Novel pyrano and vinylphenol adducts of deoxyanthocyanidins in sorghum sourdough

J Agric Food Chem. 2014 Nov 26;62(47):11536-46. doi: 10.1021/jf503330b. Epub 2014 Nov 13.

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.

Keywords: caffeic acid decarboxylase; deoxyanthocyanidins; pyranoanthocyanins; sorghum; sourdough.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anthocyanins / chemical synthesis*
  • Apigenin / chemical synthesis
  • Bread / analysis
  • Chromatography, Liquid / methods
  • Coumaric Acids / chemistry
  • Edible Grain / adverse effects*
  • Fermentation
  • Lactobacillus casei / metabolism
  • Lactobacillus plantarum / metabolism
  • Propionates
  • Pyrans / chemical synthesis*
  • Sorghum / chemistry*
  • Tandem Mass Spectrometry / methods

Substances

  • Anthocyanins
  • Coumaric Acids
  • Propionates
  • Pyrans
  • Apigenin
  • apigeninidin
  • trans-3-(4'-hydroxyphenyl)-2-propenoic acid