This study explored the utilization of a custom-formulated deep eutectic solvent (DES) comprising choline chloride and ethylene glycol in a 2:1 molar ratio as the reaction medium for the biocatalytic conversion of Rd to M1 by snailase. Remarkably, a 97 % conversion rate of M1 within 8 h was attained under the following optimized conditions: a substrate concentration of 0.5 mM, 30 % volume ChCl: EG (2:1), operating temperature of 60°C, and pH 5.0. The inclusion of DES enhanced both the affinity and catalytic efficiency of snailase towards F2, leading to a notable increase of 20 % and 32 %, respectively, thereby facilitating the hydrolysis process. Spectral analysis confirmed the preservation of the conformation of snailase in the DES environment. Moreover, employing density functional theory provided valuable insights into the molecular mechanism underlying the biotransformation of Rd by DES. The results unveiled the formation of hydrogen bonds and a substantial binding energy (-140.49 kcal mol⁻¹) between ChCl: EG (2:1) and Rd, underscoring their pivotal role in achieving high conversion efficiency. Collectively, this study demonstrated the efficacy and effectiveness of utilizing DES as a promising and sustainable approach for the production of rare ginsenosides.

中文翻译：

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人参皂甙 Rd 在深共熔溶剂系统中高效生物催化转化为 M1


本研究探讨了利用一种定制配方的低共熔溶剂 （DES），其中包含氯化胆碱和乙二醇，摩尔比为 2：1，作为蜗牛酶将 Rd 生物催化转化为 M1 的反应介质。值得注意的是，在以下优化条件下，M1 在 8 小时内达到 97% 的转化率：底物浓度为 0.5 mM，30 % 体积 ChCl：EG （2：1），工作温度为 60°C，pH 值为 5.0。DES 的加入增强了蜗牛酶对 F2 的亲和力和催化效率，分别导致显着增加 20% 和 32%，从而促进了水解过程。光谱分析证实了蜗牛酶在 DES 环境中的构象保留。此外，采用密度泛函理论为 DES 生物转化 Rd 的分子机制提供了有价值的见解。结果揭示了 ChCl：EG （2：1） 和 Rd 之间氢键的形成和实质性的结合能 （-140.49 kcal ^mol-1），强调了它们在实现高转换效率中的关键作用。总的来说，这项研究证明了利用 DES 作为一种有前途且可持续的方法来生产稀有人参皂甙的功效和有效性。