Synthesis and structure-activity relationships of radicicol derivatives and WNT-5A expression inhibitory activity.

WNT-5A, a secretory glycoprotein, is related to the proliferation of dermal papilla cells. To develop a hair-growth stimulant, we have been searching for inhibitors of WNT-5A expression. We identified radicicol (1) as an active compound, and synthesized several radicicol derivatives. Among them, 6,7-dihydro-10α-hydroxy radicicol (31) was found to function as a new potent WNT-5A expression inhibitor with relatively low toxicity and excellent stability.