Antitumor-promoting activities of various synthetic 1-O-acyl-3-O-(6'-O-acyl-beta-D-galactopyranosyl)-sn-glycerols related to natural product from freshwater cyanobacterium Anabaena flos-aquae f. flos-aquae

1-O-Acyl-3-O-(6'-O-acyl-beta-D-galactopyranosyl)-sn-glycerol, which was isolated from a nitrogen-fixing fresh water cyanobacterium, Anabaena flos-aquae f. flos-aquae, was synthesized by utilizing lipase-catalyzed acylation. The antitumor-promoting activities of these galactolipids were evaluated using a short-term in vitro assay of Epstein-Barr virus activation in Raji cells induced by 12-O-tetradecanoyl- phorbol 13-acetate (TPA). The glyceroglycolipids which have a palmitoleoyl residue at the 1-O-position exhibited more potent activities than the others in this assay.