Chen Zhong-Xiu, Guo Gang-Min, Deng Shao-Ping
Department of Applied Chemistry, College of Food and Biology Engineering, Zhejiang Gongshang University, Hangzhou, Zhejiang 310035, People's Republic of China.
J Agric Food Chem. 2009 Apr 8;57(7):2945-54. doi: 10.1021/jf803302g.
A fullerenol-based synthetic sweetness receptor model, consisting of polyhydroxy groups for potential hydrogen bond donor along with a spherical hydrophobic center, was proposed according to the widely accepted sweetness hypothesis. An isothermal titration calorimetry (ITC) technique was used to study mimetic interaction of this sweet receptor model with a series of sweeteners having increasing sweetness intensity. The results showed that ITC is an effective method to provide thorough and precise characterization of the energies of molecular complex formation. Binding of all of the studied sweeteners with fullerenols was found through two sets of site models. More heat was released from sweeter synthetic compounds binding with fullerenols than from less sweet carbohydrates. The results imply that hydrogen bond formation is necessary for the sweeteners to bind to the fullerenol receptor in the first stage, whereas hydrophobic effect and conformation changes that lead to favorable entropy changes occur in most cases. The preliminary results of this study help to cover the lack of information about the thermodynamic basis of understanding of the initiation of the sweet sensation. It also adds complementary physicochemical measurements available for comparison with the sweetness hypothesis. On the other hand, a correlation between the thermodynamic parameters and sweetness intensity has been made as well, which exhibits potential as a useful tool in sensory analysis.
基于富勒醇的合成甜味受体模型，由用于潜在氢键供体的多羟基以及球形疏水中心组成，根据广泛接受的甜味假说提出。采用等温滴定量热法（ITC）研究该甜味受体模型与一系列甜度递增的甜味剂的模拟相互作用。结果表明，ITC是一种有效方法，可对分子复合物形成的能量进行全面而精确的表征。通过两组位点模型发现所有研究的甜味剂与富勒醇的结合。与甜度较低的碳水化合物相比，甜度较高的合成化合物与富勒醇结合释放出更多热量。结果表明，氢键形成是甜味剂在第一阶段与富勒醇受体结合所必需的，而在大多数情况下会发生疏水效应和导致有利熵变的构象变化。本研究的初步结果有助于弥补在理解甜味感觉起始的热力学基础方面信息的不足。它还增加了可用于与甜味假说进行比较的补充物理化学测量。另一方面，还建立了热力学参数与甜度强度之间的相关性，这在感官分析中显示出作为有用工具的潜力。
