[Leu144,Arg147]-PLP (139-151) is a mutant peptide fragment of myelin proteolipid protein (PLP), with the tryptophan and histidine at positions 144 and 147 respectively replaced by leucine and arginine. [Leu144,Arg147]-PLP (139-151) also serves as a T cell receptor (TCR) antagonist for encephalitogenic Th1 clones, blocking their activation in vitro. Furthermore, [Leu144,Arg147]-PLP (139-151) can inhibit the development of experimental autoimmune encephalomyelitis (EAE).

Goitrin is a potent antithyroid compound found naturally in crucifers. Goitrin is responsible for the induction of glutathione S-transferases.

Candicine is a natural product from Stapelia gigantea.