In vitro binding affinity of novel synthetic polyprenoids (polyprenoic acids) to cellular retinoid-binding proteins.

A study was conducted to investigate the in vitro binding affinity of new synthetic polyprenoids to cellular retinoid-binding proteins. Among 10 synthetic polyprenoic acid derivatives, 3,7,11,15-tetramethyl-2,4,6,10,14 hexadecapentaenoic acid (compound 1) was found to have the strongest binding affinity to cellular retinoic acid-binding protein (CRABP) from rat testis. As regards the chemical structure of the polyprenoic acids, it was found that suitable carbon chain length and double bond arrangement are both essential for binding affinity to CRABP. Moreover, compound I displayed a binding affinity to cellular retinoid receptors obtained from precancerous tissues such as mouse skin papillomas and rat liver hyperplastic nodules experimentally induced.