Eisenin

Eisenin
Names
	IUPAC name (2S)-2-[[(2S)-5-amino-5-oxo-2-[[(2S)-5-oxopyrrolidine-2-carbonyl]amino]pentanoyl]amino]propanoic acid
	Other names Pyr-Gln-Ala-OH
Identifiers
CAS Number	21477-57-6;
3D model (JSmol)	Interactive image; Interactive image;
ChemSpider	5731099;
PubChem CID	7408402;
CompTox Dashboard (EPA)	DTXSID80902331;
	InChI InChI=1S/C13H20N4O6/c1-6(13(22)23)15-11(20)8(2-4-9(14)18)17-12(21)7-3-5-10(19)16-7/h6-8H,2-5H2,1H3,(H2,14,18)(H,15,20)(H,16,19)(H,17,21)(H,22,23) Key: VIPNGHPLCAMVEB-UHFFFAOYSA-N; InChI=1S/C13H20N4O6/c1-6(13(22)23)15-11(20)8(2-4-9(14)18)17-12(21)7-3-5-10(19)16-7/h6-8H,2-5H2,1H3,(H2,14,18)(H,15,20)(H,16,19)(H,17,21)(H,22,23)/t6-,7-,8-/m0/s1 Key: VIPNGHPLCAMVEB-FXQIFTODSA-N;
	SMILES CC(C(=O)O)NC(=O)C(CCC(=O)N)NC(=O)C1CCC(=O)N1; C[C@H](NC(=O)[C@H](CCC(N)=O)NC(=O)[C@@H]1CCC(=O)N1)C(=O)O;
Properties
Chemical formula	C13H20N4O6
Molar mass	328.325 g·mol−1
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Eisenin (C₁₃H₂₀N₄O₆) is a tripeptide isolated from the brown marine algae Eisenia bicyclis. It has immunological activity by augmenting natural cytotoxicity of peripheral blood lymphocytes (PBLs) in humans.^[1]

It can be synthesized by a tripeptide precursor known as y-methyl-l-glutamyl-y-methyl-l-glutamyl-l-alanine and an amide. This is done by the crystallization of the N-terminal of the y-methyl ester and the simultaneous amidation of the internal L-glutamic acid by ammonia.^[2]

References

^ Kojima, T.; Koike, A.; Yamamoto, S.; Kanemitsu, T.; Miwa, M.; Kamei, H.; Kondo, T.; Iwata, T. (January 1993). "Eisenin (L-pyroGlu-L-Gln-L-Ala), a new biological response modifier". Journal of Immunotherapy with Emphasis on Tumor Immunology. 13 (1): 36–42. doi:10.1097/00002371-199301000-00005. ISSN 1067-5582. PMID 8435430.
^ Katakai, Ryoichi; Oya, Masano (2002-05-01). "Syntheses of eisenine and its amide by the N-carboxy .alpha.-amino acid anhydride method". The Journal of Organic Chemistry. 39 (2): 180–182. doi:10.1021/jo00916a012. PMID 4816661. Retrieved 2025-10-07.

[1] Kojima, T.; Koike, A.; Yamamoto, S.; Kanemitsu, T.; Miwa, M.; Kamei, H.; Kondo, T.; Iwata, T. (January 1993). "Eisenin (L-pyroGlu-L-Gln-L-Ala), a new biological response modifier". Journal of Immunotherapy with Emphasis on Tumor Immunology. 13 (1): 36–42. doi:10.1097/00002371-199301000-00005. ISSN 1067-5582. PMID 8435430.

[2] Katakai, Ryoichi; Oya, Masano (2002-05-01). "Syntheses of eisenine and its amide by the N-carboxy .alpha.-amino acid anhydride method". The Journal of Organic Chemistry. 39 (2): 180–182. doi:10.1021/jo00916a012. PMID 4816661. Retrieved 2025-10-07.

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