organic compounds
Rauniticine-allo-oxindole B methanol monosolvate
aFaculty of Applied Sciences, Universiti Teknologi MARA, 40450 Shah Alam, Selangor, Malaysia, and bDepartment of Chemistry, University of Malaya, 50603 Kuala Lumpur, Malaysia
*Correspondence e-mail: seikweng@um.edu.my
The title pentacyclic oxindole alkadoid, isolated from Uncaria longiflora, crystallizes as a methanol solvate, C20H22N2O4·CH4O. The five-membered ring comprising the indole fused ring is nearly planar [maximum atomic deviation = 0.031 (2) Å], whereas the five-membered ring having alphatic C atoms adopts an envelope shape (with the tertiary N atom representing the flap). The six-membered ring that shares an N atom with the envelope-shaped ring adopts a chair shape; the six-membered ring having an O atom is sofa-shaped. The carboxylic acid group acts as a hydrogen-bond donor to a methanol molecule; this, in turn, acts as a hydrogen-bond donor to the double-bond carboxyl O atom of an adjacent molecule, generating a chain. Adjacent chains are linked by N—H⋯O hydrogen bonds, forming a layer motif.
Related literature
For the spectroscopic identification of rauniticine-allo-oxindole B, see: Seki et al. (1993).
Experimental
Crystal data
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Refinement
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Data collection: CrysAlis PRO (Agilent, 2010); cell CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: X-SEED (Barbour, 2001); software used to prepare material for publication: publCIF (Westrip, 2010).
Supporting information
10.1107/S1600536811016710/xu5205sup1.cif
contains datablocks global, I. DOI:Structure factors: contains datablock I. DOI: 10.1107/S1600536811016710/xu5205Isup2.hkl
Uncaria longiflora plant material was collected from Hutan Simpan Bangi, Selangor, Malaysia, and specimens were deposited at Taman Botani Putrajaya, Malaysia. Dried and ground stems were extracted with methanol for 72 h to give 25 g of crude extract. This was acidified with 5% hydrochloric acid, and non-alkaloidal material was removed followed with basification with 37% ammonium hydroxide to release the alkaloid. The alkaloid was extracted into chloroform to give 2.25 g of a crude alkaloid fraction. The fraction was dissolved in methanol and subjected to radial
(4 mm thickness silica-gel plate) with dichloromethane:ethyl acetate followed by ethyl acetate:methanol with a gradual increase of solvent polarity. Rauniticine-allo-oxindole B was separated and purified by repeated preparative thin layer using chloroform:methanol (120:5). The polar fraction afforded colorless crystals when the solvent was allowed to evaporate (53 mg).Carbon-bound H-atoms were placed in calculated positions [C—H 0.95 to 1.00 Å, Uiso(H) 1.2 to 1.5Ueq(C)] and were included in the
in the riding model approximation.The oxygen-bound H-atoms were located in a difference Fourier map, and were refined with distance restraints of O–H 0.84±0.01 Å; their temperature factors were refined.
