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.

Peonidin-3-O-(6-O-trans-feruloyl-2-O-β-glucopyranosyl-β-glucopyranoside)-5-O-β-glucopyranoside

6-Feruloylcatalpol is a natural product of Picrorhiza, Plantaginaceae. 6-Feruloylcatalpol can be used as a reference standard.