Unguisin A is a major analogue of a class of cyclic heptapeptides isolated from Emericella unguis (Aspergillus unguis) by Malstrom, University of Copenhagen, Denmark in 1999. Structurally, unguisuin A is comprised of only one proteogenic amino acid, L-phenylalanine with two D-valines, two D-alanines and a D-tryptophan. Uniquely, the macrocycle of the unguisins is annealed to ɣ-aminobutyric acid. The structure of unguisin A was confirmed by total synthesis in 2011. No reports of pharmacology of unguisin A have appeared in the literature to date.