Cyclosophoraose 類の加水分解反応に関する研究. : 高速液体クロマトグラフィーによる分析(分析化学)
1986 年 106 巻 11 号 p. 1021-1027
詳細
1986 年 106 巻 11 号 p. 1021-1027
Cyclosophoraoses (CySs) are unbranched cyclic (1→2)-β-D-glucans, produced by many strains of Agrobacterium and Rhizobium, and their degree of polymerizations (DPs) vary from 17 to at least 40. Among them CyS-A(DP 17), B(DP 18), C(DP 19), D(DP 20), E(DP 21), F(DP 22), G(DP 23), and H(DP 24) predominate. Acid hydrolyses of CyS-A-H were studied in the range of 65 to 95°C. Cyclic and linear (1→2)-β-D-glucans having the same DP in partial hydrolysates were separated by taking advantage of differences in their chromatographic behavior on C18-bonded silica and determined by high performance liquid chromatography on an NH2-bonded silica column. The hydrolyses of CySs were apparent first-order reactions, and an activation energy for each reaction was approximately 30 kcal/mol. The values of rate constants for hydrolyses of CySs decreased in order of CyS-G(DP 23)>E(DP 21)〓B(DP 18)〓H(DP 24)〓F(DP 22)〓D(DP 20)>C(DP 19)>A(DP 17).
