Refining retinoids with heteroatoms.

Retinoids are a group of synthetic compounds designed to refine the numerous biological activities of retinoic acid into pharmaceuticals for several diseases, including cancer. Designs that conformationally-restricted the rotation of the structures resulted in arotinoids that were biologically active, but with increased toxicity. Incorporation of a heteroatom in one cyclic ring of the arotinoid structures drastically reduced the toxicity, while retaining biological activity. Clinical trials of a heteroarotinoid, Tazarotene, confirmed the improved chemotherapeutic ratio (efficacy/toxicity).