ANTICYTOKININ ACTIVITY OF 4-SUBSTITUTED TRIAZOLO[4,5-D]PYRIMIDINES AND 4-SUBSTITUTED PYRAZOLO[3,4-D]PYRIMIDINES

The synthesis and physiological activity of some novel 4-substituted t riazolo[4,5-d]pyrimidines and 4-substituted pyrazolo[3,4-d]pyrimidines are described. Most of the compounds possessed high anticytokinin act ivity towards purine (benzyladenine) and phenylurea (4-PU-30) type cyt okinins. onylpiperazinyl-1H-1,2,3-triazolo[4,5-d]pyrimidine almost com pletely removed cytokinin stimulated effects-betacyanin synthesis in A maranthus caudatus cotyledons; growth of radish cotyledons and retenti on of chlorophyll in leaf explants. Some chemical structure-physiologi cal activity relationships have been established.