
C20—H20C | 0.9800 | C20A—H20E | 0.9800 |
C20—H20A | 0.9800 | C20A—H20F | 0.9800 |
C20—H20B | 0.9800 | C20A—H20D | 0.9800 |
C4—O1—C1 | 109.26 (14) | C4A—O1A—C1A | 109.39 (13) |
C8—O2—C6 | 116.35 (13) | C8A—O2A—C6A | 116.85 (13) |
C14—O4—C11 | 109.31 (13) | C11A—O4A—C14A | 109.91 (13) |
C18—O5—C16 | 116.23 (14) | C18A—O5A—C16A | 116.18 (13) |
O1—C1—C2 | 106.41 (14) | O1A—C1A—C19Aii | 107.73 (15) |
O1—C1—C19i | 107.44 (14) | O1A—C1A—C2A | 106.43 (14) |
C2—C1—C19i | 114.88 (15) | C19Aii—C1A—C2A | 115.11 (16) |
O1—C1—H1 | 109.3 | O1A—C1A—H1A | 109.1 |
C2—C1—H1 | 109.3 | C19Aii—C1A—H1A | 109.1 |
C19i—C1—H1 | 109.3 | C2A—C1A—H1A | 109.1 |
C3—C2—C1 | 104.08 (15) | C3A—C2A—C1A | 104.21 (14) |
C3—C2—H2A | 110.9 | C3A—C2A—H2AA | 110.9 |
C1—C2—H2A | 110.9 | C1A—C2A—H2AA | 110.9 |
C3—C2—H2B | 110.9 | C3A—C2A—H2AB | 110.9 |
C1—C2—H2B | 110.9 | C1A—C2A—H2AB | 110.9 |
H2A—C2—H2B | 109.0 | H2AA—C2A—H2AB | 108.9 |
C2—C3—C4 | 102.18 (16) | C2A—C3A—C4A | 102.87 (15) |
C2—C3—H3B | 111.3 | C2A—C3A—H3AB | 111.2 |
C4—C3—H3B | 111.3 | C4A—C3A—H3AB | 111.2 |
C2—C3—H3A | 111.3 | C2A—C3A—H3AA | 111.2 |
C4—C3—H3A | 111.3 | C4A—C3A—H3AA | 111.2 |
H3B—C3—H3A | 109.2 | H3AB—C3A—H3AA | 109.1 |
O1—C4—C5 | 108.68 (15) | O1A—C4A—C5A | 109.07 (15) |
O1—C4—C3 | 104.51 (14) | O1A—C4A—C3A | 104.60 (14) |
C5—C4—C3 | 113.90 (16) | C5A—C4A—C3A | 113.24 (16) |
O1—C4—H4 | 109.9 | O1A—C4A—H4A | 109.9 |
C5—C4—H4 | 109.9 | C5A—C4A—H4A | 109.9 |
C3—C4—H4 | 109.9 | C3A—C4A—H4A | 109.9 |
C4—C5—C6 | 114.89 (15) | C6A—C5A—C4A | 115.79 (15) |
C4—C5—H5B | 108.5 | C6A—C5A—H5AA | 108.3 |
C6—C5—H5B | 108.5 | C4A—C5A—H5AA | 108.3 |
C4—C5—H5A | 108.5 | C6A—C5A—H5AB | 108.3 |
C6—C5—H5A | 108.5 | C4A—C5A—H5AB | 108.3 |
H5B—C5—H5A | 107.5 | H5AA—C5A—H5AB | 107.4 |
O2—C6—C5 | 105.52 (13) | O2A—C6A—C5A | 105.61 (13) |
O2—C6—C7 | 109.66 (14) | O2A—C6A—C7A | 109.82 (15) |
C5—C6—C7 | 111.62 (15) | C5A—C6A—C7A | 111.51 (15) |
O2—C6—H6 | 110.0 | O2A—C6A—H6A | 109.9 |
C5—C6—H6 | 110.0 | C5A—C6A—H6A | 109.9 |
C7—C6—H6 | 110.0 | C7A—C6A—H6A | 109.9 |
C6—C7—H7B | 109.5 | C6A—C7A—H7AB | 109.5 |
C6—C7—H7C | 109.5 | C6A—C7A—H7AC | 109.5 |
H7B—C7—H7C | 109.5 | H7AB—C7A—H7AC | 109.5 |
C6—C7—H7A | 109.5 | C6A—C7A—H7AA | 109.5 |
H7B—C7—H7A | 109.5 | H7AB—C7A—H7AA | 109.5 |
H7C—C7—H7A | 109.5 | H7AC—C7A—H7AA | 109.5 |
O3—C8—O2 | 124.30 (15) | O3A—C8A—O2A | 124.28 (16) |
O3—C8—C9 | 124.83 (16) | O3A—C8A—C9A | 124.64 (17) |
O2—C8—C9 | 110.82 (14) | O2A—C8A—C9A | 111.00 (14) |
