PAR3 (1-6) is a synthetic peptide agonist of proteinase-activated receptor 1 (PAR1) that corresponds to residues 1-6 of the amino terminal tethered ligand sequence of human PAR3 and residues 39-44 of the full-length human sequence. PAR3 (1-6) activates p42/44 MAPK signaling in fibroblasts expressing PAR1, but not PAR3, an effect that can be blocked by the PAR1 antagonist RWJ 56110.

Indole is an aromatic heterocyclic organic compound. It has a bicyclic structure consisting of a six-membered benzene ring fused to a five-membered nitrogen-containing pyrrole ring.

L-Gulonolactone (also known as reduced ascorbic acid RAA) is the substrate of the enzyme L-gulono-14-lactone oxidoreductase (EC 1.1.3.8) which catalyzes the last step of the biosynthesis of L-ascorbic acid (vitamin C) in plants and animals.