1995 年 41 巻 6 号 p. 575-585
(all-E)-β-Apo-12'-carotenoic acid and a series of the geometrical isomers were synthesized and their biological activities to inhibit growth and to induce differentiation of human acute promyelocytic leukemia cell line HL-60 were analyzed. It was found that (all-E)-β-apo-12'-carotenoic acid (I, Fig. 1) and (15'-Z)-apo-12'-carotenoic acid (II, Fig. 1) showed strong activity both in the inhibition of growth and the induction of differentiation. The biological activity of (13'-Z)-β-apo-12'-carotenoic acid (III, Fig. 1) was modest, while that of (13', 15'-di-Z)-β-apo-12'-carotenoic acid (IV, Fig. 1) was negligible.(all-E)-β-Apo-12'- carotenoic acid and the geometrical isomers acted additively with (all-E)- retinoic acid, and synergetically with (9-Z)-retinoic acid. In accord with our previous report, biological activities of (all-E)-β-apo-14'-carotenoic acid (V, Fig. 1) and of (15'-Z)-β-apo-14'-carotenoic acid (VI, Fig. 1) were very weak. It was indicated that (all-E)-β-apo-12'-carotenoic acid, an intermediate metabolite of excentric cleavage pathway of β-carotene, per se may exert the biological function.