*2.1. Chemicals and Materials*

β HSG4112(S) and HSG4112(R) were given from Glaceum Incorporation (Suwon, Korea). Pooled rat liver microsome (RLM), mouse liver microsome (MLM), dog liver microsome (DLM), and human liver microsome (HLM) were obtained from Gentest (Woburn, MA, USA). Pooled rat intestinal microsome (RIM), mouse intestinal microsome (MIM), dog intestinal microsome (DIM), and human intestinal microsome (HIM) were obtained from Sekisui Xenotech (Kansas City, KS, USA). Glucose 6-phosphate, β-NADP+, glucose 6-phosphate dehydrogenase and alamethicin were obtained from Sigma-Aldrich (St. Louis, MO, USA). HPLC-grade acetonitrile (ACN) and formic acid were purchased from J.T. Baker (Phillipsburg, NJ, USA). Distilled water (DW) was prepared using a Milli-Q purification system (Millipore, Bedford, MA, USA).
