Phenolic Compounds - Natural Products Chemistry: Sources, Separations, and Structures - page 58

OH

HO

OH

FIGURE 6.1 Chemical structure of resveratrol.

O

O

FIGURE 6.2 The flavonoid skeleton.

6.3 ISOFLAVONES
Some isoflavones have strong insecticidal activity (e.g., rotenoids) and others possess
estrogenic/antiestrogenic activity, which may cause infertility in mammals. Many
are recognized as phytoalexins, antimicrobial compounds.
Several isoflavones are found in the soy plant and they may be responsible for
soy's health benefits. The main isoflavone, genistein, purportedly lowers both blood
pressure and cholesterol levels, especially LDL, thereby lowering the risk of cardio-
vascular disease. Genistein (Figure 6.3) has been extensively studied, particularly for
its estrogenic effects, which may reduce symptoms of menopause and reduce risks of
osteoporosis. Genistein may also inhibit the growth of tumors and is reported to be
responsible for low rates of breast and prostate cancer seen among people eating soy
products as a major part of their diet.

HO

O

OH O

OH

FIGURE 6.3 Chemical structure of genistein, an isoflavonoid found in soy.