Cyclic sulfur-containing compounds from Allium fistulosum ‘Kujou’

Abstract

Sulfur-containing compounds, allicin and ajoene, etc., were isolated from Allium species. In a recent study, some sulfur-containing cyclic compounds were isolated from A. sativum, A. cepa, and A. fistulosum. Four new compounds with multiple rings with methyl disulfide or propyl disulfide at the side chain of the 7-position, kujounins A 3 (1), B 1 (2), B 2 (3) and B 3 (4), and two new thiolane type compounds with methoxy and methyl sulfoxide moiety at the 2- and 5-positions, and allium sulfoxides A 2 (5) and A 3 (6), were isolated from the acetone extract of the fresh white parts of Allium fistulosum ‘Kujou’ with three known compounds, kujounin A 1 (7) and A 2 (8), and allium sulfoxide A 1 (9). The chemical structures of the new compounds were elucidated on the basis of physicochemical evidence. The kujounins had a rare molecular skeleton, which was tetrahydro-2H-difuro[3,2-b:2′,3′-c]furan-5(5aH)-one.