PubMed HealthSearch

SEARCH · PubMed Health

Results for “Pyridones”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources

Simultaneous micro-determination of nicotinamide and its major metabolites, N1-methyl-2-pyridone-5-carboxamide and N1-methyl-4-pyridone-3-carboxamide, by high-performance liquid chromatography.

A simultaneous micro-determination of nicotinamide and its major metabolites, N1-methyl-2-pyridone-5-carboxamide (2-py) and N1-methyl-4-pyridone-3-carboxamide (4-py) by high-performance liquid chromatography is described. The method employs a 7-ODS-L (250 mm X 4.6 mm I.D., particle size 7 microns) column eluted with 10 mM potassium dihydrogenphosphate-acetonitrile (96:4, v/v; pH adjusted to 3.0 by the addition of concentrated phosphoric acid) at a flow-rate of 1.0 ml/min. The UV detector was set at 260 nm. The detection limits for nicotinamide, 2-py and 4-py were 10 pmol (1.22 ng), 2 pmol (304 pg) and 2 pmol (304 pg), respectively, at a signal-to-noise ratio 5:1. Isonicotinamide was used as an internal standard. The technique was applied to the analysis of rat and human urines. The total analysis time was ca. 15 min.

Animals

Correlation between niacin equivalent intake and urinary excretion of its metabolites, N'-methylnicotinamide, N'-methyl-2-pyridone-5-carboxamide, and N'-methyl-4-pyridone-3-carboxamide, in humans consuming a self-selected food.

N'-methyl-4-pyridone-3-carboxamide (4-py) is the major metabolite of nicotinamide and nicotinic acid in rats. However, because it is complicated to determine 4-py in humans, there is only one report on its excretion. Recently we developed a method for the microdetermination of 4-py by high-performance liquid chromatography. Urinary excretion of 4-py in Japanese students from Teikoku Women's University who consumed self-selected foods was 7.12 +/- 3.25 mumol/d, which is about one-fourth of N'-methylnicotinamide (MNA) and about one-ninth of N'-methyl-2-pyridone-5-carboxamide (2-py) excretion. The correlation coefficient between daily niacin equivalent (NE) intake and daily 4-py excretion was 0.529, which was about the same as the correlation coefficient between daily NE intake and daily 2-py excretion and which was two times higher than the correlation coefficient between daily NE intake and daily MNA excretion.

Adult

[Synthesis of 3-substituted 6-methyl-4-pyridyl-2 (1H) pyridones and testing of their cardiovascular action].

Reaction of our previously described and in 4- and 6-, respectively, position with 3- and 4-, respectively, substituted 3-cyan-2(1H)-pyridones 4 and 5 with concentrated sulphuric acid had yielded the 3-carbamoyl-pyridones 8 and 9. Hofmann reaction was followed and the 3-amino substituted pyridones 10 and 11 were formed. As by-products the 5-bromo substituted 3-amino-pyridones 12 and 13 were obtained. 4 and 5 were refluxed in the presence of diluted sulphuric acid to yield the decarboxylated pyridones 14 and 15. Cardiotonic Activity of the compounds 4-9 compared to amrinone (Cordemcura) was investigated.

Animals

[Formation of pyridone derivates from maltose and lactose. XII. Investigations on the Maillard-reaction (authors transl)].

Maltose and lactose react with methylammoniumacetate in a hot aqueous solution giving a dark brown mixture of products. 1,2-dimethyl-3-hydroxy-4-pyridone (5) can be isolated from the volatile compounds. Maltol and Isomaltol can be converted into the pyridone 5 with methylammoniumacetate. 1-Carboxymethyl-3-hydroxy-2-methyl-4-pyridone is obtained from isomaltol and glycine.

Chemical Phenomena

Synthesis, chemistry, and antineoplastic activity of alpha-halopyridinium salts: potential pyridone prodrugs of acylated vinylogous carbinolamine tumor inhibitors.

