DSIP is a historical abbreviation, not a chemical name. Below is an identity reference for the material sold as DSIP: what the sequence is, what mass to expect, how it behaves under reverse-phase HPLC, and how a buyer can confirm that the material in a vial is what the label says. Nothing here addresses what DSIP does, and it contains no guidance on preparation, handling or dosing.
The sequence behind DSIP
DSIP is a nonapeptide, nine residues long, with the sequence Trp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu, written in one-letter code as WAGGDASGE. All nine residues are standard L-amino acids (glycine has no stereocentre). The common synthetic form has a free N-terminal amine and a free C-terminal acid, with no terminal modification.
The molecular formula is C35H48N10O15 and the average molecular mass is approximately 848.8 g/mol. As with every short peptide in this series, that number is the fastest sanity check: an observed mass that does not sit at or near 849 for the free peptide means the material is something else or a salt or adduct has not been declared.
Why the name is a historical designation
The letters stand for delta sleep-inducing peptide, a name given in the 1970s when the peptide was first isolated and sequenced, and chosen to reflect the experimental setting in which it was found. It has stayed attached to the sequence ever since, in the same way that many peptides discovered in that era kept names taken from the original isolation work. For identity purposes the name should be read purely as a historical label: it says nothing about what the molecule is chemically, and this article makes no claim about any property the name might suggest.
The practical point is the same as for the coined names elsewhere in this series, such as Epithalon or Selank. The abbreviation does not constrain what is in a vial. The printed sequence, WAGGDASGE, and the mass that goes with it are the identifiers that matter.
How a short, acidic nonapeptide behaves on reverse-phase HPLC
DSIP is small and polar. Six of its nine residues are glycine, alanine or serine, which contribute very little hydrophobic surface, and it carries two acidic residues (aspartic acid and glutamic acid) plus the C-terminal carboxyl, against only the N-terminal amine as a basic group. Its net charge around neutral pH is therefore negative. The single tryptophan at the N-terminus is its only substantially hydrophobic side chain.
That tryptophan is what keeps DSIP from behaving like the very short, very polar peptides that elute at the solvent front. It retains modestly on a C18 column and elutes early in a typical water/acetonitrile gradient with trifluoroacetic acid, but usually with enough separation from the void volume to be integrated cleanly if a shallow gradient with a low starting organic percentage is used.
The tryptophan also decides the detection question. Because it contains an indole ring, DSIP absorbs usefully at 280 nm as well as on the peptide bond at 214 nm. Purity is normally reported at 214 nm, where every peptide species is visible; a 280 nm trace is a useful cross-check, because any impurity that has lost or altered the tryptophan will look different on the two channels.
What an analysis for DSIP should show
A useful certificate reports the column chemistry and dimensions, mobile phases and gradient, detection wavelength, retention time, the integrated main peak with its integration window visible, and a mass confirmation. Our guide on how to read an HPLC chromatogram walks through each of those elements.
Two sequence features are worth knowing about. The N-terminal tryptophan can oxidise, producing species at +16 Da and +32 Da that typically elute slightly earlier than the main peak. The aspartic acid at position five can form an aspartimide during synthesis, a cyclic intermediate that loses 18 Da and can reopen to give an isomer of identical mass. Isomers of that kind are invisible to mass spectrometry alone and show up only as closely eluting peaks, which is one reason the chromatogram and the mass spectrum need to be read together.
A good DSIP certificate separates net peptide content from chromatographic purity and identifies the counter-ion. DSIP has only one basic site, so it binds relatively little trifluoroacetate compared with a strongly basic peptide, but counter-ion and residual water still add mass to the powder. Our comparison of TFA vs acetate counter-ions explains how the salt form changes the numbers.
Confirming identity independently
The sequence, not the name DSIP, is the right search key. Public chemical databases index this nonapeptide by structure and by sequence, and a search on WAGGDASGE will show quickly whether the formula and mass a vendor is quoting match the pairing used everywhere else. Our product pages carry compound identity links that query those databases directly.
How DSIP is supplied here
DSIP 2mg is supplied as a lyophilised powder in a sealed vial. Each product is analysed by independent reverse-phase HPLC, with the result published for that product. The DSIP product page lists the vial size alongside the published HPLC purity. DSIP vials carry no batch identifiers, so the crimp and cap color are what tie it to the published result.
Frequently asked questions
What is the amino acid sequence of DSIP?
Trp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu (WAGGDASGE), nine standard amino acids with a free N-terminus and a free C-terminal acid.
What does the abbreviation DSIP stand for?
Delta sleep-inducing peptide. It is a historical name from the original isolation work in the 1970s and is used here only as a designation, not as a description of any property.
What molecular weight should I expect for DSIP?
Approximately 848.8 g/mol for the free peptide, formula C35H48N10O15. A salt form will read higher, which is why the counter-ion has to be declared with the mass.
Can DSIP be detected at 280 nm?
Yes. The N-terminal tryptophan absorbs at 280 nm, although purity is normally reported at around 214 nm, where all peptide species are seen.
Research use only. All products supplied by Battle Born Peptides are laboratory reference materials for in-vitro research and analytical use by qualified professionals. They are not drugs, foods, dietary supplements, cosmetics or medical devices; they are not approved by the FDA or any other regulator for use in humans or animals; and they are not intended to diagnose, treat, cure, mitigate or prevent any disease, or to affect the structure or any function of the body of humans or animals. Nothing in this article is preparation, handling or dosing guidance. See our full research-use terms.