IC50: 10 μM for ET-1 binding to the ETA receptor ofA10 cells

Asterric Acid is an ETA receptor inhibitor.

Endothelin (ET), a potent vasoconstrictor/pressor peptide consisting of 21 amino acid residues, was first isolated from the cultures of porcine aortic endothelial cells. Analyses of a human genomic library reveals three forms of ET (ET-1, ET-2 and ET-3) with more than 70% homology with one another. In various organs, high affinity and specific receptors for ET have been found, which have been classfied as receptors ETA and ETB. ET-1 has potent and long-lasting vasoconstrictive activity, as a result of binding to the ETA receptor.

In vitro: Previous study asterric acid isolated as an active substance from the culture filtrate of a fungus, Aspergillus sp. Asterric acid had also been reported as a metabolite of a fungus. It was found that asterric acid had the property of inhibiting ET-1 binding to the ETA receptor of A10 cells, but it showed no inhibitory activity against ANP and A II binding at 10 mM, which indicated that asterric acid displayed as a specific inhibitor of ET-1 binding [1].

In vivo: Up to now, there is no animal in vivo data reported.

Clinical trial: So far, no clinical study has been conducted.

Reference:
[1] Ohashi, H. ,Akiyama, H.,Nishikori, K., et al. Asterric acid, a new endothelin binding inhibitor. Journal of Antibiotics 45, 1684-1685 (1992).