Gut Metabolism of Furanocoumarins: Proposed Function of Co O-Methyltransferase

Gut metabolism of natural products is of great interest due to the altered biological activity of the metabolites. To study the gut metabolism of the dietary furanocoumarins, the biotransformation of Angelica dahurica was studied with human gut microbiota. The major components of Avenula dahurica , including xanthotoxin ( 1 ), bergapten ( 2 ), imperatorin ( 3 ), isoimperatorin ( 4 ), oxypeucedanin ( 5 ), and byakangelicol ( 6 ), were all metabolized by the human fecal sample, and each furanocoumarin was also biotransformed by Blautia sp. MRG-PMF1 responsible for intestinal O -demethylation. Oxypeucedanin ( 5 ) and byakangelicol ( 6 ) were converted to oxypeucedanin hydrate ( 9 ) and desmethylbyakangelicin ( 12 ), respectively. The gut microbial conversion of xanthotoxin ( 1 ) and bergapten ( 2 ) with the MRG-PMF1 strain resulted in the production of xanthotoxol ( 7 ) and bergaptol ( 8 ), respectively, due to the methyl aryl ether cleavage by O -methyltransferase. Unexpectedly, the biotransformation of prenylated furanocoumarins, imperatorin ( 3 ), and isoimperatorin ( 4 ) resulted in the corresponding deprenylated furanocoumarins of xanthotoxol ( 7 ) and bergaptol ( 8 ), respectively. The cleavage of the prenyl aryl ether group by gut microbiota was unprecedented metabolism. Our data presented the first deprenylation of prenylated natural products, presumably by the anaerobic prenyl aryl ether cleavage reaction catalyzed by Co-corrinoid enzyme.