Sympathomimetics of the Adrenaline Type

Potter and co-workers [132] have separated adrenaline, noradrenaline and some of their metabolites on cellulose layers [7.5 g cellulose MN-300 (cf. p. 34) + 45 ml methanol layers dried 10 min at 105° C] at chamber saturation, using the solvent n-butanol, saturated with 3N HCl. Noradrenaline, adrenaline, isoprenaline, ephedrine and amphetamine have been chromatographed similarly on cellulose layers [20 g cellulose MN-300 G (cf. p. 499) + 100 ml water layers dried 2 h at 

Spray reagents 1. Folin-Ciocalteu (No. 122), diluted 1 + 1 with water with and without heating 10— 20 min at 110° C. 2. 5% molybdophosphoric acid in ethanol subsequent treatment with ammonia. 

This double spot formation is not observed on silica gel or alumina layers. The sensitivity to oxidation of the adrenaline derivatives is, however, increased by the metal or heavy metal impurities present in such layers. Adrenaline and noradrenaline have therefore been chromatographed on buffered silica gel layers (Sorensen buffer, pH 6.8), prepared with addition of sodium bisulphite and using 10% ethanol as solvent [163]. The sympathomimetics and the secondary products formed by oxidation tend moreover to form complex salts this manifests itself in elongated spots. Silica gel layers which had been prepared with O.IM EDTA have been used with the solvent acetone-formic acid-water (70 + 10 + 20) for the separation of adrenaline, noradrenaline and various substances of similar structure [110] silica gel HR (Krm 88) ought to be especially advisable for this purpose. On the other hand, Halmekoski [74] has made use of this very ability of the adrenaline-type of sympathomimetic to form complexes, in order to accomplish fractionation on buffered layers containing molybdate, tungstate or borax components 

The adrenaline derivatives were applied as 1% solutions in a buffer of pH 4 [92]. Temperature during separation was 19—21° C. 1 hour equilibration with the organic phase before chromatography. 

n-Amyl alcohol-acetic acid-ethanol-HaSOs 

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