We don't have synonyms for flavanoid yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are flavonoid, flavinoid and flavanone.
(n) :
Alternative form of flavonoid. [(organic chemistry) Any of many compounds that are plant metabolites, being formally derived from flavone; they have antioxidant properties, and sometimes contribute to flavor.]
(n) :
Alternative form of flavonoid. [(organic chemistry) Any of many compounds that are plant metabolites, being formally derived from flavone; they have antioxidant properties, and sometimes contribute to flavor.]