Subchronic oral toxicity (six months) of carboxyethylgermanium sesquioxide [(HOOCCH2CH2Ge)2O3]n in rats

After briefly renewing toxicological data on germanium compounds, the authors report on the subchronic oral toxicity of carboxyethylgermanium sesquioxide in rats. During six months, male and female animals received 1 g kg^?1. day^?1. No particular toxic symptoms, and no behaviour problems except a small decrease of body weight in male rats, at the end of the six-month experimentation period, were observed. A significant decrease of erythropoiesis and some significant changes in leucocyte ratios were demonstrated. The main marked effect was a moderate renal dysfunction characterized by a tubular disease with the presence of cylinders, swelling of tubulus cells and flocculus deposits. Germanium urinary excretion was constant and linked to the received dose. Six months later, no preferential accumulation in organs was evident.     

Eiwei?

Ohne Zusammenfassung     

Glutaconaldehyd als Tüpfelreagens. I

Zusammenfassung Glutaconaldehyd, der aus Pyridylpyridiniumdichlorid während der Farbreaktion gebildet wird, ist ein empfindliches Reagens auf Hydrazin und dessen organische Derivate, wie Alkyl- und Arylhydrazine mit freier Aminogruppe, Carbonsäurehydrazide, Aldehydhydrazone sowie Aryl- und Alkylaldehydhydrazone. Hydrazone von Ketonen reagieren nicht. Aldehydhydrazone des p-Nitrophenylhydrazins reagieren im Gegensatz zu den entsprechenden Metaisomeren nicht. Die Empfindlichkeit der Farbreaktion gestattet die Ausführung als Tüpfelreaktion; es werden Erfassungsgrenzen von 0,01 bis 10g gefunden. Die Farben sind Rot bis Orange. Aminoguanidin gibt eine schwache, gelbe Reaktion.

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Summary Glutaconic aldehyde, which is formed from pyridylpyridinium dichloride during the color reaction is a sensitive reagent for hydrazine and its organic derivatives, such as alkyl- and arylhydrazines with free amino groups, carboxylic acid hydrazides, aldehyde hydrazones and also aryl- and alkylaldehyde hydrazones. Hydrazones of ketones do not react. Aldehyde hydrazones ofp-nitrophenylhydrazine, in contrast to the corresponding meta isomers, do not react. The sensitivity of the color reaction permits making the test as a spot test; identification limits from 0.01 to 10 g are found. The colors are red to orange. Aminoguanidine yields a weak yellow reaction.

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Résumé L'aldéhyde glutaconique qui se forme á partir du dichlorure de pyridylpyridinium pendant la réaction colorée est un réactif sensible de l'hydrazine et de ses dérivés organiques comme les alcoyl- et les arylhydrazines avec le groupe amino libre, les acides hydrazinocarboxyliques, les hydrazones d'aldéhydes ainsi que les hydrazones d'aryl et d'alcoylaldéhydes. Les hydrazones de cétones ne reagissent pas. Les hydrazones d'aldéhydes de lap-nitrophénylhydrazine ne réagissent pas au contraire des métaisoméres correspondants. La sensibilité de la réaction colorée permet l'utilisation comme réaction á la touche; on a trouvé des limites de dilution de 0,01 á 10 g. Les colorations vont du rouge á l'orange. L'aminoguanidine donne une faible coloration jaune.

     

Zum Chemismus der Farbreaktion des Hydrochinons mit Phloroglucin. Neue Tüpfelreaktionen auf Polyhydroxybenzolderivate und Chinone

Zusammenfassung Der Chemismus der Farbreaktion zwischen Phloroglucin und Hydrochinon wird diskutiert. Rhodanin, 1-Phenyl-3-methyl-pyrazol-5-on, Barbitursäure und 2,4-Dihydroxythiazol (Senfölessigsäure) werden als Reagenzien für Brenzcatechin, Hydrochinon, Pyrogallolderivate, Chinone und Naphthochinone vorgeschlagen. Mit Hilfe von Tüpfelreaktionen lassen sich hiermit Erfassungsgrenzen von 0,1 bis 10g erreichen. Eine spezifische Reaktion für Naphthochinone mit Senfölessigsäure wird beschrieben.

