title: Novel pyrano and vinylphenol adducts of deoxyanthocyanidins in sorghum sourdough.
abstract: This study determined the fate of deoxyanthocyanidins in sorghum sourdoughs. Sourdoughs prepared from the red sorghum variety Town were fermented with the caffeic acid-decarboxylating strains Lactobacillus plantarum FUA3171 and the decarboxylase negative L. casei FUA3166. Deoxyanthocyanidins were analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Apigeninidin and methoxyapigeninidin were the major deoxyanthocyanidins prior to fermentation. During fermentation, novel deoxyanthocyanidins were formed. Purification by preparative LC, followed by NMR analysis and high-resolution MS identified two of the compounds as 6-deoxyanthocyanidin-vinylphenol and pyrano-3-deoxyanthocyanidin. To identify pathways for their formation, sorghum was fermented with single strains, L. plantarum or L. casei. 6-Deoxyanthocyanidin-vinylphenol and pyrano-3-deoxyanthocyanidin were formed only during fermentation with L. plantarum FUA3171, indicating a role of vinylphenol in their formation. Chemical synthesis confirmed that 6-deoxyanthocyanidin-vinylphenol and pyrano-3-deoxyanthocyanidin are formed from apigeninidin with vinylphenol but not with p-coumaric acid as reactants. In conclusion, the products of microbial decarboxylation of hydroxycinnamic acids convert apigeninidin and methoxyapigeninidin to pyrano-3-deoxyanthocyanidins and vinylphenol adducts.
authors.affiliation: Department of Agricultural, Food and Nutritional Science, University of Alberta , Edmonton, Alberta T6G 2P5, Canada.
authors.forename: Yunpeng
authors.initials: Y
authors.lastname: Bai
authors.forename: Brandon
authors.initials: B
authors.lastname: Findlay
authors.forename: Alma Fernanda Sanchez
authors.initials: AF
authors.lastname: Maldonado
authors.forename: Andreas
authors.initials: A
authors.lastname: Schieber
authors.forename: John C
authors.initials: JC
authors.lastname: Vederas
authors.forename: Michael G
authors.initials: MG
authors.lastname: Gänzle
mesh_terms: D000872:Anthocyanins / Q000138:chemical synthesis*; D047310:Apigenin / Q000138:chemical synthesis; D001939:Bread / Q000032:analysis; D002853:Chromatography, Liquid / Q000379:methods; D003373:Coumaric Acids / Q000737:chemistry; D002523:Edible Grain / Q000009:adverse effects*; D005285:Fermentation; D007780:Lacticaseibacillus casei / Q000378:metabolism; D048191:Lactiplantibacillus plantarum / Q000378:metabolism; D011422:Propionates; D011714:Pyrans / Q000138:chemical synthesis*; D045868:Sorghum / Q000737:chemistry*; D053719:Tandem Mass Spectrometry / Q000379:methods; D000094162:Phytoalexins
chemical_list: D000872:Anthocyanins; D047310:Apigenin; D003373:Coumaric Acids; D011422:Propionates; D011714:Pyrans; C104027:apigeninidin; D000094162:Phytoalexins; C495469:p-coumaric acid
keywords: caffeic acid decarboxylase; deoxyanthocyanidins; pyranoanthocyanins; sorghum; sourdough