Ethanol extract of persimmon fruitlets (Diospyros kaki L. cv. Hiratanenashi) contains cytokinins which stimulate strongly the growth of tobacco callus tissue in vitro. One of these cytokinins was purified with n-butanol extraction and ion exchange columns, and compared with known natural cytokinins in paper chromatography with several solvent systems. It was revealed that this cytokinin was very closely related to zeatin, but apparently distinguishable from it. Results indicate an occurrence of a novel cytokinin in the persimmon fruitlets
