scholarly journals Crystal structure of the tripeptideN-(benzyloxycarbonyl)glycylglycyl-L-norvaline

2015 ◽  
Vol 71 (3) ◽  
pp. o216-o217
Author(s):  
Sumesh Nicholas
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Amino Acid ◽  
Hydrogen Bonds ◽  
Crystal Lattice ◽  
Side Chain ◽  
Screw Axis ◽  
Terminal Amino Acid ◽  
Backbone Conformation ◽  
Terminal Amino

The title tripeptide, C17H23N3O6, contains a nonproteinogenic C-terminal amino acid residue, norvaline, which is an isomer of the amino acid valine. Norvaline, unlike valine, has an unbranched side chain. The molecule has a Gly–Gly segment which adopts an extended conformation. The norvaline residue also adopts an extended backbone conformation while its side chain has ag+tconformation. In the crystal lattice, N—H...O and O—H...O hydrogen bonds stabilize the packing. Molecules translated along the crystallographicaaxis associate through an N—H...O hydrogen bond. The remaining three hydrogen bonds are between molecules related by a21screw axis.

scholarly journals Crystal structure of 2-{[2-methoxy-5-(trifluoromethyl)phenyl]iminomethyl}-4-nitrophenol

2015 ◽  
Vol 71 (7) ◽  
pp. o466-o467 ◽  
Author(s):  
Nevzat Karadayı ◽  
Songül Şahin ◽  
Yavuz Köysal ◽  
Emine Coşkun ◽  
Orhan Büyükgüngör
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Title Compound ◽  
Helical Chain ◽  
Screw Axis ◽  
Imine Group ◽  
Compound C ◽  
Benzene Rings ◽  
Axis Parallel

In the title compound, C15H11F3N2O4, the N=C bond of the central imine group adopts anEconformation. The dihedral angle between two benzene rings is 6.2 (2)°. There is an intramolecular bifurcated O—H...(N,O) hydrogen bond withS(6) andS(9) ring motifs. In the crystal, molecules are linked by C—H...O hydrogen bonds into a helical chain along the 31screw axis parallel toc. The –CF3group shows rotational disorder over two sites, with occupancies of 0.39 (2) and 0.61 (2).

scholarly journals 3-Acetyl-1-(3-methylphenyl)thiourea

2012 ◽  
Vol 68 (8) ◽  
pp. o2574-o2574 ◽  
Author(s):  
B. Thimme Gowda ◽  
Sabine Foro ◽  
Sharatha Kumar
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Benzene Ring ◽  
Title Compound ◽  
Side Chain ◽  
Maximum Deviation ◽  
Methyl Groups ◽  
Compound C ◽  
Ring Motif

In the crystal structure of the title compound, C10H12N2OS, the conformation of the two N—H bonds areantito each other. The amide C=O and the C=S are are alsoantito each other. The N—H bond adjacent to the benzene ring issynto them-methyl groups. The dihedral angle between the benzene ring and the side chain [mean plane of atoms C—C(O)N—C—N; maximum deviation 0.029 (2) Å] is 14.30 (7)°. There is an intramolecular N—H...O hydrogen bond generating anS(6) ring motif. In the crystal, the molecules are linkedviaN—H...) hydrogen bonds, forming chains propagating along [001]. The S atom is disordered and was refined using a split model [occupancy ratio 0.56 (4):0.44 (4)].

scholarly journals Threefold helical assembly via hydroxy hydrogen bonds: the 2:1 co-crystal of bicyclo[3.3.0]octane-endo-3,endo-7-diol and bicyclo[3.3.0]octane-endo-3,exo-7-diol

2021 ◽  
Vol 77 (3) ◽  
pp. 270-276
Author(s):  
Isa Y. H. Chan ◽  
Mohan M. Bhadbhade ◽  
Roger Bishop
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Hydroxy Group ◽  
Network Structure ◽  
General Position ◽  
Three Dimensional ◽  
Screw Axis ◽  
Hydroxy Groups

