National Institute of Advanced Industrial Science and Technology (AIST), Interdisciplinary Research Center of Catalytic Chemistry, Central 5, 1-1-1 Higashi, Tsukuba, Ibaraki, 305-8565, Japan.
National Institute of Advanced Industrial Science and Technology (AIST), Open Innovation Laboratory for Food and Medicinal Resource Engineering, 1-1-1 Tennodai, Tsukuba, 305-8577, Japan.
Sci Rep. 2023 May 22;13(1):8275. doi: 10.1038/s41598-023-35423-x.
In this study, we developed a new synthetic strategy to convert secoiridoid glucosides into unique dialdehydic compounds using solid acid catalysts. Specifically, we succeeded in the direct synthesis of oleacein, a rare component of extra-virgin olive oil, from oleuropein, which is abundant in olive leaves. Whereas the conventional total synthesis of oleacein from lyxose requires more than 10 steps, these solid acid catalysts enabled the one-step synthesis of oleacein from oleuropein. A key step in this synthesis was the selective hydrolysis of methyl ester. Density functional theory calculations at the B3LYP/631+G (d) level of theory revealed the formation of a tetrahedral intermediate bonded to one HO molecule. These solid acid catalysts were easily recovered and reused at least five times by simple cleaning. Importantly, this synthetic procedure was not only applicable to other secoiridoid glucosides, but could also be employed for the corresponding scale-up reaction using oleuropein extracted from olive leaves as the starting material.
在这项研究中，我们开发了一种新的合成策略，使用固体酸催化剂将环烯醚萜葡萄糖苷转化为独特的二醛化合物。具体来说，我们成功地从橄榄叶中丰富的橄榄苦苷直接合成了特级初榨橄榄油中的稀有成分——橄榄苦苷。而从木糖合成橄榄苦苷的传统全合成方法需要超过 10 步，这些固体酸催化剂使从橄榄苦苷一步合成橄榄苦苷成为可能。该合成的关键步骤是甲酯的选择性水解。B3LYP/631+G(d)理论水平的密度泛函理论计算揭示了与一个 HO 分子键合的四面体中间体的形成。这些固体酸催化剂通过简单的清洗可至少重复使用五次以上。重要的是，该合成方法不仅适用于其他环烯醚萜葡萄糖苷，而且还可以用于使用从橄榄叶中提取的橄榄苦苷作为起始原料的相应放大反应。
