Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270110052741/gt3028sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270110052741/gt3028Isup2.hkl |
CCDC reference: 817042
For related literature, see: Bregman et al. (2006); Grell et al. (1999); Keller & Everhart (2010); Liu et al. (2007); Sánchez et al. (2006); Slater et al. (1999); Steglich (1989); Tamaoki et al. (1986); Zhu et al. (2003).
Arcyriaflavin A was purchased from Tocris Bioscience (>98% purity) and used as received without further purification. Orange needle crystals [Block given in CIF tables - please clarify] suitable for the crystallographic studies reported here were isolated over a period of one week by slow evaporation from an ethanolic solution.
H atoms bound to aromatic C atoms were placed in their idealized positions and included in the final structural model in a riding-motion approximation, with C—H = 0.95 Å, and with Uiso(H) = 1.2Ueq(C). H atoms associated with the solvent water molecule and the N—H groups were located directly from a difference Fourier map. The positions of these atoms were refined and Uiso(H) = 1.5Ueq(N,O).
Data collection: APEX2 (Bruker, 2006); cell refinement: APEX2 (Bruker, 2006); data reduction: SAINT-Plus (Bruker, 2005); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg, 2009); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).
C20H11N3O2·H2O | F(000) = 712 |
Mr = 343.33 | Dx = 1.465 Mg m−3 |
Monoclinic, P21/c | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2ybc | Cell parameters from 1965 reflections |
a = 4.7347 (1) Å | θ = 3.2–26.8° |
b = 18.1877 (7) Å | µ = 0.10 mm−1 |
c = 18.1068 (6) Å | T = 150 K |
β = 93.594 (2)° | Needle, orange |
V = 1556.17 (9) Å3 | 0.11 × 0.04 × 0.03 mm |
Z = 4 |
Bruker X8 APEXII KappaCCD diffractometer | 4172 independent reflections |
Radiation source: fine-focus sealed tube | 2477 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.057 |
ω and ϕ scans | θmax = 29.1°, θmin = 3.5° |
Absorption correction: multi-scan (SADABS; Sheldrick, 1998) | h = −6→6 |
Tmin = 0.989, Tmax = 0.997 | k = −24→24 |
13901 measured reflections | l = −23→24 |
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)] = 0.053 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.141 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.00 | w = 1/[σ2(Fo2) + (0.0682P)2] where P = (Fo2 + 2Fc2)/3 |
4172 reflections | (Δ/σ)max < 0.001 |
250 parameters | Δρmax = 0.26 e Å−3 |
0 restraints | Δρmin = −0.24 e Å−3 |
C20H11N3O2·H2O | V = 1556.17 (9) Å3 |
Mr = 343.33 | Z = 4 |
Monoclinic, P21/c | Mo Kα radiation |
a = 4.7347 (1) Å | µ = 0.10 mm−1 |
b = 18.1877 (7) Å | T = 150 K |
c = 18.1068 (6) Å | 0.11 × 0.04 × 0.03 mm |
β = 93.594 (2)° |
Bruker X8 APEXII KappaCCD diffractometer | 4172 independent reflections |
