3,4-Dihydroxyphenylalanine (Dopa) decarboxylase is a stereospecific pyridoxal 5'-phosphate (PLP)-dependent alpha-decarboxylase that converts L-aromatic amino acids into their corresponding amines. We now report that reaction of the enzyme with D-5-hydroxytryptophan or D-Dopa results in a time-dependent inactivation and conversion of the PLP coenzyme to pyridoxamine 5'-phosphate and PLP-D-amino ...

A new bimetallic nanocomposite of chitosan was prepared. Pd and Co nanoparticles were deposited on chitosan to produce a new heterogeneous recyclable catalyst for use in the bimetallic catalytic reduction reaction. The catalyst was characterized with common analysis methods for nanocomposites including Energy Dispersive X-Ray Spectroscopy, X-Ray Diffraction pattern, Thermal Gravimetric Analysis...

Both excimers and exciplexes have attracted the attention of molecular physicists and photochemists over the last decade. Owing to the use of laser photolysis, measurements of short-lived photocurrents, and pulse spectrofluorimetry, it became possible to satisfactorily explain photophysical processes occurring in molecular systems [1]. Excimers and exciplexes provide important steps of many pho...

A recent outbreak of occupational bladder cancer in a Buffalo, New York, factory confirmed the carcinogenicity of ortho-toluidine, an aromatic amine that had first been implicated in human bladder cancer cases decades earlier. Events leading to this outbreak replicated the history of numerous earlier bladder cancer outbreaks among workers exposed to beta-naphthylamine and benzidine, two other a...

Reactions of N-isocyaniminotriphenylphosphorane with cyclopentanone have been studied in the presence of aromatic carboxylic acids and primary amines, proceeds smoothly at room temperature under neutral conditions to afford sterically congested 1,3,4-oxadiazole derivatives by an intramolecular Aza-Wittig cyclization in CH2Cl2 in excellent yields. The structures of the products were deduced from...

Both long chain alkyl thiols and alkyl amines behave as size focusing agents for gold nanoparticles, a process that is under thermodynamic control. However, amines do not oxidize surface gold atoms while thiols do oxidize surface gold to gold(I) with evolution of hydrogen gas. Therefore, alkyl amines participate in digestive ripening by a different mechanism. The efficiency of alkyl amines for ...

BACKGROUND Interleukin-8 (IL-8) functions as a major chemoattractant and plays pivotal roles in the initiation and development of chronic obstructive pulmonary disease (COPD), and tobacco smoke is a most risk factor contributing to the development of COPD. Hence, we have screened some of the tobacco smoke-derived chemical compounds that potentially induce the production of IL-8 in human bronchi...

The synthesis of a new class lawsone enaminone derivatives by using lawsone, triethyl orthoformate and aromatic amines in the presence guanidinium chloride under solvent-free conditions has been developed.

A copper(I) catalyzed procedure for carbon-nitrogen bond formation utilizing aryl halides and either amines, including amino acids and diphenylamine, or aliphatic and aromatic amides is described.