DALDA

DALDA (H-Tyr-D-Arg-Phe-Lys-NH2) is a synthetic peptide derivative which acts as a potent and highly selective agonist of the mu opioid receptor. It was originally derived as a more metabolically stable analogue of dermorphin, a naturally occurring opioid peptide secreted by some species of South American frogs.^[1][2][3] DALDA is unable to cross the blood-brain barrier, making it highly peripherally selective, but it has been researched for the treatment of colitis and neuropathic pain, where peripheral opioid agonism is able to produce analgesic effects in the absence of central opioid receptor activation.^{[4][5][6][7][8][9][10][11][12]} Some derivatives of DALDA such as [Dmt1]DALDA (where the tyrosine residue has been substituted with 2,6-dimethyl groups) or more complexly modified derivatives such as KGOP01, do however cross the blood-brain barrier and produce typical opioid effects.^{[13][14][15][16][17][18][19][20]}

[Dmt1]DALDA, CAS# 255861-98-4 PMID 9809562

DALDA

Clinical data
Other names	Dermorphin [D-Arg2, Lys4] (1-4) Amide
Identifiers
IUPAC name (2S)-6-amino-2-[[(2S)-2-[[(2R)-2-[[(2S)-2-amino-3-(4-hydroxyphenyl)propanoyl]amino]-5-(diaminomethylideneamino)pentanoyl]amino]-3-phenylpropanoyl]amino]hexanamide
CAS Number	118476-85-0
PubChem CID	122222
ChemSpider	109004
UNII	FS8087FL3X
ChEMBL	ChEMBL60444
Chemical and physical data
Formula	C30H45N9O5
Molar mass	611.748 g·mol−1
3D model (JSmol)	Interactive image
SMILES C1=CC=C(C=C1)C[C@@H](C(=O)N[C@@H](CCCCN)C(=O)N)NC(=O)[C@@H](CCCN=C(N)N)NC(=O)[C@H](CC2=CC=C(C=C2)O)N
InChI InChI=1S/C30H45N9O5/c31-15-5-4-9-23(26(33)41)37-29(44)25(18-19-7-2-1-3-8-19)39-28(43)24(10-6-16-36-30(34)35)38-27(42)22(32)17-20-11-13-21(40)14-12-20/h1-3,7-8,11-14,22-25,40H,4-6,9-10,15-18,31-32H2,(H2,33,41)(H,37,44)(H,38,42)(H,39,43)(H4,34,35,36)/t22-,23-,24+,25-/m0/s1 Key:UEVAHGMTRWGMTB-JBXUNAHCSA-N