Inclusion complexes of the natural product gossypol. Crystal structure of the 2:1 complex of gossypol with amyl acrylate

The crystal structure of the 2: 1 inclusion complex of gossypol with amyl acrylate has been determined by X-ray structure analysis. The crystals of (C₃₀H₃₀O₈)₂C₈H₁₄O₂ are triclinic, space group P ,a = 14.425(2),b = 15.519(1),c = 16.409(2) Å, =97.89(1), = 117.80(1), =67.01(1)° (reduced cell:a = 14.425(2),b = 15.519(2),c = 16.017(2)Å, = 92.19(1), = 115.01(l), =67.01(1)°],V = 2986.7(5) ų,Z = 2,D _x = 1.31 g cm^–3, (CuK ) = 7.40 cm^–1,T = 292 K. The structure has been solved by direct methods and refined to the final R value of 0.059 for 5155 observed reflections. The gossypol molecules bonded via several hydrogen bonds form centrosymmetric tetramers. The two independent gossypol molecules, A and B, are related within the tetramer by a local noncrystallographic 2-fold axis. The host molecules in the crystal form cavities in which two guest molecules are placed. The ester molecule interacts via a pair of C-...H-O hydrogen bonds with two gossypol molecules of the same chirality and belonging to the same tetramer unit. The amyloxy group of the ester molecule shows a very large thermal motion. It adopts a non-extended conformation in which it can be fitted into the cavity formed by the host molecules.     

Inclusion complexes of the natural product gossypol. Crystal structures of gossypol complexes with benzene and chloroform as guests

The crystal structures of the lattice inclusion complexes of gossypol with benzene and chloroform have been determined by X-ray structure analysis. The crystals of (C₃₀H₃₀O₈)₂ · C₆H₆ (GPBNZ) are triclinic, space groupPI,a = 11.241(3),b = 14.986(4),c = 17.380(4) Å, = 98.89(2), = 99.86(2), = 98.91(2)°,V = 2800(2) ų,Z = 2,D _x = 1.32 g cm^–3, (CuK ) = 7.35 cm^–1. The structure has been refined to a finalR value of 0.050 for 6146 observed reflections. The crystals of C₃₀H₃₀O₈·CHCl₃ (GPCLF) are monoclinic, space groupC2/c,a = 28.464(4),b = 8.948(1),c = 26.480(4) Å, = 108.93(2)°,V = 6380(2) ų,Z = 8,D _x = 1.33 g cm^–3, (CuK) = 30.42 cm^–1. The structure has been refined to a finalR value of 0.100 for 1980 observed reflections.GPCLF forms an intercalate-type structure and GPBNZ a clathrate-type structure. There are, however, some similarities in the packing mode of the host molecules in these two structures. On a basis of comparison of the crystal packing of GPCLF and GPBNZ one can postulate that in the desorption process of the intercalate-type GPCLF complex an intermediate clathrate structure of the GPBNZ-type should be formed.     

Inclusion complexes of the natural product gossypol. Crystal structure of the 2:1 complex of gossypol withm-Xylene

The crystal structure of a 2: 1 inclusion complex of gossypol withm-xylene has been determined by X-ray structure analysis. The crystals of C₃₀H₃₀O₈·0.5C₈ H₁₀ are triclinic, space groupPl^–,a = 8.478(1),b = 14.087(2),c = 14.411(2) Å, = 115,39(1), = 75.11(1), = 86.80(1)°,V = 1475.2(4) ų,Z = 2,D _x = 1.29 g cm^–3,T = 295 K, (CuK ) = 7.01 cm^–1. The structure has been solved by direct methods and refined to the finalR value of 0.079 for 3910 observed reflections. The gossypol molecules are linked by intermolecular hydrogen bonds and form bimolecular layers parallel to the ab plane. Disorderedm-xylene molecules occupy cavities between these layers. All polar groups of the gossypol molecule are packed in the interior of the bilayer while non-polar groups are directed outwards. An analysis of the crystal packing of other inclusion complexes of gossypol shows that such bilayers are formed in four complexes and three of those structures are generically related to each other.Deceased.     

