Isolation and Characterization of New Onionins A₂ and A₃ from Allium cepa, and of Onionins A₁, A₂, and A₃ from Allium fistulosum

抄録

In this study, the new stable sulfur-containing compounds onionins A₂ (1) and A₃ (2) were isolated from the acetone extracts of the bulbs of Allium cepa L. and identified as the stereoisomers of onionin A₁ discovered in our previous study. Their chemical structures, 3,4-dimethyl-5-(1E-propenyl)-tetrahydrothiophene-2-sulfenic acid-S-oxides, were characterized using various spectroscopic techniques. In addition, 1 and 2 together with onionin A₁ were successfully isolated from the leaves of the Welsh onion, Allium fistulosum L. The onion-extracted fractions showed good potential to inhibit the polarization of M2 activated macrophages, indicating their possible ability to inhibit tumor cell proliferation.