Laboratory of Nutritional Biochemistry, Division of Applied Bioscience , Graduate School of Agriculture, Hokkaido University , Sapporo , Hokkaido 060-8589 , Japan.
Department of Biotechnology, Faculty of Engineering , Toyama Prefectural University , Imizu, Toyama , 939-0398 , Japan.
J Agric Food Chem. 2019 Apr 17;67(15):4240-4249. doi: 10.1021/acs.jafc.8b06929. Epub 2019 Apr 3.
Quercetin glycosides in the diet are absorbed and converted to glucuronides, sulfates, or mixed conjugates of glucuronide and sulfate in plasma. Physiological effects of quercetin conjugates (Q-conjugates) differ depending on the type and position of conjugation. We developed a comprehensive analysis of Q-conjugates, including mixed conjugates, by LC/MS/MS. The whole species of Q-conjugates in tail blood plasma was measured on days 1, 3, and 12 in rats fed a 0.24% quercetin glucoside-containing diet. Twenty-three Q-conjugate molecules were detected, and 16 Q-conjugates among these were quantified using standard compounds. The most abundant metabolite in the plasma was mixed conjugates, comprising isorhamnetin-7- O-glucuronide-4'- O-sulfate, followed by quercetin-7- O-glucuronide-4'- O-sulfate; together, they accounted for 86% of total Q-conjugates on day 12. The profile of quercetin conjugate species did not significantly change during 12 days. The total Q-conjugate molecules quantified by our method was comparable with the total Q-conjugates quantified using an enzymatic deconjugation method.
饮食中的槲皮素糖苷在血浆中被吸收并转化为葡萄糖醛酸苷、硫酸盐或葡萄糖醛酸苷和硫酸盐的混合缀合物。槲皮素缀合物（Q-缀合物）的生理效应取决于缀合的类型和位置。我们通过 LC/MS/MS 开发了一种对 Q-缀合物（包括混合缀合物）的综合分析方法。在给予含有 0.24%槲皮素葡萄糖苷的饮食的大鼠的第 1、3 和 12 天尾血浆中测量了全物种 Q-缀合物。检测到 23 种 Q-缀合物分子，并使用标准化合物对其中的 16 种 Q-缀合物进行定量。血浆中含量最丰富的代谢物是混合缀合物，由异鼠李素-7-O-葡萄糖醛酸苷-4'-O-硫酸盐组成，其次是槲皮素-7-O-葡萄糖醛酸苷-4'-O-硫酸盐；它们共同占第 12 天总 Q-缀合物的 86%。12 天内槲皮素缀合物的种类没有明显变化。我们的方法定量的总 Q-缀合物分子与使用酶去缀合方法定量的总 Q-缀合物相当。
