We don't have synonyms for polyphenol yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are polyphenols, oxyphenol and polyphenic.
(n) :
(organic chemistry, biochemistry) Any of a large class of organic compounds, of plant origin, having more than one phenol group; they tend to be colourful and to have antioxidant properties.
(n) :
(organic chemistry, biochemistry) Any of a large class of organic compounds, of plant origin, having more than one phenol group; they tend to be colourful and to have antioxidant properties.