没食子酰糖类化合物的合成及络合金属锗

Synthesis of galloyl glycans and complexation of germanium metal

摘要:

摘要：对没食子酸进行修饰，依次合成三苄基没食子酸及其酰氯，并进一步与D-阿拉伯糖、葡萄糖以及七元氮杂糖反应，经催化氢化脱苄基后，分别得到没食子酰阿拉伯糖（Ⅴ）、没食子酰葡萄糖（Ⅶ）和没食子酰七元氮杂糖（Ⅸ）三种新型没食子酰糖类单宁酸。合成的中间体与目标化合物的结构均经过1HNMR、13CNMR和HRMS确证。将上述新合成的单宁酸与含锗（Ge4+）溶液进行络合反应，经离心、冷冻干燥后得到络合物，分别对离心上清液和络合物进行锗含量分析。结果表明，离心上清液中的Ge4+浓度均低于标准溶液Ge4+浓度（10 mmol/L），说明新合成的3种单宁酸类化合物都能与Ge4+发生络合反应，并形成稳定的络合物而析出。结合对Ge4+吸附量推断，新合成的没食子酰葡萄糖络合Ge4+的能力与天然五倍子单宁酸相似，而没食子酰阿拉伯糖与没食子酰七元氮杂糖络合Ge4+能力均优于天然五倍子单宁酸。没食子酰糖类化合物与Ge4+发生络合的最佳工艺条件为调节溶液pH为2，温度50 ℃，震荡2 h。选择性实验表明，没食子酰糖类化合物络合Ge4+、Fe3+和Zn2+的优先顺序为：Fe3+ > Ge4+ > Zn2+。

Abstract:

Abstract: Gallic acid was modified to synthesize tribenzyl gallic acid and its acyl chloride, and then reacted with D-arabinose, glucose and heptaazinose. After catalytic hydrogenation debenzyl, three new gallic saccharide tannins, gallioyl-arabinose (Ⅴ), gallioyl-glucose (Ⅶ) and gallioyl-heptaazinose (Ⅸ), were obtained respectively. The structures of the synthesized intermediates and target compounds were confirmed by 1HNMR, 13CNMR and HRMS. The tannic acid was complexed with germanium (Ge4+) solution, and the complex was obtained by centrifugation and freeze-drying. The content of germanium in the supernatant and the complex were analyzed. The results showed that the concentration of Ge4+ in the supernatant was lower than that in the standard solution (10 mmol/L), indicating that the three newly synthesized tannic acid compounds could complexate with Ge4+ and form stable complexes. Based on the Ge4+ adsorption capacity, the Ge4+ complexation ability of newly synthesized gallic glucose was similar to that of natural gallic tannic acid, while the Ge4+ complexation ability of gallic arabinose and gallic heptaazinose was better than that of natural gallic tannic acid. The optimal conditions for the complexation of gallic saccharides and Ge4+ were adjusting the solution pH to 2, temperature to 50 ℃, and shaking for 2 h. The selectivity experiments showed that the priority order of complexation of Ge4+, Fe3+ and Zn2+ by gallic saccharides was: Fe3+ > Ge4+ > Zn2+.