Absorption correction: multi-scan (SADABS; Sheldrick, 1998) | 2477 reflections with I > 2σ(I) |
Tmin = 0.989, Tmax = 0.997 | Rint = 0.057 |
13901 measured reflections |
R[F2 > 2σ(F2)] = 0.053 | 0 restraints |
wR(F2) = 0.141 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.00 | Δρmax = 0.26 e Å−3 |
4172 reflections | Δρmin = −0.24 e Å−3 |
250 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 | ||
N1 | 0.5189 (3) | 0.69064 (10) | 0.14881 (9) | 0.0239 (4) | |
H1 | 0.564 (4) | 0.7334 (13) | 0.1205 (11) | 0.036* | |
N2 | 1.0080 (3) | 0.77362 (9) | 0.24051 (9) | 0.0252 (4) | |
H2 | 0.971 (4) | 0.7998 (13) | 0.1964 (12) | 0.038* | |
N3 | 0.7397 (4) | 0.51761 (10) | 0.42005 (9) | 0.0305 (4) | |
H3 | 0.757 (4) | 0.4792 (13) | 0.4543 (12) | 0.046* | |
O1 | 0.3928 (3) | 0.46754 (8) | 0.34051 (7) | 0.0331 (4) | |
O2 | 1.0902 (3) | 0.59252 (8) | 0.47367 (7) | 0.0353 (4) | |
C1 | 0.3171 (4) | 0.63734 (11) | 0.13025 (10) | 0.0236 (4) | |
C2 | 0.1380 (4) | 0.63151 (12) | 0.06676 (11) | 0.0273 (5) | |
H2A | 0.1432 | 0.6665 | 0.0279 | 0.033* | |
C3 | −0.0471 (4) | 0.57315 (12) | 0.06214 (11) | 0.0290 (5) | |
H3A | −0.1724 | 0.5682 | 0.0194 | 0.035* | |
C4 | −0.0559 (4) | 0.52084 (11) | 0.11878 (10) | 0.0270 (5) | |
H4 | −0.1868 | 0.4813 | 0.1139 | 0.032* | |
C5 | 0.1242 (4) | 0.52627 (11) | 0.18163 (10) | 0.0240 (4) | |
H5 | 0.1185 | 0.4907 | 0.2199 | 0.029* | |
C6 | 0.3147 (3) | 0.58492 (11) | 0.18796 (10) | 0.0212 (4) | |
C7 | 0.5280 (3) | 0.60824 (11) | 0.24366 (10) | 0.0208 (4) | |
C8 | 0.6491 (4) | 0.67331 (11) | 0.21664 (10) | 0.0210 (4) | |
C9 | 0.8653 (4) | 0.71063 (11) | 0.25726 (10) | 0.0224 (4) | |
C10 | 0.9719 (4) | 0.68393 (11) | 0.32719 (10) | 0.0214 (4) | |
C11 | 1.1894 (4) | 0.73449 (11) | 0.35359 (10) | 0.0226 (4) | |
C12 | 1.2044 (4) | 0.78945 (11) | 0.29831 (10) | 0.0245 (4) | |
C13 | 1.3936 (4) | 0.84801 (11) | 0.30593 (12) | 0.0302 (5) | |
H13 | 1.4011 | 0.8848 | 0.2688 | 0.036* | |
C14 | 1.5698 (4) | 0.85051 (12) | 0.36959 (12) | 0.0329 (5) | |
H14 | 1.7013 | 0.8898 | 0.3763 | 0.039* | |
C15 | 1.5596 (4) | 0.79679 (12) | 0.42438 (11) | 0.0302 (5) | |
H15 | 1.6847 | 0.8002 | 0.4673 | 0.036* | |
C16 | 1.3711 (4) | 0.73869 (11) | 0.41747 (11) | 0.0265 (4) | |
H16 | 1.3652 | 0.7025 | 0.4552 | 0.032* | |
C17 | 0.5662 (4) | 0.51610 (11) | 0.35512 (11) | 0.0261 (4) | |
C18 | 0.6368 (4) | 0.58159 (10) | 0.31263 (10) | 0.0216 (4) | |
C19 | 0.8534 (4) | 0.61916 (11) | 0.35307 (10) | 0.0215 (4) | |
C20 | 0.9177 (4) | 0.57823 (11) | 0.42180 (11) | 0.0266 (4) | |
O1W | 0.2162 (4) | 0.33447 (9) | 0.40166 (9) | 0.0430 (4) | |
H1X | 0.110 (5) | 0.3474 (15) | 0.4389 (16) | 0.064* | |
H1Y | 0.297 (5) | 0.3775 (16) | 0.3810 (14) | 0.064* |
U11 | U22 | U33 | U12 | U13 | U23 | |
N1 | 0.0245 (8) | 0.0244 (9) | 0.0227 (9) | 0.0021 (7) | 0.0014 (6) | 0.0034 (7) |
