(E)-N-(1H-Pyrrol-2-ylmethylidene)-2-{[(E)-(1H-pyrrol-2-ylmethylidene)amino]methyl}aniline

The title salophene-type compound, C17H16N4, crystallizes with two independent molecules (AandB) in the asymmetric unit. Both (pyrrol-2-yl)methanimine groups have an extended conformation, and anEconformation about the C=N bonds. The pyrrole rings are inclined to the aminobenzylamine ring by 43.7 (3) and 78.9 (2)° in moleculeA, and by 46.8 (3) and 79.3 (3)° in moleculeB, while the pyrrole rings are inclined to one another by 58.9 (3) and 59.9 (3)° in moleculesAandB, respectively. In the crystal, molecules are linked by N—H...N hydrogen bonds, forming chains propagating along thea-axis direction. The chains are linked by C—H...π interactions, forming a three-dimensional supramolecular structure.

Recombinant human antibody fragment against tetanus toxoid produced by phage display

Phage display technology is a powerful in vitro method for the identification of specific monoclonal antibodies (antibody fragments) to an antigenic target and allows the rapid generation and selection of high affinity, fully human antibodies directed toward any disease target appropriate for antibody therapy. In the present study, we exploited the phage display technology for the selection of an antigen binding fragment (Fabs) toward tetanus toxoid using human naïve phage antibody library constructed from peripheral blood lymphocytes of naïve human donors. The phages displaying Fab were subjected to three rounds of bio-panning with tetanus toxoid as antigen on a solid phase. The high affinity antibody fragments were expressed in HB2151 strain of Escherichia coli and purified by immobilized metal affinity chromatography. The binding activity and specificity of the antibody fragment was established by its reactivity toward tetanus toxoid and non-reactivity toward other related toxins as determined by enzyme-linked immunosorbent assay and immunoblot analysis. The selected Fab fragment forming the antigen-binding complexes with the toxoid in flocculation assay indicates that the Fab may have a potential neutralizing ability toward antigen.

3-Isopropyl-1-{2-[(1-methyl-1H-tetra-zol-5-yl)sulfan-yl]acet-yl}-2,6-di-phenyl-piperidin-4-one hemihydrate

In the title compound, C₂₄H₂₇N₅O₂S·0.5H₂O, the piperidine ring adopts a distorted boat conformation. The phenyl rings subtend dihedral angles of 69.7 (1) and 88.7 (1)° with the best plane through the piperidine moiety. In the crystal, symmetry-related mol­ecules are linked through a network of C—H⋯O and C—H⋯N inter­actions, the former connecting them into zigzag chains along the c-axis direction and the latter forming an R²₂(4)motif. The dimer formation (C—H⋯N) and the repetition of symmetry-related molecules (C—H⋯O) along the b-axis direction stabilize the packing mode. The water mol­ecule is located on a twofold rotation axis.

1-Di-chloro-acetyl-t-3-isopropyl-r-2,c-6-di-phenyl-piperidin-4-one

In the title compound, C22H23Cl2NO2, the piperidine ring adopts a twist-boat conformation. The phenyl rings substituted at the 2- and 6-positions of the piperidine ring subtend dihedral angles of 60.6 (2) and 84.2 (1)°, respectively, with the mean plane of the piperidine ring. In the crystal, mol-ecules are linked by C-H⋯O inter-actions into zigzag chains running along the c-axis direction.

Ethyl 3-(4-chloro-phen-yl)-2-phenyl-3-(4-phenyl-1,2,3-selena-diazol-5-yl)propano-ate

In the title compound, C25H21ClN2O2Se, the selena-diazole ring is almost planar [maximum deviation = 0.004 (2) Å], and the adjacent benzene ring is twisted by 50.6 (1)° with respect to this ring.

3,5-Dimethyl-1-{2-[(5-methyl-1,3,4-thia-diazol-2-yl)sulfan-yl]acet-yl}-2,6-diphenylpiperidin-4-one

In the title compound, C₂₄H₂₅N₃O₂S₂, the piperidine ring adopts a distorted boat conformation. The phenyl rings subtend angles of 75.6 (1)° and 86.3 (1)° with the mean plane of the piperidine ring. In the crystal, mol­ecules are linked through a network C—H⋯N hydrogen bonds, forming zigzag chains along [100]. The thia­diazol ring methyl group is disordered over two positions with an occupancy ratio of 0.69 (4):0.31 (4).

1-(2,2-Di-chloro-acet-yl)-3-ethyl-2,6-di-phenyl-piperidin-4-one

The asymmetric unit of the title compound, C21H21Cl2NO2, contains two independent mol-ecules that show similar geometrical features. The piperidine ring adopts a distorted boat conformation. The phenyl rings substituted at the 2- and 6-positions of the piperidine ring are oriented at angles of 65.4 (1) [64.7 (2)°] and 89.2 (1)° [86.3 (2)°] with respect to the least-squares plane of the piperidine ring. In the crystal, adjacent mol-ecules are linked by a network of C-H⋯O inter-actions, forming a C(6) chain along the c-axis direction.

