Synthesis, Characterization and Thermal Controlled Release Of 2‐Isopropyl‐N,2,3‐Trimethylbutyramide with Acyclic Cucurbit[n]urils Inclusion Complexes

Abstract

WS‐23 (2 ‐Isopropyl‐ N,2,3 ‐Trimethylbutyramide) is a novel flavor cooling agent, which has been widely used as additive nowadays in food, medicine, cosmetics, daily necessities products, etc. However, its inherent poor solubility and thermal instability seriously limits its further application. Herein, new inclusion systems of WS‐23 with two acyclic cucurbit[n]urils (ACBs) were prepared for the first time, and their binding behaviors in solution and solid states were investigated by means of 1H NMR, 2D ROESY, XRD, FT‐IR SEM, and Fluorescence Spectroscopy. The data reveal that the stoichiometric ratio of the inclusion complex is 1 : 1, the solubility of WS‐23 can be enhanced by ca. 19.39 ‐ 31.72 folds. Besides, the heat‐controlled release properties of WS‐23 from the solid inclusion complexes were also investigated by TGA and 1H‐NMR, and its thermal stability in two inclusion complexes are both greatly improved. WS‐23 /M1(M2) exhibited a longer retention time in tobacco products and effectively improve the sensory quality. In brief, our work provides theoretical data and technical guidance for the development and application of water soluble WS‐23 with controlled heat release, which might further application of WS‐23 in the field of commercial industry.