Tryptamine Oxidation by Extracts of Pea Seedlings: Effect of Growth Retardant β-Hydroxyethylhydrazine

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Science  21 May 1965:
Vol. 148, Issue 3673, pp. 1097-1099
DOI: 10.1126/science.148.3673.1097


β-Hydroxyethylhydrazine forces flowering of pineapple plants, possibly by reducing auxin concentration. A specific and sensitive assay showed that β-hydroxyethylhydrazine (3.3 x 10-7M) inhibits noncompetitively and almost completely the oxidation of tryptamine to indoleacetaldehyde by extracts of pea-seedling (Pisum sativum L. var. Alaska). The relative rate of oxidation of putrescine to Δ1-pyrroline compared to that of tryptamine by these extracts and the inhibition of both reactions by β-hydroxyethylhydrazine suggest that diamine oxidase is inhibited. β-Hydroxyethylhydrazine is a potent inhibitor in vivo of animal diamine oxidase.