Ba5Cl4(H2O)8(VPO5)8: a novel three-dimensional framework solid.

The novel hydrothermally synthesized title compound, pentabarium tetrachloride octahydrate octakis(oxovanadium phosphate), Ba(5)Cl(4)(H(2)O)(8)(VPO(5))(8), crystallizes in the orthorhombic space group Cmca with a unit cell containing four formula units. Two Ba(2+) cations, two Cl(-) anions and the O atoms of four water molecules are situated on the (100) mirror plane, while the third independent Ba(2+) cation is on the intersection of the (100) plane and the twofold axis parallel to a. Two phosphate P atoms are on twofold axes, while the remaining independent P atom and both V atoms are in general positions. The structure is characterized by two kinds of layers, namely anionic oxovanadium phosphate (VPO(5)), composed of corner-sharing VO(5) square pyramids and PO(4) tetrahedra, and cationic barium chloride hydrate clusters, Ba(5)Cl(4)(H(2)O)(8), composed of three Ba(2+) cations linked by bridging chloride anions. The layers are connected by Ba-O bonds to generate a three-dimensional structure.

Aqua-[N-phenyl-2-(quinolin-8-yl-oxy)acetamide]dinitratozinc(II).

In the title complex, [Zn(NO(3))(2)(C(17)H(14)N(2)O(2))(H(2)O)], the six-coordinated Zn atom is in a distorted octa-hedral geometry, the donor centers being two O atoms and one N atom from the tridentate organic ligand, a water O atom and two O atoms from two monodentate nitrate ions. In the crystal, O-H⋯O hydrogen bonds between the coordinated water mol-ecules and nitrate O atoms and N-H⋯O hydrogen bonds between the main ligand and nitrate O atoms consolidate the three-dimensional network.

Ethyl 3,4-dimethyl-5-[(E)-(phenyl-imino)-meth-yl]-1H-pyrrole-2-carboxyl-ate.

In the title compound, C(16)H(18)N(2)O(2), the mol-ecule adopts an E conformation about the C=N double bond. The dihedral angle between the pyrrole and phenyl rings is 41.55 (8)°. In the crystal structure, pairs of inter-molecular N-H⋯O hydrogen bonds link the mol-ecules into centrosymmetric dimers. In the dimer, the two pyrrole rings are almost coplanar and the two phenyl rings are parallel to each other.

Ethyl 3,4-dimethyl-1H-pyrrole-2-carboxyl-ate.

The non-H atoms of the title compound, C(9)H(13)NO(2), are almost coplanar (r.m.s. deviation = 0.0358 Å). Weak inter-molecular N-H⋯O hydrogen bonds link the mol-ecules into zigzag chains along the b axis with graph-set motif C(5). The chains are further linked into a three-dimensional network by C-H⋯O hydrogen bonds and C-H⋯π inter-actions.

The G314S KCNQ1 mutation exerts a dominant-negative effect on expression of KCNQ1 channels in oocytes.

Congenital long QT syndrome is a cardiac disorder characterized by prolongation of QT interval on the surface ECG associated with syncopal attacks and a high risk of sudden death. Mutations in the voltage-gated potassium channel subunit KCNQ1 induce the most common form of long QT syndrome (LQT1). We previously identified a hot spot mutation G314S located within the pore region of the KCNQ1 ion channel in a Chinese family with long QT syndrome. In the present study, we used oocyte expression of the KCNQ1 polypeptide to study the effects of the G314S mutation on channel properties. The results of electrophysiological studies indicate G314S, co-expressed with KCNE1 was unable to assemble to form active channel. G314S, co-expressed with WT KCNQ1 and KCNE1, suppressed I(ks) currents in a dominant-negative manner, which is consistent with long QT syndrome in the members of the Chinese family carrying G314S KCNQ1 mutation.

Congenital long QT syndrome caused by the F275S KCNQ1 mutation: mechanism of impaired channel function.

Congenital long QT syndrome is characterized by a prolongation of ventricular repolarization and recurrent episodes of life-threatening ventricular tachyarrhythmias, often leading to sudden death. We previously identified a missense mutation F275S located within the S5 transmembrane domain of the KCNQ1 ion channel in a Chinese family with long QT syndrome. We used oocyte expression of the KCNQ1 polypeptide to study the effects of the F275S mutation on channel properties. Expression of the F275 mutant, or co-expression with the wild-type S275 polypeptide, significantly decreased channel current amplitudes. Moreover, the F275S substitution decreased the rates of channel activation and deactivation. In transfected HEK293 cells fluorescence microscopy revealed that the F275S mutation perturbed the subcelluar localization of the ion channel. These results indicate that the F275S KCNQ1 mutation leads to impaired polypeptide trafficking that in turn leads to reduction of channel ion currents and altered gating kinetics.

Ethyl 5-formyl-3,4-dimethyl-1H-pyrrole-2-carboxyl-ate.

The mol-ecule of the title compound, C(10)H(13)NO(3), is approximately planar (maximum deviation 0.1424 Å). In the crystal, mol-ecules are linked into inversion dimers by pairs of N-H⋯O hydrogen bonds, and the dimeric units are linked by non-classical C-H⋯O hydrogen bonds, forming a layered structure.

Ethyl 5-[(2,3-dimethyl-5-oxo-1-phenyl-2,5-dihydro-1H-pyrazol-4-yl)imino-meth-yl]-3,4-dimethyl-1H-pyrrole-2-carboxyl-ate.

In the title compound, C(21)H(24)N(4)O(3), the mol-ecule has an E configuration about the imine C=N double bond. Inter-molecular N-H⋯O hydrogen bonds assemble mol-ecules into centrosymmetric dimers.