TRANSFORMATIONS OF THE NATURAL CYTOKININ ZEATIN IN AQUEOUS ACIDIC MEDIA

The behaviour of the naturally occurring cytokinin zeatin 1 in aqueous acidic conditions has been studied, after it was observed that this c ompound was relatively more stable than another related cytokinin, 6-( 3-methylbut-2-enylamino)purine 2. Zeatin 1 reacted readily in 1 mol dm (-3) aqueous HCl at 100 degrees C. Three products were characterized, a diol resulting from the hydration of the double bond of the aliphati c chain. and two cyclized products, a hydroxypyrrolidine and a dihydro pyrrole. A scheme is proposed to explain the formation of these produc ts. However, zeatin was found to be stable in 0.1 mot dm(-3) aqueous H Cl at 100 degrees C and in 1 mol dm(-3) aqueous HCl at 50 degrees C, c onditions which allow the hydrolysis of zeatin riboside.