What 5-Amino-1MQ is
5-Amino-1MQ is 5-amino-1-methylquinolinium, a small synthetic molecule built on a quinoline ring that carries a methyl group on the ring nitrogen, giving it a permanent positive charge, and an amino group at the 5-position. It is not a peptide. It was reported in 2017 by Stanton Watowich, Harshini Neelakantan and colleagues at the University of Texas Medical Branch as the lead compound from a programme of inhibitors of nicotinamide N-methyltransferase (NNMT), designed around the structure of the enzyme's nicotinamide substrate.
NNMT methylates nicotinamide using S-adenosylmethionine as the methyl donor. An inhibitor that occupies the nicotinamide site therefore gives researchers a tool for studying the enzyme's role in NAD+ metabolism and methyl-group balance in cultured cells. The cation has a molecular weight of approximately 159 g/mol, the CAS number for the compound is 42464-96-0, and it sits in our mitochondrial and coenzymes class alongside NAD+ and the mitochondria-targeted peptides.
The published literature on the compound, with references, is collected in the monograph.
What you receive
Each vial contains 5-Amino-1MQ as a pale yellow to yellow crystalline powder, supplied as a salt, sealed with a flip-off cap over a crimped stopper, in the net quantity stated on the label: 50 mg. There is no carrier or other excipient unless the batch certificate says otherwise. The batch number is printed on the label and matches the certificate in our register.
Reading the certificate for a 5-Amino-1MQ batch
Purity by reversed-phase HPLC is reported as the area of the main peak against all peaks and should be above 98% for a small synthetic molecule of this kind; the common impurity is the unmethylated 5-aminoquinoline starting material, which is readily separated and should be present at well under 1%. Identity by LC-MS is reported as the observed mass of the quinolinium cation against the expected value of about 159 Da. Since the compound carries a permanent positive charge it ionises very efficiently in positive-mode electrospray, and the spectrum normally shows the intact cation without the counter-ion. Net content gives the milligrams of the salt actually in the vial, as distinct from the nominal fill.
The main thing to check is that the laboratory has stated which salt was analysed, since the cation accounts for a different fraction of the gross weight depending on the counter-ion. Our guide to reading a certificate of analysis walks through annotated examples, and HPLC and LC-MS explained describes the methods.
Storage and handling
Sealed vials should be kept refrigerated at 2 to 8 °C and protected from light; the compound is a stable crystalline salt and tolerates brief periods at room temperature, but −20 °C is preferable for storage beyond a year. Quinolinium salts are moderately hygroscopic, so allow the vial to reach room temperature before opening and reseal promptly. 5-Amino-1MQ dissolves readily in water, bacteriostatic water or dimethyl sulfoxide to give a yellow solution. Aqueous solutions are stable refrigerated for some weeks if protected from light; the storage and stability guide covers solvents, concentrations and freeze-thaw behaviour for small molecules as well as peptides.