N2 | 0.0265 (8) | 0.0234 (9) | 0.0261 (9) | −0.0001 (7) | 0.0045 (7) | 0.0026 (7) |
N3 | 0.0389 (10) | 0.0268 (10) | 0.0246 (10) | −0.0077 (8) | −0.0064 (7) | 0.0065 (8) |
O1 | 0.0385 (8) | 0.0266 (8) | 0.0332 (8) | −0.0101 (7) | −0.0058 (6) | 0.0030 (7) |
O2 | 0.0439 (8) | 0.0332 (9) | 0.0270 (8) | −0.0081 (7) | −0.0115 (7) | 0.0025 (7) |
C1 | 0.0206 (9) | 0.0246 (11) | 0.0258 (10) | 0.0052 (8) | 0.0047 (8) | −0.0003 (8) |
C2 | 0.0252 (10) | 0.0334 (12) | 0.0231 (10) | 0.0067 (9) | 0.0001 (8) | 0.0025 (9) |
C3 | 0.0262 (10) | 0.0353 (13) | 0.0248 (10) | 0.0063 (9) | −0.0037 (8) | −0.0035 (9) |
C4 | 0.0238 (9) | 0.0281 (12) | 0.0290 (11) | 0.0011 (8) | 0.0007 (8) | −0.0058 (9) |
C5 | 0.0238 (9) | 0.0236 (11) | 0.0249 (10) | 0.0034 (8) | 0.0035 (7) | −0.0006 (8) |
C6 | 0.0203 (9) | 0.0226 (10) | 0.0209 (9) | 0.0062 (7) | 0.0034 (7) | −0.0017 (8) |
C7 | 0.0185 (8) | 0.0212 (10) | 0.0228 (10) | 0.0037 (7) | 0.0022 (7) | −0.0023 (8) |
C8 | 0.0211 (9) | 0.0231 (10) | 0.0188 (9) | 0.0044 (7) | 0.0023 (7) | −0.0002 (8) |
C9 | 0.0234 (9) | 0.0189 (10) | 0.0256 (10) | 0.0027 (8) | 0.0066 (7) | −0.0018 (8) |
C10 | 0.0225 (9) | 0.0202 (10) | 0.0219 (10) | 0.0034 (8) | 0.0039 (7) | −0.0027 (8) |
C11 | 0.0204 (9) | 0.0199 (10) | 0.0280 (10) | 0.0020 (7) | 0.0056 (7) | −0.0057 (8) |
C12 | 0.0233 (9) | 0.0229 (11) | 0.0279 (10) | 0.0022 (8) | 0.0073 (8) | −0.0030 (9) |
C13 | 0.0311 (10) | 0.0242 (11) | 0.0365 (12) | −0.0016 (9) | 0.0108 (9) | −0.0002 (9) |
C14 | 0.0262 (10) | 0.0283 (12) | 0.0448 (13) | −0.0064 (9) | 0.0079 (9) | −0.0078 (10) |
C15 | 0.0257 (10) | 0.0297 (12) | 0.0350 (12) | −0.0027 (9) | 0.0017 (8) | −0.0101 (10) |
C16 | 0.0248 (9) | 0.0272 (11) | 0.0275 (11) | −0.0004 (8) | 0.0022 (8) | −0.0035 (9) |
C17 | 0.0285 (10) | 0.0251 (11) | 0.0246 (10) | −0.0010 (8) | 0.0013 (8) | −0.0024 (9) |
C18 | 0.0234 (9) | 0.0195 (10) | 0.0217 (9) | 0.0011 (7) | 0.0015 (7) | −0.0011 (8) |
C19 | 0.0242 (9) | 0.0212 (10) | 0.0190 (9) | 0.0012 (8) | 0.0005 (7) | −0.0009 (8) |
C20 | 0.0292 (10) | 0.0247 (11) | 0.0257 (10) | −0.0025 (8) | −0.0011 (8) | 0.0003 (9) |
O1W | 0.0635 (11) | 0.0303 (10) | 0.0357 (9) | −0.0068 (8) | 0.0077 (8) | −0.0019 (8) |
N1—C8 | 1.376 (2) | C7—C18 | 1.407 (3) |
N1—C1 | 1.388 (2) | C7—C8 | 1.415 (3) |
N1—H1 | 0.96 (2) | C8—C9 | 1.398 (3) |
N2—C9 | 1.374 (2) | C9—C10 | 1.419 (3) |
N2—C12 | 1.386 (2) | C10—C19 | 1.398 (3) |
N2—H2 | 0.94 (2) | C10—C11 | 1.440 (3) |
N3—C20 | 1.387 (2) | C11—C16 | 1.400 (3) |
N3—C17 | 1.392 (2) | C11—C12 | 1.419 (3) |
N3—H3 | 0.93 (2) | C12—C13 | 1.393 (3) |
O1—C17 | 1.223 (2) | C13—C14 | 1.381 (3) |
O2—C20 | 1.233 (2) | C13—H13 | 0.9500 |
C1—C2 | 1.389 (3) | C14—C15 | 1.395 (3) |
C1—C6 | 1.415 (3) | C14—H14 | 0.9500 |
C2—C3 | 1.376 (3) | C15—C16 | 1.384 (3) |
