Little is known about the molecular mechanism of Schiff base hydrolysis in rhodopsin. We report here our investigation into this process focusing on the role of amino acids involved in a hydrogen bond network around the retinal Schiff base. We find conservative mutations in this network (T94I, E113Q, S186A, E181Q, Y192F, and Y268F) increase the activation energy (E(a)) and abolish the concave A...

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...

the vo(iv) complexes of tridentate ono schiff base ligands derived from 2- aminobenzoicacid and salicylaldehyde derivatives were synthesized and characterized by ir, uv–vis and elemental analysis. electrochemical properties of the vanadyl complexes were investigated by cyclic voltammetry. a good linear correlation was observed between the oxidation potentials and the electron-withdrawing charac...

some new symmetrical tetraaza schiff base ligands containing 2-quinolinecarboxaldehyde moiety formed from condensation reaction of 2-quinolinecarboxaldehyde and o-phenylenediamine derivatives, such as n, nˊ-bis(2-quinolylmethylidene)-4-methoxy-1, 2-phenylenediimine (l1), n, nˊ-bis(2-quinolylmethylidene)-4-methy-1, 2-phenylenediimine (l2), n, nˊ-bis(2-quinolylmethylidene)-4-chloro-1, 2-phenylene...

addition of potassium cyanide to a mixture of schiff base and lithium perchlorate afforded a-aminonitriles in high yields. addition of potassium cyanide to a methanolic solution of schiff base and phosphoric acid afforded a-aminonitriles. when the reaction mixture was refluxed it gave a-amino acids in high yields.

the crystal structure of the title schiff base complex is obtained by single-crystal x-ray diffraction data.the solid state structure determination reveals that the coordination geometry around the copper(ii) center istetrahedrally distorted square-planar. the crystal packing shows one dimensional infinite chains which arisesfrom the intermolecular interaction and stabilize the crystal packing.

the vo(iv) complexes of tridentate ono schiff base ligands derived from 2- aminobenzoicacid and salicylaldehyde derivatives were synthesized and characterized by ir, uv–vis and elemental analysis. electrochemical properties of the vanadyl complexes were investigated by cyclic voltammetry. a good linear correlation was observed between the oxidation potentials and the electron-withdrawing charac...

A family of novel chiral "calixsalen" Schiff base macrocycles R,R-H(3)L4, R,R-H(3)L5, containing three chiral diamino moieties were synthesized by an efficient self-assembly and characterized by (1)H and (13)C NMR, mass spectrometry, and X-ray diffraction. The systematic synthesis, structure, and coordination properties of the [2 + 2] and [3 + 3] Robson-type Schiff base macrocyclic mono-, di-, ...