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At least 19 recordsLinked to original sources
PubMed1991

[Monoamine oxidase inhibitory effects of pentanthrene type heterocyclic compounds].

Pentanthrene type heterocyclic compounds, which contain oxazole, isoxazole, oxadiazole, thiazole, isothiazole, thiadiazole or pyrrole ring as C-ring, and naphthalene, quinoline, isoquinoline or quinoxaline ring as A.B-ring, were prepared, and their monoamine oxidase (MAO) inhibitory activities were examined. As expected from our previous investigation on the structure-activity relationship of this series, most of them showed strong inhibitory potency to both MAO-A and MAO-B. However, a few indicated highly selective inhibition for either of MAO subtypes.

Animals↗
PubMed1980

Structure-toxicity relationships of selected nitrogenous heterocyclic compounds.

A series of eleven nitrogen-containing heterocyclic compounds, which may be potentially associated with aqueous effluents from coal conversion technologies, were examined to determine the relationships between their n-octanol/H2O partition coefficients, molecular weights, boiling points, and their toxicity monitored as reproduction impairment to Tetrahymena pyriformis. Toxicity increases linearly with increased partition coefficient, molecular weight, and boiling point. All of these parameters increase with increased alkyl and ring addition.

Animals↗
PubMed1987

Mode of action of nitro-heterocyclic compounds on Escherichia coli.

The inhibitory and bactericidal activities of several different nitro-heterocyclic compounds, such as nitrofuran, nitronaphthofuran, nitrobenzofuran, nitroimidazole and nitrothiazole, were assessed in vitro. All these substances except nitroimidazole were active against Escherichia coli, though to different degrees. Under anaerobic test conditions the antibacterial activity increased slightly. Nitroreductase-deficient mutants, however, were highly resistant to all nitro-compounds, indicating that only when the nitro-group is reduced to these agents get into an active antibacterial form. SOS repair-deficient strains were much more susceptible to the nitro-containing substances than repair-proficient counterparts, indicating that damage to bacterial DNA is the essential mechanism of antibacterial activity of all nitro-heterocyclic compounds.

Escherichia coli↗
PubMed1984

Abiotic synthesis of purines and other heterocyclic compounds by the action of electrical discharges.

The synthesis of purines and pyrimidines using Oparin-Urey-type primitive Earth atmospheres has been demonstrated by reacting methane, ethane, and ammonia in electrical discharges. Adenine, guanine, 4-aminoimidazole-5-carboxamide (AICA), and isocytosine have been identified by UV spectrometry and paper chromatography as the products of the reaction. The total yields of the identified heterocyclic compounds are 0.0023%. It is concluded that adenine synthesis occurs at a much lower concentration of hydrogen cyanide than has been shown by earlier studies. Pathways for the synthesis of purines from hydrogen cyanide are discussed, and a comparison of the heterocyclic compounds that have been identified in meteorites and in prebiotic reactions is presented.

Biological Evolution↗
PubMed1978

Effect of some heterocyclic compounds on human semen composition and biology.

The effect of some heterocyclic compounds on some aspects of human semen metabolism was studied. Caffeine produced stimulation of motility and lactic acid production and an inhibition of fructose utilization and oxygen uptake. Nicotinamide and riboflavin produced stimulation of motility, fructose utilization and oxygen uptake and an inhibition of lactic acid production.

Caffeine↗
PubMed1982

Inhibition of dimethylnitrosamine metabolism by some heterocyclic compounds and by substrates and inhibitors of monoamine oxidase in the rat.

Pretreatment of rats with a number of nitrogen-containing heterocyclic compounds was found to inhibit markedly the metabolism of dimethylnitrosamine (DMN) in terms of both CO2 excretion and decline in blood DMN concentration. However, many of these compounds had either much less or no inhibitory effect on the in vivo metabolism to CO2 of a typical mixed-function oxidase substrate, aminopyrine. In addition, a number of model inhibitors of monoamine oxidase (MAO) activity also inhibited DMN metabolism in the intact animal, and a number of primary amines, known substrates of hepatic MAO, inhibited DMN metabolism but not that of aminopyrine in the isolated perfused liver system. These results, together with in vitro data and previously reported studies on the effect of MAO inhibitors and substrates on the mutagenicity of DMN, suggest that the metabolism and bioactivation of DMN may be in part mediated by a MAO type of enzyme activity.

Aminopyrine↗
PubMed1981

A quantitative structure-activity analysis of the mutagenic and carcinogenic action of 43 structurally related heterocyclic compounds.

Quantitative structure-activity relationships for the carcinogenicity and mutagenicity (against Salmonella typhimurium his- TA98, TA100 and TA1537 strains) of 43 structurally related heterocyclic compounds were formulated. The compounds investigated belong to the following two series of congeners : (a) benzo(thio)-pyranoquinolines and (b) benzo(thio)pyranoindoles. Their biologic activities were correlated with the following parameters : (a) the minimal topological difference (describing the fit of the considered molecules with a possible receptor, enzyme or DNA) and (b) the lipophilicity constants. The computed regression equations suggest that the structural requirements for carcinogenicity are different from those responsible for mutagenicity in the Ames test.

Carcinogens↗
PubMed1988

[UV-spectrophotometry in drug control. 39. Spectrophotometric behavior of substances with chromophores and auxochromes in aliphatic chains, in saturated heterocyclics and the heterocyclic compounds: furan, imidazole, thiazole, thiadiazole and oxadiazole].

The spectra of 22 drug substances with chromophores and auxochromes in the aliphatic chain, in the saturated heterocyclus and in heterocyclic compounds (furan, imidazole, thiazole, thiadiazole and oxadiazole) underwent a systematic investigation and the results obtained were evaluated. Influences of substituents and solvents on shifts of the E, K, B and R bands were discussed.

Chemical Phenomena↗