In vitro synthesis of linear α-1,3-glucan and chemical modification to ester derivatives exhibiting outstanding thermal properties.
In vitro synthesis of linear α-1,3-glucan and chemical modification to ester derivatives exhibiting outstanding thermal properties.
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DOI：
10.1038/srep30479
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发表时间：
2016-07-29
影响因子：
4.6
通讯作者：
Iwata T
中科院分区：
文献类型：
--
作者：
Puanglek S;Kimura S;Enomoto-Rogers Y;Kabe T;Yoshida M;Wada M;Iwata T
生物基聚合物被认为是一种有潜力的可再生材料，可以减少石油资源的消耗。本文报道了非天然型生物基多糖α-1,3-葡聚糖的一锅法合成与开发。从唾液链球菌ATCC 25975中克隆出一种葡萄糖基转移酶GtfJ酶，以可再生原料蔗糖为葡萄糖单体来源，通过环境友好的一锅水基反应，在体外进行酶聚合合成。α-1,3-葡聚糖的结构是完全线性的，没有分支，分子量（Mw）为700 kDa。合成了α-1,3-葡聚糖乙酸酯和丙酸酯，并对其进行了表征。有趣的是，α-1,3-葡聚糖醋酸酯在339℃时的熔融温度相对较高，高于市售热塑性塑料，如PET（265℃）和尼龙6（220℃）。因此，无分支α-1,3-葡聚糖酯晶体的发现，具有较高的热稳定性和熔融温度，为进一步研究热塑性材料的应用打开了大门。
Bio-based polymer is considered as one of potentially renewable materials to reduce the consumption of petroleum resources. We report herein on the one-pot synthesis and development of unnatural-type bio-based polysaccharide, α-1,3-glucan. The synthesis can be achieved by in vitro enzymatic polymerization with GtfJ enzyme, one type of glucosyltransferase, cloned from Streptococcus salivarius ATCC 25975 utilizing sucrose, a renewable feedstock, as a glucose monomer source, via environmentally friendly one-pot water-based reaction. The structure of α-1,3-glucan is completely linear without branches with weight-average molecular weight (Mw) of 700 kDa. Furthermore, acetate and propionate esters of α-1,3-glucan were synthesized and characterized. Interestingly, α-1,3-glucan acetate showed a comparatively high melting temperature at 339 °C, higher than that of commercially available thermoplastics such as PET (265 °C) and Nylon 6 (220 °C). Thus, the discovery of crystalline α-1,3-glucan esters without branches with high thermal stability and melting temperature opens the gate for further researches in the application of thermoplastic materials.