Expanding the Genetic Alphabet:  Non-Epimerizing Nucleoside with thepyDDA Hydrogen-Bonding Pattern

2003 ◽  
Vol 68 (25) ◽  
pp. 9839-9842 ◽  
Author(s):  
Daniel Hutter ◽  
Steven A. Benner
Keyword(s):  
Hydrogen Bonding ◽  
Hydrogen Bonding Pattern ◽  
Genetic Alphabet

Five pseudopolymorphs of 6-amino-2-thiouracil: absence of N—H...S hydrogen bonds

2012 ◽  
Vol 69 (1) ◽  
pp. 93-100 ◽  
Author(s):  
Wilhelm Maximilian Hützler ◽  
Michael Bolte
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Cambridge Structural Database ◽  
Hydrogen Bonding Pattern ◽  
Crystallization Experiments ◽  
Structural Database ◽  
Thiouracil Derivatives

In order to study the preferred hydrogen-bonding pattern of 6-amino-2-thiouracil, C4H5N3OS, (I), crystallization experiments yielded five different pseudopolymorphs of (I), namely the dimethylformamide disolvate, C4H5N3OS·2C3H7NO, (Ia), the dimethylacetamide monosolvate, C4H5N3OS·C4H9NO, (Ib), the dimethylacetamide sesquisolvate, C4H5N3OS·1.5C4H9NO, (Ic), and two different 1-methylpyrrolidin-2-one sesquisolvates, C4H5N3OS·1.5C5H9NO, (Id) and (Ie). All structures containR21(6) N—H...O hydrogen-bond motifs. In the latter four structures, additionalR22(8) N—H...O hydrogen-bond motifs are present stabilizing homodimers of (I). No type of hydrogen bond other than N—H...O is observed. According to a search of the Cambridge Structural Database, most 2-thiouracil derivatives form homodimers stabilized by anR22(8) hydrogen-bonding pattern, with (i) only N—H...O, (ii) only N—H...S or (iii) alternating pairs of N—H...O and N—H...S hydrogen bonds.

scholarly journals Crystal structures of butyl 2-amino-5-hydroxy-4-(4-nitrophenyl)benzofuran-3-carboxylate and 2-methoxyethyl 2-amino-5-hydroxy-4-(4-nitrophenyl)benzofuran-3-carboxylate

2019 ◽  
Vol 75 (6) ◽  
pp. 880-887 ◽  
Author(s):  
Rosita Diana ◽  
Angela Tuzi ◽  
Barbara Panunzi ◽  
Antonio Carella ◽  
Ugo Caruso
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Molecular Structures ◽  
Antitumoral Activity ◽  
Space Group ◽  
One Dimensional ◽  
Axis Direction ◽  
Hydrogen Bonding Pattern ◽  
Butyl Group

The title benzofuran derivatives 2-amino-5-hydroxy-4-(4-nitrophenyl)benzofuran-3-carboxylate (BF1), C19H18N2O6, and 2-methoxyethyl 2-amino-5-hydroxy-4-(4-nitrophenyl)benzofuran-3-carboxylate (BF2), C18H16N2O7, recently attracted attention because of their promising antitumoral activity. BF1 crystallizes in the space group P\overline{1}. BF2 in the space group P21/c. The nitrophenyl group is inclined to benzofuran moiety with a dihedral angle between their mean planes of 69.2 (2)° in BF1 and 60.20 (6)° in BF2. A common feature in the molecular structures of BF1 and BF2 is the intramolecular N—H...Ocarbonyl hydrogen bond. In the crystal of BF1, the molecules are linked head-to-tail into a one-dimensional hydrogen-bonding pattern along the a-axis direction. In BF2, pairs of head-to-tail hydrogen-bonded chains of molecules along the b-axis direction are linked by O—H...Omethoxy hydrogen bonds. In BF1, the butyl group is disordered over two orientations with occupancies of 0.557 (13) and 0.443 (13).

Hydrogen-bond patterns in 1,4-dihydro-2,3-quinoxalinediones: ligands for the glycine modulatory site on the NMDA receptor

1996 ◽  
Vol 52 (3) ◽  
pp. 487-499 ◽  
Author(s):  
M. Kubicki ◽  
T. W. Kindopp ◽  
M. V. Capparelli ◽  
P. W. Codding
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Binding Site ◽  
Three Dimensional ◽  
Hydrogen Bonding Pattern ◽  
Wide Range ◽  
Show Evidence ◽  
Additional Hydrogen Bond ◽  
Hydrogen Bond Patterns ◽  
Solvent Molecules

The crystal structures of five 1,4-dihydro-2,3-quinoxalinediones, antagonists of the NMDA modulatory glycine binding site on the excitary amino acid (EAA) receptor complex, have been determined: (I) 6,7-dinitro-1,4-dihydro-2,3-quinoxalinedione (DNQX); (II) 5,7-dinitro-1,4-dihydro-2,3-quinoxalinedione (MNQX); (III) 6-nitro-1,4-dihydro-2,3-quinoxalinedione hydrate; (IV) 6,7-dichloro-1,4-dihydro-2,3-quinoxalinedione; (V) 5,7-dichloro-1,4-dihydro-2,3-quinoxalinedione dimethylformamide. The crystal structure of the most active compound (II) contains a unique intramolecular N—H...O(NO2) hydrogen bond, which may be important for activity, as semiempirical calculations show that this bond is stable over a wide range of dihedral angles between the planes of the molecule and of the nitro group. In the other compounds the intermolecular hydrogen bonds connect molecules into three-dimensional networks. In compounds (I), (III) and (IV) head-to-tail: π-stacking is found between molecules connected by a center of symmetry. The geometries of the hydrogen-bonded —NH—C=O fragments show evidence of π-cooperativity or resonance-assisted hydrogen bonding. Graph-set analysis of the hydrogen-bond patterns of quinoxalinedione derivatives shows a tendency to form two types of hydrogen-bonding motifs: a centrosymmetric dimeric ring and an infinite chain. Even though this pattern may be modified by the presence of additional hydrogen-bond acceptors and/or donors, as well as by solvent molecules, general similarities have been found. Comparison of all quinoxalinedione structures suggests that the hydrogen-bonding pattern necessary for the biological activity at the glycine binding site contains one donor and two acceptors.

Microsolvation effect and hydrogen-bonding pattern of taurine-water TA-(H2O)n (n = 1–3) complexes

2011 ◽  
Vol 18 (1) ◽  
pp. 265-274 ◽  
Author(s):  
Yumei Dai ◽  
Yuhua Wang ◽  
Zhengguo Huang ◽  
Hongke Wang ◽  
Lei Yu
Keyword(s):  
Hydrogen Bonding ◽  
Hydrogen Bonding Pattern
Sign in / Sign up

Export Citation Format

Share Document