Methyl 4-[N-(5-bromo-pyrimidin-2-yl)carbamo-yl]benzoate.

In the title compound, C(13)H(10)BrN(3)O(3), the pyrimidine and benzene rings are twisted with an inter-planar angle of 58.4 (1)°. The secondary amide group adopts a cis conformation with an H-N-C-O torsion angle of 14.8 (1)°. In the crystal, mol-ecules are connected into inversion dimers via pairs of N-H⋯N hydrogen bonds, generating an R(2) (2)(8) motif. The dimers are further connected through a C-Br⋯O inter-action [3.136 (1) Šand 169.31 (1)°] into a chain along [110]. Weak C-H⋯N hydrogen bonds between the methyl benzoate groups and pyrimidine rings are also observed in the crystal structure.

Methyl 4-[(5-chloro-pyrimidin-2-yl)carbamo-yl]benzoate.

Mol-ecules of the title compound, C(13)H(10)ClN(3)O(3), form centrosymmetric dimers via inter-molecular N-H⋯N hydrogen bonds generating an R(2) (2)(8) motif. The dimers are further connected through an O⋯Cl-C halogen bond [O⋯Cl = 3.233 (1) Šand O⋯Cl-C = 167.33 (1)°] into a chain along [110]. The secondary amide group adopts a cis conformation. Weak C-H⋯N hydrogen bonds among the methyl benzoate and pyrimidyl rings are also observed in the crystal structure.

Methyl 4-[(pyrimidin-2-yl)carbamo-yl]benzoate.

Mol-ecules of the title compound, C(13)H(11)N(3)O(3), are connected into centrosymmetric dimers via inter-molecular N-H⋯N hydrogen bonds, generating an R(2) (2)(8) motif. The pyrimidine and the phenyl rings are twisted with respect to each other by an inter-planar angle of 61.3 (1)°.

5-Iodo-pyrimidin-2-amine.

The mol-ecule of the title compound, C(4)H(4)IN(3), has crystallographic mirror plane symmetry. In the crystal, the mol-ecules are connected through N-H⋯N hydrogen bonds into polymeric tapes extended along the a axis, which are typical of 2-amino-pyrimidines. Each mol-ecule acts as a double donor and a double acceptor in the hydrogen bonding.

6,6'-Dimethyl-2,2'-[oxalylbis(aza-nedi-yl)]dipyridinium dichloride acetonitrile solvate.

In the crystal structure of the title compound, C(14)H(16)N(4)O(2) (2+)·2Cl(-)·CH(3)CN, weak inter-molecular N-H⋯Cl hydrogen bonds are found between the H atoms bound to the pyridine and amine N atoms and the chloride anions. The asymmetric unit consits of one half cationic mol-ecule which is located on a centre of inversion, one chloride anion in a general position and one half acetonitrile mol-ecule which is located on a twofold axis. Because of symmetry, the C-H hydrogens of the acetonitrile solvent mol-ecule are disordered over two orientations.

N,N'-Bis(6-methyl-2-pyrid-yl)oxamide.

In the crystal structure of the title compound, C(14)H(14)N(4)O(2), the mol-ecules are almost planar (mean deviation 0.028 Å) and a weak intra-molecular N-H⋯O hydrogen bond between the H atom bound to an oxamide N atom and a carbonyl O atom is found. The asymmetric unit consits of one half-mol-ecule which is located on a centre of inversion.

N-(6-Methyl-2-pyrid-yl)formamide.

The mol-ecule of the title compound, C(7)H(8)N(2)O, is essentially planar with a maximum deviation of 0.0439 (1) Šfrom the best plane. In the crystal, N-H⋯O hydrogen bonds between self-complementary amide groups join mol-ecules into centrosymmetric dimers.

N,N-Bis(2-pyrid-yl)formamidine.

In the crystal structure of the title compound, C(11)H(10)N(4), the dihedral angle between the two pyridyl rings is 36.1 (1)°. The mol-ecules are connected via two strong N-H⋯N and two weak C-H⋯N hydrogen bonds into dimers, which are located on centers of inversion. This compound adopts the s-trans-anti-s-cis conformation in the solid state.

2-{5-[N-(2-Pyridyl)carbamo-yl]pentan-amido}pyridinium hexa-fluoro-phosphate.

In the crystal structure of the title compound, C(16)H(19)N(4)O(2) (+)·PF(6) (-), the cations and anions are situated on centres of inversion. Thus, the N-H H atom is disordered over both N atoms due to symmetry. In the crystal, mol-ecules are connected via N-H⋯F and N-H⋯O hydrogen bonds. The cation adopts the ⋯AAA⋯ trans conformation in the solid state.

N,N-Bis(6-methyl-2-pyrid-yl)formamidine.

In the crystal structure of the title mol-ecule, C(13)H(14)N(4), the two pyridyl rings are not coplanar but twisted about the C-N bond with an inter-planar angle of 71.1 (1)°. In the crystal, the mol-ecules form dimers, situated on crystallographic centres of inversion, which are connected via a pair of N-H⋯N hydrogen bonds. C-H⋯π-electron ring inter-actions are also present in the crystal structure. The title mol-ecule adopts an s-cis-anti-s-cis conformation in the solid state.

Impact of serum levels and gene polymorphism of cytokines on chronic hepatitis C infection.

The factors leading to clearance or persistent infection of hepatitis C virus (HCV) were not well defined, and the importance of the host immune response has been highlighted. Therefore, the impact of the serum concentration and genetic polymorphism of several cytokines on the outcome of HCV infection warrant additional study. Enzyme-linked immunosorbent assay was employed to measure serum tumor necrosis factor-alpha (TNF-alpha), interleukin (IL)-4, and IL-10 concentrations on 72 hepatitis C patients and 180 controls. Furthermore, the association between single nucleotide polymorphism (SNP) of genes of these cytokines and hepatitis C infection was evaluated by polymerase chain reaction- restriction fragment length polymorphism and statistical analysis. These analyzed SNPs of cytokines included TNF-alpha G238A, TNF-alpha G308A, IL-4 C589T, IL-10 A1082G, IL-10 T819C, and IL-10 A592C. Serum levels of TNF-mu alpha, IL-4, and IL-10 were significantly higher in hepatitis C patients than that of controls (P < 0.001). Furthermore, the distribution of TNF-alpha G308A genotypes and alleles, but not others, was statistically different between patients and controls (P < 0.05). These data suggested the distribution of polymorphism at TNF-alpha G308A may be different between normal subjects and patients with chronic infection of hepatitis C.