Ginsenoside Rb1 is transformed into Rd and Rh2 by Microbacterium trichothecenolyticum

Ginseng (the root of Panax ginseng C.A Meyer; family Araliaceae) is one of the most popular medicinal plants, especially in Korea, Japan, China, and other Asian countries.Ginseng is used as a traditional medicine for boosting immunity, providing nutrition, and recovering from fatigue.Ginseng saponins (ginsenosides) are the principle component of ginseng, and these saponins have various pharmacological and biological activities such as anti-aging, anti-inflammation, antidiabetic [10], and antitumor activities [9].Ginsenosides can be classified into three groups: protopanaxadiol (PPD), protopanaxatriol (PPT), and oleanolic acid, based on their chemical constitutions.To date, over 40 ginsenosides have been isolated and identified.The known ginsenosides include Rb1, Rb2, Rd, Rc, Re, and Rg1, and these ginsenosides constitute more than 90% of total known ginsenosides [5].Ginsenoside Rd has exhibited encouraging neuroprotective efficacy in both laboratory and clinical studies.Based on the pathophysiological mechanisms of acute ischemic stroke, Rd can be applied to impede the ischemic cascade and can protect the ischemic brain [12].In particular, Rb1 is the most abundant ginsenoside (23%), and it can be easily converted into more pharmaceutically potent minor ginsenosides