Mannane as a Reserve Material 

 in the Seeds of Diospyros Kaki, L. 



BY 



J- Ishii, Nogakushi. 



The fruit of Diospyros Kaki, L. (date-plum) is consumed 

 in large quantities by the people of this country on account of its 

 richness in saccharine matters. There are many varieties of 

 the fruit, ranging in size from a small hen's egg to a large 

 apple. In color') of the epidermis they vary from light orange 

 yellow to deep orange red. My preliminary experiments proved 

 it probable that a wine of good quality might be prepared 

 from the fruit. It may be also mentioned here that this fruit 

 contains, when unripe, a considerable amount of a kind of tan- 

 nin which disappears entirely during the ripening of the fruit. 

 My investigations of the flesh of the fruit have shown that 

 there is a great amount of dextrose and laevulose, but neither 

 mannose nor galactose present. It is, therefore, surprising that 

 the seeds of the fruit contain no trace of starch, but a soft 

 white mass as a reserve material, which could be easily con- 

 verted into a sugar by boiling with sulphuric acid of 5% 

 for one hour. After removal of the sulphuric acid with barium 

 carbonate, the filtrate was evaporated, when a red-colored sub- 

 stance was gradually deposited ; this was filtered off and the 

 solution after being decolorized with animal charcoal was 

 further concentrated. I obtained a sweet syrup which yielded, 

 with acetate of phenylhydrazin in the cold, a considerable 

 amount of crystalline precipitate, which upon recrystallization 

 formed white tabular rhombic crystals, melting at ig5°C (man- 

 nose-phenylhydrazon). By mixing a certain quantity of acetate 

 of phenylhydrazin with the aqueous solution of the crystals 

 and heating the mixture, there were formed gradually yellow 



1) This coloring matter is turned blue by treatment with concentrated sul- 

 phuric acid. 



