Table 2

Apparent half-lives of isoflavone metabolitesa

SubjectSubject genderSubject weight (kg)GenisteinDaidzein
Glucuronides t1/2Sulfates t1/2bGlucuronides t1/2Sulfatest1/2
1M1015.3N.D.c2.35.7
2M765.66.33.24.6
3M11410.06.34.78.8
4M734.05.33.04.4
5M805.76.53.34.4
6M736.18.04.36.0
7F615.97.26.27.8
8F564.74.33.24.9
9F615.0N.D.N.D.6.0
10F606.24.02.93.2
11F636.75.93.35.2
12F607.46.55.25.2
Mean ± SE73.1 ± 5.16.0d ± 0.46.0d ± 0.043.8d ± 0.45.5d ± 0.04
  • a Hours.

  • b Calculated sulfates: [total − (glucuronides + aglycones)].

  • c N.D., not determined.

  • d Harmonic means are: genistein glucuronides, 5.7; genistein calculated sulfates, 5.8; daidzein glucuronides, 3.5; and daidzein calculated sulfates, 5.2.