Eisenin (pGlu-Gln-Ala-OH) is a peptide with immunological activity that is isolated from the Japanese marine alga, Eisenia bicyclis, which more commonly is known as, Arame
The key amino acids of the BSCI peptides required for activity have been identified, and the tripeptide AcNH-Trp-Val-Gln-OH was shown to itself be a BSCI in the low micromolar range.