What Is 5-Amino-1MQ? NNMT Inhibition, Quinolinium Chemistry and Research Context

Despite sitting among peptide listings, 5-Amino-1MQ has no kinship with them: it is a quinolinium compound of 159.21 Da, distributed as an iodide salt, that blocks the enzyme nicotinamide N-methyltransferase (NNMT). Its presence in such catalogues reflects shared research territory with metabolic peptide work — nothing more. Analytically and chemically it sits in a separate category, and laboratories that handle it as though it were a peptide will design poor experiments. Our 5-Amino-1MQ ships as lyophilized powder in sealed vials for laboratory research only.

The compound defined

Written out, the name is 5-amino-1-methylquinolinium. The molecule is a quinoline bearing a methyl group, and its ring nitrogen holds a fixed positive charge — a quaternary cation, hence the accompanying iodide counter-ion. NNMT, the enzyme it targets, resides in the cytosol and moves a methyl group from S-adenosylmethionine (SAM) onto nicotinamide, generating 1-methylnicotinamide. Because 5-Amino-1MQ structurally resembles that reaction product, it inhibits by sitting in the pocket where nicotinamide would bind.

Recognising this design principle — an analogue of the product competing for the substrate site — clarifies both why the molecule looks as it does and how selective it can reasonably be expected to be, and both are worth settling before any assay is planned around it.

Chemistry and identifiers

• Class. A quinolinium small molecule; nothing peptidic about it. Neither produced by solid-phase synthesis nor assessed using peptide analytics.
• Mass and formula. The cation is C10H11N2 at 159.21 g/mol; as supplied, the iodide salt C10H11IN2 comes in at 286.11 g/mol. Whether you use the first or second figure depends on whether the weighed material includes the counter-ion, and confusing them injects a systematic error of about 1.8-fold.
• Registry number. CAS 42464-96-0.
• Charge state. Permanently cationic, which explains why it dissolves readily in water and governs how it behaves at membranes.

Mechanism of action

NNMT occupies a crossroads between two metabolic networks. On one side it uses up nicotinamide, the salvage-route precursor to NAD+; on the other it uses up SAM, the cell's principal donor of methyl groups. Blocking the enzyme is thus reported to do two things simultaneously: it leaves more nicotinamide free to feed NAD+ salvage, and it prevents SAM from being spent on methylating nicotinamide, shifting methyl-group flux more generally.

Preclinical papers describe NNMT being over-expressed in fat tissue in models of obesity, and report that blocking it in adipocytes lifts intracellular NAD+ and boosts sirtuin activity, with knock-on changes in lipogenic gene expression and cell size. Rodent experiments using inhibition or knockdown have reported less fat mass in diet-induced obesity without altered feeding — a clear mechanistic separation from incretin agonists such as semaglutide, which work through appetite pathways.

A qualification belongs in any candid account. The enzyme's product, 1-methylnicotinamide, is itself biologically active according to published work, so blocking the enzyme subtracts a signalling species at the same time as it spares a substrate. Ascribing an observed outcome solely to NAD+ conservation therefore goes beyond what the current evidence can carry.

Selectivity warrants examination before the compound is used as a mechanistic probe. Dozens of SAM-dependent methyltransferases are encoded in the human genome, and an inhibitor shaped like a methylation product binds a pocket whose architecture is not exclusive to NNMT. Selectivity panels have been published, but for a working laboratory the lesson is that any effect seen after treatment needs corroboration before it is credited to NNMT inhibition — knocking the enzyme down, using a chemically unrelated inhibitor, or rescuing with the reaction product. Absent that, the finding describes the compound's behaviour, not the enzyme's role.

