A metabolite of baicalin detected in rabbit plasma using electrospray mass spectrometry after baicalin administration

Scutellaria baicalensis Georgi (Huangqin or Chinese Skullcap) has been used to treat inflammatory-related disorders in China and other Asian countries for centuries, and is a major ingredient of many traditional Chinese medicines. The main constituents of the root of Scutellaria, baicalin along with its aglycone, baicalein, are important components of some modern formulations. In bioavailability studies investigating baicalin, the authors found a substance, as a metabolite of baicalin in rabbit plasma, after oral administration of baicalin. Orally administered pure baicalin and the metabolite was detected in rabbit plasma using high-performance liquid chromatography, and the structure of the metabolite was elucidated using electrospray ionization mass spectrometry methods.