Monocrotaline

These species can synthesise MCT out of amino acids and can cause liver, lung and kidney damage in various organisms.

Initial stress factors are released intracellular upon binding of MCT to BMPR2 receptors and elevated MAPK phosphorylation levels are induced, which can cause cancer in Homo sapiens.

[1] MCT is a chemical with pesticide properties and therefore serves as a defence mechanism to fend off predators.

The larvae of the butterfly feed almost exclusively on Crotalaria seeds, where MCT is accumulated in their bodies.

[4] Studies concluded that the ingestion of MCT will cause centrilobular necrosis, pulmonary fibrosis and increase in blood urea nitrogen.

To form the final product retronecine, 1-hydroxymethyl pyrrolizidine is desaturated and hydroxylated respectively by unknown enzymes.

During the phase 2 reactions, dehydro MCT can react with nucleophilic biological macromolecules (NuS) which is a toxic intermediate.

Thereby, the assembly of CaSR is enhanced and triggers the mobilisation of calcium signalling, and damages pulmonary artery endothelial cells.

Cytokines such as TNF-α are released which cause activation of inflammation mechanisms, attracting neutrophils among others.

The cytokine TGF-β (also released by macrophages via chemotaxis during inflammation reactions in a positive feedback loop with TNF-α) is a transforming growth factor that is upregulated as a result of iNOS increasement, contributing to pulmonary artery proliferation.

Skeleton formula of a carbon ring, containing oxygen, hydrogen and nitrogen atoms. It is supposed to be monocrotaline
Skeleton formula of a carbon ring, containing oxygen, hydrogen and nitrogen atoms. It is supposed to be monocrotaline
Picture of the Crotalaria spectabilis.
Picture of the Crotalaria spectabilis.
Biosynthesis route of retronecine in plants.
Biosynthesis route of retronecine in plants.
Biosynthesis of monocrotaline in plants.
Biosynthesis of monocrotaline in plants.
Biotransformation route of monocrotaline in rats.
Biotransformation route of monocrotaline in rats.
Monocrotaline: mechanism of action.
Monocrotaline: schematic mechanism of action.