单萜烯醇-β-D-吡喃葡萄糖苷的合成及热降解机理研究

The key factors that limit flavor industry development are the long residual action and high temperature stability properties of flavor and fragrance. In this research, the synthesis, purification, and structure identification of series monoterpenol-β-D- glucopyranosides (MTG) flavor precursors will be combined with thermal analysis, and the pyrolysis products and thermal decomposition mechanism of the glycosides will be extensively investigated by thermo-analysis techniques. Modified Koenigs-Knorr method will be adapted. More than 10 kinds of MTG compounds will be synthesized stereo-selectively. TLC and HPLC etc. for purification and EA, FT-IR, and NMR, LC-MS for identification as the naturally identical structure). Thermo-analysis techniques, such as TGA, DTA, and DSC, will be used to study thermal behavior. The characteristic thermo-analysis curves and the important thermo-chemistry foundation data will be obtained through simultaneous and real-time online techniques, such as TGA-MS, TGA-FTIR, Py-GC-MS, and GC-O, to analyze the thermal decomposition compounds and to trace the aroma release process. Using the laws of thermodynamics, the characteristics and the regularity of the thermo-chemistry properties and molecular structure of MTG will be determined to clarify the thermal decomposition and aroma release control mechanisms. Providing scientific basis for glycoside flavor precursors as thermo-stability flavor raw materials has important theoretical significance and latent application prospects.

香精香料的长效性和高温稳定性是制约香料工业发展的瓶颈。本项目将系列单萜烯醇-β-D-吡喃葡萄糖苷(MTG)香料前体的合成、纯化、分子结构谱学表征和热分析紧密结合，对糖苷的热降解机理进行系统研究。采用改进的Koenigs-Knorr法，立体选择性合成十多种MTG化合物，经TLC、HPLC等分离纯化，EA、FT-IR、NMR和LC-MS等确证其为天然等同结构；利用TGA、DTA和DSC等热分析技术研究其热解行为，获得特征的热谱曲线和重要的热化学基础数据；通过TGA-MS、TGA-FTIR、Py-GC-MS及GC-O等联用及实时在线检测技术分析糖苷在程序升温条件下的热降解产物，追踪其释香历程。以热力学定律为指导，通过对实验数据的深入分析和归纳总结，揭示MTG的热化学性质随结构变化规律性，阐明MTG的热降解机理。为研究糖苷类香料前体作为耐高温香料的可行性提供理论依据和实验支持。

香精香料的长效性和高温稳定性是制约香料工业发展的瓶颈，本项目对系列单萜烯醇糖苷的合成、表征、热行为及热降解机制进行了深入系统研究，为耐高温香料研制及产业化应用提供基础数据。.以香茅醇、玫瑰醇、香叶醇、橙花醇、芳樟醇、α-松油醇、丁香酚、异丁香酚、薄荷醇、叶醇为配体，立体选择性合成以单萜烯醇-β-D-吡喃葡萄糖苷为主的系列化合物。优化改进的Koenigs-Knorr合成法，制备高效担持催化剂；经TLC、SGCC、HPLC等对目标产物分离纯化，获得样品含量分别为99.36%、99.23%、98.40%、99.08%、96.52%、97.67%、98.06%、97.85%、99.99%、99.90%，以FT-IR、NMR和LC-MS-MS等对各糖苷进行分子结构谱学表征，确证为天然等同结构。.研究糖苷热行为及热降解产物。利用TGA/SDTA和DSC研究了系列糖苷从室温到500℃热解行为，各糖苷分解温度均在250-350℃之间，说明发生了糖苷键裂解，TGA/SDTA与DSC结果一致，表明降解为熔融与分解同时发生，获得大量特征的热谱曲线和重要的热化学基础数据。通过Py-GC-MS等联用及实时在线检测定性、定量分析糖苷在200-700℃程序升温热降解产物，追踪释香历程。结果表明，糖苷类化合物分解释放配体呈现先增长后降低趋势，与裂解温度直接相关。以热力学定律为指导，揭示MTG热化学性质随结构变化规律性，以糖苷键断裂为主的复杂降解过程。通过Phadnis-Deshpande 法探讨降解机理函数，Friedman法和Flynn-Wall-Ozawa法计算糖苷活化能Ea，揭示糖苷热降解遵循一维扩散运动机理。.将糖苷添加到低焦油云烟中，进行了卷烟的整支燃吸和分段燃吸以及感官品评实验，测定了香气转移率和释香稳定性，验证糖苷缓释增香作用。为研究糖苷类香料前体作为耐高温香料的可行性提供了理论依据和实验支持。