Quercetin derivatives are deconjugated and converted to hydroxyphenylacetic acids but not methylated by human fecal flora in vitro - Aura, A M; OʼLeary, K A; Williamson, G; Ojala, M; Bailey, M; Puupponen-Pimia, R; Nuutila, A M; Oksman-Caldentey, K M; Poutanen, K (J Agric Food Chem, 2002)