In Vitro Anti-inflammatory Activity of Tyrosol and Tryptophol: Metabolites of Yeast via the Ehrlich Pathway

Abstract

Soy isoflavonoids were applied to commercially available baker’s yeast in vitro to find metabolites. Tyrosol, an ingredient in olive oil and wine, and tryptophol were found in the culture media. To test whether tyrosol is a metabolite of soy isoflavonoids, we prepared 2,4-dideuterated equol and applied it to yeast. According to LC-MS analysis of the culture media, deuterated tyrosol was not produced. Therefore, tyrosol is assumed to be a tyrosine metabolite of yeast known as the Ehrlich pathway. We then evaluated the in vitro activities of the 2 amino acid-derived alcohols. Both tyrosol and tryptophol similarly showed anti-inflammatory activity, as evaluated by monocyte chemoattractant protein-1 in 3T3-L1 murine adipocytes in vitro. Our results suggested that the amino acid-derived alcohols may contribute to the anti-inflammatory activity of fermented foods.