Valentová Kateřina, Vrba Jiří, Bancířová Martina, Ulrichová Jitka, Křen Vladimír
Department of Medical Chemistry and Biochemistry, Faculty of Medicine and Dentistry, Palacký University, Hněvotínská 3, CZ-775 15 Olomouc, Czech Republic; Laboratory of Biotransformation, Institute of Microbiology, Academy of Sciences of the Czech Republic, Vídeňská 1083, Prague 4 CZ-142 20, Czech Republic; Centre of Drug-Dietary Supplements Interactions and Nutrigenetics, Faculty of Medicine and Dentistry, Palacký University, Hněvotínská 3, CZ-775 15 Olomouc, Czech Republic.
Department of Medical Chemistry and Biochemistry, Faculty of Medicine and Dentistry, Palacký University, Hněvotínská 3, CZ-775 15 Olomouc, Czech Republic.
Food Chem Toxicol. 2014 Jun;68:267-82. doi: 10.1016/j.fct.2014.03.018. Epub 2014 Mar 27.
The flavonoid isoquercitrin (quercetin-3-O-β-d-glucopyranoside) is commonly found in medicinal herbs, fruits, vegetables and plant-derived foods and beverages. This article reviews the occurrence, preparation, bioavailability, pharmacokinetics, toxicology and biological activity of isoquercitrin and "enzymatically modified (α-glucosylated) isoquercitrin" (EMIQ). Pure isoquercitrin can now be obtained on a large scale by enzymatic rutin hydrolysis with α-l-rhamnosidase. Isoquercitrin has higher bioavailability than quercetin and displays a number of chemoprotective effects both in vitro and in vivo, against oxidative stress, cancer, cardiovascular disorders, diabetes and allergic reactions. Although small amounts of intact isoquercitrin can be found in plasma and tissues after oral application, it is extensively metabolized in the intestine and the liver. Biotransformation of isoquercitrin includes deglycosylation, followed by formation of conjugated and methylated derivatives of quercetin or degradation to phenolic acids and carbon dioxide. The acceptable daily intake of (95%) isoquercitrin and of EMIQ was estimated to be 5.4 and 4.9mg/kg/day, respectively. Adverse effects of higher doses in rats included mostly (benign) chromaturia; nevertheless some drug interactions may occur due to the modulation of the activity and/or expression of drug metabolizing/transporting systems. With respect to the safety, affordability and beneficial pharmacological activities, highly pure isoquercitrin is a prospective substance for food supplementation.
黄酮类化合物异槲皮苷（槲皮素 - 3 - O - β - D - 吡喃葡萄糖苷）常见于药草、水果、蔬菜以及植物源性食品和饮料中。本文综述了异槲皮苷和“酶法改性（α - 葡萄糖基化）异槲皮苷”（EMIQ）的存在形式、制备方法、生物利用度、药代动力学、毒理学及生物活性。如今，通过用α - L - 鼠李糖苷酶对芦丁进行酶促水解，可大规模获得纯异槲皮苷。异槲皮苷比槲皮素具有更高的生物利用度，并且在体外和体内均表现出多种化学保护作用，可对抗氧化应激、癌症、心血管疾病、糖尿病和过敏反应。尽管口服后在血浆和组织中可发现少量完整的异槲皮苷，但它在肠道和肝脏中会被广泛代谢。异槲皮苷的生物转化包括去糖基化，随后形成槲皮素的共轭和甲基化衍生物，或降解为酚酸和二氧化碳。（95%）异槲皮苷和EMIQ的每日可接受摄入量分别估计为5.4和4.9mg/kg/天。大鼠中较高剂量的不良反应主要包括（良性）血尿；然而，由于药物代谢/转运系统的活性和/或表达受到调节，可能会发生一些药物相互作用。就安全性、可承受性和有益的药理活性而言，高纯度异槲皮苷是一种有前景的食品补充剂物质。
