0000000000001823
AUTHOR
M Carmen González
Nitic oxide promotes strong cytotoxicity of phenolic compounds against escherichia coli. The influence of antioxidant defenses
[EN] The induction of mutagenic and cytotoxic effects by simple phenolics, including catechol (CAT), 3,4dihydroxyphenylacetic acid (DOPAC), hydroquinone (HQ), and 2,5-dihydroxyphenylacetic (homogentisic) acid (HGA), appears to occur through an oxidative mechanism based on the ability of these compounds to undergo autoxidation, leading to quinone formation with the production of reactive oxygen species. This is supported by the detection of such adverse effects in plate assays using Escherichia coli tester strains deficient in the OxyR function, but not in OxyR(+) strains. The OxyR protein is a redox-sensitive regulator of genes encoding antioxidant enzymes including catalase and alkyl hydro…
Circumdatin H, a new inhibitor of mitochondrial NADH oxidase, from Aspergillus ochraceus
Circumdatin H (1), a new alkaloid from the culture broth of Aspergillus ochraceus, has been isolated, together with a known circumdatin, circumdatin E (2) and other known compounds: flavacol (3) and stephacidin A (4). The structure of 1 was established on the basis of chemical and spectral evidence. All of these alkaloids showed biological activity as inhibitors of the mammalian mitochondrial respiratory chain.