The
was assumed to be that from a spectropic study (Seki et al., 1993); in the absence of heavy atoms, 1853 Friedel pairs were merged.Data collection: CrysAlis PRO (Agilent, 2010); cell
CrysAlis PRO (Agilent, 2010); data reduction: CrysAlis PRO (Agilent, 2010); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: X-SEED (Barbour, 2001); software used to prepare material for publication: publCIF (Westrip, 2010).Fig. 1. Thermal ellipsoid plot (Barbour, 2001) of C20H22N2O4.CH3OH at the 70% probability level; hydrogen atoms are drawn as spheres of arbitrary radius. | |
Fig. 2. Hydrogen-bonded layer structure. |
C20H22N2O4·CH4O | F(000) = 412 |
Mr = 386.44 | Dx = 1.323 Mg m−3 |
Monoclinic, P21 | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: P 2yb | Cell parameters from 4552 reflections |
a = 9.2330 (3) Å | θ = 2.4–29.2° |
b = 7.2110 (2) Å | µ = 0.10 mm−1 |
c = 14.7678 (4) Å | T = 100 K |
β = 99.313 (3)° | Prism, colorless |
V = 970.27 (5) Å3 | 0.20 × 0.10 × 0.05 mm |
Z = 2 |
Agilent SuperNova Dual diffractometer with an Atlas detector | 2381 independent reflections |
Radiation source: SuperNova (Mo) X-ray Source | 2181 reflections with I > 2σ(I) |
Mirror monochromator | Rint = 0.039 |
Detector resolution: 10.4041 pixels mm-1 | θmax = 27.5°, θmin = 2.4° |
ω scans | h = −11→11 |
Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2010) | k = −9→9 |
Tmin = 0.981, Tmax = 0.995 | l = −19→19 |
9109 measured reflections |
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) = 0.093 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.05 | w = 1/[σ2(Fo2) + (0.0455P)2 + 0.2288P] where P = (Fo2 + 2Fc2)/3 |
2381 reflections | (Δ/σ)max = 0.001 |
266 parameters | Δρmax = 0.21 e Å−3 |
4 restraints | Δρmin = −0.19 e Å−3 |
C20H22N2O4·CH4O | V = 970.27 (5) Å3 |
Mr = 386.44 | Z = 2 |
Monoclinic, P21 | Mo Kα radiation |
a = 9.2330 (3) Å | µ = 0.10 mm−1 |
b = 7.2110 (2) Å | T = 100 K |
c = 14.7678 (4) Å | 0.20 × 0.10 × 0.05 mm |
β = 99.313 (3)° |
Agilent SuperNova Dual diffractometer with an Atlas detector | 2381 independent reflections |
Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2010) | 2181 reflections with I > 2σ(I) |
Tmin = 0.981, Tmax = 0.995 | Rint = 0.039 |
9109 measured reflections |
R[F2 > 2σ(F2)] = 0.037 | 4 restraints |
wR(F2) = 0.093 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.05 | Δρmax = 0.21 e Å−3 |
2381 reflections | Δρmin = −0.19 e Å−3 |