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Summary The chemism of the color reaction between phloroglucinol and hydroquinone is discussed. Rhodanine, 1-phenyl-3-methyl-pyrazole-5-one, barbituric acid and 2,4-dihydroxythiazole (mustard oil acetic acid) are proposed as reagents for pyrocatechol, hydroquinone, pyrogallol derivatives, quinones, and naphthoquinones. Detection limits of 0.1 to 10g can thus be attained by means of spot test reactions. A specific test for naphthoquinones with mustard oil-acetic acid is described.

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Résumé On discute le mécanisme de la réaction colorée entre le phloroglucinol et l'hydroxyqninone. On propose la rhodanine, la phényl-1 méthyl-3 pyrazolone-5, l'acide barbiturique et le dihydroxy 2,4 thiazole (acide sénévolacétique) comme réactifs de la pyrocatéchine, de l'hydroquinone, des dérivés du pyrogallol, de la quinone et de la naphtoquinone. On peut atteindre ainsi, par réactions à la touche, les limites d'identification de 0,1 à 10g. On décrit une réaction spécifique de la naphtoquinone avec l'acide sénévolacétique.

     

Results of a European interlaboratory study for the determination of oxytetracycline in pig muscle by HPLC.

An interlaboratory study was organised in 1996 in order to determine laboratory testing performance for measuring oxytetracycline (OTC) and 4-epioxytetracycline (4-epiOTC) residues in pig muscle. The organisation was designed according to the 'International Harmonised Protocol for Proficiency Testing of (Chemical) Analytical Laboratories' produced by the Association of Official Analytical Chemists (AOAC International) and the International Union of Pure and Applied Chemistry (IUPAC). Fourteen National Reference Laboratories (NRLs) out of the 15 asked to participate agreed to analyse the samples. These laboratories were from 13 different European Union (EU) Member States and each participant was allowed to use the extraction method of their own choice but had to use liquid chromatography as the analytical technique. Most of the methods used were based on UV detection (simple wavelength or diode-array detection) but some involved fluorimetric detection. The production of incurred samples was prepared on-site. The OTC and 4-epiOTC concentrations present in the samples were determined by taking the mean of the results (excluding outliers) and the deviation of each result from the assigned value was measured. The performance of the laboratories was evaluated by calculating the 'z-scores'. The results were globally satisfactory and showed that all 14 laboratories were capable of determining OTC and 4-epiOTC in pig muscle with satisfactory accuracy. Only two laboratories obtained a questionable result in terms of repeatability.     

Diastereo‐ and Enantioselective Synthesis of Organometallic Bis(helicene)s by a Combination of C?H Activation and Dynamic Isomerization

Homochiral and heterochiral cis‐bis‐cycloplatinated‐[6]helicene derivatives 1 b^{1, 2} , as representative examples of platina[6]helicenes that share a common platinum center, have been prepared. A diastereo‐ and enantioselective synthesis, which combines CH activation and dynamic isomerization from heterochiral structure 1 b² into homochiral structure 1 b¹ , is also described. Overall, this isomerization process results in the transfer of chiral information from one helicene moiety to the other one. The chiroptical properties of homochiral (P)‐ and (M)‐ 1 b¹ were greatly modified upon oxidation into their corresponding (P)‐ and (M)‐diiodo‐Pt^IV complexes ( 5 ). The changes were also analyzed by performing theoretical calculations. C? H activation in the synthesis of organometallic helicenes is further demonstrated by the preparation of cis‐bis‐cycloplatinated‐[8]helicene 1 c .     

Influence of Cyclodextrins on the Kinetics of Oxidation of Amino Acids and BSA by Hydrazyl Radicals

The kinetics of oxidation of amino acids (Arg, His, Lys, Phe, Thr and Tyr), a dipeptide (Gly-His), and BSA (bovine serum albumin) by two persistent water soluble free radicals of the hydrazyl type has been studied.The rate decreases in the order Arg>Lys>Tyr>Thr>HisBSAPheGly-His with bothfree radicals. Addition to the reaction mixture of - and -cyclodextrin decreases the oxidation rate, probably due to amino acidencapsulation in the cyclodextrin cavity. -Cyclodextrin protects more efficiently against oxidation than -cyclodextrin.