Inclusion complexes of the natural product gossypol. Crystal structure of the 1 : 1 complex of gossypol with isovaleric acid

The crystal structure of the 1 : 1 lattice inclusion complex of gossypol with isovaleric acid has been determined by X-ray structure analysis. The crystals of C₃₀H₃₀O₈C₅H₁₀O₂ are monoclinic, space groupC2/c,a=28.835(7),b=9.063(2),c=26.880(4)Å, =109.66(1)°,V=6615(2) ų,Z=8,D _x = 1.25 g cm^–3, (CuK) = 7.14 cm^–1,T = 295 K. The structure was solved by direct methods and refined with isotropic thermal parameters to the finalR value of 0.132 for 1114 observed reflections. Hydrogen bonded gossypol molecules form columns along the [1 0 1] direction. These columns pack into layers parallel to the (101) plane. The layers of gossypol molecules are separated by the layers of isovaleric acid. The acid molecules are connectedvia a pair of O-H...O hydrogen bonds forming centrosymmetric dimers. There is no hydrogen bond interaction between the carboxylic acid dimers and gossypol molecules.     

Crystal and molecular structure of the diterpene alkaloid talatisine

As a result of x-ray studies, the spatial structure and conformation of the talatisine molecule have been determined. The mean bond lengths are C-C 1.539(6) Å, N-C 1.493 (5) Å, HO-C(sp³) 1.429(5) Å. The six-membered rings A and B have the chair conformation, and rings C and D have distorted boat conformations. The five-membered rings E, F, and G have the envelope conformation.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 335–341, May–June, 1981.     

Inclusion complexes of the natural product gossypol. Clathrate type inclusion complexes of gossypol with carbonyl group containing guests

The crystal structures of 2:1 inclusion complexes of gossypol with methyl propionate (GPMEP) and ethyl acetoacetate (GPEAA) have been determined by X-ray structure analysis. The crystals of GPMEP, C₃₀H₃₀O₈l/2 C₄H₈O₂, are monoclinic, space groupC2/c,a=11.079(3),b = 30.724(7), c = 16.515(5) Å, = 90.46(2)°,V = 5621(3) Å,Z = 8,D _x = 1.33 g cm^–3. The structure has been refined to the finalR value of 0.059 for 1899 observed reflections. The crystals of GPEAA, C₃₀H₃₀O₈l/2 C₆H₁₀O₃, are monoclinic, space groupC2/c,a=11.095(2),b=30.604(9),c = 16.955(5) Å, = 88.27(2)°,V = 5754(3) Å,Z = 8,D _x = 1.35 g cm^–3. The structure has been refined to the finalR value of 0.056 for 2502 observed reflections.In contrast to previously investigated inclusion complexes of gossypol the host molecules do not form centrosymmetric dimersvia hydrogen bonds. In the crystal structures the racemic gossypol is separated into enantiomers forming alternating bimolecular layers. Nearly perpendicular to these chiral bilayers run elongated cavities enclosed on each side by layers of opposite chirality. The surface of these layers is hydrophobic, the polar groups are hidden inside the layer. Guest molecules which are hydrogen bonded to the host are included in cylindrically shaped cavities. Possible hydrogen bonds between host and guest are analysed for this isostructural class of complexes.     

Crystal and molecular structure of the diterpene alkaloid talatisine

As a result of x-ray studies, the spatial structure and conformation of the talatisine molecule have been determined. The mean bond lengths are C-C 1.539(6) Å, N-C 1.493 (5) Å, HO-C(sp³) 1.429(5) Å. The six-membered rings A and B have the chair conformation, and rings C and D have distorted boat conformations. The five-membered rings E, F, and G have the envelope conformation.     

Inclusion complexes of the natural product gossypol. Strong influence of the guest on the host structure in channel-type isostructural inclusion complexes of gossypol

The crystal structures of 1 : 1 inclusion complexes of gossypol with tetrahydrofuran (GPTHF), cyclohexanone (GPCHN) and butanal (GPBTA) have been determined by X-ray structure analysis. The crystals of GPTHF are triclinic, space group P,a = 10.788(2),b = 10.979(3),c = 13,880(2) Å, = 80. 11(2), = 103.87(1), = 77.96(2)°,V = 1517.8(6) ų,Z = 2,R = 0.052 for 2701 observed reflections. The crystals of GPCHN are triclinic, space groups P,a = 10.803(4),b = 11.157(5),c = 15.428(6) Å, = 108.75(3), = 106.93(3), = 103.34(3)°,V = 1573(1) ų,Z = 2,R = 0.071 for 1879 observed reflections. The crystals of GPBTA are triclinic, space group P,a = 10.190(2),b = 11.335(1),c = 14.665(2) Å, = 73.04(1), = 103.74(1), = 81.07(1)°,V = 1529.9(5) ų,Z = 2,R = 0.068 for 2964 observed reflections. Crystal data for another 13 isostructural inclusion complexes are given.[/p]In this isostructural group of complexes guest molecules are accommodated in channels and are hydrogen bonded to the host molecules via an 0(1)-H....O(1) hydrogen bond. The molecular association changes significantly with the shape and size of the guest component. In GPTHF centrosymmetric dimers of gossypol formedvia O(5)-H...O(3) hydrogen bonds are associated in columns via a weak O(4)-H...O(8) hydrogen bond. In GPCHN the latter bond disappears as the distance O(4)-O(8) is increased to 3.73 Å. In GPBTA the O(5)-H...O(3) bond is replaced by three centre hydrogen bonds O(5)-H...O(2) and O(3)-H...O(5), and a centrosymmetric dimer of a new type is formed. These dimers are further connected by two weak hydrogen bonds to form columns. The butanal molecule interacts with the host structure via two hydrogen bonds. This indicates that a guest component can activate or deactivate different functional groups of the host in channel inclusion complexes of gossypol for hydrogen bond formation.     

