AICAR

1 Identity

Non-peptide small molecule - purine-biosynthesis intermediate nucleoside analog

Sequence

No defined sequence - not a peptide and no peptide bond is present. The article is a nucleoside: 5-aminoimidazole-4-carboxamide, an imidazole bearing an amine at position 5 and a primary carboxamide at position 4, N-glycosidically linked at ring N1 to beta-D-ribofuranose. Four stereocenters, all in the ribose ring, and all of them fixed by the beta-D-ribofuranosyl designation - so the molecule is chiral, the anomeric configuration is part of the identity, and anomeric or ring-size isomers are exactly isobaric with the correct article. A chiral or anomeric-resolving method is therefore required here for a reason that does not apply to most small molecules in this catalog, and it is required as an identity test rather than as an enantiomeric-purity test.

Molecular formula

C9H14N4O5 (free nucleoside). Sodium and other salt forms circulate in this channel undeclared; no salt formula is asserted because no supplier in this channel declares one.

Average mass

258.234 Da (C9H14N4O5); listings commonly print the rounded 258.23. The derivation: the aglycone 5-aminoimidazole-4-carboxamide is C4H6N4O at 126.12, ribose is C5H10O5 at 150.13, and the N-glycosidic bond forms with loss of water, giving C4H6N4O plus C5H10O5 minus H2O equals C9H14N4O5.

Monoisotopic mass

258.0964 Da, from the formula. [M+H]+ 259.1037; [M-H]- 257.0891.

Salt / variant note

(1) the Phosphorylated species, which is A separate catalog article and is routinely confused with this one: AICAR 5'-monophosphate (ZMP), C9H15N4O8P, 338.21 average / 338.0628 monoisotopic - 79.98 Da heavier, one phosphate, and a different substance in every respect that matters to a specification. (2) the aglycone with no sugar on it: 5-aminoimidazole-4-carboxamide, C4H6N4O, 126.12 / 126.0542 - the synthetic precursor and the hydrolysis product, 132.11 Da lighter, and by far the cheapest thing that could be in the bottle. Its presence is also the stability-indicating attribute, since the N-glycosidic bond is the labile feature of the molecule. (3) free ribose from the same hydrolysis, C5H10O5, 150.13 / 150.0528. (4) the isobaric set that no mass spectrometer resolves at any resolution: the alpha-anomer, the ribopyranoside ring-size isomer, and the N3-linked regioisomer are all C9H14N4O5 at 258.234 average and 258.0964 monoisotopic, identical to the correct article at every decimal place. Only NMR, or chromatographic retention against a characterized authentic standard, separates them. This is the identity risk on this molecule and it is invisible to the test most certificates in this channel actually run. (5) structurally adjacent nucleosides that are far cheaper and sit within 10 Da: adenosine, C10H13N5O4, 267.25 / 267.0968, 9.01 Da heavier; inosine, C10H12N4O5, 268.23 / 268.0808, 10.00 Da heavier. Both are commodity chemicals, both are white crystalline solids, and a nominal-mass certificate reading '258 to 268' catches neither. (6) salt form against itself: the sodium salt C9H13N4O5Na computes to 280.22 / 280.0784, an 8.5% weight difference against the free nucleoside for the same number of molecules, and no seller in this channel declares which is supplied.

2 Class & testing panel

Form

Single article

Testing panel

P6 — panel definition

3 Primary sources & evidence

The index reports the design and provenance of the literature, not a conclusion about effect.

This record carries no citation set for this article: no PMID, no DOI, no trial registration and no chemical database record. What can be stated is regulatory rather than scientific: the substance is named on the WADA Prohibited List at S4.4, metabolic modulators, in the same clause as SR9009, and it is cataloged in the research-peptide channel under a marketed mechanism-of-action label that this record does not reproduce. This catalog does not manufacture references.

4 Storage & specification

Storage

The crystalline nucleoside is held in an amber glass bottle with a desiccant sachet, at -20 degrees C plus or minus 5 degrees C, desiccated and protected from light, with reconstituted stock solutions aliquoted single-use and held at -80 degrees C and never refrozen. The N-glycosidic bond is acid-labile, so the label carries an explicit incompatibility statement for acidic diluents, and moisture control is a specification rather than housekeeping.

Shelf life

Each lot is dated from QA release and carries a printed retest date, with first-expiry-first-out enforced against that date. The interval is set on stability data for this article rather than on a default, and the attributes that limit it are the products of hydrolysis at the N-glycosidic bond, the free aglycone 5-aminoimidazole-4-carboxamide and free ribose, together with water content.