Glu-urea-Lys is a molecular scaffold that targets PSMA and can be used as a prostate cancer imaging agent to study prostate-specific membrane antigens.

Endogenous peptide agonist of Mas related GPR X2 (MRGPRX2, EC50 = 251 nM). Also a noncompetitive nicotinic cholinergic antagonist. Inhibits nicotine-stimulated catecholamine secretion from PC12 cells in vitro, and from sympathetic nerve endings and adrenal chromaffin cells in vivo. Corresponds to amino acids 1 - 20 of proadrenomedullin. Antihypertensive.

Gymnoside IX (compound 2) can be isolated from the methanolic extract from the tubers of Gymnadenia conopsea.