The thermostable GH78 family α-L-rhamnosidase DthRha from Dictyoglomus thermophilum DSM3960 was found to have the ability to remove the α-L-rhamnose moiety that was directly linked to the aglycone by an α-1-rhamnosidic bond at the C-3 position of epimedium flavonoids. It exhibited high specific activity on p-nitrophenyl-α-L-rhamnopyranoside (pNPR) (281.06 U/mg), followed by epimedin C (30.42 U/mg), icariin (9.74 U/mg), baohuoside I (1.02 U/mg) and 2’-O-rhamonosylicariside II (3.74 U/mg). In addition, the thermostable glucosidase Dth3 from Dictyoglomus thermophilum DSM3960, which exhibits β-xylosidase activity and β-glucosidase activity, was purified. The main enzymatic properties of the two thermostable glycosidases were compared, and these glycosidases were successfully utilized in the preparation of pharmacologically active icaritin from the total flavonoid extract of epimedium. Finally, 5 g/L of the total flavonoid extract of epimedium was completely transformed into 207.95 mg/L icaritin at pH 5.5 and 80 °C for a total of 4 h. This is the first report on the efficient biotransformation of the total flavonoid extract of epimedium into icaritin by two thermostable enzymes with high productivity. The cost of icaritin preparation will be substantially reduced by converting all the major ingredients in the total flavonoid extract of epimedium.

发现来自嗜热纤维菌DSM3960的热稳定GH78家族α-L-鼠李糖苷酶DthRha具有去除通过C-3位置通过α-1-鼠李糖键直接与糖苷配基连接的α-L-鼠李糖部分的能力。淫羊类黄酮。它对对硝基苯基-α-L-鼠李糖吡喃糖苷（pNPR）（281.06 U / mg），其次为表必达木素C（30.42 U / mg），柠檬素（9.74 U / mg），宝hu苷I（1.02 U / mg）表现出高比活性。mg）和2'-O-鼠李糖苷II（3.74 U / mg）。另外，嗜热单核球菌的热稳定的葡糖苷酶Dth3纯化了表现出β-木糖苷酶活性和β-葡萄糖苷酶活性的DSM3960。比较了两种热稳定的糖苷酶的主要酶学性质，并将这些糖苷酶成功地用于从淫羊ium总黄酮提取物中制备具有药理活性的icaritin。最后，将5 g / L淫羊ium总黄酮提取物在pH 5.5和80°C下完全转化为207.95 mg / L icaritin，共需4 h。这是关于淫羊thermo总黄酮提取物通过两种热稳定性高的酶高效生物转化为icaritin的报道。通过将淫羊ium总黄酮提取物中的所有主要成分进行转化，可以大大降低艾卡利丁的制备成本。