Biosynthesis of niacin from 3-hydroxyanthranilic acid (3-OHAA) in normal and streptozotocin diabetic rats was studied in vivo and in vitro. Streptozotocin (SZ) diabetic rats were found to excrete lesser quantities of 3-OHAA, quinolinic acid, niacin and N1-methylnicotinamide (nmn) in their urines following 3-OHAA administration than corresponding normal rats. In vitro studies indicated that SZ d...

Macrophages exposed to macrophage colony-stimulating factor acquire the capacity to suppress T cell proliferation; this effect is associated with de novo expression of the tryptophan-catabolizing enzyme indoleamine 2,3-dioxygenase (IDO). We have purified IDO and tested its activity in in vitro models of T cell activation. IDO was able to inhibit proliferation of CD4(+) T lymphocytes, CD8(+) T l...

Previously obtained picolinic acid benzylamide is a potent anticonvulsant with low neurotoxicity. In search for new effective anticonvulsants twelve new benzylamides (1-12) were synthesized and preliminary evaluated in the Anticonvulsant Screening Program (ASP) of Antiepileptic Drug Development Program (ADDP) of NIH. Two of them appeared the most promising: 1-cyclopentenecarboxylic acid benzyla...

Hankes and Henderson (I), Gholson et al. (2), and Gholson and Henderson (3) demonstrated that nL-tryptophan-7cu-14C was metabolized by the rat to r4C02 via acetate-1-r4C. Subsequently, Gholson et al. (4) indicated that 3-hydroxyanthranilic acid was an intermediate in the major pathway for the degradation of the benzene ring of tryptophan. Further experiments in viva have provided evidence that ...

Stoichiometry and stability of antitumor ruthenium(II)-η-p-cymene complexes of picolinic acid and its 6-methyl and 6-carboxylic acid derivatives were determined by pHpotentiometry, H NMR spectroscopy and UV/Vis spectrophotometry in aqueous solution in the presence or absence of coordinating chloride ions. The picolinates form exclusively monoligand complexes in which they can coordinate via the...

The reaction of 4-(dimethyl-amino)-pyridine, picolinic acid and stannic chloride yields the title salt, (C(7)H(11)N(2))[SnCl(4)(C(6)H(4)NO(2))], in which the Sn(IV) atom is N,O-chelated by the picolinate ion in a cis-SnNOCl(4) octa-hedral geometry. The cation is linked to the anion by an N-H⋯O hydrogen bond.

In the title compound, [Zn(C(6)H(4)NO(3))(2)(H(2)O)(2)], the Zn atom is located on a centre of inversion and shows a distorted octa-hedral coordination geometry. Two aqua ligands occupy the axial positions and four O atoms of the two chelating picolinic acid N-oxide ligands are located in the equatorial plane. Inter-molecular hydrogen bonds between aqua ligands and organic ligands link mol-ecul...