C2—H2A | 0.9500 | C15—H15 | 0.9500 |
C3—C4 | 1.402 (3) | C16—H16 | 0.9500 |
C3—H3A | 0.9500 | C17—C18 | 1.468 (3) |
C4—C5 | 1.382 (3) | C18—C19 | 1.400 (2) |
C4—H4 | 0.9500 | C19—C20 | 1.466 (3) |
C5—C6 | 1.397 (3) | O1W—H1X | 0.90 (3) |
C5—H5 | 0.9500 | O1W—H1Y | 0.96 (3) |
C6—C7 | 1.446 (2) | ||
C8—N1—C1 | 108.61 (16) | C8—C9—C10 | 120.72 (18) |
C8—N1—H1 | 123.9 (12) | C19—C10—C9 | 117.37 (17) |
C1—N1—H1 | 127.4 (12) | C19—C10—C11 | 136.10 (17) |
C9—N2—C12 | 108.82 (16) | C9—C10—C11 | 106.54 (17) |
C9—N2—H2 | 122.9 (13) | C16—C11—C12 | 119.28 (17) |
C12—N2—H2 | 128.3 (13) | C16—C11—C10 | 134.35 (18) |
C20—N3—C17 | 111.15 (16) | C12—C11—C10 | 106.37 (16) |
C20—N3—H3 | 123.5 (14) | N2—C12—C13 | 129.09 (19) |
C17—N3—H3 | 124.6 (14) | N2—C12—C11 | 108.99 (17) |
N1—C1—C2 | 128.97 (18) | C13—C12—C11 | 121.92 (18) |
N1—C1—C6 | 109.22 (16) | C14—C13—C12 | 117.32 (19) |
C2—C1—C6 | 121.81 (18) | C14—C13—H13 | 121.3 |
C3—C2—C1 | 117.55 (18) | C12—C13—H13 | 121.3 |
C3—C2—H2A | 121.2 | C13—C14—C15 | 121.63 (19) |
C1—C2—H2A | 121.2 | C13—C14—H14 | 119.2 |
C2—C3—C4 | 121.83 (18) | C15—C14—H14 | 119.2 |
C2—C3—H3A | 119.1 | C16—C15—C14 | 121.43 (19) |
C4—C3—H3A | 119.1 | C16—C15—H15 | 119.3 |
C5—C4—C3 | 120.60 (19) | C14—C15—H15 | 119.3 |
C5—C4—H4 | 119.7 | C15—C16—C11 | 118.42 (19) |
C3—C4—H4 | 119.7 | C15—C16—H16 | 120.8 |
C4—C5—C6 | 118.94 (18) | C11—C16—H16 | 120.8 |
C4—C5—H5 | 120.5 | O1—C17—N3 | 123.34 (19) |
C6—C5—H5 | 120.5 | O1—C17—C18 | 130.11 (18) |
C5—C6—C1 | 119.26 (17) | N3—C17—C18 | 106.55 (16) |
C5—C6—C7 | 134.47 (18) | C19—C18—C7 | 120.77 (18) |
C1—C6—C7 | 106.26 (16) | C19—C18—C17 | 107.77 (16) |
C18—C7—C8 | 117.47 (16) | C7—C18—C17 | 131.46 (17) |
C18—C7—C6 | 135.99 (18) | C10—C19—C18 | 122.13 (17) |
C8—C7—C6 | 106.53 (16) | C10—C19—C20 | 130.25 (17) |
N1—C8—C9 | 129.09 (18) | C18—C19—C20 | 107.62 (17) |
N1—C8—C7 | 109.37 (16) | O2—C20—N3 | 123.89 (18) |
C9—C8—C7 | 121.53 (16) | O2—C20—C19 | 129.20 (19) |
N2—C9—C8 | 130.00 (18) | N3—C20—C19 | 106.90 (16) |
N2—C9—C10 | 109.28 (16) | H1X—O1W—H1Y | 110 (2) |
C8—N1—C1—C2 | −178.92 (18) | C9—N2—C12—C13 | −179.37 (18) |
C8—N1—C1—C6 | 0.8 (2) | C9—N2—C12—C11 | 0.6 (2) |
N1—C1—C2—C3 | −179.33 (18) | C16—C11—C12—N2 | 179.52 (16) |
C6—C1—C2—C3 | 1.0 (3) | C10—C11—C12—N2 | −0.3 (2) |
C1—C2—C3—C4 | −0.4 (3) | C16—C11—C12—C13 | −0.5 (3) |
C2—C3—C4—C5 | −0.3 (3) | C10—C11—C12—C13 | 179.64 (16) |
C3—C4—C5—C6 | 0.2 (3) | N2—C12—C13—C14 | −179.52 (18) |
C4—C5—C6—C1 | 0.4 (2) | C11—C12—C13—C14 | 0.5 (3) |
C4—C5—C6—C7 | 179.78 (19) | C12—C13—C14—C15 | −0.1 (3) |
N1—C1—C6—C5 | 179.23 (16) | C13—C14—C15—C16 | −0.3 (3) |
C2—C1—C6—C5 | −1.0 (3) | C14—C15—C16—C11 | 0.3 (3) |
N1—C1—C6—C7 | −0.31 (19) | C12—C11—C16—C15 | 0.1 (3) |
C2—C1—C6—C7 | 179.41 (17) | C10—C11—C16—C15 | 179.89 (19) |
