Dried leaves (99 g) were extracted with EtOH:EtOAc
(50:50) followed by H2O:MeOH (30:70), to obtain
3.7 g and 11.2 g dry extracts, respectively. As
previously described, the EtOAc flash fraction (120
mg) was generated, with 50 mg of same fractionated
by preparative C18 HPLC from CH3CN–H2O (3:7 to
7:3) collecting 40 one minute fractions. The isolation
of individual compounds from preparative HPLC fraction
15 was performed using semi-preparative Keystone
BetaMax Neutral C18 (8 · 250 mm ID, 5 mm) as described
above.