ABSTRACT
References .......................................................................................................................... 388
Isoflavonoid phytoestrogens such as the soy isoflavones genistein and daidzein are plant-
derived nonsteroidal estrogen mimics, often referred to as phytoestrogens (other phytoestro-
gens include lignans such as secoisolariciresinol, coumestans such as coumestrol, and prenyl-
flavonoids such as 8-prenylnaringenin; see Figure 7.1), that are extensively investigated to
determine their potential, particularly in the protection of human health.1-9
Isoflavonoids include the isoflavones genistein and daidzein, which occur mainly as the
glycosides genistin and daidzin (see Figure 7.2), respectively, in soybeans and consequently
in a wide range of soy-derived foods and to a lesser extent in other legumes.10-12 Traditional
OH
HO
HO
HO
CH3
O
OH OH
O
O
O
OH
O
O
OH
OH
OH
O
CH3
CH3H3C
CH3
OH
OH
O
HO
HO
Estradiol
Genistein
Coumestrol
8-Prenylnaringenin
Secoisolariciresinol
A
B
FIGURE 7.1 The structural relationship between phytoestrogens and 17b-estradiol.
