Melanotan-I

Identity

Field	Value
IUPAC name	(4S)-4-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-acetamido-3-hydroxypropanoyl]amino]-3-(4-hydroxyphenyl)propanoyl]amino]-3-hydroxypropanoyl]amino]hexanoyl]amino]-5-[[(2S)-1-[[(2R)-1-[[(2S)-1-[[(2S)-1-[[2-[[(2S)-6-amino-1-[(2S)-2-[[(2S)-1-amino-3-methyl-1-oxobutan-2-yl]carbamoyl]pyrrolidin-1-yl]-1-oxohexan-2-yl]amino]-2-oxoethyl]amino]-3-(1H-indol-3-yl)-1-oxopropan-2-yl]amino]-5-carbamimidamido-1-oxopentan-2-yl]amino]-1-oxo-3-phenylpropan-2-yl]amino]-3-(1H-imidazol-4-yl)-1-oxopropan-2-yl]amino]-5-oxopentanoic acid
SMILES	CCCC[C@@H](C(=O)N[C@@H](CCC(=O)O)C(=O)N[C@@H](CC1=CNC=N1)C(=O)N[C@H](CC2=CC=CC=C2)C(=O)N[C@@H](CCCNC(=N)N)C(=O)N[C@@H](CC3=CNC4=CC=CC=C43)C(=O)NCC(=O)N[C@@H](CCCCN)C(=O)N5CCC[C@H]5C(=O)N[C@@H](C(C)C)C(=O)N)NC(=O)[C@H](CO)NC(=O)[C@H](CC6=CC=C(C=C6)O)NC(=O)[C@H](CO)NC(=O)C
InChI	InChI=1S/C78H111N21O19/c1-5-6-19-52(91-75(116)61(41-101)97-72(113)57(34-46-24-26-49(103)27-25-46)94-74(115)60(40-100)88-44(4)102)68(109)92-54(28-29-64(105)106)70(111)96-59(36-48-38-83-42-87-48)73(114)93-56(33-45-16-8-7-9-17-45)71(112)90-53(22-14-31-84-78(81)82)69(110)95-58(35-47-37-85-51-20-11-10-18-50(47)51)67(108)86-39-63(104)89-55(21-12-13-30-79)77(118)99-32-15-23-62(99)76(117)98-65(43(2)3)66(80)107/h7-11,16-18,20,24-27,37-38,42-43,52-62,65,85,100-101,103H,5-6,12-15,19,21-23,28-36,39-41,79H2,1-4H3,(H2,80,107)(H,83,87)(H,86,108)(H,88,102)(H,89,104)(H,90,112)(H,91,116)(H,92,109)(H,93,114)(H,94,115)(H,95,110)(H,96,111)(H,97,113)(H,98,117)(H,105,106)(H4,81,82,84)/t52-,53-,54-,55-,56+,57-,58-,59-,60-,61-,62-,65-/m0/s1
InChIKey	UAHFGYDRQSXQEB-LEBBXHLNSA-N

Chemistry

Field	Value
Compound class	Tridecapeptide (13 aa, α-MSH analog)
Formula	C₇₈H₁₁₁N₂₁O₁₉
Molecular weight	1646.87
CAS	75921-69-6
PubChem	PubChem CID 16154396 (opens in a new tab)

2D structure

PubChem 2D depiction · CID 16154396

3D structure

Computed conformer: one plausible shape of a flexible molecule, not a measured structure · RDKit

Additional properties

Computed
Property	Value
Exact mass	1645.83651040 Da
Monoisotopic mass	1645.83651040 Da
XLogP3	-3.5
Topological polar surface area	643 Å²
Hydrogen bond donors	23
Hydrogen bond acceptors	22
Rotatable bonds	51
Heavy atoms	118

Also known as

(Nle4,D-Phe7)-alpha-MSH, scenesse, MBJ 05

Identifiers

Registry identifiers
Registry	Value
UNII	QW68W3J66U (opens in a new tab)

Sources

Data sources
Source	Kind	Retrieved
PubChem CID 16154396 (opens in a new tab)	PubChem	Oct 12, 2026
Computed conformer (RDKit ETKDGv3 + MMFF94)	Internal	Oct 12, 2026

Products containing this compound

Not used in any listed product.