Purification and Structural Analysis of Substances in Wasabi (Eutrema wasabi Maxim.) that Suppress the Growth of MKN-28 Human Stomach Cancer Cells

Abstract

The objective of this paper is to identify growth-suppressing substances in wasabi on MKN-28 human stomach cancer cells. A water extract fraction(<molecular weight 5000) of wasabi suppressed the growth of MKN-28 derived from human stomach cells. The growth-inhibitting principles were purified from the extract and analyzed. The active fractions were isolated by repeated column chromatography on gel filtration and reverse-phase HPLC. The P-5 fraction, one of the fractions separated by Sephadex G-15 gel filtration, showed the most marked suppressive effect on MKN-28 among the fractions. The P-5 fraction suppressed the growth of MKN-28 stronger than the antitumor agents such as 5-fluorouracil and Mitomycin C. On the final step of isolation, the sample that had showed the suppressive effect was divided into four fractions by the reverse-phase HPLC. Structural analysis was performed using the fraction (retention time=12min) with the greatest suppressing activity. Examination by FAB-MS and EI-MS yielded a molecular weight of 205 with a chemical composition of C₈, H₁₅, N₁, O₁, S₂. By using IR and NMR, we have identified 6-metylsulfinylhexyl isothiocyanate as one of the suppressing components on the growth of MKN-28 in wasabi.