5-Amino 1MQ (5-amino-1-methylquinolinium) is a synthetic small-molecule research compound developed as a selective inhibitor of the metabolic enzyme Nicotinamide N-methyltransferase (NNMT). It is widely studied in metabolic biology, obesity research, and NAD⁺ regulation.

Origin of 5-Amino 1MQ

1. Academic development

5-Amino 1MQ was developed through medicinal chemistry research aimed at understanding why NNMT is elevated in obesity and metabolic disease.

Key origin points:

• Developed by research teams at the University of Texas Medical Branch

• Key researchers include Watowich and Neelakantan

• Originated from quinolinium-based compound libraries

• Identified through structure–activity relationship (SAR) screening

2. Why it was created

Researchers were investigating NNMT because:

• NNMT is often overexpressed in obese fat tissue

• It consumes nicotinamide (vitamin B3 derivative) and methyl groups

• This reduces availability for NAD⁺ production and cellular energy metabolism

5-Amino 1MQ was designed to:

• Block NNMT activity

• Preserve NAD⁺ precursors

• Improve metabolic efficiency in fat tissue

3. Timeline of discovery

• 2017: First identification as a potent NNMT inhibitor in chemical screening studies

• 2018: Animal studies showed reduced fat mass and improved metabolic markers in obese mice

• Ongoing: Continued use as a research tool compound in metabolic and aging studies

Chemical and Physical Properties

Chemical identity

• Name: 5-Amino-1-methylquinolinium

• Class: Quinolinium-based small molecule (not a peptide)

• Formula (cation): C₁₀H₁₁N₂⁺

• Common salt forms: iodide (most common), chloride

Molecular characteristics

Molecular weight:

• ~159 g/mol (free cation)

• ~286 g/mol (iodide salt form)

Structure type:

Aromatic heterocycle with:

• Quinoline ring system

• Permanent positive charge (quaternary-like nitrogen)

• 5-position amino group

Physical properties

Appearance

• Off-white to light yellow or orange crystalline powder

Solubility

• Highly water soluble

• Soluble in polar solvents (e.g., DMSO)

• Poor solubility in oils or non-polar solvents

Charge behavior

• Permanently positively charged (cationic molecule)

• Exists as a salt with iodide or chloride

Stability

• Chemically stable under normal storage conditions

• More stable than peptides (no enzymatic degradation risk)

Lipophilicity

• Moderate (aromatic structure increases membrane interaction, but charge increases water affinity)

Functional Properties (Why its structure matters)

The chemical structure directly explains its biological function:

• Quinolinium ring → enables binding to NNMT enzyme pocket

• Positive charge → enhances interaction with active site residues

• Amino group → increases potency and selectivity

• Small molecular size → supports cellular permeability

This combination makes it a high-affinity NNMT inhibitor in preclinical models.

Biological Role (Context of its function)

Although not a natural compound, it interacts with a key metabolic pathway:

Target enzyme: NNMT

NNMT normally:

• Converts nicotinamide → 1-methylnicotinamide

• Uses methyl groups from SAM

• Reduces NAD⁺ precursor availability

By inhibiting NNMT, 5-Amino 1MQ:

• Preserves nicotinamide for NAD⁺ production

• Reduces methyl-group consumption

• Supports mitochondrial energy metabolism

Research Status

• Type: Research-use-only compound

• Human approval: None (not FDA-approved)

• Evidence base: Preclinical (cell + animal studies only)

• Regulatory status: Not approved for medical use; classified as a non-approved research chemical in many contexts

Key Summary

5-Amino 1MQ is:

A synthetic quinolinium small molecule

Developed at UTMB (University of Texas Medical Branch)

Designed to inhibit NNMT, a metabolic enzyme linked to obesity

Structurally characterized by:

• Aromatic quinoline core

• Permanent positive charge

• Amino substitution at position 5

Its physical and chemical properties make it:

• Highly water-soluble

• Stable

• Cell-permeable

• Suitable for metabolic enzyme targeting in research models

Bottom Line

5-Amino 1MQ originates from academic medicinal chemistry research into metabolic disease, and its properties reflect a carefully designed small, charged, water-soluble NNMT inhibitor intended to modulate NAD⁺ and fat metabolism pathways in experimental systems.