Sensory rhodopsin I (SRI) in Halobacterium salinarum acts as a receptor for single-quantum attractant and two-quantum repellent phototaxis, transmitting light stimuli via its bound transducer HtrI. Signal-inverting mutations in the SRI-HtrI complex reverse the single-quantum response from attractant to repellent. Fast intramolecular charge movements reported here reveal that the unphotolyzed SR...

3-Formyl-4-hydroxyphenylguanidine hydrochloride and its Schiff base copper(II), zinc(II), and iron(III) chelates were synthesized and their inhibitory activity against bovine beta-trypsin were determined. Syntheses of Schiff base metal chelates were carried out from 3-formyl-4-hydroxyphenylguanidine, various L-amino acids, and divalent metal acetate. Their structures were established on the bas...

New coordination complexes of Co, Ni and Zn with Schiff base N’-((2-thioxo-1,2-dihydroquinoline-3yl)methylene) pyridine-4-carbohydrazide have been synthesized and characterized by several techniques using elemental analysis (C, H, N), IR spectra and 1HNMR spectra. The new Schiff base has been synthesized by the reaction of pyridine-4-carbohydrazide and 2-thioxo-1,2dihydroquinoline-3-carbaldehyd...

The application of an external electric field to dry films of Asp-85-->Asn mutant bacteriorhodopsin causes deprotonation of the Schiff base, resulting in a shift of the optical absorption maximum from 600 nm to 400 nm. This is in marked contrast to the case of wild-type bacteriorhodopsin films, in which electric fields produce a red-shifted product whose optical properties are similar to those ...

The complexes of Fe(II), Mn(II) and Ni(II) with a combination of a Schiff base, nitrogen-donor ligand or macrocyclic ligand and trithiocyanuric acid (ttcH3) were prepared and characterized by elemental analysis and spectroscopies. Crystal and molecular structures of the iron complex of composition [Fe(L1)](ttcH2)(ClO4)·EtOH·H2O (1), where L1 is Schiff base derived from tris(2-aminoethyl)amine a...

In an effort to develop new antibacterial drugs, some novel bisindolylmethane derivatives containing Schiff base moieties were prepared and screened for their antibacterial activity. The synthesis of the bisindolylmethane Schiff base derivatives 3-26 was carried out in three steps. First, the nitro group of 3,3'-((4-nitrophenyl)-methylene)bis(1H-indole) (1) was reduced to give the amino substit...

The title compound, C(28)H(20)N(2)O(2)·2H(2)O, comprises a Schiff base mol-ecule with an imposed inversion centre in the middle of p-phenyl-enediamine unit and water mol-ecules of crystallization. In the structure, the Schiff base mol-ecule is present as the keto-amino tautomer with a strong intra-molecular N-H⋯O hydrogen bond. The Schiff base mol-ecules and water mol-ecules of crystallization ...

A novel Schiff base was synthesized by the reaction of piperonal and anthranilic acid, which was further utilized in the synthesis of five novel complexes by reaction with different metal salts ultrasonically. Time for the reaction was greatly reduced through ultrasound irradiations and the yield of reactions was also high as compared to the conventional methods using reflux conditions. The...

The synthesis, characterization and biological activity of Cu(II) and Ni(II) complexes derived from tridentate Schiff base ligand 3-hydroxy-4-(pyridine-2-yl methylene amino) benzoic acid (HL) was obtained by the condensation of 2-Pyridine carboxaldehyde with 4-amino 3-hydroxy benzoic acid has been described. The complexes were characterized based on elemental analyses, molar conductivity measur...

The Schiff base molecule of the title compound, C(14)H(12)N(4)O(6)·C(5)H(5)N, was obtained from the condensation reaction of 2-hy-droxy-3-meth-oxy-benzaldehyde and 2,4-dinitro-phenyl-hydrazine. The C=N bond of the Schiff base has a trans arrangement and the dihedral angle between the two benzene rings is 3.49 (10)°. An intra-molecular N-H⋯O hydrogen bond generates an S(6) ring. In the crystal, ...