A number of adenine derivatives with cytokinin activity were isolated from immature sweet corn (Zea mays) kernels. The following structures were assigned: 9+-D-ribofuranosylzeatin, 9-fi-D-ribofuranosylzeatin 5'-monophosphate, 6-(l-carboxy-2-hydroxypropylamino)-9-ribofuranosylpurine, 6-(2,3,4 trihydroxy-3-methylbutylamino)purine, 2-hydroxy-6-(4-hydroxy-3-methylbut-trans-2-enylamino)purine, 6-(3,4-dihydroxy-3-methylbutylamino)purine, a 9-glycoside of zeatin (identity of sugar moiety not established), and 6-(1,2-dicarboxyethylamino)-9-gD-ribofuranosylpurine.