Affiliations: Department of Food and Nutritional Sciences,
University of Shizuoka, 52-1 Yada, Shizuoka 422-8526, Japan
Note: [] Address for correspondence: Tsutomu Nakayama, Department of Food
and Nutritional Sciences, University of Shizuoka, 52-1 Yada, Shizuoka 422-8526,
Japan. Tel.: +81 54 264 5522; Fax: +81 54 264 5551; E-mail:
[email protected]
Abstract: Three parameters, i.e., the proportion of the amount incorporated
into the liposomes, the partition coefficient in a system of
n-octanol/phosphate buffered saline, and the retention times
by HPLC, were measured to determine the lipophilicity of isoflavonoids. The
presence of a hydroxyl group at 5-position of the A-ring and a methoxyl group
at 4'-position of the B-ring in the isoflavonoid structure
increased the three parameters. The localization of isoflavonoids in lipid
bilayers was investigated by a liposome system with fluorescent probes. The
location of the isoflavonoid depended on its structure. The cytotoxicity of
isoflavonoids was investigated by a colony-formation assay with Chinese hamster
lung fibroblast V79 cells. The structure-activity relationship of the cytotoxic
activity partly reflected those of the three parameters. This suggests that the
biological activities of isoflavonoids in vitro could be attributable to
their affinity for lipid components in the cases where the estrogen receptors
have no role.
