TABLE 2

Kinetic parameters of glucuronidation of formononetin and biochanin A in pure form or in red clover extract by rat liver and intestinal microsomes

Site
Duodenum
Jejunum
Ileum
Colon
Liver
M1
M2
M1
M2
M1
M2
M1
M2
M1
M2
Pure formononetin
Vmax (nmol/min/mg) 0.791 0.471 0.413 0.485 0.209
Km (μM) 5.653 6.794 4.972 8.419 5.138
Vmax/Km (ml/min/mg) 0.140 0.069 0.083 0.058 0.041
R 0.999 0.995 0.963 0.994 0.999
Pure biochanin A
Vmax (nmol/min/mg) 2.349 0.666 1.291 0.256 0.970 0.254 0.790 0.140 0.323 0.024
Km (μM) 6.994 2.116 5.358 2.101 5.653 2.066 3.636 1.213 2.694 0.628
Vmax/Km (ml/min/mg) 0.397 0.416 0.241 0.163 0.172 0.148 0.217 0.115 0.120 0.038
R 2 0.998 0.998 0.998 0.996 0.999 0.998 0.997 0.990 0.973 0.995
Biochanin A in red clover
Vmax (nmol/min/mg) 0.336 0.337 0.613 0.275
Km (μM) 2.089 20.693 8.349 18.876
Vmax/Km (ml/min/mg) 0.161 0.016 0.073 0.015
R 2
0.986
0.996
0.994
0.999