Detti Cassandra, Dos Santos Nascimento Luana Beatriz, Brunetti Cecilia, Ferrini Francesco, Gori Antonella
Department of Agriculture, Food, Environment and Forestry (DAGRI), University of Florence, Sesto Fiorentino, 50019 Florence, Italy.
National Research Council of Italy, Institute for Sustainable Plant Protection (IPSP), Sesto Fiorentino, 50019 Florence, Italy.
Plants (Basel). 2020 Nov 3;9(11):1482. doi: 10.3390/plants9111482.
leaves are used in several applications, thanks to their polyphenolic abundance. Thiswork aimed to characterize the polyphenols and to optimize the extraction conditions to shorten the time, decrease the consumption of solvent, and to maximize the yield of different classes of phenolics, which have diverse industrial applications. The variables were optimized by applying a Box-Behnken design. Galloyl and myricetin derivatives were the most abundant compounds, and two new tetragalloyl derivatives were identified by LC-MS/MS. According to the models, the maximum yields of polyphenols (51.3 ± 1.8 mg g DW) and tannins (40.2 ± 1.4 mg g DW) were obtained using 0.12 L g of 40% ethanol at 50 °C. The highest content of flavonoids (10.2 ± 0.8 mg g DW) was obtained using 0.13 L g of 50% ethanol at 50 °C, while 0.1 L g of 30% ethanol at 30 °C resulted in higher amounts of myricitrin (2.6 ± 0.19 mg g DW). Our optimized extraction decreased the ethanolic fraction by 25% and halved the time compared to other methods. These conditions can be applied differently to obtain extracts richer in tannins or flavonoids, which might be employed for various purposes.
由于其丰富的多酚类物质，树叶被用于多种应用。本研究旨在对多酚进行表征，并优化提取条件，以缩短时间、减少溶剂消耗，并使具有不同工业应用的各类酚类物质的产量最大化。通过应用Box-Behnken设计对变量进行了优化。没食子酰基和杨梅素衍生物是含量最丰富的化合物，通过液相色谱-串联质谱法（LC-MS/MS）鉴定出了两种新的四没食子酰基衍生物。根据模型，在50℃下使用0.12L/g 的40%乙醇可获得多酚（51.3±1.8mg/g干重）和单宁（40.2±1.4mg/g干重）的最大产量。在50℃下使用0.13L/g的50%乙醇可获得最高含量的黄酮类化合物（10.2±0.8mg/g干重），而在30℃下使用0.1L/g的30%乙醇可得到更高含量的杨梅苷（2.6±0.19mg/g干重）。与其他方法相比，我们优化后的提取方法使乙醇用量减少了25%，时间减半。这些条件可根据不同需求应用，以获得富含单宁或黄酮类化合物的提取物，这些提取物可用于各种目的。
