Nitrite-mediated decarboxylative conjugation of caffeic acid with glutathione under mildly acidic conditions

In acetate buffer, pH 4, at room temperature, nitrite ions can mediate an unusual decarboxylative conjugation of caffeic acid with glutathione leading to novel isomeric 2-(3,4-dihydroxyphenyl)-2-S-glutathionylacetaldehyde oximes. These results hint at a possible role of endogenous and/or dietary glutathione in the mechanisms by which caffeic acid can affect the burden of carcinogenic N-nitroso compounds in the digestive tract.