On the tannin of the bark of Salix koliyanagi KIMURA. (I)

Abstract

The authors studied the tannin of the bark of Salix kori yanagi Kimura. The results obtained are as follows;
1. According to the Procter's classification the tannin of KORIYANAGI (Salix koriyanagi Kimura) bark belongs to the catechol tannin II.
2. The results of the quantitative analysis of the air-dried materials are as follows. (The quantity of the tannin has been determined by the Löwenthal's method.)
Moisture 14.230% Water soluble solid 11.881%
Non-tannin 5.425% Tannin 6.456%
3. The results of the extract tests are as follows.
1) There was no wide difference in the extract quantity at different crush degrees, but the quantity showed the tendency of becoming largest when the mesh of the sieve is from 2 to 10mm.
2) The whole length of the bark from top to bottom was divided in to three parts, i. e. upper, middle and lower parts.
The extract quantity was the largest in the lower part of the bark, the middle part came next and the upper part wat the smallest.
3) The extract quantity increased with the rise in temperature and it became the largest in 100—405°C.
4) In low temperature the increase in extract quantity was gradual while in high temperature almost no increase was recorded, i. e. on the whole, the time for extracting has little effect on the quality extracted.