passages.id: split_4_test_2937_passage
passages.type: progene_text
passages.text: Regarding replacements of quinazoline by other heterocyclic rings , pyrazolo [ 3,4-d]pyrimidine ( 39a , IC(50) = 0.17 microM ) and quinoline ( IC(50) of 40a is 0.18 microM ; IC(50) of 40b is 0.09 microM ) derivatives showed potent activity .