Hydrolysis of carbohydrates is a major bioreaction in nature, catalyzed by glycoside hydrolases (GHs). We used neutron diffraction and high-resolution x-ray diffraction analyses to investigate the hydrogen bond network in inverting cellulase PcCel45A, which is an endoglucanase belonging to subfamily C of GH family 45, isolated from the basidiomycete Phanerochaete chrysosporium. Examination of t...

Highly potent and selective inhibitors of neuronal nitric oxide synthase (nNOS) possessing a 2-aminopyridine group were recently designed and synthesized in our laboratory and were shown to have significant in vivo efficacy. In this work, analogs of our lead compound possessing 2- and 4-aminothiazole rings in place of the aminopyridine were synthesized. The less basic aminothiazole rings will b...

The Acamprosate is a significant drug for alcohol abuse therapy, which may be an effective treatment for tinnitus, too. The Acamprosate has two possible tautomers, Keto and Enol tautomers. Each of the tautomers involves two important conformers. In this work, employing density functional theory (DFT) and handling the solvent effects with the PCM model, the structural parameters, energetic behav...

The coordination of iron(II) ions by a homoditopic ligand L with two tridentate chelates leads to the tautomerism-driven emergence of complexity, with isomeric tetramers and trimers as the coordination products. The structures of the two dominant [Fe(II) 4 L4 ](8+) complexes were determined by X-ray diffraction, and the distinctness of the products was confirmed by ion-mobility mass spectrometr...

The rates of tautomerization of 2-nitrocyclohexanone (2-NCH) have been measured spectrophotometrically at 25.0 +/- 0.1 degrees C in several organic aprotic solvents and their binary mixtures. In cyclohexane the reaction is effectively catalyzed by bases and inhibited by acids while the so-called "spontaneous reaction" appears essentially due to autocatalysis. Apparent second order rate constant...

Over the years, probing and controlling tautomerization has attracted significant attention because of its fundamental importance in various chemical biological phenomena. So far, light, force, electrons, electric field have been employed to alter characteristics porphyrin phthalocyanine derivatives. Here, we show that engineering photophysics molecules through interaction with vacuum electroma...

Eleven conjugates between dihydroartemisinin (DHA) with thiols containing both ether and thioether bonds were designed, synthesized by a two-step procedure including etherification S-alkylation. Analysis of the NMR spectral data indicated that dimer DHA 6-mercaptopurine 2-mercaptoimidazole was produced yields 31% 62%, respectively. Furthermore, tautomerization thiol 5-methoxy-2-mercaptobenzimid...

This work includes synthesis a series of some new derivatives triazine from reaction between the sulfur amino acid (L-cysteine) and different aldehydes in dry ethanol to obtain thiazolidine ring as diastereo isomers (Cis Trans)- 2- alkylthiazolidine-4- carboxylic acids (1).
 The (1) suffered esterfication presence drops concentrated sulfuric catalyst give esters :
 ethyl alkylthiazoli...

A new 2-amino imidazole derivative, 5-(4-chlorophenyl)-N,1-di-o-tolyl-1H-imidazole-2-amine (3), has been synthesized using a green approach. The reaction was conducted in ChCl (cholinium chloride)/urea eutectic mixture, which is nature-inspired and environmentally friendly medium. proposed mechanism involves the preliminary regioselective alkylation of Nsp2 guanidine (2), followed by an intramo...

An efficient and straightforward four-component synthetic protocol has been developed to synthesize imidazo[1,2-a]pyridines and imidazo[1,2,3-ij][1,8]naphthyridine derivatives incorporating medicinally privileged heterosystems from heterocyclic ketene aminals, aldehydes, diketene, and amines via cascade reactions, including diketene ring-opening, Knoevenagel condensation, aza-ene reaction, imin...