Abstract
The polysaccharide C prepared from gum tragacanth powder (U. S. P. grade) by the precipitation method with 85% ethanol was a neutral polysaccharide, $[{\alpha}]^{30}_D-72.2$. The polysaccharide C consisted of L-rhamnose, D-xylose, L-arabinose and D-galactose in the molar ratio 2:1:17:9 (Table 1, 2, 3, ). The polysaccharide C was methylated with dimethylsulphate and 40% NaOH, and Purdies regent. The hydrolyzate of fully methlated product ($[{\alpha}]^{22}_D-102$ in chloroform, the methoxy content 40.6%) was composed of 2, 3, 5-tri-O-methyl-L-arabofuranose (I), 3,4-di-O-methyl-L-rhamnopyranose (II), 2,3-di-O-methyl-D-xylose (III), 2,3,4-tri-O-methyl-D-galactopyranose (IV), 2,4-di-O-methyl-L-arabopyranose (?), 2,4-di-O-methyl-D-galactose(VI), 2-O-methyl-D-arabinose (VII), and L-arabopyranose(VIII) (Table 4, 5, and Fig. 4). The first partial hydrolysis (A) of the polysaccharide C with 0.05N-HCl for 4.5 hours at $80-85^{\circ}C$ released only L-arabinose: the second hydrolysis (B) with 0.1N-HCl for 5 hours at $80-85^{\circ}C$, L-arabinose and D-galactose; and the third hydrolysis (C) with 0.3N-HCl at $90-95^{\circ}C$ in sealed tube, L-rhamnose, D-xylose, L-arabinose and D-galactose. From the unhydrolyzate A' were found L-rhamnose, D-xylose, L-arabinose, and D-galactose; from B' L-rhamnose, d-xylose, L-arabinose and D-galactose; and from C' D-xylose and D-galactose respectively (Table 6). The periodate consumption and formic acid production of the polysaccharide C were measured at various time intervals. After 120 hours periodat was consumed by 1.23 mole per $C_5H_8O_4$ and formic acid was produced 0.78 mole per $C_5H_8O_4$ (Table 7). Although a definite chemical structure for this polysaccharide C may not be formulated, experimental data, especially, from methylation, partial hydrolysie and determination of its molar ratio, and periodate analysis showed that the polysaccharide C is a highly branched polysaccharide and would be constructed of galactoaraban as a main chain residue and L-arabofuranose, D-galactopyranosyl $(1{\rightarrow}1)$-L-arabofuranose, D-xylopyranosyl $(1{\rightarrow}2)$-L-rhamnopyranosyl $(1{\rightarrow}1)$-L-arabofuranose, and L-rhamnopyranosyl $(1{\rightarrow}1)$-arabofuranose, and D-galactopyranosyl-$(1{\rightarrow}2)$-L-arabopyranosyl-$(1{\rightarrow}1)$-I-arabofuranose as a branch chain or end group (page 21).
tragacanth gum의 화학구조(化學構造)를 구명(究明)하기 위(爲)하여 미국(美國) 약전(藥典)의 tragacanth gum 분말(粉末)을 가지고 다음의 실험(實驗)을 통(通)하여 이의 성분(成分)의 하나인 polysaccharide C를 분리(分離)하여 이의 화학구조(化學構造)를 밝혔다. (1) tragacanth gum을 85% 주정(酒精)으로 처리(處理)해서 중성다당류(中性多糖類)로 polysaccharide C를 분리(分離)하였으며 구성당(構成糖)으로 L-rhamnose, D-xylose, L-arabinose 및 D-galactose를 paper chromatography와 Cellulose column chromatography로 분리(分離), 동정(同定)하였다. 이의 molar ratio는 2:1:17:9이며 비선광도(比旋光度)는 $[{\alpha}]^{30}_D-72.2이다. (2) 구성당(構成糖)의 결합위치(結合位置)를 구명(究明)하기 위(爲)해 Hawarth 법(法)과 Purdietldir(試藥)을 가지고 methyl화(化)시켜 methyl화(化) polysaccharide C를 얻었으며 비선광도(比旋光度) $[{\alpha}]^{22}_D-102를 보였다. 이것을 가수분해(加水分解)시켜 paper chromatography와 column chromatography를 통(通)해 methyl화단당(化單糖)으로 1,3,5-tri-O-methyl-L-arabofuranose, 3,4-di-O-methyl-L-rhamnose, 2,3-di-O-methyl-D-xylose, 2,3,4-tri-O-methyl-D-galactopyranose, 2,4-di-O-methyl-L-arabopyronose, 2,4-di-O-methyl-D-galactose, 2-O-methyl-L-arabinose 및 L-arabinose를 분리(分離), 동정(同定)하였다. (3) 산(酸)의 각종농도(各種濃度)에 따른 부분적(部分的) 가수분해(加水分解)를 시켜 polysaccharide C의 end group, 측지(側枝) 또는 주쇄(主鎖)를 이루는 구성당(構成糖)을 밝히기 위(爲)하여 0.05 N-HCl로 제1차(第一次) 가수분해(加水分解). 0.1N-HCl로 제2차(第二次) 가수분해(加水分解), 0.3N-HCl로 제3차(第三次) 가수분해(加水分解)를 하여 가수분해물(加水分解物)과 비가수분해물(非加水分解物)에서 각각(各各) 다음과 같은 구성단당(構成單糖)을 검출(檢出)하고 이들의 molar ratio를 측정(測定)하였다. 제1차(第一次) 가수분해물(加水分解物)(A)에서 L-arbinose, 비가수분해물(非加水分解物)(A')에서 L-rhamnose, D-xylose, L-arabinose 및 D-galactose; 제2차(第二次) 가수분해물(加水分解物)(B)에서 L-arabinose와 D-galactose, 비가수분해물(非加水分解物)(B')에서 L-rhamnose, D-xylose, L-arabinose, 및 D-galactose; 제3차(第三次) 가수분해물(加水分解物)(C)에서 L-rhamnose, D-xylose, L-arabinose 및 D-galactose, 비가수분해물(非加水分解物)(C')에서 D-xylose와 D-galactose를 검출(檢出)하였다. (4) 구성당(構成糖)의 형태(形態)와 구조(構造)를 밝히기 위(爲)해 polysaccharide C에 대한 periodate산화(酸化) 실험(實驗)을 하여 $C_5H_8O_4$당(當) periodate의 소비(消費)와 formic acid의 생성량(生成量)을 측정(測定)하였는데 periodate의 소비량(消費量)은 1.23 mole, formic acid의 생성량(生成量)은 0.78 mole이다.