266 parameters |
x | y | z | Uiso*/Ueq | ||
O1 | 1.30437 (18) | 1.0011 (3) | 0.98971 (12) | 0.0253 (4) | |
O2 | 1.06782 (16) | 0.9207 (3) | 0.96906 (11) | 0.0226 (4) | |
O3 | 1.42440 (17) | 0.5574 (3) | 0.85208 (12) | 0.0257 (4) | |
O4 | 1.04085 (17) | 0.6078 (3) | 0.54863 (11) | 0.0214 (4) | |
O5 | 1.20768 (17) | 1.2803 (3) | 1.08162 (11) | 0.0233 (4) | |
N1 | 0.9975 (2) | 0.3485 (3) | 0.71523 (12) | 0.0181 (4) | |
N2 | 0.8390 (2) | 0.7963 (3) | 0.52546 (13) | 0.0204 (4) | |
C1 | 1.1933 (2) | 0.8909 (3) | 0.95551 (14) | 0.0180 (5) | |
C2 | 1.2329 (2) | 0.7332 (4) | 0.90209 (15) | 0.0180 (5) | |
C3 | 1.3739 (2) | 0.6984 (4) | 0.89692 (15) | 0.0224 (5) | |
H3 | 1.4447 | 0.7818 | 0.9280 | 0.027* | |
C4 | 1.3173 (3) | 0.4343 (4) | 0.79913 (16) | 0.0218 (5) | |
H4 | 1.2837 | 0.4902 | 0.7373 | 0.026* | |
C5 | 1.3986 (3) | 0.2554 (4) | 0.7878 (2) | 0.0339 (6) | |
H5A | 1.4810 | 0.2807 | 0.7553 | 0.051* | |
H5B | 1.3316 | 0.1667 | 0.7525 | 0.051* | |
H5C | 1.4359 | 0.2032 | 0.8484 | 0.051* | |
C6 | 1.1853 (2) | 0.4113 (4) | 0.84882 (15) | 0.0188 (5) | |
H6 | 1.2229 | 0.3627 | 0.9117 | 0.023* | |
C9 | 1.0709 (2) | 0.2749 (4) | 0.80272 (15) | 0.0200 (5) | |
H9A | 1.1188 | 0.1557 | 0.7924 | 0.024* | |
H9B | 0.9975 | 0.2512 | 0.8433 | 0.024* | |
C10 | 0.9215 (2) | 0.5222 (3) | 0.72771 (15) | 0.0163 (5) | |
H10 | 0.8512 | 0.4990 | 0.7713 | 0.020* | |
C11 | 1.0279 (2) | 0.6712 (3) | 0.76820 (14) | 0.0168 (5) | |
H11A | 0.9735 | 0.7855 | 0.7786 | 0.020* | |
H11B | 1.0963 | 0.7006 | 0.7251 | 0.020* | |
C12 | 1.1150 (2) | 0.6013 (3) | 0.86019 (15) | 0.0164 (5) | |
H12 | 1.0443 | 0.5862 | 0.9043 | 0.020* | |
C13 | 0.8837 (3) | 0.2265 (4) | 0.66791 (16) | 0.0229 (5) | |
H13A | 0.8237 | 0.1735 | 0.7114 | 0.028* | |
H13B | 0.9272 | 0.1239 | 0.6368 | 0.028* | |
C14 | 0.7913 (3) | 0.3531 (4) | 0.59816 (15) | 0.0201 (5) | |
H14A | 0.6853 | 0.3293 | 0.5968 | 0.024* | |
H14B | 0.8151 | 0.3324 | 0.5359 | 0.024* | |
C15 | 0.8317 (2) | 0.5561 (3) | 0.63129 (15) | 0.0167 (5) | |
C16 | 0.9193 (2) | 0.6518 (3) | 0.56509 (15) | 0.0179 (5) | |
C17 | 0.7091 (2) | 0.8212 (4) | 0.56293 (15) | 0.0189 (5) | |
C18 | 0.6022 (2) | 0.9545 (4) | 0.54169 (16) | 0.0223 (5) | |
H18 | 0.6081 | 1.0452 | 0.4958 | 0.027* | |
C19 | 0.4849 (3) | 0.9504 (4) | 0.59050 (16) | 0.0242 (5) | |
H19 | 0.4095 | 1.0408 | 0.5780 | 0.029* | |
C20 | 0.4765 (2) | 0.8163 (4) | 0.65720 (16) | 0.0239 (5) | |
