Ultra performance liquid chromatography/quadrupole-time-of-flight mass spectrometry (UPLC/QTOF-MS) technique combined with MetabolynxTM software was used for analysis of the metabolic profile of baicalin in Radix scutellariae extracts by the intestinal bacteria from normal and type 2 diabetic mice.
The amount of baicalin壮s aglycone (baicalein) in type 2 diabetic mice samples were remarkably more than that in normal mice samples and oroxylin A only existed in type 2 diabetic mice samples. Intestinal bacteria produced not only a small amount of baicalein, but also some conjugates such as hydrogenated baicalin and methylated baicalin.
We proposed that 尾-d-glucuronidases contributed to the deglycosylation prior to absorption. Intestinal bacteria from pathological state mice produced more baicalein, which was well absorbed contributing to the treatment of type 2 diabetes. Additionally, the pharmacological effects of oroxylin A were associated with type 2 diabetes. Hence, the production of metabolites of baicalin might influence the effects of traditional medicines. Thus the study on the metabolism of baicalin by intestinal bacteria from normal and type 2 diabetic mice was of great importance to understanding the effects of traditional medicines. Furthermore, this work demonstrated the potential of the ultra performance liquid chromatography/quadrupole time-of-flight mass spectrometry approach with MetaboLynx for quite rapid, simple, reliable and automated identification of metabolites of natural products.