Isolation and identification of oleamide as a growth inhibitory compound from the medium conditioned by colon cancer cells treated with conjugated linoleic acid

with PGE2 and LTB4 antisera, cells were incubated in serumfree medium containing 50 μM CLA, and the conditioned media were collected. The conditioned media were acidified with glacial acetic acid, and eicosanoid-like material(s) was extracted with ethyl acetate, concentrated, and separated by column chromatography (CH3OH-CHCl3 1 : 9) on silica gel. TLC analysis of the ethyl acetate-extract revealed three spots, and the major spot showing at 0.52 in R f value (CH3OH-CHCl3 1 : 9) was isolated using the flash column chromatography. The amount of other minor two spots on the TLC plate was relatively too small to isolate. The resulting white solid was recrystallized from ethanol and its melting point was determined to be 74-75 o C. High