H20 | 0.3963 | 0.8172 | 0.6902 | 0.029* | |
C21 | 0.5849 (2) | 0.6802 (4) | 0.67598 (15) | 0.0205 (5) | |
H21 | 0.5786 | 0.5875 | 0.7209 | 0.025* | |
C22 | 0.7016 (2) | 0.6830 (3) | 0.62794 (14) | 0.0165 (5) | |
C23 | 1.2794 (3) | 1.4465 (4) | 1.11555 (17) | 0.0266 (6) | |
H23A | 1.2064 | 1.5366 | 1.1290 | 0.040* | |
H23B | 1.3332 | 1.4979 | 1.0693 | 0.040* | |
H23C | 1.3483 | 1.4195 | 1.1718 | 0.040* | |
H1 | 1.273 (3) | 1.083 (4) | 1.0219 (19) | 0.041 (9)* | |
H5 | 1.1180 (14) | 1.304 (5) | 1.065 (2) | 0.043 (9)* | |
H2 | 0.870 (3) | 0.878 (3) | 0.4885 (16) | 0.034 (8)* |
U11 | U22 | U33 | U12 | U13 | U23 | |
O1 | 0.0214 (8) | 0.0253 (10) | 0.0282 (9) | −0.0040 (8) | 0.0009 (7) | −0.0078 (8) |
O2 | 0.0186 (8) | 0.0237 (10) | 0.0254 (8) | 0.0002 (7) | 0.0033 (6) | −0.0060 (8) |
O3 | 0.0181 (8) | 0.0299 (11) | 0.0298 (9) | 0.0030 (8) | 0.0052 (7) | −0.0029 (8) |
O4 | 0.0241 (8) | 0.0194 (9) | 0.0225 (8) | 0.0002 (7) | 0.0096 (6) | −0.0014 (7) |
O5 | 0.0190 (8) | 0.0246 (10) | 0.0255 (9) | −0.0013 (8) | 0.0017 (6) | −0.0026 (8) |
N1 | 0.0226 (9) | 0.0140 (10) | 0.0174 (9) | 0.0007 (8) | 0.0022 (7) | −0.0008 (8) |
N2 | 0.0237 (10) | 0.0199 (11) | 0.0180 (9) | −0.0018 (9) | 0.0045 (8) | 0.0034 (8) |
C1 | 0.0185 (10) | 0.0188 (13) | 0.0155 (10) | −0.0008 (10) | −0.0004 (8) | 0.0021 (9) |
C2 | 0.0176 (10) | 0.0196 (12) | 0.0169 (10) | −0.0003 (9) | 0.0033 (8) | 0.0034 (9) |
C3 | 0.0199 (10) | 0.0266 (14) | 0.0205 (11) | −0.0017 (11) | 0.0026 (9) | 0.0017 (11) |
C4 | 0.0219 (11) | 0.0238 (13) | 0.0206 (10) | 0.0037 (10) | 0.0063 (9) | −0.0016 (11) |
C5 | 0.0315 (13) | 0.0286 (15) | 0.0446 (16) | 0.0093 (12) | 0.0153 (12) | 0.0015 (13) |
C6 | 0.0209 (11) | 0.0187 (12) | 0.0169 (10) | 0.0030 (10) | 0.0027 (8) | 0.0011 (10) |
C9 | 0.0232 (11) | 0.0160 (12) | 0.0212 (11) | 0.0008 (10) | 0.0046 (9) | 0.0035 (10) |
C10 | 0.0182 (10) | 0.0154 (11) | 0.0159 (10) | 0.0010 (9) | 0.0051 (8) | 0.0014 (9) |
C11 | 0.0176 (10) | 0.0153 (11) | 0.0172 (10) | 0.0013 (9) | 0.0019 (8) | 0.0001 (9) |
C12 | 0.0173 (10) | 0.0165 (11) | 0.0156 (10) | 0.0015 (9) | 0.0035 (8) | 0.0001 (9) |
C13 | 0.0284 (12) | 0.0188 (13) | 0.0216 (11) | −0.0028 (10) | 0.0040 (9) | −0.0010 (10) |
C14 | 0.0241 (11) | 0.0173 (12) | 0.0191 (11) | −0.0031 (10) | 0.0040 (9) | −0.0011 (10) |
C15 | 0.0187 (10) | 0.0157 (12) | 0.0161 (10) | 0.0002 (9) | 0.0042 (8) | −0.0015 (9) |
