01 / Molecular architecture
A closer look at the chain.
The 13-residue reference replaces position 4 with norleucine and position 7 with D-phenylalanine. It also has an acetylated N-terminus and amidated C-terminus.
- 13 residues
- Nle4 / D-Phe7
- Linear reference chain
- 1Ser
- 2Tyr
- 3Ser
- 4Nle
- 5Glu
- 6His
- 7D-Phe
- 8Arg
- 9Trp
- 10Gly
- 11Lys
- 12Pro
- 13Val
Reference information: [1][2]. Actual lot identity must be verified separately.
Two substitutions inside a linear chain.
Nle4 and D-Phe7 specify the modified residues at positions 4 and 7. Norleucine is written Nle; D-Phe specifies both phenylalanine and its configuration. Keeping the positional labels helps distinguish this thirteen-residue analog from its parent reference and other melanocortin-family peptides.
Modified ends do not make a cyclic backbone.
The reference has an acetyl group at the N-terminus and an amide at the C-terminus. These describe end-group chemistry. They do not join the two ends or create the Asp–Lys side-chain ring found in the shorter Melanotan-2 reference. Linear and unmodified are therefore not synonyms.
Structure and research references: [1]
02 / Read the evidence
Research & analytical context.
This reference belongs to melanocortin-receptor research. Its substitutions distinguish it from native alpha-MSH and from the shorter cyclic Melanotan-2 molecule.
The distinction that matters
A shared family name does not make Melanotan-1 and Melanotan-2 interchangeable. Their chain lengths, ring structures and terminal chemistry must be identified separately.
03 / From reference to record
Know the lot, too.
A publication describes its own test material. Your lot’s certificate describes what was tested on that lot. Keep the compound name, batch number and reported methods together when reviewing a result.
Identity & composition
Check sequence or chemical form, terminal modifications, counterion and—where relevant—each blend component.
Analytical results
Read purity, content, sterility and endotoxin results as separate measurements. Only call a test passed when the actual report supports it.
Handling & storage notes
Lyophilized material: Store at −20°C; protect from light and moisture.
Follow the material-specific label and supporting storage documentation. These temperatures do not establish a shelf life.
How to store lyophilized peptides04 / Reference questions
A few details, explained.
What does NDP-alpha-MSH refer to?
It is a reference name associated with the norleucine and D-phenylalanine substitutions. Afamelanotide is another name used for this identity. Compare the full specification when matching records.
Is Melanotan-1 simply a longer Melanotan-2?
The distinction involves more than length. The reference chains differ in residue composition and connectivity, including the ring present in Melanotan-2.
Read alongside the references: [1]
05 / Continue reading
Go to the source.
Each source is labeled by its type. External sources are not Pioneer batch certificates.