Pyrrolizidine alkaloid monocrotaline metabolic activation

Figure 6.7 The structure of the pyrrolizidine alkaloid monocrotaline and the microsomal enzyme-mediated metabolic activation of the pyrrolizidine alkaloid nucleus.

Wang Y-P, Yan J, Beger RD, Fu PP, Chou MW (2005) Metabolic activation of the tumorigenic pyrrolizidine alkaloid, monocrotaline, leading to DNA adduct formation in vivo. CancCT Lett 226 27-35... 

Monocrotaline (170) has been the subject of extensive metabolic study with mammalian and microbiological systems. Pyrrolizidine alkaloids such as monocrotaline require metabolic activation to the corresponding pyrrole derivatives or dehydro alkaloids before they are capable of forming covalent bonds with critical macromolecules within the cell. The X-ray structure of dehydromonocrotaline has recently been determined (226), and the ability of dihydroretronicine derived from monocrotaline to react with deoxyguanosine has been demonstrated in vitro (225). 

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