Antagonism by deoxyribosides of the inhibitory action of certain hydroxamic acids on deoxyribonucleic acid synthesis

Résumé L'action inhibitrice de l'hydroxyurée (HU) sur une synthèse de DNA peut être antagonisée par des déoxyribosides (dR). De même, un mélange de déoxyadénosine, de déoxyguanosine, et de déoxycytidine annule complètement l'action de l'acide oxanyl hydroxamique (OHA) et inverse, en partie, les effets de l'acide salicylhydroxamique (SHA) et de l'acide (dihydroxybenzoyl-2.3)-hydroxamique (DHB). Lorsqu'on ajoute de la thymidine à une solution de dR, le schéma général d'antagonisme est similaire. De plus, en présence des quatre dR, l'action de l'acétoxyoxamide (AOA) est en partie antagonisée. Il a été conclu que ces acides hydroxamiques, comme l'HU, interviennent, à un degré plus ou moins grand, avec réduction des ribosides.

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Aided by grant No. GM-13958 from the National Institutes of Health, United States Public Health Service.     

Urease inhibition by hydroxamic acids

Summary Ureases from jack beans andRhodototorula pilimanae were observed to be inhibited by primary hydroxamic acids but were not inhibited by acyclic-secondary (N-alkyl) hydroxamic acids.This project was supported by a Lamar University organized research grant.     

Synthesis of N-aryl-N-glycolyl hydroxamic acids: Nonmicrosomal metabolites of nitrosoaromatics

Summary A method for the synthesis of N-aryl-N-glycolyl hydroxamic acids is described. This method consists of N-acylation of an arylhydroxylamine by glycolic acid in the presence of dicyclohexylcarbodiimide.This study was supported by grant No. CA 21668 from the National Cancer Institute, DHEW.     

Genetic and allied effects of certain esters of inorganic acids inAspergillus nidulans

Resumen Fueron investigados los efectos mutagénicos de cinco esteres de acidos inorgánicos sobre el mutante bi^–1; meth^–1 delAspergillus nidulans. El método empleado fué el teste de retrocruzamiento con algunas variaciones. El dimetil sulfato se ha mostrado como el mas poderoso mutagénico, seguido por el di-etil sulfato. El mecanismo de induccion mutacional fue discutido y se estableció una hipótesis para explicarla.     

Observations on salicyl hydroxamic acid,an experimental trypanocide

Summary The inferior in vivo efficacy of salicyl hydroxamic acid against trypanosomiasis may be explained by its short half-life, high degree of protein binding and low tissue levels.     

Effects of storage and processing on the nutritive value of certain Nigerian foods

Summary The effects of storage and processing on the nutritive value of two Nigerian foods-raw cowpea (Vigna unguiculata) flour and palm oil, have been investigated. Increased retention of both thiamine and riboflavin as a result of increased water activity (A_w) were recorded for cowpea flour stored for 6 months. A storage temperature of 5°C led to minimal losses of both vitamins in the stored flour. Differences in physico-chemical characteristics were observed between palm oil produced by the traditional method and that produced by a modern commercial method. Increasing A_w led to decreasing loss of unsaturation in the traditionally-produced palm oil during 4-week storage at ambient temperature (25°C).     

Effects of storage and processing on the nutritive value of certain Nigerian foods

The effects of storage and processing on the nutritive value of two Nigerian foods--raw cowpea (Vigna unguiculata) flour and palm oil, have been investigated. Increased retention of both thiamine and riboflavin as a result of increased water activity (Aw) were recorded for cowpea flour stored for 6 months. A storage temperature of 5 degrees C led to minimal losses of both vitamins in the stored flour. Differences in physico-chemical characteristics were observed between palm oil produced by the traditional method and that produced by a modern commercial method. Increasing Aw led to decreasing loss of unsaturation in the traditionally-produced palm oil during 4-week storage at ambient temperature (25 degrees C).     

Template preference of polymerases and its relevance to oncogenic RNA virus replication

Zusammenfassung DNS-Polymerae aus Kalbsthymus (in50%-Glycerin-haltigem Puffer gelöst) zeigt bei Kühlaufbewahrung Alterung mit Änderung ihrer Template-Präferenz von einstrangiger zu doppelstrangiger DNS.

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Supported by U.S. Public Health Service and Damon Runyon Grants.