C5—C6—C7—C18 | 1.9 (4) | C20—N3—C17—O1 | 179.32 (18) |
C1—C6—C7—C18 | −178.7 (2) | C20—N3—C17—C18 | −0.8 (2) |
C5—C6—C7—C8 | −179.69 (19) | C8—C7—C18—C19 | 1.0 (3) |
C1—C6—C7—C8 | −0.25 (19) | C6—C7—C18—C19 | 179.36 (19) |
C1—N1—C8—C9 | 179.70 (18) | C8—C7—C18—C17 | −178.38 (18) |
C1—N1—C8—C7 | −0.9 (2) | C6—C7—C18—C17 | −0.1 (4) |
C18—C7—C8—N1 | 179.50 (15) | O1—C17—C18—C19 | −179.1 (2) |
C6—C7—C8—N1 | 0.73 (19) | N3—C17—C18—C19 | 1.0 (2) |
C18—C7—C8—C9 | −1.1 (3) | O1—C17—C18—C7 | 0.4 (4) |
C6—C7—C8—C9 | −179.85 (16) | N3—C17—C18—C7 | −179.48 (19) |
C12—N2—C9—C8 | 179.86 (18) | C9—C10—C19—C18 | −0.4 (3) |
C12—N2—C9—C10 | −0.6 (2) | C11—C10—C19—C18 | −179.86 (19) |
N1—C8—C9—N2 | −0.9 (3) | C9—C10—C19—C20 | 179.69 (18) |
C7—C8—C9—N2 | 179.85 (17) | C11—C10—C19—C20 | 0.2 (4) |
N1—C8—C9—C10 | 179.67 (17) | C7—C18—C19—C10 | −0.3 (3) |
C7—C8—C9—C10 | 0.4 (3) | C17—C18—C19—C10 | 179.22 (16) |
N2—C9—C10—C19 | −179.20 (16) | C7—C18—C19—C20 | 179.60 (16) |
C8—C9—C10—C19 | 0.4 (3) | C17—C18—C19—C20 | −0.8 (2) |
N2—C9—C10—C11 | 0.41 (19) | C17—N3—C20—O2 | 179.34 (19) |
C8—C9—C10—C11 | 179.98 (16) | C17—N3—C20—C19 | 0.3 (2) |
C19—C10—C11—C16 | −0.4 (4) | C10—C19—C20—O2 | 1.3 (4) |
C9—C10—C11—C16 | −179.9 (2) | C18—C19—C20—O2 | −178.6 (2) |
C19—C10—C11—C12 | 179.5 (2) | C10—C19—C20—N3 | −179.72 (18) |
C9—C10—C11—C12 | −0.05 (19) | C18—C19—C20—N3 | 0.4 (2) |
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1···O1Wi | 0.96 (2) | 2.16 (2) | 3.065 (2) | 155.6 (17) |
N2—H2···O1Wi | 0.94 (2) | 2.03 (2) | 2.939 (2) | 161.8 (19) |
N3—H3···O2ii | 0.93 (2) | 1.95 (2) | 2.858 (2) | 163.1 (19) |
O1W—H1X···O2iii | 0.90 (3) | 2.19 (3) | 3.062 (2) | 164 (2) |
O1W—H1Y···O1 | 0.96 (3) | 1.86 (3) | 2.810 (2) | 171 (2) |
Symmetry codes: (i) −x+1, y+1/2, −z+1/2; (ii) −x+2, −y+1, −z+1; (iii) −x+1, −y+1, −z+1. |
Experimental details
Crystal data | |
Chemical formula | C20H11N3O2·H2O |
Mr | 343.33 |
Crystal system, space group | Monoclinic, P21/c |
Temperature (K) | 150 |
a, b, c (Å) | 4.7347 (1), 18.1877 (7), 18.1068 (6) |
β (°) | 93.594 (2) |
V (Å3) | 1556.17 (9) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.10 |
Crystal size (mm) | 0.11 × 0.04 × 0.03 |
Data collection | |
Diffractometer | Bruker X8 APEXII KappaCCD diffractometer |
Absorption correction | Multi-scan (SADABS; Sheldrick, 1998) |
Tmin, Tmax | 0.989, 0.997 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 13901, 4172, 2477 |
Rint | 0.057 |
(sin θ/λ)max (Å−1) | 0.684 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.053, 0.141, 1.00 |
No. of reflections | 4172 |
No. of parameters | 250 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.26, −0.24 |
Computer programs: APEX2 (Bruker, 2006), SAINT-Plus (Bruker, 2005), SHELXTL (Sheldrick, 2008), DIAMOND (Brandenburg, 2009).
