Structure–activity studies of β-carbolines. 2. Crystal and molecular structures of N-ethyl-3-carbamoyl-β-carboline

1984 ◽  
Vol 62 (9) ◽  
pp. 1803-1806 ◽  
Author(s):  
Alastair K. S. Muir ◽  
Penelope W. Codding
Keyword(s):  
Molecular Conformation ◽  
Current Model ◽  
Benzodiazepine Receptor ◽  
Molecular Structures ◽  
Side Chain ◽  
Receptor Binding Site ◽  
Crystal And Molecular Structures ◽  
Structure Activity ◽  
Synthetic Ligand ◽  
Packing Arrangement

The crystal and molecular structures of N-ethyl-3-carbamoyl-β-carboline, C14H13N3O, a synthetic ligand of the benzodiazepine receptor are reported. The space group is C2/c with a = 16.220(4), b = 7.728(4), c = 19.623(6) Å, β = 104.16(1)°, Z = 8. The carboxyamide side chain assumes an extended conformation and is almost coplanar with the β-carboline skeleton. The observed molecular conformation is compared to the current model for the receptor binding site. Hydrogen bonding and aromatic ring stacking determine the molecular packing arrangement.

Structure-activity studies of β-carbolines. 4. Crystal and molecular structures of t-butyl β-carboline-3-carboxylate and 2-(methoxycarbonyl)canthine-6-one

1988 ◽  
Vol 66 (12) ◽  
pp. 2981-2988 ◽  
Author(s):  
Penelope W. Codding ◽  
Maria B. Szkaradzinska ◽  
Aleksander W. Roszak ◽  
Lorraine J. Aha ◽  
Timothy J. Hagen ◽  
...  
Keyword(s):  
Molecular Structures ◽  
Side Chain ◽  
Stacking Interactions ◽  
Lower Affinity ◽  
Space Group ◽  
High Affinity ◽  
Crystal And Molecular Structures ◽  
Structure Activity ◽  
The Difference

The crystal and molecular structures of two ligands for the benzodiazepine (BZ) receptor, t-butyl β-carboline-3-carboxylate, I (C16H16N2O2), and 2-(methoxycarbonyl)canthin-6-one, II (C16H10N2O3), are reported. The t-butyl β-carboline compound has high affinity for the receptor and is an antagonist; in contrast, the canthin-6-one has a 10-fold lower affinity for the receptor and no determinable in vivo activity. The space group for I is P21/c with a = 11.756(1), b = 11.2324(8), c = 11.964(1) Å, and β = 105.99(1)°. For II, the space group is also P21/c with a = 9.317(1), b = 7.964(1), c = 17.180(3) Å, and β = 104.173(7)°. The orientation of the alkyl-carboxylate side chain is different in the two molecules and may be related to the difference in affinity and in vivo activity of the ligands. In addition, the packing arrangements in the two structures are dominated by π-stacking interactions; and, in the case of the t-butyl compound, by hydrogen bonding.

Structure–activity studies of β-carbolines. 3. Crystal and molecular structures of methyl β-carboline-3-carboxylate

1985 ◽  
Vol 63 (10) ◽  
pp. 2752-2756 ◽  
Author(s):  
Alastair K. S. Muir ◽  
Penelope W. Codding
Keyword(s):  
Nitrogen Atom ◽  
Biological Response ◽  
Benzodiazepine Receptor ◽  
Carbonyl Oxygen ◽  
Molecular Structures ◽  
Side Chain ◽  
Amine Nitrogen Atom ◽  
Amine Nitrogen ◽  
Crystal And Molecular Structures ◽  
Affinity Ligand

The crystal and molecular structures of methyl β-carboline-3-carboxylate, C13H10N2O, a high-affinity ligand for the benzodiazepine receptor, are reported. This candidate for the endogenous ligand for the receptor produces a biological response that is opposite to the anxiety-reducing effect of the usual agonists of the receptor and is, therefore, classified as an inverse-agonist. The space group is P21/c with a = 11.4866(9), b = 5.8091(3), c = 32.417(3) Å, β = 97.111(3)°, Z = 8. In both of the unique molecules, the ester side chain has an extended conformation and is coplanar with the β-carboline moiety. The carbonyl oxygen atom and the aromatic nitrogen atom are cis and form a three-centre hydrogen bond to the amine nitrogen atom of the other molecule in the asymmetric unit.