C16 | 0.0214 (10) | 0.0173 (12) | 0.0146 (10) | −0.0041 (9) | 0.0015 (8) | −0.0036 (9) |
C17 | 0.0198 (10) | 0.0190 (13) | 0.0168 (10) | −0.0048 (10) | −0.0001 (8) | −0.0024 (9) |
C18 | 0.0258 (11) | 0.0188 (12) | 0.0198 (11) | −0.0026 (10) | −0.0039 (9) | 0.0001 (10) |
C19 | 0.0239 (11) | 0.0209 (13) | 0.0248 (12) | 0.0033 (11) | −0.0052 (9) | −0.0036 (11) |
C20 | 0.0209 (11) | 0.0275 (15) | 0.0234 (12) | 0.0021 (11) | 0.0033 (9) | −0.0040 (11) |
C21 | 0.0226 (11) | 0.0197 (12) | 0.0186 (10) | −0.0016 (10) | 0.0019 (9) | −0.0005 (10) |
C22 | 0.0191 (10) | 0.0140 (11) | 0.0150 (10) | −0.0028 (9) | −0.0010 (8) | −0.0032 (9) |
C23 | 0.0237 (11) | 0.0261 (14) | 0.0296 (13) | −0.0006 (11) | 0.0030 (10) | −0.0057 (12) |
O1—C1 | 1.331 (3) | C10—C11 | 1.512 (3) |
O1—H1 | 0.84 (3) | C10—C15 | 1.547 (3) |
O2—C1 | 1.227 (3) | C10—H10 | 1.0000 |
O3—C3 | 1.338 (3) | C11—C12 | 1.547 (3) |
O3—C4 | 1.458 (3) | C11—H11A | 0.9900 |
O4—C16 | 1.228 (3) | C11—H11B | 0.9900 |
O5—C23 | 1.421 (3) | C12—H12 | 1.0000 |
O5—H5 | 0.84 (3) | C13—C14 | 1.529 (3) |
N1—C9 | 1.458 (3) | C13—H13A | 0.9900 |
N1—C13 | 1.459 (3) | C13—H13B | 0.9900 |
N1—C10 | 1.462 (3) | C14—C15 | 1.569 (3) |
N2—C16 | 1.356 (3) | C14—H14A | 0.9900 |
N2—C17 | 1.411 (3) | C14—H14B | 0.9900 |
N2—H2 | 0.88 (3) | C15—C22 | 1.505 (3) |
C1—C2 | 1.464 (3) | C15—C16 | 1.530 (3) |
C2—C3 | 1.340 (3) | C17—C18 | 1.377 (3) |
C2—C12 | 1.502 (3) | C17—C22 | 1.393 (3) |
C3—H3 | 0.9500 | C18—C19 | 1.395 (3) |
C4—C5 | 1.515 (4) | C18—H18 | 0.9500 |
C4—C6 | 1.530 (3) | C19—C20 | 1.392 (4) |
C4—H4 | 1.0000 | C19—H19 | 0.9500 |
C5—H5A | 0.9800 | C20—C21 | 1.397 (3) |
C5—H5B | 0.9800 | C20—H20 | 0.9500 |
C5—H5C | 0.9800 | C21—C22 | 1.383 (3) |
C6—C9 | 1.522 (3) | C21—H21 | 0.9500 |
C6—C12 | 1.537 (3) | C23—H23A | 0.9800 |
C6—H6 | 1.0000 | C23—H23B | 0.9800 |
C9—H9A | 0.9900 | C23—H23C | 0.9800 |
C9—H9B | 0.9900 | ||
C1—O1—H1 | 109 (2) | H11A—C11—H11B | 108.3 |
C3—O3—C4 | 117.88 (17) | C2—C12—C6 | 108.58 (17) |
C23—O5—H5 | 108 (3) | C2—C12—C11 | 113.2 (2) |
C9—N1—C13 | 113.6 (2) | C6—C12—C11 | 111.30 (19) |
C9—N1—C10 | 111.33 (18) | C2—C12—H12 | 107.8 |
C13—N1—C10 | 104.68 (17) | C6—C12—H12 | 107.8 |
C16—N2—C17 | 111.6 (2) | C11—C12—H12 | 107.8 |
C16—N2—H2 | 125 (2) | N1—C13—C14 | 104.1 (2) |
C17—N2—H2 | 122 (2) | N1—C13—H13A | 110.9 |
O2—C1—O1 | 121.6 (2) | C14—C13—H13A | 110.9 |
O2—C1—C2 | 123.3 (2) | N1—C13—H13B | 110.9 |
O1—C1—C2 | 115.10 (19) | C14—C13—H13B | 110.9 |
