marmesin and nodakenin

When nodakenin (1) was anaerobically incubated with human intestinal bacteria, nodakenetin (2) was found as a main biotransformed product. We developed a simple and selective reversed-phase high-performance liquid chromatographic method for simultaneous quantification of 1 and 2 in incubated system of human intestinal bacteria with 1. Chromatographic separation of 1 and 2 was performed on an analytical C(18) column, with a mobile phase of MeOH-H(2)O (4:6, v/v) at a flow rate of 1.0 ml/min and the UV detection was at 330 nm. The calibration curves were linear over the range of 0.15-24.0 microg/ml for 1 and 0.7-13.2 microg/ml for 2. The lower limits of detection and quantification were 0.01 and 0.1 microg/ml for 1, and 0.005 and 0.05 microg/ml for 2. The recoveries were (87.66 +/- 1.66), (79.89 +/- 2.53), and (82.96 +/- 5.61)% at 1.0, 2.0, and 8.0 microg/ml, respectively, for 1 and (88.32 +/- 4.12), (78.15 +/- 4.39), and (76.22 +/- 3.29)% at 1.0, 4.0, and 16.0 microg/ml, respectively, for 2. The intra- and interday precision and accuracy were validated by relative standard deviation, which were in the ranges of 1.25-4.16 and 2.16-6.12% for 1, and 1.98-6.45 and 2.56-4.57% for 2, respectively. This method has been applied to the simultaneous quantitation of 1 and 2 in incubated system of human intestinal bacteria with 1.

Topics: Biotransformation; Chromatography, High Pressure Liquid; Coumarins; Drugs, Chinese Herbal; Feces; Glucosides; Humans; Intestines; Male