Crystal and Molecular Structures of the Sulfur-Rich Organic Polysulfanes Heptathiacyclononane (C2H4S7) and Bis(triphenylmethyl)pentaand hexasulfane

1993 ◽  
Vol 48 (7) ◽  
pp. 928-934 ◽  
Author(s):  
Monika Kustos ◽  
Joachim Pickardt ◽  
Jörg Albertsen ◽  
Ralf Steudel
Keyword(s):  
Molecular Conformation ◽  
Accurate Solution ◽  
Molecular Structures ◽  
Torsion Angles ◽  
Crystal And Molecular Structures ◽  
Ring Molecules ◽  
Solvent Molecules ◽  
A Chain ◽  
Single Bonds

Determination of the first structure of a chain-like polysulfane with five sulfur atoms in the chain has been attempted. Bis(triphenylmethyl)pentasulfane forms monoclinic crystals containing disordered solvent molecules preventing an accurate solution of the structure. The (Ph3C)2S5 molecules consist of a helical C–S–S–S–S–S–C backbone (all torsion angles of same sign) and triphenylmethyl groups of normal conformation. The analogous (Ph3C)2S6 forms triclinic crystals; the molecular conformation of the C–S6–C chains is not helical, but the motif of torsion angles is + + – – +. In both compounds the C– S bonds are considerably longer (191 pm) than comparable C–S single bonds as in cyclo-C2H4S7. The latter forms monoclinic crystals consisting of ring molecules of C1 symmetry which can formally be derived from the crown-shaped S8 ring by substituting one sulfur atom by a C2H4 group of approximate C2h symmetry.

Structure-Activity Studies of Non-Steroidal Aromatase Inhibitors: The Crystal and Molecular Structures of CGS 16949A and CGS 18320B

1991 ◽  
Vol 5 (2) ◽  
pp. 119-132 ◽  
Author(s):  
Patrick Van Roey ◽  
Keith A. Bullion ◽  
Yoshio Osawa ◽  
Leslie J. Browne ◽  
Robert M. Bowman ◽  
...  
Keyword(s):  
Aromatase Inhibitors ◽  
Molecular Structures ◽  
Crystal And Molecular Structures ◽  
Structure Activity ◽  
Steroidal Aromatase Inhibitors

Structure–activity studies of β-carbolines. 1. Molecular structure and conformation of cis-3-carboxylic acid-1,2,3,4-tetrahydroharmane dihydrate

1983 ◽  
Vol 61 (3) ◽  
pp. 529-532 ◽  
Author(s):  
Penelope W. Codding
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Carboxylic Acid ◽  
Benzodiazepine Receptor ◽  
Chair Conformation ◽  
Water Molecules ◽  
Space Group ◽  
Structure Activity ◽  
Packing Arrangement

The crystal structure of cis-3-carboxylic acid-1,2,3,4-tetrahydroharmane dihydrate, C13H13N2O2•2H2O, a putative ligand of the benzodiazepine receptor is reported. The space group is P21/c with a = 14.850(4), b = 6.560(3), c = 14.746(4) Å and β = 117.411(8)°, Z = 4. The molecule crystallizes as a zwitterion with the unsaturated ring in a half-chair conformation. Hydrogen bonding to the water molecules included in the lattice determines the molecular packing arrangement.