A series of 4- and 5-[2,3-dihydro-6,7-bis[[(N-alkylcarbamoyl)oxy]methyl]-1H-pyrrol izin-5- yl]-2-halopyridinium iodides were synthesized. The rates of hydrolysis of the alpha-halopyridinium salts to the corresponding pyridones, and the reactivities of the carbamate moieties were studied as a function of pH, buffer composition, and ionic strength. The 4- and 5-pyrrolizinyl-2-halopyridinium iodides and the corresponding pyridones were evaluated against P388 lymphocytic leukemia in vivo. The alpha-fluoropyridinium compounds were active but the alpha-chloro compounds were not. This activity was correlated with the rates of hydrolysis of the alpha-halopyridinium compounds to the active pyridone. Compounds that were active in the P388 screen were evaluated in L1210 leukemia, M5076 carcinoma, and MX-1 mammary xenograft assays in mice.

Animals

Synthesis and cytotoxic activity of 1-(3-oxoprop-1-enyl)-2-pyridones.

1-(3-Oxoprop-1-enyl) derivatives of nuclear substituted 2-pyridones (7a-i), 2-pyridinethione (7j), 1-isoquinolone (9), and the 1,4-dihydropyridine (11) have been synthesized and tested for biological activity. The 2-pyridones (7) and the 1-isoquinolone (9) were all active cytotoxic agents as determined in the in vitro L1210 screen, exhibiting activity in the ED50 0.5-3.5 micrograms/ml range. The nature and position of nuclear substituents present in 7 and 9 did not alter activity significantly. The unsubstituted (7a) and 5-ethoxycarbonyl-2-pyridones (7g), and the 1-isoquinolone derivative (9) were active antineoplastic agents (%T/C = 133-135) in vivo exhibiting activity comparable to 5-fluorouracil.

Animals

Pyridones as potential antitumor agents.

Based on the finding that 3-acetoxy-2-pyridone had reproducible activity against murine P-388 lymphocytic leukemia, derivatives in this series were synthesized and evaluated to determine structural parameters important for activity. Of the 32 compounds tested, 10 were active. At least two oxygen-containing functional groups are required for P-388 activity, and the 2,3-isomeric arrangement provides the greatest activity. Carbamate or acyloxy groups in the 3-position produced the most active 2-pyridones.

Animals

Cytotoxic pyridone alkaloids from the leaves of Piper aborescens.

Bioactivity-guided fractionation of a CHCl3 extract of the leaves of Piper aborescens afforded a new cytotoxic pyridone alkaloid, N-(3-methoxy-4,5-methylenedioxydihydrocinnamoyl)-delta 3-pyridin-2-one [1], as well as three known cytotoxic pyridone alkaloids, N-(3-methoxy-4,5-methylenedioxycinnamoyl)-delta 3-pyridin-2-one [2], piplartine [3], and piplartine dimer A [4].

Alkaloids

Inhibition of wool follicle DNA synthesis by mimosine and related 4(1H)-pyridones.

The in vitro incorporation of [3H]thymidine has been examined in thin slices of sheep skin. Most of the radioactivity (88%) was incorporated into the bulb cells of the wool follicles, and the technique is therefore suitable for the study of some aspects of wool follicle DNA synthesis. The effect of mimosine and a number of related 4(1H)-pyridones on [3H]thymidine incorporation into sheep skin slices was examined. Mimosine was shown to inhibit the incorporation at a concentration of 0-2 mM. At this concentration, the incorporation of [3H]uridine or [14C]leucine was not affected. The inhibition of [3H]thymidine incorporation was time dependent, 2 h of incubation being required for maximal inhibition of DNA synthesis, and was readily reversible by removal of mimosine from the incubation medium. The 3-hydroxyl-4-oxo function of the pyridone ring appears to be directly involved in DNA synthesis inhibition. The amino acid side chain is not a toxophoric centre, but changes in its polarity have been shown to affect the inhibitory activity. The results suggest that the primary action of mimosine on the inhibition of wool biosynthesis in vivo is the inhibition of follicle bulb cell DNA synthesis and consequently of cell division.

