Isoflavonoids are a class of
flavonoid phenolic compounds, many of which are biologically active. Isoflavonoids and their derivatives are sometimes referred to as
phytoestrogens, as many isoflavonoid compounds have biological effects via the
estrogen receptor.
Medically, isoflavonoids and related compounds have been used in many
dietary supplements but the medical and scientific community[who?] is generally skeptical of their use. Recently, some natural isoflavonoids have been identified as toxins, including
biliatresone which may cause
biliary atresia when infants are exposed to the plant product.[1]
The isoflavonoid group is broad, and includes many structurally similar groups, including:
While
flavonoids (in the narrow sense) have the 2-phenylchromen-4-one backbone, isoflavonoids have the 3-phenylchromen-4-one backbone with no hydroxyl group substitution at position 2 (case of the isoflavones) or the 3-phenylchroman (isoflavan) backbone (case of isoflavanes, such as
equol).