PACAP (6-38), human, ovine, rat TFA is a potent PACAP receptor antagonist with IC50s of 30, 600, and 40 nM for PACAP type I receptor, PACAP type II receptor VIP1, and PACAP type II receptor VIP2, respectively.

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.

Methylophiopogonanone A has anti-inflammatory and anti-oxidative properties.