Synthesis, Spectroscopic Characterization and Crystal and Molecular Structures of {Ph4P[(Se04 )(SnPh3 )(SnPh3X)]}n (X = Cl, Br)

2001 ◽  
Vol 56 (3) ◽  
pp. 233-238 ◽  
Author(s):  
C. A. Diop ◽  
L. Diop ◽  
U. Russo ◽  
A. Sánchez-Díaz ◽  
A. Castiñeiras
Keyword(s):  
Coordination Polyhedron ◽  
Spectroscopic Characterization ◽  
Molecular Structures ◽  
Trigonal Bipyramid ◽  
Side Chain ◽  
X Ray ◽  
Crystal And Molecular Structures ◽  
Distorted Trigonal Bipyramid ◽  
Nmr Techniques ◽  
Polymeric Structures

Abstract The reactions of bis[triphenyltin(IV)] selenate monohydrate [(Ph3Sn)2O4Se · H2O ] with tetraphenylphosphonium halides Ph4PX (X = Cl, Br) led to the formation of 1:1 complexes of formula {Ph4P[(SeO4)(SnPh3 (SnPh3X)]k [X = Br (I) or Cl (II)], which were characterized by infrared, Mössbauer and H, 13C and Sn 119Sn NMR techniques and by X-ray diffractometry. The complexes have polymeric structures in which the [SnPh3]+ units alternate with bridging [SeO4]2- units, each of which also bears an SnPh3X side chain. In both the [SnPh3]+ and the [SnPh3X] units the coordination polyhedron of the tin atom is a distorted trigonal bipyramid.

A Solvent-Dependent and Electrochemically Controlled Self-Assembling/Disassembling System

2003 ◽  
Vol 68 (9) ◽  
pp. 1647-1662 ◽  
Author(s):  
Valeria Amendola ◽  
Massimo Boiocchi ◽  
Yuri Diaz Fernandez ◽  
Carlo Mangano ◽  
Piersandro Pallavicini
Keyword(s):  
Equilibrium Mixture ◽  
Bidentate Ligand ◽  
Molecular Structures ◽  
The Self ◽  
Molar Ratio ◽  
Crystal And Molecular Structures ◽  
Self Assembling ◽  
Irreversible Oxidation ◽  
Irreversible Reduction ◽  
Metal Ligand

The bis-bidentate ligand R,S-1,2-diphenyl-N,N'-bis(2-quinolinemethylidene)ethane-1,2-diamine (ligand 4), containing two (iminomethyl)quinoline moieties separated by a cis-1,2-diphenylethylene spacer, forms stable complexes with both CuI and CuII. With CuII, the monomeric 1:1 complex [CuII(4)]2+ is obtained both in CH3CN and CH2Cl2. With CuI and overall 1:1 metal/ligand molar ratio, an equilibrium mixture is obtained in CH3CN, consisting of [CuI(4)2]+, [CuI2(4)2]2+ and [CuI2(4)(CH3CN)4]2+. The preponderant species is the two-metal one-ligand "open" complex [CuI2(4)(CH3CN)4]2+, in which each Cu+ cation is coordinated in a tetrahedral fashion by one (iminomethyl)quinoline unit and by two CH3CN molecules. Precipitation from the equilibrium mixture yields only crystals of [CuI2(4)(CH3CN)4](ClO4)2·2CH3CN, whose crystal and molecular structures have been determined. On the other hand, in the poorly coordinating CH2Cl2 solvent, only the dimeric helical [CuI2(4)2]2+ complex is obtained, when the overall metal/ligand 1:1 molar ratio is chosen. Addition of large quantities of acetonitrile to solutions of [CuI2(4)2]2+ in dichlorometane results in the formation of [CuI2(4)(CH3CN)4]2+, i.e. in the solvent-driven disassembling of the CuI helicate. While electrochemistry in CH3CN is poorly defined due to the presence of more than one CuI species, cyclic voltammetry experiments carried out in CH2Cl2 revealed a well defined behavior, with irreversible oxidation of [CuI2(4)2]2+ and irreversible reduction of [CuII(4)]2+ taking place at separate potentials (∆E ≈ 700 mV). Irreversibility and separation of the redox events are due to the self-assembling and disassembling processes following the reduction and oxidation, respectively.

Sign in / Sign up

Export Citation Format

Share Document