Previous studies have shown that the reaction of p-nitrophenyl acetate with imidazole and amino groups may be studied under pseudo-first order conditions (2, 3). The reaction with an imidazole derivative is catalytic, the imidazole being regenerated by the spontaneous decomposition of the acylimidazole. The reaction with an amine yields a stable acylamino derivative but is most readily studied ...

The preparation of two types of imidazole derivatives bearing a hydrazide group was achieved by treatment of the corresponding esters with NH2NH2·H2O in MeOH at room temperature. In the case of 4-(ethoxycarbonyl)-1H-imidazole 3-oxides 3, hydrazides of type 1 were formed with retention of the N-oxide structure (Scheme 1). Interestingly, due to a strong H-bonding, no deoxygenation of the N-O func...

The asymmetric unit of the title compound, [Ag(3)Yb(C(5)HN(2)O(4))(2)(H(2)O)(2)](n), contains three Ag(I) ions, one Yb(III) ion, two imidazole-4,5-dicarboxyl-ate ligands and two coordinating water mol-ecules. The Yb(III) atom is eight-coordinated, in a bicapped trigonal prismatic coordination geometry, by six O atoms from three imidazole-4,5-dicarboxyl-ate ligands and two coordinating water mol...

The CO-specific heme-based sensor CooA regulates the ability of Rhodospirillum rubrum to grow on CO as an energy source. Only CO triggers the conformational change of CooA essential for the protein to function as a transcriptional activator. A structurally informed mutagenesis, followed by an in vivo screening method, allowed the isolation of a series of novel CooA variants that show very subst...

The asymmetric unit of the title compound, {[CoGd(2)(C(5)H(2)N(2)O(4))(2)(SO(4))(2)(H(2)O)(4)]·H(2)O}(n), contains one Co(II) ion, two Gd(III) ions, two imidazole-4,5-dicarboxyl-ate ligands, two SO(4) (2-) anions, four coordinated water mol-ecules and one uncoordinated water mol-ecule. The Co(II) ion is six-coordinated by two O atoms from two coordinated water mol-ecules, as well as two O atoms...

BACKGROUND The paper examines Co(II)-amino acid-imidazole systems (where amino acid = L-α-amino acid: alanine, asparagine, histidine) which, when in aqueous solutions, activate and reversibly take up dioxygen, while maintaining the structural scheme of the heme group (imidazole as axial ligand and O2 uptake at the sixth, trans position) thus imitating natural respiratory pigments such as myoglo...

In the title compound, C(12)H(14)ClN(3)O(3), the imidazole ring adopts a half-chair conformation. The dihedral angle between the pyridine and imidazole rings is 70.0 (1)°. In the crystal, the molecules are linked by C-H⋯O inter-actions, forming chains parallel to the c axis.

In the title compound, C(10)H(8)N(6), the tetra-zole and benzene rings are close to being coplanar [dihedral angle = 9.90 (16)°], but the imidazole ring is rotated 37.18 (09)° out of the benzene plane. In the crystal, mol-ecules are connected through tetra-zole-imidazole N-H⋯N hydrogen bonds, giving rise to zigzag chains, which extend along [010].

Imidazole was tethered to the C5 position of thymine in an ATP-binding DNA aptamer with two types of linkers, and the affinities of each aptamer for ATP and AMP were determined by surface plasmon resonance measurements. The imidazole-tethered aptamers exhibited higher affinity for ATP, almost independently of the linker structure or the modification site.