Anticytokinin Activity of N-Phenyl- and N-Pyridylcarbamates

A new class o f non-adenylate anticytokinins, alkyl and phenyl N -phenylcarbam ates and re­ lated phenyl N-pyridylcarbam ates, has been developed. They have a structure that has an im ­ m ediate resem blance to the non-adenylate class o f cytokinins, N ,N '-diphenylureas, and N -pyridyl-N '-phenylureas, and the design o f the m olecule was m ade based on insight into the bioisoteric nature between the previous, non-adenylate s-triazine anticytokinins and the carba­ m ate and urea structures. The activity in terms o f the ho value o f the m ost potent members, 4-fluoroand 4-chlorophenyl N -(2-chloro-4-pyridyl)carbam ates, was 0 .3 -0 .5 x 10~ 6 M when exam ined by the tobacco (Nicotiana tabacum L.) callus assay in the presence o f 0.05 x 10“ 6 m kinetin.