Reduction of bicyclo[3.3.0]octane-3,7-dione yields a mixture of the endo-3,endo-7-diol and endo-3, exo-7-diol (C8H14O2) isomers (5 and 6). These form (5)2·(6) co-crystals in the monoclinic P21/n space group (with Z = 6, Z′ = 1.5) rather than undergoing separation by means of fractional recrystallization or column chromatography. The molecule of 5 occupies a general position, whereas the molecule of 6 is disordered over two orientations across a centre of symmetry with occupancies of 0.463 (2) and 0.037 (2). Individual diol hydroxy groups associate around a pseudo-threefold screw axis by means of hydrogen bonding. The second hydroxy group of each diol behaves in a similar manner, generating a three-dimensional hydrogen-bonded network structure. This hydrogen-bond connectivity is identical to that present in three known helical tubuland diol–hydroquinone co-crystals, and the new crystal structure is even more similar to two homologous aliphatic diol co-crystals.

scholarly journals Carbohydrate is linked through ethanolamine to the C-terminal amino acid of Trypanosoma brucei variant surface glycoprotein

1983 ◽  
Vol 209 (1) ◽  
pp. 261-262 ◽  
Author(s):  
A A Holder
Keyword(s):  
Amino Acid ◽  
Aspartic Acid ◽  
Trypanosoma Brucei ◽  
Carboxy Group ◽  
Surface Glycoprotein ◽  
Variant Surface Glycoprotein ◽  
Side Chain ◽  
Serine Residue ◽  
Terminal Amino Acid ◽  
Terminal Amino

The C-terminal amino acid of the variant surface glycoprotein from Trypanosoma brucei is glycosylated. For two variant proteins that terminate in an aspartic acid and a serine residue respectively, it was shown that the sugar side chain is linked through ethanolamine to the alpha-carboxy group of the amino acid.

L-2-Aminobutyric acid: two fully ordered polymorphs with Z′ = 4

2010 ◽  
Vol 66 (2) ◽  
pp. 253-259 ◽  
Author(s):  
Carl Henrik Görbitz
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Amino Acid ◽  
Diffraction Data ◽  
Aminobutyric Acid ◽  
Side Chain ◽  
Hydrogen Bond Network ◽  
Asymmetric Unit ◽  
Space Groups ◽  
Bond Network

The crystal structure of L-2-aminobutyric acid, an L-alanine analogue with an ethyl rather than a methyl side chain, has proved elusive owing to problems growing diffraction quality crystals. Good diffraction data have now been obtained for two polymorphs, in space groups P21 and I2, revealing surprisingly complex, yet fully ordered crystalline arrangements with Z′ = 4. The closely related structures are divided into hydrophilic and hydrophobic layers, the latter being the thinnest ever found for an amino acid (other than α-glycine). The hydrophobic layers furthermore contain conspicuous pseudo-centers-of-symmetry, leading to overall centrosymmetric intensity statistics. Uniquely, the four molecules in the asymmetric unit can be divided into two pairs that each forms an independent hydrogen-bond network.

scholarly journals Crystal structure of diethyl 2-acetoxy-2-[3-(4-nitrophenyl)-3-oxo-1-phenylpropyl]malonate

2016 ◽  
Vol 72 (2) ◽  
pp. 257-260
Author(s):  
Nóra Veronika May ◽  
Gyula Tamás Gál ◽  
Zsolt Rapi ◽  
Péter Bakó
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Three Dimensional ◽  
Side Chain ◽  
Compound C ◽  
Side Chain Conformation ◽  
Graph Set ◽  
Aromatic Ring Interactions

In the racemic title compound, C24H25NO9, the dihedral angle between the planes of the two benzene-ring systems is 80.16 (6)°, while the side-chain conformation is stabilized by a methylene–carboxyl C—H...O hydrogen bond. Weak intermolecular C—H...O hydrogen bonds form inversion dimers [graph setR22(16)] which are linked into chains extending alonga. Further C—H...O hydrogen bonding extends the structure alongbthrough cyclicR22(10) motifs. Although no π–π aromatic ring interactions are present in the structure, C—H...π ring interactions acrosscgenerate an overall three-dimensional supramolecular structure.

scholarly journals Crystal structure of 7,8-benzocoumarin-4-acetic acid

2015 ◽  
Vol 71 (8) ◽  
pp. o617-o618
Author(s):  
R. Ranga Swamy ◽  
Ramakrishna Gowda ◽  
K. V. Arjuna Gowda ◽  
Mahantesha Basanagouda
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Acetic Acid ◽  
Hydrogen Bonds ◽  
Torsion Angle ◽  
Ring System ◽  
Side Chain ◽  
Acceptor Atom ◽  
Fused Ring ◽  
Fused Ring System

