Empfindliche Methoden zum Nachweis von Wasserstoffperoxyd und seiner Entstehung bei einigen Dehydrierungs‐Vorgängen

Schales, Otto

doi:10.1002/cber.19380710244

Cited by 42 publications

(5 citation statements)

References 26 publications

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“…6A). Hydrogen peroxide is formed during the oxidation of adrenaline (Schales 1938). Hartung (1946) and Falk (1949)· suggested that it is formed in the oxidation of leu co-adrenochrome to adrenochrome; no evidence for this location was found in the present work.…”

Section: S09contrasting

confidence: 70%

The Early Stages of the Oxidation of Adrenaline in Dilute Solution

Trautner¹,

Bradley²

1951

Aust. Jnl. Of Bio. Sci.

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SummaryThe auto-oxidation of adrenaline in concentrations of M/500 to M/10,000 and at pH 6-8 starts after a time lag that is dependent on the conditions but independent of the adrenaline concentration. This is followed by a short period of rapid acceleration of the oxidation rate and then by a period of steady oxidation of constant rate for several hours, proportional to the adrenaline concentration. The solutions are red, later orange to brown, melanin is formed, and the oxygen uptakes, six to seven atoms for one molecule of adrenaline, indicate destructive oxidation beyond opening of the ring structure.It is suggested that during the time lag the oxidation of adrenaline is started by traces of metallic ions (Fe and Cu) present, adrenochrome being formed in the process and further catalysing the reaction. The acceleration of the oxidation rate and the onset of destructive oxidation are due to the formation of more readily oxidizable compounds of indoxyl structure, the reaction probably involving a free radical mechanism. The later, constant oxidation proceeds over the quinonoid redox systems of adrenochrome and oxocadrenochrome that are established during the period of acceleration. At this stage the reaction mixture consists of unreacted adrenaline, the quinonoid systems, and of further oxidation products, which act as hydrogen donors towards the quinones. The regulation of the oxidation rate is ascribed to the effect of the hydrogen transfers on the redox potential of the quinonoid systems and possibly to the inhibiting influence of later oxidation products. Finally the ring structures are consumed and, apart from condensation products like melanin, the reaction mixture consists. of late oxidation products which without the action of redox systems, undergo further atmospheric oxidation. Tentative formulations of the earlier steps of adrenaline oxidation are proposed.The influence of catalysts, heavy metal ions (Fe and Cu, also haematin and methaemoglobin), and adrenochrome is confined to the initial stages of the reaction sequence; they shorten the time lag and cause a transient period of more rapid oxygen uptake, the duration of which depends on their concentration. In catalytic amounts they do not appreciably affect the rate of the final oxidation.The auto-oxidation of adrenochrome begins after a time lag and shows a period of more rapid oxidation before the final stefldy oxidation rate is established.Oxidizing red adrenaline solutions or adrenochrome solutions form strongly fluorescent colourless to yellow solutions on reduction imd on addition of free alkali with or without the admission of air. It is suggested that, depending on the conditions, leuco-adrenochrome or N-methyl-5 : 6-dihydroxy-indoxyl, but usually mixtures of both compounds are formed. If at lower pH (7-8.5) adrenaline is allowed to oxidize in the presence of reducing agents ( sulphite, " Department of Physiology, University of Melbourne. 304 E. M. TRAUTNER AND T. R. BRADLEY amino acids, etc.) almost colourless fluorescent solutions are for...

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Section: S09contrasting

confidence: 70%

The Early Stages of the Oxidation of Adrenaline in Dilute Solution

Trautner¹,

Bradley²

1951

Aust. Jnl. Of Bio. Sci.

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“…Die beiden Acetonperoxyde konnten wir auch aus den Autoxydationsprodukten des Diisopropyl-äthers isolieren 25 ). Criegee und Mitarbeiter haben dies erneut bestätigt und den Bildungsmechanismus der mehrfach molekularen und cyclischen Ketonperoxyde am Cyclohexanon bewiesen 9 ). Die Übersicht 6 zeigt die Ähnlichkeit von…”

Section: Peroxyde Der Carbonyl-verbindungen Allgemeinesunclassified

Über Peroxyde der Äther, der Carbonyl‐Verbindungen und die Ozonide

Rieche

1958

Angewandte Chemie

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“…The residual amounts of n ‐alkanes in the culture liquid filtrate were removed by extraction with the mixture of ethyl acetate and hexane (2:1). The content of peroxide traces was determined using very sensitive reaction with phenolphthalein in the presence of 1 drop of 0.01 M copper sulfate , as necessary, the peroxide was decomposed in the presence of catalytic amounts of manganese dioxide. This procedure was combined with the treatment of solution with activated charcoal.…”

Section: Resultsmentioning

confidence: 99%

Succinic acid production from n‐alkanes

Kamzolova

Vinokurova

Yusupova

et al. 2012

Engineering in Life Sciences

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A novel process of production of succinic acid (SA) has been developed, which includes the synthesis of alpha‐ketoglutaric acid by a thiamine‐auxotrophic yeast strain Yarrowia lipolytica VKM Y‐2412 from n‐alkanes and subsequent oxidation of the acid by hydrogen peroxide to SA. The concentration of SA in the culture broth and its yield were found to be 38.8 g/L and 82.45% of n‐alkane consumed, respectively. The isolation procedure involved the extraction of the residual alkanes with the mixture of ethyl acetate and hexane, the decomposition of H2O2 in the filtrate followed by filtrate bleaching and acidification with a mineral acid; the evaporation of filtrate and the ethanol extraction of SA from lyophilized residue. The purity of the SA isolated from the culture liquid filtrate reached 99.5%.

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Empfindliche Methoden zum Nachweis von Wasserstoffperoxyd und seiner Entstehung bei einigen Dehydrierungs‐Vorgängen

Cited by 42 publications

References 26 publications

The Early Stages of the Oxidation of Adrenaline in Dilute Solution

The Early Stages of the Oxidation of Adrenaline in Dilute Solution

Über Peroxyde der Äther, der Carbonyl‐Verbindungen und die Ozonide

Succinic acid production from n‐alkanes

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