梅片树中高纯度右旋龙脑制备及其性质表征

摘要

In this study, we investigated the preparation of highly pure D-borneol from the essential oil extracted from the leaves of Dryobalanops aromatica through steam distillation. Crude D-borneol was obtained after the essential oil was subjected to freeze-drying and centrifugation. Then, the crude product was purified by recrystallization in petroleum ether, 120# gasoline, and anhydrous ethanol, respectively. The chemical composition, optical rotation, morphology and thermal properties of the as-obtained crystals were characterized. The results showed that the content of D-borneol in the essential oil was about 68.10%, and its purity was more than 98% after recrystallization. There were no obvious differences in mass spectrum or optical rotation between D-bormeol standard and the solvent recrystallized crystals. The appearance of the petroleum ether and gasoline 120# recrystallized crystals showed regular hexagons with clear boundary, while the ethanol recrystallized crystal was irregularly and granularly dispersed or aggregated. However, the results of thermal analysis showed that the thermal properties of all three recrystallized crystals were the same, indicating that the appearance of crystals did not affect their thermal performance. Furthermore, Mo's equation could describe the non-isothermal crystallization process of D-borneol crystal. This study can provide an important technical reference for the exploitation and utilization of Dryobalanops aromatica and the production of high-purity D-borneol.%通过水蒸气蒸馏法从梅片树叶中提取挥发油,冷冻、离心得粗右旋龙脑,用石油醚、120号汽油和无水乙醇分别进行重结晶,得到高纯度右旋龙脑晶体,并对晶体的成分、旋光性、形态和热性能进行了表征.结果表明,梅片树树叶挥发油中右旋龙脑含量为68.10%;重结晶后纯度达98%以上,质谱图分析结果和标准品基本一致,旋光度也相近;石油醚和120号汽油重结晶晶体呈规则六边形大片状,边界清晰,无水乙醇重结晶晶体形状不规则,呈分散或团聚的小颗粒状,但两者的热分析结果基本相同,说明重结晶晶体形貌不影响其热性能.右旋龙脑晶体非等温结晶过程中,莫志深方程能很好地描述右旋龙脑的非等温结晶动力学.本实验结果可为梅片树的综合利用及高纯度天然右旋龙脑新资源的研究开发提供参考.