Dimethylaziridine carboxylic acid

Dimethylaziridine carboxylic acid (also pleurocybell aziridine) is a naturally occurring non-proteinogenic amino acid and an aziridine. It is found in pleurocybella porrigens (angel wing) and has been responsible for mushroom poisoning in the past.

Dimethylaziridine carboxylic acid
Identifiers
3D model (JSmol)
ChEBI
ChemSpider
  • InChI=1S/C5H9NO2/c1-5(2)3(6-5)4(7)8/h3,6H,1-2H3,(H,7,8)
    Key: LQNRQHXPYZSWHH-UHFFFAOYSA-N
  • (2S): InChI=1S/C5H9NO2/c1-5(2)3(6-5)4(7)8/h3,6H,1-2H3,(H,7,8)/t3-/m1/s1
    Key: LQNRQHXPYZSWHH-GSVOUGTGSA-N
  • CC1(C(N1)C(=O)O)C
  • (2S): CC1([C@H](N1)C(=O)O)C
Properties
C5H9NO2
Molar mass 115.13 g·mol−1
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Occurrence

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Dimethylaziridine carboxylic acid is found in the auriculated white mushroom

Dimethylaziridine carboxylic acid occurs in enantiomer form in the pleurocybella porrigens. The compound is very unstable, but can be isolated as an ester of benzhydrol by reacting an extract in methanol with diphenyldiazomethane. Some mushrooms contain large amounts of dimethylaziridine carboxylic acid; in one case, 23 mg of the ester derivative was isolated from 4 g of freeze-dried mushrooms.[1] The compound is synthesized by the mushroom from valine biosynthesis, involving an oxygenase that uses α-ketoglutaric acid and iron as cofactors.[2]

Synthesis

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The synthesis is based on a derivative of serine methyl ester in which the hydroxy group and amino group are protected by a protecting group, and the nitrogen atom carries a Boc protecting group. In the first step, the methyl ester is reacted with methylmagnesium bromide to form the tertiary alcohol. The acetonide is then deprotected with pyridinium para-toluenesulfonate. The hydroxyl group thus released is oxidized to carboxylic acid. The oxidation succeeds with TEMPO, sodium chlorite, and diacetoxyiodobenzene in acetonitrile. The carboxylic acid group is reacted with diazomethane to form the methyl ester. The Boc group is removed by reaction with gaseous hydrogen chloride in methanol, and the amino group is protected with dinitrobenzenesulfonyl chloride using 2,6-lutidine as base. The aziridine is formed by reaction with diethyl azodicarboxylate or diisopropyl azodicarboxylate and triphenylphosphane (Mitsunobu reaction). The protecting group is removed by reaction with propylamine in dichloromethane.[1]

Toxicology

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The pleurocybella porrigens occurs worldwide in temperate climates and is a particularly popular edible mushroom in Japan. In 2004, 17 people died there after eating the mushrooms. The affected individuals mainly suffered from chronic kidney failure, which explains why the mushrooms can often be consumed without any recognizable health consequences. The toxicity is attributed to dimethylaziridine carboxylic acid, which damages oligodendrocytes and can thus cause encephalopathy.[1]

References

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  1. ^ a b c Toshiyuki Wakimoto, Tomohiro Asakawa, Saeko Akahoshi, Tomohiro Suzuki, Kaoru Nagai, Hirokazu Kawagishi, Toshiyuki Kan (February 2011), "Proof of the Existence of an Unstable Amino Acid: Pleurocybellaziridine in Pleurocybella porrigens", Angewandte Chemie, vol. 123, no. 5, pp. 1200–1202, Bibcode:2011AngCh.123.1200W, doi:10.1002/ange.201004646{{citation}}: CS1 maint: multiple names: authors list (link)
  2. ^ Reito Bunno, Takayoshi Awakawa, Takahiro Mori, Ikuro Abe (2021-07-12), "Aziridine Formation by a Fe II /α-Ketoglutarate Dependent Oxygenase and 2-Aminoisobutyrate Biosynthesis in Fungi", Angewandte Chemie International Edition, vol. 60, no. 29, pp. 15827–15831, doi:10.1002/anie.202104644, PMID 33973699{{citation}}: CS1 maint: multiple names: authors list (link)