C3—C2—C1 | 120.4 (2) | H13A—C13—H13B | 109.0 |
C3—C2—C12 | 120.3 (2) | C13—C14—C15 | 105.55 (18) |
C1—C2—C12 | 119.10 (19) | C13—C14—H14A | 110.6 |
O3—C3—C2 | 126.2 (2) | C15—C14—H14A | 110.6 |
O3—C3—H3 | 116.9 | C13—C14—H14B | 110.6 |
C2—C3—H3 | 116.9 | C15—C14—H14B | 110.6 |
O3—C4—C5 | 105.80 (19) | H14A—C14—H14B | 108.8 |
O3—C4—C6 | 109.42 (18) | C22—C15—C16 | 101.90 (19) |
C5—C4—C6 | 114.1 (2) | C22—C15—C10 | 115.61 (18) |
O3—C4—H4 | 109.1 | C16—C15—C10 | 113.55 (18) |
C5—C4—H4 | 109.1 | C22—C15—C14 | 114.13 (18) |
C6—C4—H4 | 109.1 | C16—C15—C14 | 110.19 (18) |
C4—C5—H5A | 109.5 | C10—C15—C14 | 101.82 (18) |
C4—C5—H5B | 109.5 | O4—C16—N2 | 124.5 (2) |
H5A—C5—H5B | 109.5 | O4—C16—C15 | 127.2 (2) |
C4—C5—H5C | 109.5 | N2—C16—C15 | 108.30 (19) |
H5A—C5—H5C | 109.5 | C18—C17—C22 | 122.9 (2) |
H5B—C5—H5C | 109.5 | C18—C17—N2 | 128.5 (2) |
C9—C6—C4 | 113.91 (19) | C22—C17—N2 | 108.6 (2) |
C9—C6—C12 | 110.48 (18) | C17—C18—C19 | 117.1 (2) |
C4—C6—C12 | 109.8 (2) | C17—C18—H18 | 121.5 |
C9—C6—H6 | 107.5 | C19—C18—H18 | 121.5 |
C4—C6—H6 | 107.5 | C20—C19—C18 | 121.2 (2) |
C12—C6—H6 | 107.5 | C20—C19—H19 | 119.4 |
N1—C9—C6 | 110.5 (2) | C18—C19—H19 | 119.4 |
N1—C9—H9A | 109.5 | C19—C20—C21 | 120.5 (2) |
C6—C9—H9A | 109.5 | C19—C20—H20 | 119.7 |
N1—C9—H9B | 109.5 | C21—C20—H20 | 119.7 |
C6—C9—H9B | 109.5 | C22—C21—C20 | 118.7 (2) |
H9A—C9—H9B | 108.1 | C22—C21—H21 | 120.6 |
N1—C10—C11 | 111.33 (17) | C20—C21—H21 | 120.6 |
N1—C10—C15 | 102.46 (18) | C21—C22—C17 | 119.6 (2) |
C11—C10—C15 | 117.98 (19) | C21—C22—C15 | 131.2 (2) |
N1—C10—H10 | 108.2 | C17—C22—C15 | 109.2 (2) |
C11—C10—H10 | 108.2 | O5—C23—H23A | 109.5 |
C15—C10—H10 | 108.2 | O5—C23—H23B | 109.5 |
C10—C11—C12 | 109.15 (19) | H23A—C23—H23B | 109.5 |
C10—C11—H11A | 109.8 | O5—C23—H23C | 109.5 |
C12—C11—H11A | 109.8 | H23A—C23—H23C | 109.5 |
C10—C11—H11B | 109.8 | H23B—C23—H23C | 109.5 |
C12—C11—H11B | 109.8 | ||
O2—C1—C2—C3 | −173.7 (2) | N1—C10—C15—C22 | 158.78 (18) |
O1—C1—C2—C3 | 5.8 (3) | C11—C10—C15—C22 | −78.6 (3) |
O2—C1—C2—C12 | 0.8 (3) | N1—C10—C15—C16 | −83.9 (2) |
O1—C1—C2—C12 | −179.7 (2) | C11—C10—C15—C16 | 38.7 (3) |
C4—O3—C3—C2 | 3.7 (4) | N1—C10—C15—C14 | 34.5 (2) |
C1—C2—C3—O3 | 178.6 (2) | C11—C10—C15—C14 | 157.11 (19) |
C12—C2—C3—O3 | 4.1 (4) | C13—C14—C15—C22 | −135.9 (2) |
C3—O3—C4—C5 | −158.8 (2) | C13—C14—C15—C16 | 110.2 (2) |
C3—O3—C4—C6 | −35.5 (3) | C13—C14—C15—C10 | −10.6 (2) |
