Methylene cyclopropyl acetic acid

Methylene cyclopropyl acetic acid

Names
IUPAC name 2-(2-methylidenecyclopropyl)acetic acid
Other names MCPA; Methylenecyclopropaneacetic acid
Identifiers
CAS Number	1073-00-3 Y
3D model (Jmol)	Interactive image
ChEMBL	ChEMBL314481 Y
ChemSpider	8389873 Y
ECHA InfoCard	100.189.911
PubChem	10214381
InChI InChI=1S/C6H8O2/c1-4-2-5(4)3-6(7)8/h5H,1-3H2,(H,7,8) Y Key: QJBXAEKEXKLLLZ-UHFFFAOYSA-N Y
SMILES OC(=O)CC1CC1=C
Properties
Chemical formula	C6H8O2
Molar mass	112.13 g·mol−1
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Methylene cyclopropyl acetic acid (MCPA) is found in lychee seeds and also a toxic metabolite in mammalian digestion after ingestion of hypoglycin.

Overview

Methylene cyclopropyl acetic acid (MCPA) is a compound found in lychee seeds.^[1] It is also a metabolite in mammalian digestion after ingestion of hypoglycin, a rare and potentially toxic amino acid, chemically related to the common amino acid lysine. (Hypoglycin is found in the unripe ackee fruit in Africa.)

Dihydrosterculic acid is the major carbocyclic fatty acid in the seed oils of Litchi chinensis. It is a cyclopropene fatty acid; these have been found in many plants of the order Malvales (Sterculiaceae, Malvaceae, Bombaceae and Tiliaceae), in up to 60% of seed oil content, depending on the species but also in leaves, roots and shoots.^[2] They are accompanied by small amounts of their cyclopropanoid analogues, i.e. cyclopropyl acetic acid.

Symptoms and signs of poisoning

The symptoms of poisoning are intolerance to prolonged fasting, vomiting, altered mental status with lethargy, progressing to unconsciousness, coma and death.^[3]

Mechanism of toxicity per animal studies

MCPA is a potent inhibitor of acyl CoA dehydrogenase, thus preventing the metabolism of fatty acids. The intolerance to prolonged fasting is due to inability to switch from glucose to fatty acid oxidation, impaired ketogenesis. There is increased urinary excretion of dicarboxylic acids, due to omega oxidation that occurs in the endoplasmic reticulum.^[4]

References