C8—C9—C10 | 110.90 (15) | C10A—C9A—C8A | 111.14 (15) |
C8—C9—C11 | 107.44 (14) | C10A—C9A—C11A | 113.34 (15) |
C10—C9—C11 | 113.12 (15) | C8A—C9A—C11A | 108.43 (14) |
C8—C9—H9 | 108.4 | C10A—C9A—H9A | 107.9 |
C10—C9—H9 | 108.4 | C8A—C9A—H9A | 107.9 |
C11—C9—H9 | 108.4 | C11A—C9A—H9A | 107.9 |
C9—C10—H10B | 109.5 | C9A—C10A—H10F | 109.5 |
C9—C10—H10C | 109.5 | C9A—C10A—H10E | 109.5 |
H10B—C10—H10C | 109.5 | H10F—C10A—H10E | 109.5 |
C9—C10—H10A | 109.5 | C9A—C10A—H10D | 109.5 |
H10B—C10—H10A | 109.5 | H10F—C10A—H10D | 109.5 |
H10C—C10—H10A | 109.5 | H10E—C10A—H10D | 109.5 |
O4—C11—C12 | 106.72 (14) | O4A—C11A—C12A | 107.01 (14) |
O4—C11—C9 | 107.80 (14) | O4A—C11A—C9A | 108.02 (15) |
C12—C11—C9 | 115.20 (15) | C12A—C11A—C9A | 115.04 (15) |
O4—C11—H11 | 109.0 | O4A—C11A—H11A | 108.9 |
C12—C11—H11 | 109.0 | C12A—C11A—H11A | 108.9 |
C9—C11—H11 | 109.0 | C9A—C11A—H11A | 108.9 |
C13—C12—C11 | 103.88 (14) | C13A—C12A—C11A | 103.43 (15) |
C13—C12—H12B | 111.0 | C13A—C12A—H12C | 111.1 |
C11—C12—H12B | 111.0 | C11A—C12A—H12C | 111.1 |
C13—C12—H12A | 111.0 | C13A—C12A—H12D | 111.1 |
C11—C12—H12A | 111.0 | C11A—C12A—H12D | 111.1 |
H12B—C12—H12A | 109.0 | H12C—C12A—H12D | 109.0 |
C14—C13—C12 | 102.53 (15) | C14A—C13A—C12A | 102.76 (16) |
C14—C13—H13B | 111.3 | C14A—C13A—H13C | 111.2 |
C12—C13—H13B | 111.3 | C12A—C13A—H13C | 111.2 |
C14—C13—H13A | 111.3 | C14A—C13A—H13D | 111.2 |
C12—C13—H13A | 111.3 | C12A—C13A—H13D | 111.2 |
H13B—C13—H13A | 109.2 | H13C—C13A—H13D | 109.1 |
O4—C14—C15 | 108.98 (15) | O4A—C14A—C15A | 109.05 (15) |
O4—C14—C13 | 104.79 (14) | O4A—C14A—C13A | 104.26 (14) |
C15—C14—C13 | 114.07 (16) | C15A—C14A—C13A | 113.45 (16) |
O4—C14—H14 | 109.6 | O4A—C14A—H14A | 110.0 |
C15—C14—H14 | 109.6 | C15A—C14A—H14A | 110.0 |
C13—C14—H14 | 109.6 | C13A—C14A—H14A | 110.0 |
C14—C15—C16 | 115.43 (15) | C14A—C15A—C16A | 115.35 (15) |
C14—C15—H15A | 108.4 | C14A—C15A—H15D | 108.4 |
C16—C15—H15A | 108.4 | C16A—C15A—H15D | 108.4 |
C14—C15—H15B | 108.4 | C14A—C15A—H15C | 108.4 |
C16—C15—H15B | 108.4 | C16A—C15A—H15C | 108.4 |
H15A—C15—H15B | 107.5 | H15D—C15A—H15C | 107.5 |
O5—C16—C15 | 105.87 (14) | O5A—C16A—C15A | 106.03 (14) |
O5—C16—C17 | 109.23 (14) | O5A—C16A—C17A | 109.56 (14) |
C15—C16—C17 | 111.78 (15) | C15A—C16A—C17A | 111.62 (16) |
O5—C16—H16 | 110.0 | O5A—C16A—H16A | 109.9 |
C15—C16—H16 | 110.0 | C15A—C16A—H16A | 109.9 |
C17—C16—H16 | 110.0 | C17A—C16A—H16A | 109.9 |
C16—C17—H17B | 109.5 | C16A—C17A—H17E | 109.5 |
