ELQ-300, a bioavailable antimalarial agent, is a potent inhibitor of the reductive (Qi) site of the cytochrome bc1 complex (cyt bc1).

β-NADP is an electron acceptor which acts as a key cofactor for electron transfer in the metabolism. Its oxidized form and reduced form are NADP+ and NADPH.

Rotenone is a proven complex I inhibitor with IC50 value of 1.7 - 2.2 μM.

Annonacin, a natural product isolated and purified from the herbs of Annona glabra, is mitochondrial complex I inhibitor, reported to be more toxic than rotenone to mesencephalic neurons, and can cause significant cell death in various cancer cell lines.