p -Quinone Methide-Mediated Nonenzymatic Formation of Chalcane-Containing Dimers in Dragon's Blood.

Chalcane-containing dimers are major compounds identified from dragon's blood, the red resin that accumulates in Dracaena trees after injury. The key step for the formation of these dimers was a p -quinone methide ( p -QM, 3 ) mediated nonenzymatic Michael addition. Compound 3 is derived from the spontaneous dehydration of chalcane alcohol-M274 ( 2 ). Two dihydroflavonol-4-reductases, discovered in D. cambodiana , reduce dihydrochalcone-M272 ( 7 ) to 2 . Moreover, the application potential of p -QMs was demonstrated using a 3 -like p -QM to synthesize diverse dimeric derivatives.