C16—C17—H17C | 109.5 | C16A—C17A—H17F | 109.5 |
H17B—C17—H17C | 109.5 | H17E—C17A—H17F | 109.5 |
C16—C17—H17A | 109.5 | C16A—C17A—H17D | 109.5 |
H17B—C17—H17A | 109.5 | H17E—C17A—H17D | 109.5 |
H17C—C17—H17A | 109.5 | H17F—C17A—H17D | 109.5 |
O6—C18—O5 | 124.51 (16) | O6A—C18A—O5A | 124.56 (16) |
O6—C18—C19 | 124.44 (16) | O6A—C18A—C19A | 124.30 (16) |
O5—C18—C19 | 111.01 (15) | O5A—C18A—C19A | 111.07 (14) |
C18—C19—C20 | 111.13 (15) | C18A—C19A—C20A | 111.10 (15) |
C18—C19—C1i | 107.63 (14) | C18A—C19A—C1Aii | 107.00 (14) |
C20—C19—C1i | 113.65 (15) | C20A—C19A—C1Aii | 113.76 (15) |
C18—C19—H19 | 108.1 | C18A—C19A—H19A | 108.3 |
C20—C19—H19 | 108.1 | C20A—C19A—H19A | 108.3 |
C1i—C19—H19 | 108.1 | C1Aii—C19A—H19A | 108.3 |
C19—C20—H20C | 109.5 | C19A—C20A—H20E | 109.5 |
C19—C20—H20A | 109.5 | C19A—C20A—H20F | 109.5 |
H20C—C20—H20A | 109.5 | H20E—C20A—H20F | 109.5 |
C19—C20—H20B | 109.5 | C19A—C20A—H20D | 109.5 |
H20C—C20—H20B | 109.5 | H20E—C20A—H20D | 109.5 |
H20A—C20—H20B | 109.5 | H20F—C20A—H20D | 109.5 |
C4—O1—C1—C2 | −11.20 (18) | C4A—O1A—C1A—C19Aii | −136.51 (15) |
C4—O1—C1—C19i | −134.72 (15) | C4A—O1A—C1A—C2A | −12.53 (19) |
O1—C1—C2—C3 | −12.57 (18) | O1A—C1A—C2A—C3A | −10.4 (2) |
C19i—C1—C2—C3 | 106.18 (17) | C19Aii—C1A—C2A—C3A | 108.91 (18) |
C1—C2—C3—C4 | 29.74 (18) | C1A—C2A—C3A—C4A | 27.58 (19) |
C1—O1—C4—C5 | 152.53 (14) | C1A—O1A—C4A—C5A | 151.88 (15) |
C1—O1—C4—C3 | 30.57 (18) | C1A—O1A—C4A—C3A | 30.45 (19) |
C2—C3—C4—O1 | −37.09 (18) | C2A—C3A—C4A—O1A | −35.69 (18) |
C2—C3—C4—C5 | −155.55 (15) | C2A—C3A—C4A—C5A | −154.32 (16) |
O1—C4—C5—C6 | 70.54 (18) | O1A—C4A—C5A—C6A | 67.9 (2) |
C3—C4—C5—C6 | −173.42 (14) | C3A—C4A—C5A—C6A | −176.07 (15) |
C8—O2—C6—C5 | −157.11 (14) | C8A—O2A—C6A—C5A | −160.66 (14) |
C8—O2—C6—C7 | 82.53 (18) | C8A—O2A—C6A—C7A | 78.98 (18) |
C4—C5—C6—O2 | 64.67 (17) | C4A—C5A—C6A—O2A | 61.86 (19) |
C4—C5—C6—C7 | −176.28 (15) | C4A—C5A—C6A—C7A | −178.90 (16) |
C6—O2—C8—O3 | −0.7 (2) | C6A—O2A—C8A—O3A | −1.4 (2) |
C6—O2—C8—C9 | 176.93 (13) | C6A—O2A—C8A—C9A | 175.63 (13) |
O3—C8—C9—C10 | −23.0 (2) | O3A—C8A—C9A—C10A | −15.5 (2) |
O2—C8—C9—C10 | 159.41 (14) | O2A—C8A—C9A—C10A | 167.51 (14) |
O3—C8—C9—C11 | 101.08 (19) | O3A—C8A—C9A—C11A | 109.70 (19) |
O2—C8—C9—C11 | −76.50 (17) | O2A—C8A—C9A—C11A | −67.27 (18) |
C14—O4—C11—C12 | 10.38 (19) | C14A—O4A—C11A—C12A | 10.86 (18) |
C14—O4—C11—C9 | 134.66 (15) | C14A—O4A—C11A—C9A | 135.25 (15) |
C8—C9—C11—O4 | 176.17 (14) | C10A—C9A—C11A—O4A | −61.34 (19) |
