Author's Organization：Faculty of Pharmaceutical Sciences, University of Tokyo Faculty of Pharmaceutical Sciences, University of Tokyo Faculty of Pharmaceutical Sciences, University of Tokyo Faculty of Pharmaceutical Sciences, University of Tokyo College of General Education, University of Tokyo
Cytokinins initiate or promote cell division and cell differentiation of plants. N-(4-Pyridyl)-N'-phenylureas with an electronegative substituent (s) at positions 2 and 6 of the pyridine ring are the strongest cytokinins so far known. Structure-activity relationships between urea- and purine-cytokinins were discussed.
