Hu Jinyue, Song Lingling, Zhao Le, Zheng Xiaoke, Feng Weisheng, Jia Haoyu
School of Pharmacy, Henan University of Chinese Medicine, Zhengzhou 450046, China.
The Engineering and Technology Center for Chinese Medicine Development of Henan Province, Zhengzhou 450046, China.
Molecules. 2025 Jul 3;30(13):2847. doi: 10.3390/molecules30132847.
Icariside I, a bioactive flavonoid derivative derived from , demonstrates better pharmacological properties compared to its precursor icariin. Enzymatic conversion of icariin to icariside I using α-L-rhamnosidase represents an efficient biotechnological approach. In this study, we characterized a GH78 family α-L-rhamnosidase from (Rha) with promising biocatalytic properties. The recombinant Rha displayed optimal activity at 55 °C and pH 6.0, with remarkable thermostability (retaining > 80% activity after 1 h at 45-65 °C) and pH stability (pH 5.0-7.0). The kinetic parameters , and / values for pNPR of 0.44 mM, 7.99 s and 18.16 s mM, respectively. Notably, Rha exhibited good organic solvent tolerance, retaining > 50% activity after 4 h in 10% DMSO. Applied in a DMSO cosolvent system, Rha achieved 92.3% conversion of icariin to icariside I within 4 h under optimized conditions. Interestingly, elevating the substrate concentration to 10 mM resulted in a consistently high icariin conversion of 95.8%. The enzymatic hydrolysis method can be applied to the industrial production of Icariside I. Furthermore, Rha not only cleaves the α-1,2 glycosidic bond between glucoside and rhamnoside in compounds like naringin, but also exhibits tolerance to organic solvents, making it suitable for the hydrolysis of other poorly soluble flavonoids.
淫羊藿次苷I是一种从[来源未提及]衍生而来的生物活性黄酮类衍生物，与其前体淫羊藿苷相比，具有更好的药理特性。使用α-L-鼠李糖苷酶将淫羊藿苷酶促转化为淫羊藿次苷I是一种有效的生物技术方法。在本研究中，我们对来自[来源未提及]的具有良好生物催化特性的GH78家族α-L-鼠李糖苷酶（Rha）进行了表征。重组Rha在55°C和pH 6.0时表现出最佳活性，具有显著的热稳定性（在45 - 65°C下1小时后保留> 80%的活性）和pH稳定性（pH 5.0 - 7.0）。对pNPR的动力学参数Km、Vmax和kcat/Km值分别为0.44 mM、7.99 s⁻¹和18.16 s⁻¹ mM⁻¹。值得注意的是，Rha表现出良好的有机溶剂耐受性，在10% DMSO中4小时后保留> 50%的活性。应用于DMSO助溶剂体系中，在优化条件下，Rha在4小时内实现了92.3%的淫羊藿苷向淫羊藿次苷I的转化。有趣的是，将底物浓度提高到10 mM导致淫羊藿苷转化率持续保持在95.8%的高水平。酶促水解方法可应用于淫羊藿次苷I的工业化生产。此外，Rha不仅能切割柚皮苷等化合物中葡萄糖苷和鼠李糖苷之间的α-1,2糖苷键，还表现出对有机溶剂的耐受性，使其适用于其他难溶性黄酮类化合物的水解。