C10—C9—C11—O4 | −61.10 (19) | C8A—C9A—C11A—O4A | 174.75 (14) |
C8—C9—C11—C12 | −64.82 (19) | C10A—C9A—C11A—C12A | 58.1 (2) |
C10—C9—C11—C12 | 57.9 (2) | C8A—C9A—C11A—C12A | −65.8 (2) |
O4—C11—C12—C13 | 12.60 (19) | O4A—C11A—C12A—C13A | 12.08 (18) |
C9—C11—C12—C13 | −107.01 (17) | C9A—C11A—C12A—C13A | −107.91 (17) |
C11—C12—C13—C14 | −29.15 (18) | C11A—C12A—C13A—C14A | −28.74 (18) |
C11—O4—C14—C15 | −151.88 (15) | C11A—O4A—C14A—C15A | −151.05 (14) |
C11—O4—C14—C13 | −29.41 (18) | C11A—O4A—C14A—C13A | −29.57 (18) |
C12—C13—C14—O4 | 36.07 (18) | C12A—C13A—C14A—O4A | 35.78 (18) |
C12—C13—C14—C15 | 155.17 (16) | C12A—C13A—C14A—C15A | 154.30 (15) |
O4—C14—C15—C16 | −65.7 (2) | O4A—C14A—C15A—C16A | −68.49 (18) |
C13—C14—C15—C16 | 177.61 (15) | C13A—C14A—C15A—C16A | 175.80 (14) |
C18—O5—C16—C15 | 162.34 (13) | C18A—O5A—C16A—C15A | 155.57 (14) |
C18—O5—C16—C17 | −77.15 (18) | C18A—O5A—C16A—C17A | −83.84 (18) |
C14—C15—C16—O5 | −64.19 (19) | C14A—C15A—C16A—O5A | −65.87 (18) |
C14—C15—C16—C17 | 176.97 (15) | C14A—C15A—C16A—C17A | 174.89 (15) |
C16—O5—C18—O6 | 1.7 (2) | C16A—O5A—C18A—O6A | 1.4 (2) |
C16—O5—C18—C19 | −175.86 (13) | C16A—O5A—C18A—C19A | −175.66 (14) |
O6—C18—C19—C20 | 14.7 (2) | O6A—C18A—C19A—C20A | 23.8 (2) |
O5—C18—C19—C20 | −167.69 (14) | O5A—C18A—C19A—C20A | −159.07 (15) |
O6—C18—C19—C1i | −110.31 (18) | O6A—C18A—C19A—C1Aii | −100.9 (2) |
O5—C18—C19—C1i | 67.27 (17) | O5A—C18A—C19A—C1Aii | 76.21 (17) |
Symmetry codes: (i) −x+3/2, y, −z+1/2; (ii) −x+3/2, y, −z+3/2. |
Experimental details
Crystal data | |
Chemical formula | C40H64O12 |
Mr | 736.91 |
Crystal system, space group | Monoclinic, P2/n |
Temperature (K) | 100 |
a, b, c (Å) | 28.252 (10), 5.569 (2), 28.270 (11) |
β (°) | 113.120 (19) |
V (Å3) | 4090 (3) |
Z | 4 |
Radiation type | Cu Kα |
µ (mm−1) | 0.71 |
Crystal size (mm) | 0.55 × 0.20 × 0.12 |
Data collection | |
Diffractometer | Bruker SMART APEXII area-detector diffractometer |
Absorption correction | Multi-scan (SADABS; Bruker, 2009) |
Tmin, Tmax | 0.694, 0.918 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 51667, 7460, 7285 |
Rint | 0.024 |
(sin θ/λ)max (Å−1) | 0.608 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.043, 0.110, 1.05 |
No. of reflections | 7460 |
No. of parameters | 478 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.55, −0.20 |
Computer programs: APEX2 (Bruker, 2009), SAINT-Plus (Bruker, 2009), SHELXTL (Sheldrick, 2008) and OLEX2 (Dolomanov et al., 2009).
