The utilization of inedible parts of persimmon: persimmon calyx for specific medicine of hiccups

The calyx of persimmon is characteristically used as a specific medicine for hiccups in Eastern traditional medicines. It is listed as Kaki Calyx (Latin name as a crude drug) in “The Japanese Standards for Non-Pharmacopoeial Crude Drugs (Non-JPS)” and is defined as the persistent calyx of the mature fruit of Diospyros kaki Thunb. Today, all Kaki Calyx used in Japan (about 1 t year^-1) is imported from China. Therefore, we aim the domestic production of Kaki Calyx from the both points of views of the stable supply of safe crude drugs and utilization of inedible parts of persimmon. However, there are some problems of their preparation. First, the cost is too much for preparing them. Second, the batch we prepared in 2018 didn’t meet the criteria of Non-JPS because of the insufficiency of dilute ethanol-soluble extract content, and it was impossible to use them as crude drugs. In order to solve these problems, we investigated to expand the cultivars for the material to meet both economical demand and Non-JPS criteria of the quality by comparing dilute ethanol-soluble extract contents or polyphenolic constituents among various samples. We prepared samples from ‘Tonewase,’ ‘Hiratanenashi,’ ‘Horenbo,’ and ‘Fuyu’ by several ways; prepared from fresh fruits or dried persimmon and collected from the branches after the fruits have ripen and dropped. As a result of dilute-ethanol soluble extract measurement and Folin-Ciocaluteu assay, samples from ‘Fuyu’ showed comparably high content in both assays, whereas samples from dried fruits showed high value only in the assay of dilute-ethanol soluble extract. ‘Fuyu’ cultivar can be expected for material of domestic Kaki Calyx, but further investigation is needed.