Cytokinins are substances close to purine bases (substituted adenins). It is a family of phytohormones essential for the development of the plant as well as auxin, which acts as hormones in plants.

The most common form of naturally occurring cytokinin in plants is zeatin, but many other natural cytokinins have been isolated, including dihydrozeatin, isopentenyladenine, or benzyladenine.

Dihydrozeatin (DHZ) is a naturally occuring cytokinin that is generally very active. DHZ derivatives are commonly found in plant tissues and are frequent metabolites of applied zeatin. In a bioassay, DHZ and its conjugates are equally active as their zeatin ana-logues. In studies where DHZ has been externally supplied to plants it appears to be more ‘stable’ than zeatin. This may be because DHZ is not a substrate for cytokinin oxidase. DHZ may be important in the maintenance of cytokinin activity levels in an oxidative environment.