Research applications

• Biochemistry. Assays with purified NNMT to determine potency and inhibition mode, alongside counter-screens against other methyltransferases — an essential control, given how many SAM-dependent enzymes there are.
• Cell work. Adipocyte cultures assessing NAD+ concentrations, sirtuin activity, lipogenic transcripts and lipid accumulation.
• Animal work. Diet-induced obesity models reporting reduced fat mass, plus studies of muscle regeneration and of tumour models, where NNMT over-expression is a recurring finding.
• Human evidence. There is none in print. No clinical programme exists for this compound, and the peer-reviewed literature contains no human pharmacokinetic or safety data. Every statement made about it traces back to cells and animals.

Our explainer on NNMT as a metabolic target goes deeper into the pathway, and the adipose tissue hub situates it among other strategies.

Available formats and vial sizes

Vials here hold more material than peptide vials do, simply because a 159 Da molecule needs much greater mass to deliver an equivalent number of moles: 50 mg of this compound is roughly 175 micromoles of cation, whereas 50 mg of a 4 kDa peptide is only about 12 micromoles. Current sizes appear on the 5-Amino-1MQ product page, with an oral presentation as 5-Amino-1MQ capsules; both belong to the fat-loss and metabolic collection.

Reconstitution and storage at the bench

Its fixed positive charge makes the compound water-soluble, and bacteriostatic water suffices for most bench preparation, while DMSO serves for concentrated stocks in cell assays as it does for small molecules generally. Worked through: dissolving 50 mg in 5 mL yields 10 mg/mL, that is 10,000 mcg/mL, so 0.1 mL of that solution delivers 1,000 mcg. Turning this into a molarity means choosing a mass basis — calculated on the 286.11 g/mol salt, 10 mg/mL works out to roughly 35 mM.

Hold the solid at minus 20 degrees Celsius, sealed away from light and damp; keep solutions between 2 and 8 degrees Celsius and consume them within the study period. Small molecules generally survive handling better than peptides do, but iodide salts are light-sensitive, so amber glass or foil wrapping is prudent. Consult our reconstitution guide and the note on molecular weight and moles.

Two additional practical contrasts with peptides deserve attention. First, a permanent cation does not slip across membranes by passive diffusion the way an uncharged lipophilic molecule can, so uptake in cell assays should be checked rather than assumed — when enzyme-assay potency and cell-assay potency disagree, transport is usually the culprit rather than pharmacology. Second, DMSO stocks impose their own ceiling: the solvent reaching the cells has to stay below the level that perturbs the readout, which limits how dilute a working solution can be made from a given stock. Both are everyday considerations in small-molecule work and are routinely missed by groups whose instincts were shaped by peptides.

Purity and reading the certificate of analysis

Certificates for small molecules are not structured like peptide certificates, and expectations should shift accordingly. HPLC purity is still the leading number, but there is no net peptide content to weigh up; its counterpart is the salt form and counter-ion fraction, which together determine how much active cation a weighed portion actually supplies. Identity is usually established by mass spectrometry, and for a well-characterised small molecule ideally by NMR as well, which pins down structure in a way mass cannot. Residual solvent analysis is pertinent here in a way it is not for peptides. See how to read a COA.

Keep tissue context in mind when interpreting data. NNMT levels differ markedly between tissues and are reported to rise in adipose tissue in obesity models and in various tumours, so what inhibition achieves depends heavily on how much enzyme a tissue carries to begin with. A cell line starting with little NNMT will barely respond no matter how potent the inhibitor, and that says something about the model rather than about the compound. Verifying baseline expression before treating a negative result as meaningful is standard practice.

Regulatory position

No jurisdiction has approved 5-Amino-1MQ as a medicine, and no clinical development programme exists. It is not a peptide, and it is not an ingredient with recognised food-supplement standing. It is supplied strictly as a laboratory reference chemical, not for human consumption, and its appearance in consumer capsule products sold elsewhere does not alter that position.

Related compounds and comparisons

Within our range the nearest comparison is 5-Amino-1MQ vs SLU-PP-332, a different small molecule tackling metabolic questions by another route. For work centred on NAD, see NAD+.