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Single C (single + c)
Selected AbstractsA single amino acid exchange shifts the serological reactivity of the novel HLA-B*4442 allele product from HLA-B44 to HLA-B21INTERNATIONAL JOURNAL OF IMMUNOGENETICS, Issue 3 2006F. Mrazek Summary A novel HLA-B (human leukocyte antigen-B) allele, HLA-B*4442, was identified both in a Czech patient with leukaemia and in his mother. The presence of a novel allele was initially suspected because conflicting results were obtained by serological and DNA typing techniques. The HLA typing using the polymerase chain reaction,sequence-specific primers (PCR,SSP) at the two-digit level indicated an allele belonging to the HLA-B*44 group, whereas serological typing indicated HLA-B21. Typing with PCR,sequence-specific oligonucleotides (PCR,SSO) resulted in a unique reaction pattern that could not be assigned to a known allele, PCR,SSP typing at the four-digit level did not match any known B*44 allele, either. The sequencing-based typing of the HLA-B locus then revealed the novel B*4442 allele that is identical with B*4405 except a single C,G nucleotide exchange at position 572. This exchange results in an amino acid substitution from serine to tryptophan at position 167 of the expressed HLA-B protein. The B21 serological reactivity of the novel B*4442 allele product was confirmed by employing an additional serological panel of typing sera. Our findings support previous reports claiming that serine at the position 167 in the alpha-2 domain of the HLA-B protein is a major determinant of the HLA-B44(12) serological epitope. [source] Polymorphs and pseudopolymorphs of N,N,-dithiobisphthalimideACTA CRYSTALLOGRAPHICA SECTION B, Issue 2 2002Dorcas M. M. Farrell N,N,-Dithiobisphthalimide, C16H8N2O4S2 (I), forms a wide range of polymorphs and solvates (pseudopolymorphs). When (I) is crystallized from methanol it yields a solvent-free polymorph (4), in Pna21 with Z, = 1, in which the molecules are linked into chains by a single C,H,O hydrogen bond: crystallization from either acetonitrile or dimethylformamide produces a monoclinic polymorph (5), in P21/c with Z, = 2, also solvent-free, in which the molecules are linked into molecular ladders. Nitromethane forms a monosolvate, C16H8N2O4S2·CH3NO2 (6), in P21/c with Z, = 1, in which the solvent molecules are linked to the molecules of (I) not only via a conventional C,H,O hydrogen bond but also via a polarized multicentre interaction involving all three C,H bonds of the solvent molecule. Chlorobenzene forms a precise hemisolvate, C16H8N2O4S2·0.5C6H5Cl (7), in P with Z, = 1, while ethylbenzene forms an approximate hemisolvate 2C16H8N2O4S2·0.913C6H5C2H5·0.087H2O (8), in P21/c with eight molecules of (I) per unit cell. In both solvates the molecules of (I) are linked, in (7) by ,,, stacking interactions augmented by weak C,H,O hydrogen bonds and in (8) by stronger C,H,O hydrogen bonds: the solvent molecules lie in isolated cavities, disordered across inversion centres in (7) and fully ordered in general positions in (8). Crystallization of (I) either from tetrahydrofuran or from wet tert -butanol yields isomorphous solvates (9) and (10), respectively, in C2/c with Z, = 0.5, in which molecules of (I) lie across twofold rotation axes and are linked by ,,, stacking interactions and very weak C,H,O