Fraction B2 was then developed on silica gel (1500 g), eluting with CHCl3-MeOH-H2O (7:3:0.5). The silica gel column was separated into 20 fractions; each fraction was eluted with MeOH (400 mL) and concentrated
FractionB2 was then developed on silica gel (1500 g), eluting withCHCl3-MeOH-H2O (7:3:0.5). The silica gel column wasseparated into 20 fractions; each fraction was eluted withMeOH (400 mL) and concentrated