(−)-Norfluoro­curarine ethanol monosolvate

Shahobiddin M Adizov; Jamshid Ashurov; Zokir Karimov; Pattax Kh Yuldashev; Bakhodir Tashkhodjaev

doi:10.1107/S1600536813015365

. 2013 Jun 15;69(Pt 7):o1100. doi: 10.1107/S1600536813015365

(−)-Norfluorocurarine ethanol monosolvate

Shahobiddin M Adizov ^a,^*, Jamshid Ashurov ^b, Zokir Karimov ^c, Pattax Kh Yuldashev ^a, Bakhodir Tashkhodjaev ^a

PMCID: PMC3770376 PMID: 24046661

Abstract

The title compound, C₁₉H₂₀N₂O·C₂H₅OH, is an ethanol solvate of an indol alkaloid which was extracted from the plant Vinca erecta. The fused piperidine ring adopts an approximate boat conformation and the pyrrolidine ring an envelope conformation with one of the methylene C atoms at the flap. An intramolecular N—H⋯O hydrogen bond forms an S6 ring motif. In the crystal, norfulorocurarine and ethanol molecules are linked into a chain along the c-axis direction through N—H⋯O and O—H⋯N hydrogen bonds.

Related literature

For the biological activity of plants containing norfluorocurarine class alkaloids, see: Lavrenova & Lavrenov (1997 ▶). For the isolation of norfluorocurarine from the plant Vinca erecta, see: Yunusov & Yuldashev (1952 ▶, 1957 ▶). For the physical properties and crystal structures of several norfluorocurarine solvates, see: Tashkhodjaev et al. (2011 ▶). graphic file with name e-69-o1100-scheme1.jpg

Experimental

Crystal data

C₁₉H₂₀N₂O·C₂H₆O
M _r = 338.44
Orthorhombic,
a = 7.0138 (5) Å
b = 16.090 (1) Å
c = 16.490 (2) Å
V = 1860.9 (3) Å³
Z = 4
Cu Kα radiation
μ = 0.62 mm⁻¹
T = 293 K
0.60 × 0.30 × 0.20 mm

Data collection

Oxford Xcalibur, Ruby diffractometer
Absorption correction: multi-scan (CrysAlis PRO; Oxford Diffraction, 2009 ▶) T _min = 0.801, T _max = 0.884
5608 measured reflections
3178 independent reflections
2393 reflections with I > 2σ(I)
R _int = 0.027

Refinement

R[F ² > 2σ(F ²)] = 0.051
wR(F ²) = 0.142
S = 0.99
3178 reflections
237 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.33 e Å⁻³
Δρ_min = −0.19 e Å⁻³

Data collection: CrysAlis PRO (Oxford Diffraction, 2009 ▶); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXS97 (Sheldrick, 2008 ▶); molecular graphics: SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: SHELXTL.

Supplementary Material

Crystal structure: contains datablock(s) I, GLOBAL. DOI: 10.1107/S1600536813015365/is5277sup1.cif

e-69-o1100-sup1.cif^{(28KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536813015365/is5277Isup2.hkl

e-69-o1100-Isup2.hkl^{(155.9KB, hkl)}

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1⋯O1	0.87 (3)	2.31 (3)	2.785 (4)	115 (3)
N1—H1⋯O2	0.87 (3)	2.17 (3)	2.961 (4)	152 (3)
O2—H2⋯N4ⁱ	0.96 (5)	1.85 (5)	2.805 (4)	172 (5)

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Symmetry code: (i) Inline graphic .

Acknowledgments

We thank the Academy of Sciences of the Republic of Uzbekistan for supporting this study (grant No. FA-F7-T185)

supplementary crystallographic information

Comment

Because of possessing high biological activity, plants containing norfluorocurarine class alkaloids have been widely used in traditional medicine. A number of plants as Vinca major L. and Vinca herbacea Waldst. et Kit. are examples which are used as a healing agent in traditional medicine (Lavrenova et al., 1997). Norfluorocurarine for the first time was extracted from the root of Vinca erecta and called vincanine (Yunusov & Yuldashev, 1952). Later the alkaloid was extraxted from the upper parts of the same plant (Yunusov & Yuldashev, 1957).

Earlier unsolvated crystal form of (-)-norfluorocurarine was obtained from acetone and stereochemistry studied by Tashkhodjaev et al. (2011). When we used ethanol as a solvent, XRD experiments showed the solvated structure in the molar ratio 1:1. Crystals which were obtained in acetone and in ethanol showed the same absolute configuration of alkaloid molecule. But the crystal packing and intermolecular bonds are quite different.

In the molecule, the carbonyl group is oriented to N1—H group. The torsion angle of C2═C16—C17═O1 atoms is -11.7 (5)°. Therefore, the carbonyl group and N1—H group form an intramolecular hydrogen bond N1—H···O1═ C17 (Table 1). In the crystal, the hydroxyl group of solvated ethanol molecules forms intermolecular hydrogen bonds with norfluorocurarine N1 and N4 atoms (Table 1). The hydrogen bonds links the norfluorocurarine and ethanol molecules along the c axis.

Experimental

The title compound was isolated from the chloroform fraction of the plant Vinca erecta by a known method (Yunusov et al., 1957). Norflurocurarine was dissolved in ethanol and evaporated in room temperature and obtained suitable for X-ray crystals. Since the crystal was unstable in air, we covered it with epoxide glue.