5-Amino-1MQ

5-Amino-1-methylquinolinium (5-Amino-1MQ) is a small molecule inhibitor of nicotinamide N-methyltransferase (NNMT) with a molecular weight of approximately 173 Da and a CAS registry number of 42675-71-0. Unlike the peptide therapeutics that dominate the research compound landscape, 5-Amino-1MQ is a substituted quinolinium salt, a simple organic molecule that is orally bioavailable and does not require injection or reconstitution. Its compact structure enables cell membrane penetration and access to cytoplasmic NNMT.

NNMT is a cytoplasmic enzyme that catalyzes the transfer of a methyl group from S-adenosylmethionine (SAM) to nicotinamide, producing 1-methylnicotinamide (1-MNA) and S-adenosylhomocysteine (SAH). This reaction has two metabolic consequences: it consumes SAM (the body's universal methyl donor) and it diverts nicotinamide away from the NAD+ salvage pathway. The NAD+ salvage pathway, catalyzed by NAMPT (nicotinamide phosphoribosyltransferase), converts nicotinamide to NMN and then to NAD+. When NNMT activity is high, less nicotinamide enters this pathway and intracellular NAD+ levels fall. NNMT expression is significantly upregulated in white adipose tissue during obesity (3-5 fold) and increases with age across multiple tissues, creating a metabolic drain on both the NAD+ pool and the methylation budget.

5-Amino-1MQ inhibits NNMT with an IC50 of approximately 1.2 micromolar. When NNMT is blocked, nicotinamide is redirected back into the NAD+ salvage pathway, increasing intracellular NAD+ concentrations approximately 2-fold in treated adipocytes. Higher NAD+ activates the sirtuin family of NAD+-dependent deacetylases, particularly SIRT1, which deacetylates PGC-1alpha (promoting mitochondrial biogenesis), FOXO transcription factors (enhancing stress resistance), and NF-kappaB (reducing inflammation). Simultaneously, SAM levels rise due to reduced consumption by NNMT, supporting methylation reactions critical for DNA maintenance, epigenetic regulation, and neurotransmitter synthesis.

The key preclinical data for 5-Amino-1MQ were published by Neelakantan et al. in Biochemical Pharmacology (2018). In 3T3-L1 adipocyte cultures, 5-Amino-1MQ treatment reduced adipocyte size by approximately 40%, decreased expression of lipogenic genes DGAT1 and DGAT2 (diacylglycerol acyltransferases responsible for triglyceride synthesis), and reduced total lipid accumulation. Gene expression profiling showed upregulation of fatty acid oxidation genes including CPT1A and ACADM, indicating a metabolic shift from lipid storage toward lipid utilization.

In diet-induced obesity (DIO) mouse models, 5-Amino-1MQ administered intraperitoneally produced a 7% reduction in body weight over 11 days compared to vehicle-treated controls, despite no change in food intake. Glucose tolerance tests showed significant improvement (reduced area under the curve for blood glucose after glucose challenge). Hepatic steatosis was visibly reduced on histological examination. Notably, the weight loss was not driven by appetite suppression, distinguishing 5-Amino-1MQ from GLP-1 agonists and other appetite-modulating compounds.

5-Amino-1MQ is orally bioavailable as a small charged molecule. While formal pharmacokinetic parameters (Cmax, AUC, t1/2) have not been published in peer-reviewed literature for oral dosing in humans, its low molecular weight (173 Da), positive charge, and water solubility support intestinal absorption. The compound is typically administered as an oral capsule, which represents a significant convenience advantage over injectable peptides.

Storage requirements for 5-Amino-1MQ are straightforward. As a stable small molecule salt, it does not require refrigeration for short-term storage and is not sensitive to reconstitution-related degradation issues that affect peptides. Capsules should be stored in a cool, dry place away from direct sunlight. For long-term storage of bulk powder, keeping it desiccated at room temperature or refrigerated is sufficient.

The safety profile of 5-Amino-1MQ is characterized primarily from preclinical data. In the DIO mouse studies, no adverse effects on liver enzymes, kidney function markers, or hematologic parameters were reported during the treatment period. NNMT-knockout mice are viable and fertile with an obesity-resistant phenotype, suggesting that pharmacological NNMT inhibition does not disrupt essential developmental or reproductive processes. However, no formal human clinical trials have been completed, so human safety and tolerability data remain limited to anecdotal reports.