O3—C4—C6—C9 | −176.11 (19) | C17—N2—C16—O4 | −175.5 (2) |
C5—C4—C6—C9 | −57.8 (3) | C17—N2—C16—C15 | 5.0 (2) |
O3—C4—C6—C12 | 59.4 (2) | C22—C15—C16—O4 | 174.9 (2) |
C5—C4—C6—C12 | 177.6 (2) | C10—C15—C16—O4 | 49.9 (3) |
C13—N1—C9—C6 | −178.73 (19) | C14—C15—C16—O4 | −63.6 (3) |
C10—N1—C9—C6 | −60.9 (2) | C22—C15—C16—N2 | −5.7 (2) |
C4—C6—C9—N1 | −68.4 (3) | C10—C15—C16—N2 | −130.7 (2) |
C12—C6—C9—N1 | 55.7 (2) | C14—C15—C16—N2 | 115.8 (2) |
C9—N1—C10—C11 | 62.3 (2) | C16—N2—C17—C18 | 178.7 (2) |
C13—N1—C10—C11 | −174.57 (18) | C16—N2—C17—C22 | −2.0 (3) |
C9—N1—C10—C15 | −170.65 (18) | C22—C17—C18—C19 | 1.9 (3) |
C13—N1—C10—C15 | −47.5 (2) | N2—C17—C18—C19 | −178.8 (2) |
N1—C10—C11—C12 | −57.0 (2) | C17—C18—C19—C20 | −0.4 (3) |
C15—C10—C11—C12 | −174.97 (18) | C18—C19—C20—C21 | −0.9 (4) |
C3—C2—C12—C6 | 20.8 (3) | C19—C20—C21—C22 | 0.9 (3) |
C1—C2—C12—C6 | −153.8 (2) | C20—C21—C22—C17 | 0.5 (3) |
C3—C2—C12—C11 | −103.4 (3) | C20—C21—C22—C15 | −178.8 (2) |
C1—C2—C12—C11 | 82.0 (2) | C18—C17—C22—C21 | −2.0 (3) |
C9—C6—C12—C2 | −177.57 (17) | N2—C17—C22—C21 | 178.6 (2) |
C4—C6—C12—C2 | −51.1 (2) | C18—C17—C22—C15 | 177.5 (2) |
C9—C6—C12—C11 | −52.3 (2) | N2—C17—C22—C15 | −1.9 (2) |
C4—C6—C12—C11 | 74.2 (2) | C16—C15—C22—C21 | −176.1 (2) |
C10—C11—C12—C2 | 175.10 (18) | C10—C15—C22—C21 | −52.5 (3) |
C10—C11—C12—C6 | 52.4 (2) | C14—C15—C22—C21 | 65.2 (3) |
C9—N1—C13—C14 | 162.01 (19) | C16—C15—C22—C17 | 4.5 (2) |
C10—N1—C13—C14 | 40.4 (2) | C10—C15—C22—C17 | 128.1 (2) |
N1—C13—C14—C15 | −17.1 (2) | C14—C15—C22—C17 | −114.2 (2) |
D—H···A | D—H | H···A | D···A | D—H···A |
O1—H1···O5 | 0.84 (3) | 1.83 (3) | 2.662 (3) | 173 (4) |
O5—H5···O2i | 0.84 (3) | 1.91 (3) | 2.728 (2) | 165 (4) |
N2—H2···O4ii | 0.88 (3) | 1.97 (3) | 2.805 (3) | 158 (3) |
Symmetry codes: (i) −x+2, y+1/2, −z+2; (ii) −x+2, y+1/2, −z+1. |
Experimental details
Crystal data | |
Chemical formula | C20H22N2O4·CH4O |
Mr | 386.44 |
Crystal system, space group | Monoclinic, P21 |
Temperature (K) | 100 |
a, b, c (Å) | 9.2330 (3), 7.2110 (2), 14.7678 (4) |
β (°) | 99.313 (3) |
V (Å3) | 970.27 (5) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 0.10 |
Crystal size (mm) | 0.20 × 0.10 × 0.05 |
Data collection | |
Diffractometer | Agilent SuperNova Dual diffractometer with an Atlas detector |
Absorption correction | Multi-scan (CrysAlis PRO; Agilent, 2010) |
