Relationships between structure and activity of retinoids.

Structure-function relationships of 19 retinoids were studied in three in vitro systems in defined, serum-free medium. These systems measure effects on differentiation and growth, as well as toxic effects. The ring, side chain, and polar terminal group of natural retinoids all may be modified synthetically to yield highly active compounds. Several retinoid ethers were found to be significantly less toxic than the corresponding carboxylic acids or alcohols.