The first indoleamine-2,3-dioxygenase-1 (IDO1) inhibitors containing carborane

Indoleamine-2,3-dioxygenase-1 (IDO1) is a critical immunoregulatory enzyme responsible for the metabolism of tryptophan during inflammation and disease. Based upon a pyranonaphthoquinone framework, the first examples of indoleamine-2,3-dioxygenase-1 (IDO1) inhibitors containing a carborane cage are reported. The novel closo-1,2-carboranyl-N-pyranonaphthoquinone derivatives display low mu M binding affinity for the human recombinant enzyme, with IC50 values ranging from 0.78 to 1.77 mu M.