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PubMed1977

Studies on anticoccidial agents. 10. Synthesis and anticoccidial activity of 5-nitronicotinamide and its analogues.

5-Nitronicotinamide (1) was prepared from 5-bromonicotinoyl chloride by treatment with ammonia and then oxidation with fuming H2SO4 and 30% H202. 2-Cholor-, 2-alkoxy-2-benzyloxy,2-phenoxy-,2-alkylamino-, and 2-benzylamino-5-nitronicatinamides were also prepared via 2-chloro-3-cyano-5-nitropyridine. 2-Methyl-5-nitronicotinamide (2) was obtained from ethyl 2-methyl-5-nitronicotinate by treatment with ammonia; the 4-methyl analogue 3 was from 3-cyano-2,6-dihydroxy-4 methylpyridine by nitration, chlorination, and dechlorination, and the 6-methyl analogue 4 was prepared by transforming 2-chloro-3-cyano-6-methyl-5-nitropyridine to the corresponding amide, followed by dechlorination. Of these compounds, the 5-nitronicotinamide, the 2-methyl and 4-methyl but not the 6-methyl, analogue showed significant anticoccidial activity against eimeria tenella. N-Substituted analogues of 5-nitronicotinamide and 2-methyl-5-nitronicotinamide were prepared in a conventional manner and optimal anticoccidial activity was attained with their lower N-alkyl analogues, N-alkanoyl and -alkenoyl analogues, and N-aromatic acyl analogues together with these parent compounds.

Coccidiostats↗
PubMed2000

Total synthesis of polyamine toxin HO-416b and Agel-489 using a 2-nitrobenzenesulfonamide strategy.

Total synthesis of spider toxins HO-416b (1) and Agel-489 (2) was accomplished using the 2-nitrobenzenesulfonamide (Ns) group as both a protecting and activating group. In this strategy, the C-N bonds were constructed by alkylation of sulfonamides with alkyl halides or Mitsunobu reaction with the corresponding alcohol. Beginning with monoprotection of the symmetrical diamine, the construction of the backbone from diamine 3 was efficiently accomplished in 7 steps for 14 and 9 steps for 29. Removal of the Ns group while the substrate was attached to a novel solid support enabled the efficient isolation of this highly polar compound.

Indoles↗
PubMed1993

Comparison of the azoreductase and nitroreductase from Clostridium perfringens.

The purified azoreductase and nitroreductase of Clostridium perfringens, which have similar electrophoretic properties, both reacted in a Western blot (immunoblot) with a polyclonal antibody raised against the azoreductase. The activity of both enzymes was enhanced by flavin adenine dinucleotide and was inhibited by menadione, o-iodosobenzoic acid, and the antibody against azoreductase. Reduction of the azo dye Direct Blue 15 by the azoreductase was inhibited by nitroaromatic compounds. The apparent Km of the enzyme for reduction of Direct Blue 15 in the presence of 1-nitropyrene was higher than the Km with the azo dye alone, demonstrating competitive inhibition. The data show that the same protein is involved in the reduction of both azo dyes and nitroaromatic compounds.

Azo Compounds↗
PubMed1971

Antifungal activity of substituted nitrobenzenes and anilines.

Series of 1,3-dihalogeno-5-nitrobenzenes, 3- and 3,5-halogenoanilines, and 2,6-dihalogeno-4-nitroanilines were tested for fungitoxicity against Aspergillus niger, A. oryzae, Trichoderma viride, Myrothecium verrucaria, and Trichophyton mentagrophytes in shaken culture by using Sabouraud dextrose broth enriched with yeast extract as the test medium. 1,3-Dichloro-5-nitrobenzene, 1,3-dibromo-5-nitrobenzene, 3-iodoaniline, 3,5-dichloroaniline, and 3,5-dibromoaniline were found to possess sufficient activity, compared with 8-quinolinol, to warrant further study.

Aniline Compounds↗
PubMed1987

Ethanenitronate is a peroxide-dependent suicide substrate for catalase.

We find ethanenitronate (formula; see text) to be a H2O2- (and peracetic acid-) dependent suicide substrate for bovine liver catalase (E) which converts E to Em, a modified form of the enzyme. The catalytic and suicide pathways are related to E, Em, Compound I, and Compound II according to the following scheme. (formula; see text) The catalytic cycle generates free radical products (EN.) which then participate in an O2-dependent chain reaction. Within experimental error the exclusive target for inactivation by EN- is Compound II. This partitions in the ratio (k4 = 1.2 M-1 s-1)/(k3 = 1.6 M-1 s-1) to generate Em and E, respectively. The species Em acquires 1 eq of 14C/ferriheme from [1-14C]ethanenitronate which is firmly (presumably covalently) affixed to the protein moiety. According to the standard H2O2 assay, Em is 7% as active catalytically as E. We regard inactivation as resulting from that fraction of EN. in the E...EN. complex which fails to diffuse from the complex because it is trapped by reaction with a neighboring amino acid residue to generate Em irreversibly. (formula; see text) This mechanism is identical to that deduced previously for suicide inactivation of horseradish peroxidase by alkane nitronates (Porter, D. J. T., and Bright, H. J. (1983) J. Biol. Chem. 258, 9913-9924) with the exception that EN. is trapped in that case by a methine carbon at the edge of the ferriheme rather than by the apoenzyme. The labeled residue in the catalase apoenzyme probably resides at or near the site of reduction of Compound II.

Animals↗
PubMed1977

Alterations in fecal microflora enzymes related to diet, age, lactobacillus supplements, and dimethylhydrazine.

The bacterial enzymes, beta-glucuronidase, azoreductase, and nitroreductase, have been measured in the fecal microflora of rats. The effects of diet, advanced age, Lactobacillus acidophilus supplements, and dimethylhydrazine on these microbial enzymes activities have been determined. The shift from a grain to a meat diet resulted in 1.5--2.5-fold increase in the activity of all three enzymes. Animals over 20 months of age, consuming a meat diet, showed further increases in fecal beta-glucuronidase activity, while the levels of all three microbial enzymes increased in old rats fed a grain diet. Feeding supplement of L. acidophilus significantly lowered the activity of fecal nitroreductase and azoreductase in meat-eating animals, but had no effect on nitroreductase activity in grain-fed animals. Dimethylhydrazine increased the fecal beta-glucuronidase activity in both grain- and meat-fed animals, but the carcinogen had no effect on nitroreductase or azoreductase activity. These findings have relevance to known features of the epidemiology and etiology of large bowel cancer, and suggest certain approaches to prevention.

Aging↗