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1···O1Wi | 0.96 (2) | 2.16 (2) | 3.065 (2) | 155.6 (17) |
N2—H2···O1Wi | 0.94 (2) | 2.03 (2) | 2.939 (2) | 161.8 (19) |
N3—H3···O2ii | 0.93 (2) | 1.95 (2) | 2.858 (2) | 163.1 (19) |
O1W—H1X···O2iii | 0.90 (3) | 2.19 (3) | 3.062 (2) | 164 (2) |
O1W—H1Y···O1 | 0.96 (3) | 1.86 (3) | 2.810 (2) | 171 (2) |
Symmetry codes: (i) −x+1, y+1/2, −z+1/2; (ii) −x+2, −y+1, −z+1; (iii) −x+1, −y+1, −z+1. |
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Arcyriaflavin A is a natural product belonging to the family of indolocarbazole alkaloids. This family has potential therapeutic application in the treatment of cancer (Sánchez et al., 2006) because of its ability to inhibit protein kinases. The most widely known indolocarbazole alkaloid is staurosporine, a potent inhibitor of phospholipid/Ca2+-dependent protein kinase (protein kinase C) from rat brain (Tamaoki et al., 1986). Several of its derivatives have already entered clinical trials as anticancer agents (Sánchez et al., 2006), and it was also the model drug for the study of Meggers and co-workers on the design of metal complexes as protein kinase inhibitors (Bregman et al., 2006). The title compound, (I), is an attractive aglycone staurosporine derivative, first isolated from the myxomycete Arcyria denudata (Steglich, 1989). It has a wide span of cytotoxic and antiproliferative action, ranging from moderate antibiotic activity against fungi and bacteria (Keller & Everhart, 2010) to in vitro antiviral properties towards the human cytomegalovirus (Slater et al., 1999) and cytotoxicity towards the K562 human chronic myelogenous leukemia cell line (Liu et al., 2007). In addition, it also works via kinase inhibition, namely of the cyclin-dependent kinase 4 (CDK4) (Zhu et al., 2003).
The asymmetric unit of (I) comprises an arcyriaflavin A molecule and a solvent water molecule (Fig. 1). The organic molecules arrange themselves in a zig-zag fashion, forming layers parallel to the (1 0 2) plane (Fig. 2a). Within these layers, the molecules are interconnected by strong directional hydrogen bonds [D···A distances in the range 2.811 (2)–3.066 (2) Å, D—H···A angles greater than ca 156°; see Table 1 for specific details (dashed lines in Fig. 2)]. On the other hand, the dominant supramolecular contacts between adjacent layers are π–π stacking forces (Fig. 2b), with a distance between aromatic rings of ca 3.38 Å.
Within each layer, the arcyriaflavin A molecules are arranged into dimers via two N···O hydrogen bonds related by a centre of inversion, forming a hydrogen-bonding pattern that can be described by an R22(8) graph-set motif (Grell et al., 1999). It is noteworthy that the two molecular units are not coplanar, with the mean planes being ca 0.65 Å from each other. The β-diamine group (atoms N1 and N2) acts as a two-proton donor to the neighbouring solvent water molecule, forming a ring of graph set R12(7). The water molecule bridges adjacent arcyriaflavin A molecules from two distinct supramolecular layers via O—H···O hydrogen-bonding interactions with the carbonyl groups (atoms O1 and O2). One of these interactions (O1W···O1), together with the aforementioned R12(7) and R22(8) rings, promotes the formation of the two-dimensional supramolecular layers. The remaining interaction of the water molecule [O1W···O2iii; symmetry code: (iii) -x + 1, -y + 1, -z + 1] connects different layers, as shown in Fig. 2(b).