The title compound, C10H10N4O3, was synthesized by the esterification of hy-droxy-phenyl tetra-zole. There is an intra-molecular O-H⋯N hydrogen bond present involving the hy-droxy group and the tetra-zole ring. The tetra-zole ring is inclined to the phenol ring by 2.85 (13)°, while the methyl acetate group is almost normal to the tetra-zole ring, making a dihedral angle of 82.61 (14)°. In the c...

The crystal structure of the title compound, C(15)H(14)N(4), contains chains of coplanar tetra-zole rings with the chain direction along b. These are formed through weak hydrogen bonds, donated by the tetra-zole H atoms and by one of the H atoms of the methyl-ene group, and accepted by two neighbouring N atoms of the adjacent tetra-zole ring. The chains are connected to each other in a staircas...

The four-base loops that cap many double-helical structures in rRNA (the so-called "tetra-loops") exhibit highly invariant to highly variable sequences depending upon their location in the molecule. However, in the vast majority of these cases the sequence of a tetra-loop is independent of its location and conforms to one of three general motifs, GNRA, UNCG, and (more rarely) CUUG. For the most...

The title compound, (C21H20OP)(C19H15N4)[CuCl4], was obtained by reacting CuCl2·2H2O with a mixture of one equivalent of acetonyltri-phenyl-phospho-nium chloride and one equivalent of 2,3,5-tri-phenyl-tetra-zolium chloride in aceto-nitrile. In the structure, the Cu centre in the dianion is bonded to four chloride ligands and adopts a distorted tetra-hedral geometry. The phospho-nium cation like...

Trichloroethylene (TRI) and tetrachloroethylene (TETRA) are solvents that have been widely used in a variety of industries, and both are widespread environmental contaminants. In order to provide a better basis for understanding their toxicokinetics at environmental exposures, seven human volunteers were exposed by inhalation to 1 ppm of TRI or TETRA for 6 h, with biological samples collected f...

The crystal structures of Flavobacterium heparinium chondroitin AC lyase (chondroitinase AC; EC 4.2.2.5) bound to dermatan sulfate hexasaccharide (DS(hexa)), tetrasaccharide (DS(tetra)), and hyaluronic acid tetrasaccharide (HA(tetra)) have been refined at 2.0, 2.0, and 2.1 A resolution, respectively. The structure of the Tyr234Phe mutant of AC lyase bound to a chondroitin sulfate tetrasaccharid...

In the title compound, C22H24N2O6, the indole ring has a twist conformation and the tetra-hydro-2H-pyran-2-one ring a half-chair conformation. One of the pyrrolidine rings adopts an envelope conformation on the N atom, while the other has a twist conformation; the 'butterfly' angle between their mean planes is 62.98 (11)°. The dioxolane ring adopts a twist conformation and the tetra-hydro-furan...

DNA CpG methylation has been associated with chromatin compaction and gene silencing. Whether DNA methylation directly contributes to chromatin compaction remains an open question. In this study, we used fluorescence fluctuation spectroscopy (FFS) to evaluate the compaction and aggregation of tetra-nucleosomes containing specific CpG patterns and methylation levels. The compactness of both unme...

The title compound, C33H35N3O5, is the product of the multicomponent condensation of 1-benzyl-4-eth-oxy-carbonyl-piperidin-3-one with 1,5-bis-(2-formyl-phen-oxy)-3-oxapentane and ammonium acetate. The mol-ecule comprises a penta-cyclic system containing the aza-14-crown-4-ether macrocycle, tetra-hydro-pyrimidine, tetra-hydro-pyridine and two benzene rings. The aza-14-crown-4-ether ring adopts a...

The crystal structure of the title compound, C(15)H(11)FN(6)S, forms a three-dimensional network stabilized by π-π inter-actions between the imidazole core and the tetra-zole ring of the tetra-zolopyridine-unit; the centroid-centroid distance is 3.627 (1) Å. The crystal structure also displays bifurcated N-H⋯(N,N) hydrogen bonding and C-H⋯F inter-actions. The former involve the NH H atom of the...