A bacterial strain 5HP capable of degrading and utilizing 5-hydroxypicolinic acid as the sole source of carbon and energy was isolated from soil. In addition, the isolate 5HP could also utilize 3-hydroxypyridine and 3-cyanopyridine as well as nicotinic, benzoic and p-hydroxybenzoic acids for growth in the basic salt media. On the basis of 16S rRNA gene sequence analysis, the isolate 5HP was shown to belong to the genus Pusillimonas. Both the bioconversion analysis using resting cells and the enzymatic assay showed that the degradation of 5-hydroxypicolinic acid, 3-hydroxypyridine and nicotinic acid was inducible and proceeded via formation of the same metabolite, 2,5-dihydroxypyridine. The activity of a novel enzyme, 5-hydroxypicolinate 2-monooxygenase, was detected in the cell-free extracts prepared from 5-hydroxypicolinate-grown cells. The enzyme was partially purified and was shown to catalyze the oxidative decarboxylation of 5-hydroxypicolinate to 2,5-dihydroxypyridine. The activity of 5-hydroxypicolinate 2-monooxygenase was dependent on O2, NADH and FAD.

ABSTRACT:The novel 4H-thiazolo[3,2-d]

[2,3-g] or [2,3-h]quinoline derivatives were prepared from 7-(or 8, or 9)amino-1,5-benzodiazepin-2-ones by the Doebner-von Miller quinoline synthesis. The structure of the cyclized products depends on the position of the primary amino group and on the substituents of the diazepine ring of the starting compounds. The regiochemical outcome of the reaction was estimated by calculating average local ionization energies on the molecular surface at the Density Functional Theory (DFT) level of theory.

A simple and efficient general approach to various tetracyclic 6,7-dihydroquinazolino[3,2-a] [1,5]benzodiazepin-13(5H)-ones has been demonstrated by reductive N-heterocyclization of 5-alkyl-or benzoyl-1-(2-nitrobenzoyl)-1,3,4,5-tetrahydro-2H-1,5-benzodiazepin-2-ones. These 2-nitrobenzoylamides were obtained by acylation of the starting 5-alkyl-or benzoyl-1,5-benzodiazepin-2-ones with 2-nitrobenzoyl chloride. A theoretical understanding of the features of the reductive N-heterocyclization reaction was provided by means of quantum chemical reactivity descriptors calculations.

No abstract