of popcorn were fractionated at 10-12 OC on a water-cooled
column (20 cm X 1 cm) packed with a slurry of silica gel in pentane/
diethyl ether (95:5 v/v). Stepwise elution was performed
with 25 mL of pentane/diethyl ether (95:5 v/v; fraction A), 50
mL of pentane/diethyl ether (85:15 v/v; fraction B), 45 mL of
pentane/diethyl ether (7:3 v/v; fraction C), and 150 mL of diethyl
ether (fraction D).