Hydration and sweetness of synthetic sweeteners

Recently, the degree of sweetness of natural sugars has been associated and correlated to their hydration shell (strength, orientation and length of their hydrogen bonds with water). In this context, we propose to extend previous studies performed on SANDALS to the study of the hydration of synthetic sweeteners. These have high-potency sweetness and it seems that are not recognized by the same receptor of natural sugars. Thus it is interesting to address whether H-bonds play a role also in this case, in order to seek for an explanation, at the atomic scale, of the sweet taste chemoreception. We have chosen three sweeteners, namely saccharin, acesulfame-K and aspartame, where saccharin and acesulfame-K are associated to the same receptor, while aspartame to a different one. Their sweetness spans from about 150 to 300 times the sweetness of sucrose.近年来，研究证实天然糖类的甜度与其水合壳层（hydration shell）密切相关，其与水分子形成氢键的强度、取向与长度正是该壳层的核心特征。在此研究背景下，我们提出将此前基于SANDALS的相关研究拓展至人工甜味剂的水合作用研究。这类人工甜味剂具有高倍甜度，且其识别受体与天然糖类的受体并不相同。因此，探究氢键在该类体系中是否同样发挥作用，有助于从原子尺度阐释甜味化学感受的分子机制，具备重要研究价值。本次研究选取了三种人工甜味剂：糖精（saccharin）、乙酰磺胺酸钾（acesulfame-K）与阿斯巴甜（aspartame），其中糖精与乙酰磺胺酸钾可被同一受体识别，而阿斯巴甜的识别受体则有所不同。这三种甜味剂的甜度约为蔗糖（sucrose）的150至300倍。