The box is the smallest rectangular box encompassing the nonactin molecule. |
Space group | Symmetry | Box dimensions (Å) | Box volume (Å3) | |
Nonactin – molecule O1 | P2/n | C2 | 9.09 × 17.21 × 17.24 | 2695.44 |
Nonactin – molecule O1a | P2/n | C2 | 9.02 × 17.74 × 17.95 | 2871.62 |
Na(nonactin)(NCS) | C2/c | C2 | 12.43 × 15.16 × 15.25 | 2873.93 |
Ca(nonactin)(ClO4)2 | Pnna | C2 | 12.21 × 13.83 × 13.998 | 2362.09 |
K(nonactin)(NCS) | Pnna | C2 | 12.27 × 13.12 × 13.04 | 2099.10 |
Cs(nonactin)(NCS) | P2/n | C2 | 12.47 × 12.15 × 12.70 | 1922.78 |
(NH4)(nonactin)(NCS) | P1 | 12.57 × 13.84 × 13.40 | 2329.54 |
The important van der Waals radii used for these computations were H = 1.20 Å, C = 1.70 Å and O = 1.52 Å. |
Nonactin is a naturally occurring optically inactive macrotetrolide antibiotic whose activity includes the ability to transport cations across biological and artificial membranes. New antibiotics are urgently needed to combat persistent, emerging and re-emerging infectious diseases, hospital-acquired resistance, and bioterrorism agents. Currently, there is a renaissance of drug discovery from natural products. Exploration of microbial diversity in underexplored environments offers renewed hope for the discovery of novel antibiotics, anticancer agents, and other drugs from nature. In a pilot effort to explore the Great Lakes as an untapped freshwater environment for microbial resources from which new chemical entities may be obtained as antibiotics, dozens of actinomycete isolates were obtained from Lake Michigan sediment samples and found to produce [have?] antimicrobial activities. In particular, a Streptomyces sp. isolate was found to produce a significant amount of what was proven later to be nonactin anhydride.
Nonactin has been isolated previously from numerous bacterial sources as an antibiotic and anticancer agent (Corbaz et al., 1955; Solov'eva, 1973; Wallhaeusser et al., 1964). This macrotetrolide ionophor consists of the (+)(-)(+)(-)-ester linkage of the enantiomeric nonactic acid building blocks. However, the elucidation of the solid-state structure of nonactin has proven difficult. Dunitz (1964) determined that impure crystals (described as `not highly purified') of nonactin gave diffraction patterns with para-orthorhombic symmetry. Dornberger-Schiff (1966) noted that the structure may be of the type `order–disorder'. The unit-cell dimensions were determined by Dominguez et al. (1962) as a = 47.6, b = 31.5, c = 5.70 Å and Dobler (1972) reported the room- temperature order–disorder structure of nonactin in this cell, but noted that the superposition structure corresponds to the orthorhombic spacegroup Pbam with a unit cell of a/2, b/2, c. Although Dobler reported the atomic parameters, he commented that the large magnitude of the standard deviations on bond distances and angles did not allow for a detailed discussion of the molecular geometry of nonactin. Dobler observed diffuse streaks in the diffraction pattern of crystals of nonactin; we also recorded streaking in the diffraction pattern of our crystal.