The fused-ring system in the title compound [systematic name: 2-(2-oxo-2H-benzo[h]chromen-4-yl)acetic acid], C15H10O4, is almost planar (r.m.s. deviation = 0.031 Å) and the Car—C—C=O (ar = aromatic) torsion angle for the side chain is −134.4 (3)°. In the crystal, molecules are linked by O—H...O hydrogen bonds, generating [100]C(8) chains, where the acceptor atom is the exocyclic O atom of the fused-ring system. The packing is consolidated by a very weak C—H...O hydrogen bond to the same acceptor atom. Together, these interactions lead to undulating (001) layers in the crystal.

scholarly journals Crystal structure of 2′-hydroxyacetophenone 4-methylthiosemicarbazide

2015 ◽  
Vol 71 (4) ◽  
pp. o244-o245
Author(s):  
Junita Jamsari ◽  
Nur Fatihah Abas ◽  
Thahira Begum S. A. Ravoof ◽  
Edward R. T. Tiekink
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Dihedral Angle ◽  
Torsion Angle ◽  
Organic Molecule ◽  
Side Chain ◽  
Water Molecules ◽  
Ethyl Group

In the organic molecule of the title hydrate, C11H15N3OS·H2O, {systematic name: 3-ethyl-1-{(E)-[1-(2-hydroxyphenyl)ethylidene]amino}thiourea monohydrate}, a dihedral angle of 5.39 (2)° is formed between the hydroxybenzene ring and the non-H atoms comprising the side chain (r.m.s. deviation = 0.0625 Å), with the major deviation from planarity noted for the terminal ethyl group [the C—N—C—C torsion angle = −172.17 (13)°]. The N—H H atoms aresynand an intramolecular hydroxy–imine O—H...N hydrogen bond is noted. In the crystal, the N-bonded H atoms form hydrogen bonds to symmetry-related water molecules, and the latter form donor interactions with the hydroxy O atom and with a hydroxybenzene ring, forming a O—H...π interaction. The hydrogen bonding leads to supramolecular tubes aligned along thebaxis. The tubes are connected into layersviaC—H...O interactions, and these stack along thecaxis with no directional interactions between them.

scholarly journals Crystal structure of 5-{4′-[(2-{2-[2-(2-ammonioethoxy)ethoxy]ethoxy}ethyl)carbamoyl]-4-methoxy-[1,1′-biphenyl]-3-yl}-3-oxo-1,2,5-thiadiazolidin-2-ide 1,1-dioxide: a potential inhibitor of the enzyme protein tyrosine phosphatase 1B (PTP1B)

2015 ◽  
Vol 71 (4) ◽  
pp. 336-338
Author(s):  
Kasi Viswanatharaju Ruddraraju ◽  
Roman Hillebrand ◽  
Charles L. Barnes ◽  
Kent S. Gates
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Protein Tyrosine Phosphatase ◽  
Title Compound ◽  
Tyrosine Phosphatase ◽  
Side Chain ◽  
Protein Tyrosine Phosphatase 1B ◽  
Enzyme Protein ◽  
Compound C

The title compound, C24H32N4O8S, (I), crystallizes as a zwitterion. The terminal amine N atom of the [(2-{2-[2-(2-ammonioethoxy)ethoxy]ethoxy}ethyl)carbamoyl] side chain is protonated, while the 1,2,5-thiadiazolidin-3-one 1,1-dioxide N atom is deprotonated. The side chain is turned over on itself with an intramolecular N—H...O hydrogen bond. The 1,2,5-thiadiazolidin-3-one 1,1-dioxide ring has an envelope conformation with the aryl-substituted N atom as the flap. Its mean plane is inclined by 62.87 (8)° to the aryl ring to which it is attached, while the aryl rings of the biphenyl unit are inclined to one another by 20.81 (8)°. In the crystal, molecules are linked by N—H...O and N—H...N hydrogen bonds, forming slabs lying parallel to (010). Within the slabs there are C—H...O and C—H...N hydrogen bonds and C—H...π interactions present.

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