X-Ray Crystal Structure of Four Inclusion Complexes of the Novel Host Gossindane: An Oxidation Product of Gossypol

Gossindane, the oxidation product of gossypol, demonstrates inclusion properties towards four solvents chosen accidentally. The crystal data of these complexes with ethanol (I), ethylacetate (II), dichloromethane (III) and water (IV) are: (I): C26H30O6· 2C2H5OH, monoclinic, P2/c, a = 8.687(2) Å, b = 10.986(3) Å, c = 14.778(3) Å = 110.94° V = 1317 Å3, Z = 2, R = 0.069, N = 1368; (II): C26H30O6· 0.5C4H8O2, monoclinic, P21/c, a = 8.960(2) Å, b = 21.937(5) Å, c = 14.712(3) Å, = 111.98(2)°, V = 2681 Å3, Z = 4, R = 0.083, N = 2653; (III): C26H30O6· CH2Cl2, monoclinic, P21/c, a = 8.886(2) Å, b = 21.778(6) Å, c = 14.996(4) Å, = 111.31(3)°, V = 2704 Å3, Z = 4, R = 0.131, N = 1580; (IV): C26H30O6·2H2O, monoclinic, C2/c, a = 29.422(9) Å, b = 6.720(2) Å, c = 27.525(9) Å, = 117.43(2)°, V = 4830 Å3, Z = 8. R = 0.096, N = 2240.In the solvates H-bonded host molecules form bilayers with very similar structures and a nearly hydrophobic surface. Guest molecules are placed in channels formed between these bilayers and may be H- bonded to host molecules (ethanol). In the hydrate two water molecules using their H-bonding capacity incorporate gossindane molecules into bilayers.     

Crystal and molecular structure of Dicyanotetrasulfane S4(CN)2

S₄(CN)₂ crystallizes in the monoclinic space group P2₁/c with a = 885.7 pm, b = 794.2 pm, c = 1032.6 pm, β = 109.0° (at 173 K). The molecules occupy general sites but are of approximate C₂ symmetry. The conformation of the molecules is all-trans with torsional angles CSSS = 74.6° and 81.7° and SSSS = 84.8°. The central SS bond (201.7 pm) is much shorter than the terminal SS bonds (av. 206.8 pm). There are no stronger than van-der-Waals type intermolecular interactions.     

Crystal and molecular structure of β-cyclodextrin inclusion complex with succinic acid

The crystal complex of β-cyclodextrin with succinic acid, intermediate product of hydrolysis reaction of succinic anhydride in the presence of β-cyclodextrin, was isolated and studied by X-ray analysis (monoclinic, space group P2₁, a = 15.1977(7) Å, b = 10.1763(5) Å, c = 20.6943(6) Å, β = 109.239(4)°, V = 3021.8(2) Å³, Z = 2, R ₁ = 0.0359, wR ₂ = 0.0947). It was proved that β-cyclodextrin and succinic acid form an inclusion complex, which exists in crystal state as a heptahydrate. The molecule of succinic acid is fully included in the β-cyclodextrin cavity with its carboxyl groups accessible for water molecules. Water molecules located at borders of cavity rims and in interstices between molecules of β-cyclodextrin participate in formation of intermolecular hydrogen bonds. The overall structure does not contain disordered fragments. The crystal conformation of succinic acid corresponds to one of possible conformers of the molecule in vacuo and is almost not disturbed by intermolecular interactions in crystal. Based on the analysis of structural features of the crystal conformation of succinic acid and character of its location in the β-cyclodextrin cavity, it was suggested that hydrolysis of succinic anhydride via ring opening and formation of succinic acid is mediated by cyclodextrin microenvironment and it likely occurs near the narrow rim of the macrocycle cavity.     

