The Chemistry of the "Aminochromes": Part Ii. The Preparation, Paper Chromatography, and Spectroscopic Properties of Pure Adrenolutin; The Infrared Spectrum of Adrenochrome

Abstract

The preparation of adrcnoluti~i monohydrate in pure crystallirie for111 has been carried out fly the a1l;alinc rearrangement of aqlreous solutions of adrcriochro~nc, prepared from the silver oxide oxidntio~l of aclrenaline in aqueous solution. AII anion-exchange resin (Dowes-l (C1-)) was employeti to renlove inorganic coutan~inarits froni the reaction mixture prior to treatment with allcali. The pure anhydrous material has been prepared by the high vacuum sublimation of the rnoriol~ydrate. The paper cl~rou~atograptiic, spectroscopic, and Rc~orin~etric characteristics of aclrenolutin have been invcstigatecl. On the basis of the ilifrarecl s p c c t r~~~n it is suggestecl that ill the solicl state, atlrcnolutiri exists in the Iccto form, i.e. 2,s-dit~ydro- 5,6-dil~ydrox)~-N-~netl~yl-3-lictoincloleThe infrared spectrum of adrenochron~e, in the solid statc, agrees with the zwitterionic for~nulatiori si~ggestccl for this compound.Adrenoluti11 (usually formulated as 3,5,6-trihydroxy-i\i-methylindole, I ) , the substance mainly responsible for the intense yellow-green fluorescence that develops in adrenaline solutions that have undergone oxidation in alltaline media, ~v a s first isolated in crystalline form and correctly identified by Lund in 1949 (I), from the alltaline real-rangement products of adrenochrome (11), although the correct structure had been assigned to the substance on theoretical grou~lds a year earlier (Ehrlen (2)).

Toxicology update: the cardiotoxicity of the oxidative stress metabolites of catecholamines (aminochromes)

“…However, it was not until some three decades later that the structure of this fluorescent alkaline rearrangement product was deduced. 11 This substance is adrenolutin, or 5,6-dihydroxy-N -methylindoxyl, which is formulated more often as 3,5,6-trihydroxy-N -methyl indole.…”

Adrenaline and Noradrenaline: Partners and Actors in the Same Play"

“…Although at physiological pH, the oxidation of catecholamines seems to occur very slowly, it has been found to occur in vivo namely in the septic shock (Macarthur et al, 2000). The oxidation of catecholamines ultimately produces a family of indole semiquinonic/quinonic species usually termed catecholaminochromes because of their orange-reddish colour (Heacock and Mahon, 1958). The oxidation of aqueous extracts of mammal suprarenal capsules was first reported by Vulpian (Vulpian, 1856).…”

“…For ADR, at physiological pH, partial deprotonation of the amine group of the side chain leads to an irreversible 1,4-intramolecular cyclization, a reaction that occurs through nucleophilic attack of the nitrogen atom at position 6 of the quinone ring, to form "leucoadrenochrome"; leucoadrenochrome is subsequently oxidized to form adrenochrome (Heacock and Mahon, 1958, Bindoli et al, 1992, Bindoli et al, 1999. This indole is often represented as a zwitterionic structure in aqueous solutions (Heacock and Mahon, 1958, Costa et al, 2007 (Figure 5). In summary, the oxidation of catecholamines occurs through two-stages whereby a total of four electrons is removed and an indole is formed by cyclization (Costa et al, 2011).…”

Electronic and Raman spectroscopic studies of copper adrenalin complexes and copper induced compounds

“…The band at 1680 cm-I is assigned to a stretching vibration of aliphatic carbonyl group (4). Heacock and co-workers noticed that the infrared spectra of iodoadrenochrome and adrenolutin have the absorption at this frequency and they assigned this band as aliphatic carbonyl stretching (18). Since indoxy carbonyl groups have stretching frequencies between 1750 and 1710cm-' and acetophenone carbonyl absorbs at 1686cm-I (18, 19) the Raman scattered peak in the copper(l1) adrenalin complex cannot be due to311e carbonyl group in the aromatic ring.…”