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Thin-layer chromatographic detection of zeranol and estradiol in fortified plasma and tissue extracts with Fast Corinth V.

In an attempt to improve sensitivity of thin-layer chromatographic (TLC) analysis and selectivity of visualizing agents for detection of estrogenic anabolic hormones, several dyes were screened for their chromogenic interactions with estrone, estradiol, diethylstilbestrol (DES), zeranol (zearalanol), zearalanone, and mycotoxins, zearalenone and zearalenol. Fast Corinth V salt was selected for its relatively high sensitivity. These anabolic compounds were separated by TLC and visualized with Corinth V and the results compared to iodine and starch visualization. Fortified bovine plasma and tissues (kidney, liver and muscle) and chicken muscles were analyzed after a clean-up procedure using solid-phase dual columns of alumina and anion-exchange resin. Iodine-starch clearly detected 4 ng of estradiol and DES while zeranol and zearalenone were detected at higher levels (10 ng). Fast Corinth V showed distinct spots with 2 ng of zeranol and 4 ng of zearalenone while faint spots were observed with estradiol and estrone standards. DES was not detectable at these levels. Less background interference was observed with Corinth V than with iodine-starch. The former confirmed spots detected by iodine-starch. This study suggests its selectivity for detection of zeranol and its metabolite, zearalanone, in the presence of steroidal compounds.

Animals↗

Specific binding activity of isolated light chains of antibodies.

Free light chains isolated from specifically purified antibody have been shown to bind specific hapten. This proves that part of the binding site does exist on the light chain. The light chains were obtained from antibody directed against the 4-azonaphthalene-1-sulfonate group, and the binding of the simple hapten 4-anilinonaphthalene-1-sulfonate was determined by the fluorescence-enhancement technique. Since this hapten undergoes a striking increase in fluorescence on binding to light chains (and also on binding to specific antibody), the presence of small amounts of bound hapten could be determined, even in the presence of the high concentrations of unbound hapten required because of the low binding constant.

Aniline Compounds↗

Inflammatory reactions from organic pigments in red tattoos.

Two different red pigments used for tattooing were found to give rise to inflammatory reactions in the skin. No inorganic component was found in the pigments. NMR and MS analyses elucidated the molecular structures of two different organic compounds. A bright red pigment was found to be an aromatic azo-derivative, and a red-violet pigment was found to be linear quinacridone. A strong exposure to UV-light was reported in most cases prior to the onset of the inflammation.

Acridines↗

Metabolic activation of aromatic amines and azo dyes.

Aromatic amines, amides and nitro compounds are a class of chemicals that produce tumors in a wide variety of tissues in experimental animals, including liver, urinary bladder, forestomach, small intestine, Zymbal's gland, subcutaneous tissue or skin. In man, exposure to some aromatic amines is associated with tumours of the urinary bladder and carcinoma of the renal pelvis. Their biological activity as carcinogens or genotoxic agents is, in all the cases that have been studied in detail, dependent on metabolic activation in vivo, occurring by multiple pathways. Differences in these metabolic pathways may largely account for the differences in tissues and species susceptibilities to cancer induction. Carcinogenicity of aromatic amines or amides is dependent on their oxidation to N-hydroxy derivatives, whilst the carcinogenicity of aromatic nitro compounds is linked to their reduction to hydroxylamines. Further conversion of the N-hydroxylamine or N-hydroxyamide to reactive intermediates can occur in several ways, which include (i) esterification of the N-hydroxy group, (ii) non-enzymic protonation of the nitrogen of the hydroxylamine and (iii) oxidation to a free radical of arylhydroxamic acids. Following generation of such reactive electrophilic intermediates in tissues or cells, macromolecular binding has been observed to nucleic acids and proteins. In many cases, arylamidated and arylaminated products are formed with nucleic acid bases; in the case of the well-studied 2-acetylaminofluorene, nucleophilic atoms of guanine are the predominant site of reaction. Relatively little is known of the structure and biological consequences of DNA adducts formed from other aromatic amines, amides or nitro compounds; more research in these directions is warranted.

1-Naphthylamine↗