Determination of lignans in human plasma by liquid chromatography with coulometric electrode array detection

Dietary sources of lignans and isoflavones modulate responses to estradiol in estrogen reporter mice

“…Due to the limited sample volume, serum from the wheat-, rye-, and flax-fed mice was only analyzed for lignans and serum from the soy-fed mice for isoflavones. The samples were prepared for the analyses according to a slight modification of the method previously described by Nurmi and Adlercreutz [31] and Peaealvo et al [32]. Briefly, samples were thawed and 200 lL was hydrolyzed overnight at 378C with four volumes of 0.2 M sodium acetate buffer pH 5, containing 0.2 Units/mL of b-glucuronidase and 2 Units/mL of sulfatase.…”

“…Samples from the AIN mice were first dissolved in methanol, then half of the volume was taken for further purification carried out prior to lignan analysis, and the other half was evaporated under N 2 -flow again and dissolved in half the original volume of 70% methanol for isoflavone analysis. Samples for the lignan analysis were purified with QAE-Sephadex A-25 in acetate form as described earlier [32]. Isoflavones, lignans, and their metabolites were analyzed with an HPLC-CEAD under conditions reported earlier for food isoflavones [28,30].…”

Possible Risks in Caucasians by Consumption of Isoflavones Extracts Based

“…Soy isoflavones in samples were quantified as previously reported [30,38,39] using a HPLC systems equipped with a Coularray detector or diode array detection. Peaks corresponding to soy isoflavones were confirmed by LC/MS-MS as previously reported [39].…”

“…Peaks corresponding to soy isoflavones were confirmed by LC/MS-MS as previously reported [39]. Synthetic standards were used for quantification through calibration curves, and control samples, were introduced between run to assure repeatability was acceptable (CV <15%) over the analysis time.…”

“…Results are mean values of triplicate analyses, and were only accepted when coefficient of variation (CV) between the replicates was <15%. Only values above the limits of quantification of the method for each isoflavone (1 ppm, depending on the analyte) are reported [39]. All values are expressed as aglycone equivalents.…”