Methylnitronitrosoguanidine Explained

Methylnitronitrosoguanidine (MNNG^[1] or MNG, NTG when referred to colloquially as nitrosoguanidine^[2]) is a biochemical tool used experimentally as a carcinogen and mutagen. It acts by adding alkyl groups to the O⁶ of guanine and O⁴ of thymine, which can lead to transition mutations between GC and AT. These changes do not cause a heavy distortion in the double helix of DNA and thus are hard to detect by the DNA mismatch repair system.

In organic chemistry, MNNG is used as a source of diazomethane when reacted with aqueous potassium hydroxide.^[3]

MNNG is a probable human carcinogen listed as an IARC Group 2A carcinogen.^[4]

Stability

MNNG produces diazomethane, a known methylating agent of DNA and other substrates, in basic aqueous solutions, and nitrous acid, a mutagen, in acidic solutions.^[5]

Notes and References

1. Lawley . P. D. . Thatcher . Carolyn J. . Methylation of deoxyribonucleic acid in cultured mammalian cells by N-methyl-N′-nitro-N-nitrosoguanidine. The influence of cellular thiol concentrations on the extent of methylation and the 6-oxygen atom of guanine as a site of methylation . Biochemical Journal . Portland Press Ltd. . 116 . 4 . 1970-02-01 . 0306-3283 . 10.1042/bj1160693 . 693–707. 5435496 . 1185415 .
2. Web site: Forward and reverse mutagenesis in C. elegans . WormBook . 2021-12-01.
3. Aldrichimica Acta . 16 . 1 . 1983 . 3–10 . The Preparation and Reactions of Diazomethane . T. Howard Black . 2024-10-13 . 2019-02-03 . https://web.archive.org/web/20190203030451/http://www.thblack.com/chemistry/AActa1983_16_3.pdf .
4. http://www.inchem.org/documents/iarc/suppl7/mnng.html N-METHYL-N-NITRO-N-NITROSOGUANIDINE (MNNG)
5. Book: Hollaender, Alexander . Chemical Mutagens: Principles and Methods for Their Detection . 1 . . 1971 . 978-1-4615-8966-2 . 851813793 . 188.