Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing 210037, China.
College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, China.
Molecules. 2019 Aug 22;24(17):3042. doi: 10.3390/molecules24173042.
Isorhamnetin-3--rhamnoside was synthesized by a highly efficient three-enzyme (rhamnosyltransferase, glycine max sucrose synthase and uridine diphosphate (UDP)-rhamnose synthase) cascade using a UDP-rhamnose regeneration system. The rhamnosyltransferase gene (78D1) from was cloned, expressed, and characterized in . The optimal activity was at pH 7.0 and 45 °C. The enzyme was stable over the pH range of 6.5 to 8.5 and had a 1.5-h half-life at 45 °C. The and for isorhamnetin were 0.646 U/mg and 181 μM, respectively. The optimal pH and temperature for synergistic catalysis were 7.5 and 25 °C, and the optimal concentration of substrates were assayed, respectively. The highest titer of isorhamnetin-3--rhamnoside production reached 231 mg/L with a corresponding molar conversion of 100%. Isorhamnetin-3--rhamnoside was purified and the cytotoxicity against HepG2, MCF-7, and A549 cells were evaluated. Therefore, an efficient method for isorhamnetin-3--rhamnoside production described herein could be widely used for the rhamnosylation of flavonoids.
山柰酚-3-O-鼠李糖苷通过使用 UDP-鼠李糖再生系统的高效三酶（鼠李糖基转移酶、大豆蔗糖合酶和尿苷二磷酸（UDP）-鼠李糖合酶）级联反应合成。从 克隆、表达和表征了 中的鼠李糖基转移酶基因（78D1）。最佳活性在 pH 7.0 和 45°C。该酶在 pH 6.5 至 8.5 范围内稳定，在 45°C 下半衰期为 1.5 小时。 和 对于山柰酚分别为 0.646 U/mg 和 181 μM。协同催化的最佳 pH 和温度分别为 7.5 和 25°C，最佳底物浓度分别进行了测定。山柰酚-3-O-鼠李糖苷的最高产量达到 231mg/L，相应的摩尔转化率为 100%。山柰酚-3-O-鼠李糖苷得到了纯化，并评估了其对 HepG2、MCF-7 和 A549 细胞的细胞毒性。因此，本文描述的山柰酚-3-O-鼠李糖苷生产的有效方法可广泛用于类黄酮的鼠李糖基化。
