Early and Late Steps of Quinine Biosynthesis

The enzymatic basis for quinine 1 biosynthesis was investigated. Transcriptomic data from the producing plant led to the discovery of three enzymes involved in the early and late steps of the pathway. A medium-chain alcohol dehydrogenase (CpDCS) and an esterase (CpDCE) yielded the biosynthetic intermediate dihydrocorynantheal 2 from strictosidine aglycone 3. Additionally, the discovery of an O-methyltransferase specific for 6'-hydroxycinchoninone 4 suggested the final step order to be cinchoninone 16/17 hydroxylation, methylation, and keto-reduction.

Automated summary

Transcriptomic data led to the discovery of three enzymes involved in the biosynthesis of quinine, with a medium-chain alcohol dehydrogenase and an esterase being key in producing the biosynthetic intermediate dihydrocorynantheal from strictosidine aglycone. Additionally, the specific O-methyltransferase for 6'-hydroxycinchoninone suggested the final step order to be cinchoninone hydroxylation, methylation, and keto-reduction.