Department of Nutrition, Food Science and Gastronomy-XARTA-INSA, Faculty of Pharmacy and Food Science, University of Barcelona, Barcelona, Spain.
Food Funct. 2017 Jul 19;8(7):2419-2424. doi: 10.1039/c7fo00558j.
Phenolic compounds are present in human fluids (plasma and urine) mainly as glucuronidated and sulfated metabolites. Up to now, due to the unavailability of standards, enzymatic hydrolysis has been the method of choice in analytical chemistry to quantify these phase II phenolic metabolites. Enzymatic hydrolysis procedures vary in enzyme concentration, pH and temperature; however, there is a lack of knowledge about the stability of polyphenols in their free form during the process. In this study, we evaluated the stability of 7 phenolic acids, 2 flavonoids and 3 prenylflavanoids in urine during enzymatic hydrolysis to assess the suitability of this analytical procedure, using three different concentrations of β-glucuronidase/sulfatase enzymes from Helix pomatia. The results indicate that enzymatic hydrolysis negatively affected the recovery of the precursor and free-form polyphenols present in the sample. Thus, enzymatic hydrolysis does not seem an ideal analytical strategy to quantify glucuronidated and sulfated polyphenol metabolites.
酚类化合物主要以结合型（葡萄糖醛酸和硫酸酯）代谢物的形式存在于人体液（血浆和尿液）中。到目前为止，由于缺乏标准品，酶解一直是分析化学中用于定量这些 II 相酚类代谢物的首选方法。酶解程序在酶浓度、pH 值和温度方面存在差异；然而，对于在该过程中游离形式的多酚的稳定性，人们知之甚少。在这项研究中，我们评估了 7 种酚酸、2 种类黄酮和 3 种黄烷醇在尿液中经过酶解时的稳定性，以评估使用三种不同浓度的赫氏曲霉来源的β-葡糖苷酸酶/硫酸酯酶进行该分析程序的适用性。结果表明，酶解会对样品中存在的前体和游离形式的多酚的回收率产生负面影响。因此，酶解似乎不是定量结合型和硫酸酯化多酚代谢物的理想分析策略。
