Catalyzes the hydrolysis of a non-reducing terminal alpha-L-arabinopyranosidic linkage in ginsenoside Rb2 (alpha-L-arabinopyranosyl-(1->6)-alpha-D-glucopyranosyl) to release alpha-D-glucopyranosyl (Rd). It is not able to hydrolyze alpha-L-arabinofuranosyl-(1->6)-alpha-D-glucopyranosyl (Rc). Completely inhibited by Cu(2+) and Fe(2+). Optimum pH is between 5.5 and 6. Optimum temperature is 40 degrees Celsius. Homotetramer. Belongs to the glycosyl hydrolase 3 family.