Annunziata Francesca, Contente Martina L, Pinna Cecilia, Tamborini Lucia, Pinto Andrea
Department of Pharmaceutical Sciences, University of Milan, Via Mangiagalli 25, 20133 Milan, Italy.
Department of Food, Environmental and Nutritional Sciences, University of Milan, Via Celoria 2, 20133 Milan, Italy.
Antioxidants (Basel). 2021 Jul 19;10(7):1142. doi: 10.3390/antiox10071142.
Tyrosol (Ty) and hydroxytyrosol (HTy) are valuable dietary phenolic compounds present in olive oil and wine, widely used for food, nutraceutical and cosmetic applications. Ty and HTy are endowed with a number of health-related biological activities, including antioxidant, antimicrobial and anti-inflammatory properties. In this work, we developed a sustainable, biocatalyzed flow protocol for the chemo- and regio-selective oxidation of Ty into HTy catalyzed by free tyrosinase from in a gas/liquid biphasic system. The aqueous flow stream was then in-line extracted to recirculate the water medium containing the biocatalyst and the excess ascorbic acid, thus improving the cost-efficiency of the process and creating a self-sufficient closed-loop system. The organic layer was purified in-line through a catch-and-release procedure using supported boronic acid that was able to trap HTy and leave the unreacted Ty in solution. Moreover, the acetate derivatives (TyAc and HTyAc) were produced by exploiting a bioreactor packed with an immobilized acyltransferase from (MsAcT), able to selectively act on the primary alcohol. Under optimized conditions, high-value HTy was obtained in 75% yield, whereas TyAc and HTyAc were isolated in yields of up to 80% in only 10 min of residence time.
酪醇（Ty）和羟基酪醇（HTy）是存在于橄榄油和葡萄酒中的有价值的膳食酚类化合物，广泛用于食品、营养保健品和化妆品应用。Ty和HTy具有多种与健康相关的生物活性，包括抗氧化、抗菌和抗炎特性。在这项工作中，我们开发了一种可持续的、生物催化的流动方案，用于在气/液双相系统中由来自[具体来源未给出]的游离酪氨酸酶将Ty化学选择性和区域选择性氧化为HTy。然后对水流进行在线萃取，以使含有生物催化剂和过量抗坏血酸的水介质再循环，从而提高该过程的成本效益并创建一个自给自足的闭环系统。有机层通过使用负载型硼酸的捕获-释放程序进行在线纯化，负载型硼酸能够捕获HTy并使未反应的Ty留在溶液中。此外，通过利用填充有来自[具体来源未给出]的固定化酰基转移酶（MsAcT）的生物反应器来生产乙酸酯衍生物（TyAc和HTyAc），MsAcT能够选择性地作用于伯醇。在优化条件下，以75%的产率获得了高价值的HTy，而在仅10分钟的停留时间内，TyAc和HTyAc的分离产率高达80%。
