Synthesis of 2-(p-chlorobenzyl)-3-aryl-6-methoxybenzofurans as selective ligands for antiestrogen-binding sites. Effects on cell proliferation and cholesterol synthesis
摘要:
A series of nonsteroidal compounds, 2-(p-chlorobenzyl)-3-aryl-6-methoxybenzofurans derived from the 2-(p-chlorobenzyl)-6-methoxy-3(2H)-benzofuranones has been synthesized. The key steps in the synthesis were reactions of 2-(p-chlorobenzyl)-6-methoxy-3(2H)-benzofuranones with the arylorganometallic reagents followed by dehydration of the resulting carbinols. The benzofurans are ligands for antiestrogen-binding sites (AEBS) and display no significant interaction with the estrogen receptor (ER). All bind to AEBS with equivalent or greater affinity than tamoxifen. These compounds decrease [H-3]thymidine incorporation in AEBS-containing EL4 lymphoid cells and MCF7 breast cancer cells in a concentration-dependent manner between 10(-8) and 10(-6) M and are generally more inhibitory than tamoxifen. In contrast, they have no effect on [H-3]thymidine incorporation by an AEBS-deficient variant of the MCF7 cell line, RTx6. The present findings of (1) selective and high affinity binding of the benzofurans to AEBS, (2) their concentration-dependent inhibition of [H-3]thymidine incorporation in AEBS-containing cells, and (3) their lack of antiproliferative effect in an AEBS-deficient cell line suggest a functional role for AEBS in mediating the antigrowth effect of these compounds. Two of the more active benzofuran compounds also significantly inhibited de novo cholesterol biosynthesis in EL4 cells which lack ER. This effect could be obtained after 5 h of treatment and preceded significant loss of cell viability. This is the first demonstration that selective ligands of AEBS (other than the known nonsteroidal antiestrogens) interfere with cholesterol biosynthesis-an action that may contribute to their antigrowth effect.
2-(benzyl)-3-arylbenzofurans as antitumour and hypocholesterolemic agents
申请人:National University of Singapore
公开号:US05354861A1
公开(公告)日:1994-10-11
The synthesis and the biological evaluation of a series of basic ethers of 2-benzyl-3-arylbenzofurans as antitumor agents is described. These compounds bind significantly to the antiestrogen-binding sites but only poorly to the estrogen receptor sites and are cytotoxic to tumor cells. Some of these compounds also significantly inhibited de novo cholesterol biosynthesis in an estrogen receptor negative lymphoma cell line rich in antiestrogen-binding sites.