The First Orally Active Low Molecular Weight Agonists for the LH Receptor: Thienopyr(im)idines with Therapeutic Potential for Ovulation Induction

Pregnancy in pill form? The identification of low molecular weight (LMW) agonists for receptors normally triggered by high molecular weight (HMW) endogenous ligands is a great challenge for medicinal chemists. Thienopyrimidines and thienopyridines of general structures 1 and 2, respectively, are the first orally active LMW agonists for the G-protein-coupled luteinizing hormone receptor, which is responsible for ovulation induction. The LMW agonists display micromolar to nanomolar potencies and in vivo ovulation induction could be demonstrated in mice after oral administration. Thus, these compounds mimic the mode of action of the endogenous HMW glycopeptidic luteinizing hormone.