Studies on differentiation inducers. VI. Lignan derivatives from Arctium fructus. (2).

In the previous paper, we reported the differentiation inducing activities of lignoids from Arctium Fructus (the fruits of Arctium lappa L., Compositae) against mouse myeloid leukemia cells (M1). We reinvestigated the active components of this extract and isolated three new dilignans. Furthermore, structure modifications were carried out using the most active lignan (arctigenin, 1) and its structure-activity relationship was investigated. Its aliphatic esters were more effective in inducing the differentiation of M1 cells than its aromatic esters. Especially, n-decanoate, which was the most active derivative, induced more than half of the M1 cells into phagocytic cells at a concentration of 2 microM.