M1G explained

M₁G (pyrimido[1,2-''a'']purin-10(3H)-one) is a heterocyclic compound which is a by-product of base excision repair (BER) of a specific type of DNA adduct called M₁dG. The M₁dG adduct in turn is formed by a condensation reaction between guanosine nucleotides in DNA and either malondialdehyde (propanedial) ^[1] or acrolein.^[2] If not repaired, these adducts are mutagenic and carcinogenic.

Malondialdehyde is an end product of lipid peroxidation^[2] while acrolein is a result of DNA peroxidation.^[3]

M₁dG is the major endogenous DNA adduct in humans. M₁dG adducts have been detected in cell DNA in liver, leucocytes, pancreas and breast in concentrations of 1-120 per 10⁸ nucleotides.^[1] Detection and quantification of M₁dG adducts in the body as measured by free M₁G is a tool for detecting DNA damage that may lead to cancer. Free M₁G is also biomarker for oxidative stress.^[1]

Notes and References

1. Marnett LJ . Lipid peroxidation-DNA damage by malondialdehyde . Mutat. Res. . 424 . 1–2 . 83–95 . 1999 . 10064852 . 10.1016/S0027-5107(99)00010-X . 1999MRFMM.424...83M .
2. Seto H, Okuda T, Takesue T, Ikemura T . Reaction of Malonaldehyde with Nucleic Acid. I. Formation of Fluorescent Pyrimido[1,2-a]purin-10(3H)-one Nucleosides . Bulletin of the Chemical Society of Japan . 56 . 6 . 1799–1802 . 1983 . 10.1246/bcsj.56.1799 . free .
3. Knutson CG, Akingbade D, Crews BC, Voehler M, Stec DF, Marnett LJ . Metabolism in vitro and in vivo of the DNA base adduct, M1G . Chem. Res. Toxicol. . 20 . 3 . 550–7 . March 2007 . 17311424 . 10.1021/tx600334x . free .