Animals

Effects of ethylenediaminetetraacetic acid and gentamicin on the antibacterial activity of pyridone carboxylic acid derivatives against gram-negative bacilli.

Ofloxacin (9-fluoro-3-methyl-10-(4-methyl-1-piperazynyl)-7-oxo-2,3-dihydro-7 H-pyrido-(1,2,3-de)1,4-benzoxazine-6-carboxylic acid) and enoxacin (1-ethyl-6-fluoro-1,4-dehydro-4-oxo-7-(1-piperazinyl)-1, 8-naphthyridine-3-carboxylic acid) are newly developed pyridone carboxylic acid derivatives with broad and potent antibacterial activities against Gram-negative and Gram-positive bacteria. Antibacterial activities of six pyridone carboxylic acid derivatives, including these two new antibiotics, were examined against Gram-negative bacilli in the presence and absence of ethylenediaminetetraacetic acid (EDTA) or gentamicin. The minimal inhibitory concentrations (MICs) of nalidixic acid, cinoxacin and piromidic acid were reduced by the addition of EDTA or gentamicin. However, the MICs of pipemidic acid, ofloxacin and enoxacin were unaffected. These findings indicated the high permeability of pipemidic acid, ofloxacin and enoxacin through the outer membrane. The effects of EDTA and gentamicin against Serratia marcescens were different from those against other Gram-negative bacilli.

Anti-Bacterial Agents

Effect of supplementing low protein diets with the limiting amino acids on the excretion of N1-methylnicotinamide and its pyridones in rats.

We have hypothesized that the ratio of the excreted by-products of niacin metabolism, N1-methyl-2-pyridone-5-carboxamide (2-pyr) + N1-methyl-4-pyridone-3-carboxamide (4-pyr)/N1-methylnicotinamide (MNA), might be useful as an index to assess the adequacy of amino acid intake in rats. The experiment reported herein was performed to test this hypothesis. When a 10, 20 or 40% casein diet supplemented with 0.1, 0.2 or 0.4% L-methionine, respectively, was fed to rats, the urinary excretion of MNA decreased, and that of 4-pyr increased, as the level of dietary casein and methionine increased. Therefore, the ratio of (2-pyr + 4-pyr)/MNA increased with increasing dietary casein and methionine levels. When the limiting amino acids of casein or soy protein isolate were added to a low casein or low soy protein isolate diet, the urinary ratio of (2-pyr + 4-pyr)/MNA also increased. These results indicate that the increased urinary ratio of (2-pyr + 4-pyr)/MNA can serve as a biological marker for adequate amino acid intake.

Amino Acids

Synthesis and cytotoxic activity of (E)-1-(2-nitrovinyl) and 1-[N-(tert-butylformiminyl)]-substituted 1,4-dihydropyridines and 2-pyridones.

1-(2-Nitrovinyl) derivatives of nuclear substituted 1,4-dihydropyridines (7a-c), and 1-(N-tert-butyl-formiminyl) derivatives of 1,4-dihydropyridines (9a-c) or 2-pyridones (11a-c) were synthesized for evaluation as cytotoxic agents (see Table I for structures). The in vitro cytotoxic activities, determined in the L1210 assay, indicated that the 4-substituent on a 1,4-dihydropyridine ring system was a determinant of activity in both the 1-(2-nitrovinyl) (7) and 1-(N-tert-butylformiminyl) (9) series, the relative activity order being n-Bu > Ph > Me. In the 1-(N-tert-butylformiminyl) series, the 1,4-dihydropyridine derivatives (9) were generally more cytotoxic than the 2-pyridone derivatives (11). The most active compound was 1-(N-tert-butylformiminyl)-3-(4,4-dimethyloxazolin-2-yl)-4-n -butyl-1,4- dihydropyridine (9b), but it was 2-3 log units less active than the reference standard melphalan.

Animals