Crystal structure of lansoprazole sulfone

The structure of 2-({[3-methyl-4-(2,2,2-trifluoroethoxy)-2-pyridinyl]methyl} sulfonyl)-1H-1,3-benzimidazole, C₁₆H₁₄N₃O₃F₃S, has been solved. The compound belongs to the monoclinic space group (P2₁/c) with cell parameters a = 8.8693(9) Å, b = 23.369(2) Å, c = 8.6141(8) Å, β = 104.68(1)°, V = 1727.2(3) ų, Z = 4. The final R and wR(F ²) values were 0.070 and 0.147, respectively. The title molecule has a ‘Z’ shape in the crystal structure. The fused benzimidazole moiety and the pyridine ring are nearly coplanar. The molecules are linked by N-H…N and C-H…O hydrogen bonds into chains of edge-fused R ₂ ² (14), R ₂ ² R ₂ ² (8), and R ₂ ² (18) rings along the c-axis. The crystal lattice is further strengthened by π-π stacking interactions.     

Crystal and molecular structure of the alkaloid dictysine

In order to determine the spatial structure of the diterpene alkaloid dictysine unambiguously, x-ray structural analysis has been performed: diffractometer, CuK radiation, 1028 reflections, direct method, R factor 0.118. It has been established that dictysine has not a songorine but a denudatine skeleton. All the hydroxy groups participate in inter- and intramolecular hydrogen bonds.Institute of Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 230–235, March–April, 1982.     

Crystal and molecular structure of the alkaloid dictysine

In order to determine the spatial structure of the diterpene alkaloid dictysine unambiguously, x-ray structural analysis has been performed: diffractometer, CuK_α radiation, 1028 reflections, direct method, R factor 0.118. It has been established that dictysine has not a songorine but a denudatine skeleton. All the hydroxy groups participate in inter- and intramolecular hydrogen bonds.     

Crystal and molecular structure of pyridazine-3-carboxylic acid hydrochloride and zinc(II) pyridazine-3-carboxylate tetrahydrate

Crystals of pyridazine-3-carboxylic acid hydrochloride contain almost planar molecular sheets in which the cations, composed of acid molecules each with a hydrogen atom attached to one of the ring-nitrogen atoms, interact with chloride anions via a network of weak hydrogen bonds. Van der Waals interactions between sheets are indicated by the intersheet spacing of 3.47?Å. The crystal structure of di(aqua-O)bis(trans-pyridazine-3-carboxylato-N,O)zinc(II) dihydrate is composed of monomeric molecules in which the zinc(II) ion at the center of symmetry is coordinated by two ligand molecules each via its N,O bonding moiety. The ligand molecules and the metal ion form a trans-planar configuration. Two water oxygen atoms, above and below the plane, complete a distorted octahedron. A network of weak hydrogen bonds holds the monomers together.     

Crystal and molecular structure of the macrocyclic pyrrolizidine alkaloid trichodesmine

An x-ray structural investigation (diffractometer, Cu, 1286 reflections, direct method, MLS in the anisotropic approximation to R=0.085) of the alkaloid trichodesmine has been performed. The crystals are monoclinic, a=23.30, b=15.11, c=8.79 Å, =144.3°, space group B2, z=4. The conformation of the trichodesmine macrocycle differs substantially from that of the other alkaloids of this series that have been studied.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 368–373, May–June, 1979.     

Crystal and molecular structure of the macrocyclic pyrrolizidine alkaloid incanine

An x-ray structural investigation (diffractometer, Cu, 1001 reflections, direct method, MLS in the anisotropic approximation to R=0.066), of the alkaloid incanine has been performed. The crystals are rhombic, a=10.07, b=16.20, c=14.04 Å, space group P2₁2₁2₁, z=4. The conformation of the backbone of the macrocycle in incanine practically coincides with those in fulvine and axillarine.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 363–367, May–June, 1979.     

Asymmetric synthetic access to the hetisine alkaloids: total synthesis of (+)-nominine

A dual cycloaddition strategy for the synthesis of the hetisine alkaloids has been developed, illustrated by a concise asymmetric total synthesis of (+)-nominine (7). The approach relies on an early-stage intramolecular 1,3-dipolar cycloaddition of a 4-oxido-isoquinolinium betaine dipole with an ene-nitrile dipolarophile. Subsequent late-stage pyrrolidine-induced dienamine isomerization/Diels-Alder cascade allows for rapid construction of the carbon--nitrogen polycyclic skeleton within this class of C(20)-diterpenoid alkaloids.