L,L-Dityrosine (o,o'-Dityrosine) is a constituent of acid hydrolysates of a number of biological materials, including the insect cuticular resilin.

This is amino acids 86 to 100 fragment of class II-associated invariant chain peptide called CLIP. The major histocompatibility complex class II molecule displays peptide fragments of foreign proteins to trigger a defensive reaction from the immune system. Before insertion of the foreign peptides into the binding groove, a place-holding peptide CLIP is removed. This is accomplished by the molecule DM, which is shown to increase the dissociation rate of a CLIP peptide from class II.

Ethyl (E)-dec-4-enoate (Ethyl (E)-4-decenoate) is a volatile substance isolated from hot sauce and is a RIFM flavor.