Herein we report molecular parameters of nonactin established with high precision. Our low-temperature (100 K) structural investigation of a colorless unknown (consequently proven to be nonactin) proceeded as follows. The initial indexing of the unit cell suggested a C-centered orthorhombic lattice consistent with the reported dimensions (a = 31.147, b = 47.166, c = 5.569 Å, V = 8180.55 Å3), which is frequently a sign of trouble. The program CELL_NOW (Sheldrick, 2009) was used to index the reflections and the crystal appeared to be single. A full sphere of data was collected. The program XPREP (Sheldrick, 2008) suggested the space group Cmma, which is encountered in the Cambridge Structural Database (CSD; Allen, 2002) only 36 times. Not surprisingly, the structure could not be solved in this space group and a monoclinic unit cell was selected instead. Systematic absences were consistent with the space groups P2/n and Pn and the E statistics were indiscriminate as to the centrosymmetry. Although the structure was successfully solved in P2/n, the refinement stalled, with an R factor of ~22%. Scrutiny of the data revealed many Fobs values much higher than the corresponding Fcalc values, a likely indication of twinning. The program PLATON (Spek, 2009) was then used to analyze the data, and indeed pseudo-merohedral twinning was detected. The suggested transformation matrix (0 0 - 1, 0 - 1 0, -1 0 0) corresponds to interchange of the a and c axes that have very similar lengths. The suggested twin law was incorporated into the instruction file with a TWIN/BASF combination for the program XL (Sheldrick, 2009) and the batch scale factor refined to indicate a 45.08 (11)% contribution of the minor twin component. The resulting refinement converged to an R factor of 4.30%. Fig. 1 shows the relationship between the primitive monoclinic unit cell and the apparent incorrect C-centered orthorhombic unit cell. The monoclinic unit cell can be converted into the C-centered orthorhombic cell with a transformation matrix (1 0 1, -1 0 1, 0 - 1 0). A recent related example of pseudo-merohedral twinning of cyclopentadecanone was reported by Noe et al. (2008).
Nonactin (Fig. 2) crystallizes in a centrosymmetric lattice of P2/n symmetry with two symmetry-independent half-molecules in the asymmetric unit (four molecules in the unit cell, Z = 4). Each molecule occupies a crystallographic twofold axis. The two independent molecules have virtually identical conformations with an approximate S4 symmetry. The twofold and pseudo-S4 axes pass through the molecular center of mass and are perpendicular to the plane of the macrocycle. The molecules form stacks in the [010] direction. There is a solvent-accessible void in the center of the macrocycle with an approximate volume of 69 Å3 (PLATON). The dimensions of this molecular cavity can be described with the centroid–centroid distances between the tetrahydrofurane rings related by the twofold axes. These dimensions are 7.688 (2) x 7.544 (2) Å in the O1 molecule and 7.563 (3) x 7.593 (2) Å in the O1A molecule. These continuous voids form channels in the crystal along the b axis (Fig. 3).
The conformation of `free' nonactin was compared with that observed in the previously reported nonactin complexes of Na+ (Dobler & Phizackerley, 1974), K+ (Kilbourn et al., 1967), Cs+ (Sakamaki et al., 1977), Ca2+ (Vishwanath et al., 1983) and NH4+(Neupert-Laves & Dobler, 1976) using a new subroutine WBOX developed specifically for this project in the program OLEX2 (Dolomanov et al., 2009) to compute the dimensions of the smallest parallelepiped superscribing each of the nonactin complexes (Fig. 4). The obtained dimensions (Table 1) clearly show that `free' nonactin per se is unfolded and relatively square-planar, but becomes globular when encapsulating a cation, a fact noted by others and now supported quantitatively. For example, the dimensions of the parallelepiped superscribing nonactin are ~9 x 17 x 17 Å, whereas those for the parallelepiped encompassing nonactin bonded to a Ca2+ cation are ~12 x 14 x 14 Å. In the four metal cationic complexes of nonactin, the macrocycle coordinates to the metal with four carbonyl and four tetrahydrofurane O atoms in a distorted cubic arrangement. In the cases of the smaller Na+and Ca2+ cations (hard Lewis bases) the metal–oxygen distances to the carbonyl O atoms are shorter, whereas in the cases of the larger Cs+ and K+ cations (softer Lewis bases) the distances to the ether O atoms are shorter. It is noteworthy that encapsulation of larger Cs+ and K+ cations produces more spheroidal and compact structures – the `encompassing' box sizes for the corresponding complexes are smaller than those for Na+ and Ca2+ (Table 1). This is likely due to the better fit between the sizes of the larger cations and the internal nonactin cavity. In the case of the ammonium, the four H atoms of the cation form hydrogen-bonding interactions with four ether O atoms. Thus, the conformational changes of nonactin are, as expected, dependent on the size and nature of the encapsulated cation.
The elusive structure of anhydrous `free' nonactin has finally been unambiguously established. Nonactin crystallizes in a pseudo-merohedrally twinned primitive monoclinic cell with two twin components of similar sizes.