Tmin, Tmax | 0.981, 0.995 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 9109, 2381, 2181 |
Rint | 0.039 |
(sin θ/λ)max (Å−1) | 0.649 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.037, 0.093, 1.05 |
No. of reflections | 2381 |
No. of parameters | 266 |
No. of restraints | 4 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.21, −0.19 |
Computer programs: CrysAlis PRO (Agilent, 2010), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), X-SEED (Barbour, 2001), publCIF (Westrip, 2010).
D—H···A | D—H | H···A | D···A | D—H···A |
O1—H1···O5 | 0.84 (3) | 1.83 (3) | 2.662 (3) | 173 (4) |
O5—H5···O2i | 0.84 (3) | 1.91 (3) | 2.728 (2) | 165 (4) |
N2—H2···O4ii | 0.88 (3) | 1.97 (3) | 2.805 (3) | 158 (3) |
Symmetry codes: (i) −x+2, y+1/2, −z+2; (ii) −x+2, y+1/2, −z+1. |
Acknowledgements
We thank the University of Malaya for supporting this study.
References
Agilent (2010). CrysAlis PRO. Agilent Technologies, Yarnton, England. Google Scholar
Barbour, L. J. (2001). J. Supramol. Chem. 1, 189–191. CrossRef CAS Google Scholar
Seki, H., Takayama, H., Aimi, N., Sakai, S. & Ponglux, D. (1993). Chem. Pharm. Bull. 41, 2077–2086. CrossRef CAS Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Westrip, S. P. (2010). J. Appl. Cryst. 43, 920–925. Web of Science CrossRef CAS IUCr Journals Google Scholar
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The genus Uncaria is a source of diverse bioactive compounds, and parts of the plant are use for medicinal purposes. The structure of rauniticine-allo-oxindole B was previously elucidated by NMR spectroscopy in on study on heteroyohimbine-type oxindole alkaloids (Seki et al., 1993). The assignment is confirmed in the present study on the methanol-solvated compound (Scheme I) isolated from Uncaria longiflora. The pentacyclic oxindole alkadoid, C20H22N2O4, features a five-membered ring that adopts the shape of an envelope (with the tertiary N atom representing the flap). The six-membered ring that shares an N atom with the envelope-shaped ring adopts the shape of a chair; the six-membered ring having an O atom is sofa-shaped (Fig. 1). The carboxylic acid portion of the molecule is hydrogen-bond donor to a methanol molecule; this, in turn, is hydrogen-bond donor to the double-bond carboxyl O atom of an adjacent molecule to generate a chain. Adjacent chains are linked by an N–H···O hydrogen bond to form a layer motif (Table 1, Fig. 2).