hydrogen bonds, forming a framework enclosing continuous channels: highly disordered solvent molecules lie within these channels. p -Xylene and toluene form isomorphous hemisolvates (11) and (12) with unit cells metrically very similar to those of (9) and (10), but in P21/n with Z, = 1: in these two solvates the molecules of (I) are linked into a framework by very short C,H,O hydrogen bonds; the solvent molecules lie within continuous channels, but they are localized across inversion centres so that the toluene is disordered across an inversion centre. [source] Two similarly substituted benzo[h]pyrazolo[3,4- b]quinoline-5,6(10H)-diones: supramolecular structures in two and three dimensionsACTA CRYSTALLOGRAPHICA SECTION C, Issue 6 2010Yurina Díaz The molecules of 8-methyl-7,10-diphenyl-5H -benzo[h]pyrazolo[3,4- b]quinoline-5,6(10H)-dione, C27H17N3O2, (I), are weakly linked into chains by a single C,H...O hydrogen bond, and these chains are linked into sheets by a ,,, stacking interaction involving pyridyl and aryl rings. In 8-methyl-7-(4-methylphenyl)-10-phenyl-5H -benzo[h]pyrazolo[3,4- b]quinoline-5,6(10H)-dione, C28H19N3O2, (II), the molecules are linked into a three-dimensional framework structure by a combination of C,H...N, C,H...O and C,H...,(arene) hydrogen bonds, together with a ,,, stacking interaction analogous to that in (I). [source] (E)- N2 -{4-[(E)-2-(4-Chlorobenzoyl)ethenyl]-3-methyl-1-phenyl-1H -pyrazol-5-yl}- N1,N1 -dimethylformamidine: polarized molecules within sheets of ,-stacked hydrogen-bonded chainsACTA CRYSTALLOGRAPHICA SECTION C, Issue 5 2010Jairo Quiroga The molecules of the title compound, C22H21ClN4O, are conformationally chiral, and in the space group P212121 each crystal contains only one conformational enantiomer. The intramolecular dimensions provide evidence for polarization of the electronic structure. Molecules are linked by a single C,H...,(arene) hydrogen bond into chains, which are themselves weakly linked into sheets by an aromatic ,,, stacking interaction. [source] Hydrogen-bonded dimers, chains and rings in six differently substituted 2-vinyltetrahydro-1,4-epoxy-1-benzazepinesACTA CRYSTALLOGRAPHICA SECTION C, Issue 4 2010Lina M. Acosta In (2SR,4RS)-2- exo -vinyl-2,3,4,5-tetrahydro-1H -1,4-epoxy-1-benzazepine, C12H13NO, (I), the molecules are linked by two independent C,H...,(arene) hydrogen bonds to form sheets, such that all of the molecules in a given sheet are of the same configuration. The molecules of (2SR,4RS)-7-chloro-2- exo -(2-methylprop-1-enyl)-2,3,4,5-tetrahydro-1H -1,4-epoxy-1-benzazepine, C14H16ClNO, (II), are linked by a C,H...O hydrogen bond into C(4) chains, where all the molecules in a given chain are of the same configuration, whereas the molecules of (2SR,4RS)-8-chloro-9-methyl-2- exo -(2-methylprop-1-enyl)-2,3,4,5-tetrahydro-1H -1,4-epoxy-1-benzazepine, C15H18ClNO, (III), are linked into centrosymmetric dimers by pairs of symmetry-related C,H...,(arene) hydrogen bonds. (2RS,4RS)-8-Chloro-9-methyl-2- endo -(2-methylprop-1-enyl)-2,3,4,5-tetrahydro-1H -1,4-epoxy-1-benzazepine, C15H18ClNO, (IV), is a diastereoisomer of (III) and, as for (II), a single C,H...O hydrogen bond links the molecules into C(4) chains, each containing molecules of a single configuration. The structure of (2SR,4RS)-8-chloro-9-methyl-2- exo -(prop-1-en-2-yl)-2,3,4,5-tetrahydro-1H -1,4-epoxy-1-benzazepine, C14H16ClNO, (V), contains a C,H...O hydrogen bond which links pairs of molecules into centrosymmetric R22(6) dimers. (2SR,4RS)-7,9-Dichloro-2- exo -(prop-1-en-2-yl)-2,3,4,5-tetrahydro-1H -1,4-epoxy-1-benzazepine, C13H13Cl2NO, (VI), is an inversion twin containing both the (2S,4R) and (2R,4S) enantiomers in the space group P21, and a C,H...O hydrogen bond links molecules of a given configuration into simple C(3) chains. [source] Hydrogen-bonding patterns in two aroylthiocarbamates and two aroylimidothiocarbonatesACTA CRYSTALLOGRAPHICA SECTION C, Issue 3 2010Henry Insuasty In O -ethyl N -benzoylthiocarbamate, C10H11NO2S, the molecules are linked into sheets by a combination of two-centre N,H...O and C,H...S hydrogen bonds and a three-centre C,H...(O,S) hydrogen bond. A combination of two-centre N,H...O and C,H...O hydrogen bonds links the molecules of O -ethyl N -(4-methylbenzoyl)thiocarbamate, C11H13NO2S, into chains of rings, which are linked into sheets by an aromatic ,,, stacking interaction. In O,S -diethyl N -(4-methylbenzoyl)imidothiocarbonate, C13H17NO2S, pairs of molecules are linked into centrosymmetric dimers by pairs of symmetry-related C,H...,(arene) hydrogen bonds, while the molecules of O,S -diethyl N -(4-chlorobenzoyl)imidothiocarbonate, C12H14ClNO2S, are linked by a single C,H...O hydrogen bond into simple chains, pairs of which are linked by an aromatic ,,, stacking interaction to form a ladder-type structure. [source] Four differently substituted 2-aryl-2,3,4,5-tetrahydro-1H -1,4-epoxy-1-benzazepines: hydrogen-bonded structures in one, two and three dimensionsACTA CRYSTALLOGRAPHICA SECTION C, Issue 9 2009Sandra L. Gómez In (2RS,4SR)-7-chloro-2- exo -(2-chloro-6-fluorophenyl)-2,3,4,5-tetrahydro-1H -1,4-epoxy-1-benzazepine, C16H12Cl2FNO, (I), molecules are linked into chains by a single C,H...,(arene) hydrogen bond. (2RS,4SR)-2- exo -(2-Chloro-6-fluorophenyl)-2,3,4,5-tetrahydro-1H -1,4-epoxy-1-benzazepine, C16H13ClFNO, (II), is isomorphous with compound (I) but not strictly isostructural with it, as the hydrogen-bonded chains in (II) are linked into sheets by an aromatic ,,, stacking interaction. The molecules of (2RS,4SR)-7-methyl-2- exo -(4-methylphenyl)-2,3,4,5-tetrahydro-1H -1,4-epoxy-1-benzazepine, C18H19NO, (III), are linked into sheets by a combination of C,H...N and C,H...,(arene) hydrogen bonds. (2S,4R)-2- exo -(2-Chlorophenyl)-2,3,4,5-tetrahydro-1H -1,4-epoxy-1-benzazepine, C16H14ClNO, (IV), crystallizes as a single enantiomer and the molecules are linked into a three-dimensional framework structure by a combination of one C,H...O hydrogen bond and three C,H...,(arene) hydrogen bonds. [source] Four 7-aryl-substituted pyrido[2,3- d]pyrimidine-2,4(1H,3H)-diones: similar molecular structures but different crystal structuresACTA CRYSTALLOGRAPHICA SECTION C, Issue 4 2009Jorge Trilleras Molecules of 1,3-dimethyl-7-(4-methylphenyl)pyrido[2,3- d]pyrimidine-2,4(1H,3H)-dione, C16H15N3O2, (I), are linked by paired C,H...O hydrogen bonds to form centrosymmetric R22(10) dimers, which are linked into chains by a single ,,, stacking interaction. A single C,H...O hydrogen bond links the molecules of 7-(biphenyl-4-yl)-1,3-dimethylpyrido[2,3- d]pyrimidine-2,4(1H,3H)-dione, C21H17N3O2, (II), into C(10) chains, which are weakly linked into sheets by a ,,, stacking