Herbal medicines are widely used as therapeutic products in many countries. Fructus Corni, a traditional herb medicine, has been clinically used to cure chronic nephropathy for thousands of years. It could be converted by gut microflora in vivo to shape its pharmacological profiles. Thus, metabolic profiles of major active constituents in Fructus Corni extracts by gut microflora from rats in healthy and nephropathy state were firstly investigated in vitro by ultraperformance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS) in this study. According to the features of protonated ions, five metabolites (M1, M2, M3, M5 and M6) were found and preliminarily authenticated. Intestinal bacteria were capable of converting N0 (loganin) to its aglycone M1 (loganetin). The latter was further hydrogenated to the corresponding M2 (hydrogenated loganetin) and subsequently to M3 (hydrogenated and demethylated loganetin) by demethylation; While M5 (demethylated morronisid aglycone) and M6 (dehydroxylated morronisid aglycone) were identified as the two metabolites of N4 (morronisid) through demethylation and dehydroxylation. Gut microflora from healthy and nephropathy rats could degrade loganin and morronisid to the above metabolites. However, healthy rat intestinal bacteria showed more powerful degradation and much more amounts of M1 and M6 were obtained in their samples. Additionally, this work demonstrated that UPLC-Q-TOF/MS approach connected with MetaboLynx™ analysis software was rapid and reliable for screening and authentication of natural product metabolites.

草药在许多国家被广泛用作治疗产品。山茱ru是一种传统的草药，已经在临床上用于治疗慢性肾病已有数千年的历史了。它可以通过肠道菌群在体内转化以形成其药理特性。因此，首先在体外研究了健康和肾病状态下大鼠肠道菌群的山茱extract提取物中主要活性成分的代谢谱。本研究中使用超高效液相色谱结合四极杆飞行时间质谱（UPLC-Q-TOF / MS）进行分析。根据质子化离子的特征，发现并初步鉴定了五种代谢物（M1，M2，M3，M5和M6）。肠道细菌能够将N0（loganin）转化为其糖苷配基M1（loganetin）。将后者进一步氢化成相应的M2（氢化的对数锡），随后通过脱甲基化成M3（氢化的和脱甲基的对数锡）。通过脱甲基和脱羟基作用，M5（去甲基化的morronisid糖苷配基）和M6（去羟基化的morronisid糖苷配基）被确定为N4的两个代谢产物（morronisid）。来自健康和肾病大鼠的肠道菌群可以将loganin和morronisid降解为上述代谢物。然而，健康的大鼠肠道细菌表现出更强的降解能力，并且在其样品中获得了更多的M1和M6。此外，这项工作表明，与MetaboLynx™分析软件连接的UPLC-Q-TOF / MS方法可快速可靠地用于天然产物代谢产物的筛选和鉴定。