2-Amino-6-methylpyridinium 4-hydroxybenzoate

In the title mol­ecular salt, C₆H₉N₂⁺·C₇H₅O₃⁻, the dihedral angle between the benzene ring and the CO₂ group in the anion is 6.1 (2)°. In the crystal, the cation and anion are linked by N—H⋯O and C—H⋯O hydrogen bonds, and the anions are connected by O—H⋯O hydrogen bonds, forming a three-dimensional network.

1-Dichloro-acetyl-t-3,t-5-dimethyl-r-2,c-6-diphenyl-piperidin-4-one

In the title compound, C21H21Cl2NO2, the piperidine ring adopts a distorted boat conformation. The phenyl rings substituted at the 2- and 6-positions of the piperidine ring subtend angles of 87.9 (7) and 70.8 (9)°, respectively, with the best plane through the piperidine ring. In the crystal, mol-ecules are connected by C-H⋯O and C-H⋯Cl inter-actions into layers in the ab plane.

5-[1-(4-Methyl-phen-yl)-2-nitro-but-yl]-4-phenyl-1,2,3-selenadiazole

In the title compound, C19H19N3O2Se, the selenadiazole ring is roughly planar [maximum deviation 0.033 (6) Å]. The attached phenyl ring is twisted away at an angle of 47.5 (1)°. The butyl group is in an extended conformation [C-C-C-C torsion angle = 174.7 (2)°]. In the crystal, C-H⋯O inter-actions form C(10) chains running aling the c-axis direction.

2-Amino-5-chloropyridinium 4-aminobenzoate

In the title molecular salt, C₅H₆ClN₂⁺·C₇H₆NO₂⁻, the cations and anions are connected by cation-to-anion and anion-to-anion N—H⋯O hydrogen bonds into a three-dimensional network. The dihedral angle between the ring and the CO₂ group in the anion is 7.14 (7)°.

Ethyl 3-(4-meth-oxy-phen-yl)-2-phenyl-3-(4-phenyl-1,2,3-selenadiazol-5-yl)propano-ate

In the title compound, C(26)H(24)N(2)O(3)Se, the selenadiazole ring is planar [maximum deviation = 0.002 (2) Å]. The dihedral angle between the selenadiazole ring and the attached phenyl ring is 49.00 (13)°. The crystal structure is stabilized by inter-molecular C-H⋯N and C-H⋯π inter-actions.

5-[1-(4-Meth-oxy-phen-yl)-2-nitro-but-yl]-4-phenyl-1,2,3-selenadiazole

In the title compound, C(19)H(19)N(3)O(3)Se, the selenadiazole ring is essentially planar (r.m.s. deviation = 0.001 Å). The heterocyclic ring makes dihedral angles of 50.2 (2) and 76.3 (9)°, respectively, with the meth-oxy-phenyl and phenyl rings.

5-(2-Nitro-1-phenyl-but-yl)-4-phenyl-1,2,3-selenadiazole

In the title compound, C(18)H(17)N(3)O(2)Se, the selenadiazole ring is planar [maximum deviation = 0.012 (2) Å for the ring C atom bearing the phenyl substituent]. The dihedral angle between the selenadiazole ring and the attached benzene ring is 46.5 (1)°. There is one short intra-molecular C-H⋯Se contact.

Ethyl 2-phenyl-3-(4-phenyl-1,2,3-selenadiazol-5-yl)-3-p-tolyl-propano-ate

In the title compound, C(26)H(24)N(2)O(2)Se, the selenadiazole ring is essentially planar [maximum deviation = 0.004 (3) Å]. The dihedral angle between the selenadiazole ring and the attached benzene ring is 50.17 (1)°. The crystal packing is stabilized by inter-molecular C-H⋯N inter-actions.

Ethyl 2-[N-(2-formylphenyl)benzenesulfonamido]acetate

In the mol­ecule of the title compound, C₁₇H₁₇NO₅S, the two aromatic rings are oriented at an angle of 30.13 (10)°. The ethyl acetate group assumes an extended conformation. Mol­ecules are linked into C(7) chains running along the a axis by inter­molecular C—H⋯O hydrogen bonds, and the chains are crosslinked via C—H⋯π inter­actions, with the sulfonyl-bound phenyl ring acting as an acceptor.

5,7-Bis(1-benzothiophen-2-yl)-2,3-dihydrothieno[3,4-b][1,4]dioxine

In the title compound, C₂₂H₁₄O₂S₃, the dioxane ring is disordered over two sites [site occupancies = 0.623 (3) and 0.377 (3)]; both components adopt half-chair conformations. The two benzothio­phene ring systems are asymmetrically twisted away from the attached thio­phene ring [dihedral angles = 20.57 (3) and 6.70 (3)°] and are oriented at an angle of 26.83 (3)°. No significant hydrogen bonding or π–π inter­actions are observed in the crystal structure.