interaction. In 7-(4-fluorophenyl)-3-methylpyrido[2,3- d]pyrimidine-2,4(1H,3H)-dione, C14H10FN3O2, (III), an N,H...O hydrogen bond links the molecules into C(6) chains, which are linked into sheets by a ,,, stacking interaction. The molecules of 7-(4-methoxyphenyl)-3-methylpyrido[2,3- d]pyrimidine-2,4(1H,3H)-dione, C15H13N3O3, (IV), are also linked into C(6) chains by an N,H...O hydrogen bond, but here the chains are linked into sheets by a combination of two independent C,H...,(arene) hydrogen bonds. [source] 4-Hydroxy-2-vinyl-2,3,4,5-tetrahydro-1-benzazepine and its 7-fluoro and 7-chloro analogues are isomorphous but not strictly isostructuralACTA CRYSTALLOGRAPHICA SECTION C, Issue 3 2009Lina M. Acosta 4-Hydroxy-2-vinyl-2,3,4,5-tetrahydro-1-benzazepine, C12H15NO, (I), and its 7-fluoro and 7-chloro analogues, namely 7-fluoro-4-hydroxy-2-vinyl-2,3,4,5-tetrahydro-1-benzazepine, C12H14FNO, (II), and 7-chloro-4-hydroxy-2-vinyl-2,3,4,5-tetrahydro-1-benzazepine, C12H14ClNO, (III), are isomorphous, but with variations in the unit-cell dimensions which preclude in compound (III) one of the weaker intermolecular interactions found in compounds (I) and (II). Thus the compounds are not strictly isostructural in terms of the structurally significant intermolecular interactions, although the corresponding atomic coordinates are very similar. The azepine rings adopt chair conformations. The molecules are linked by a combination of N,H...O and O,H...N hydrogen bonds into chains of edge-fused R33(10) rings, which in compounds (I) and (II) are further linked into sheets by a single C,H...,(arene) hydrogen bond. The significance of this study lies in its observation of isomorphism in compounds (I),(III), and its observation of a sufficient variation in one of the cell dimensions effectively to alter the range of significant hydrogen bonds present in the crystal structures. [source] Hydrogen-bonded sheets in benzylmethylammonium hydrogen maleateACTA CRYSTALLOGRAPHICA SECTION C, Issue 10 2007Lynay Santacruz In the title compound, C8H12N+·C4H3O4,, there is a short and almost linear but asymmetric O,H...O hydrogen bond in the anion. The ions are linked into C22(6) chains by two short and nearly linear N,H...O hydrogen bonds and the chains are further weakly linked into sheets by a single C,H...O hydrogen bond. [source] Cyclic and acyclic products from the reactions between methyl 3-oxobutanoate and arylhydrazinesACTA CRYSTALLOGRAPHICA SECTION C, Issue 8 2007James L. Wardell The molecules of methyl 3-(2-nitrophenylhydrazono)butanoate, C11H13N3O4, (I), and methyl 3-(2,4-dinitrophenylhydrazono)butanoate, C11H12N4O6, (II), both prepared from methyl 3-oxobutanoate and the corresponding nitrophenylhydrazine, exhibit polarized molecular electronic structures; in each of (I) and (II), the molecules are linked into chains by a single C,H...O hydrogen bond. The molecules of 5-hydroxy-3-methyl-1-phenyl-1H -pyrazole, C10H10N2O, (III), prepared by the reaction of methyl 3-oxobutanoate and phenylhydrazine, are linked into chains by a single O,H...N hydrogen bond. The reaction between methyl 3-oxobutanoate and 3-nitrophenylhydrazine yields 5-hydroxy-3-methyl-1-(3-nitrophenyl)-1H -pyrazole, (IV), which when crystallized from acetone yields 4-isopropylidene-3-methyl-1-(3-nitrophenyl)-1H -pyrazol-5(4H)-one, C13H13N3O3, (V). [source] | ||||||||||