Abstract
【Introduction】 In many cases of fruit production, dwarfism is induced by grafting into a dwarfingstock. A dwarf apple has some advantages in fruit production, which are easy to maintain, an early harvesting and so on. However, the mechanism of dwarfism has been unknown. We are trying to isolate plant growth regulators from a dwarf apple branch. 【Bioassay】 The shoots of Japanese radish planted for 5 days were used for bioassay after cutting the root part. The explants were then incubated in the 1/20 MS medium containing sample. After 5 days incubation in the 16h light at 25℃, the number of adventitious roots was counted. 【Result】 The branches of dwarf apple (JM7, 20kg) were dipped in 80% MeOH for a month at room temperature. The extract contained at least four active compounds. The highest molecular weight compound was difficult to purify by HPLC. The second compound was identified as a zeatin riboside by retention time of HPLC and UV spectrum. The third compound was isolated and investigated by MS and 1H NMR. The structure was presumed to be a glycoside of phenol derivative. The major active compound was isolated and investigated by MS, 1H NMR, DQF-COSY, and ROESY. The structure of this compound was estimated to be a novel glucoside of hydroxystilbene derivative. Now, we are synthesizing this compound to confirm the estimated structure.
