| Popis: |
Some 5-amino substituted 7-chloro-imidazo[1,2- c ]pyrimidines and 7-chloro-8-methylthio-imidazo[1,2- c ]pyrimidines were synthesized for further information on the role of the purine ring in cytokinin structure/activity relationships. Their cytokinin-like activity was examined using four different tests: expansion of cucumber etiolated cotyledons; formation of chlorophyll in etiolated cotyledons of cucumber; preservation of chlorophyll breakdown in sections of barley leaves; inhibition of root growth in intact wheat seedlings. Compounds with the imidazopyrimidine ring were generally less active than those with the purine ring, with the exception of the pentenylamino derivatives, which showed an activity comparable with that of the control, kinetin. |
