Determination Of Daidzein Research Articles

Validation and determination of Daidzein in Aspergillus oryzae using thin-layer chromatography-densitometry

Background: Daidzin (glycosidic isoflavone) bioconversion into daidzein (aglyconic isoflavone) increases its bioactivity. This bioconversion can be carried out using fermentation, using a fungus that has been widely used for making tempeh in Indonesia, Aspergillus oryzae. Objective: This study aimed to validate the method of analysis used and to determine the daidzein content in A. oryzae-fermented edamame using TLC densitometry. Method: Daidzein content determination was carried out on non-fermented (D0) and fermented edamame on days one to four (D1-D4) using the TLC densitometry method. The validation method of analysis was done previously using linearity, the limit of detection (LOD), the limit of quantification (LOQ), selectivity, specificity, precision, and accuracy parameters. Result: The TLC densitometry method used met all the validation method of analysis parameters, except for the selectivity. The daidzein content in edamame from D0 to D4 were 0.0433 ± 0.00221; 0.0336 ± 0.00698; 0.0276 ± 0.00039; 0.0219 ± 0.00041; 0.1002 ± 0.00924 % w/w, respectively. Conclusion: The highest daidzein level was obtained in day four of A. oryzae-fermented edamame.

Determination of daidzein in vegetable oil by HPLC-tandem mass spectrometry

Determination of daidzein in vegetable oil by HPLC-tandem mass spectrometry

Determination of daidzein and genistein in Soy Milk in Iran by using HPLC Analysis Method

Determination of daidzein and genistein in Soy Milk in Iran by using HPLC Analysis Method

Determination of Daidzein and Genistein in Soy Milk in Iran by Using HPLC Analysis Method

The HPLC system separated completely isofavonoids such as daidzein (15.2 min) and genistein (17.3 min). Initially, the concentrations of major isoflavone Genistein and Daidzein in the tested soy milk were determined. Commercial soy milk samples were analyzed for isoflavones and two major isoflavones detected: genistein 25.86 (mg L(-1)) +/- 0.66 SD and daidzein 8.25 (mg L(-1)) +/- 1.13 SD. Concentrations of genistein in soy milk were higher than daidzein. The results obtained in this study can serve as a basis for estimating amount of soy milk can be consumed by people as related to its main isoflavone content.

Determination of Daidzein in Rat Plasma by LC

Daidzein (4′,7-dihydroxylisoflavone), a water-insoluble isoflavone, is mainly present in leguminous plants. This study was aimed at investigating the absorption characteristics of daidzein across the intestinal membranes. Borneol has been used to enhance the intestinal absorption and bioavailability of daidzein. We chose an in vitro diffusion chamber system using isolated rat intestinal membranes as a model. A sensitive, accurate and reliable LC method was developed and validated to determine daidzein in rat plasma. A linear relationship for daidzein was found in the range of 20–800 ng mL−1. The mean absolute recoveries of daidzein determined over three concentrations were 89.8 ± 4.8, 91.3 ± 2.8 and 95.4 ± 1.7%. The coefficients of variation for inter-day and intra-day assay were found to be less than 6.1%. The plasma concentration of daidzin following oral administration was significantly increased by coadministration of borneol in rats, and a 1.5-fold enhancement of relative bioavailability of daidzein was observed as compared to daidzein administered alone.

Determination of daidzein and genistein in soybean foods by automated on-line in-tube solid-phase microextraction coupled to high-performance liquid chromatography

An automated on-line method for the determination of the isoflavones, daidzein and genistein, was developed using in-tube solid-phase microextraction coupled to high-performance liquid chromatography (in-tube SPME–HPLC). In-tube SPME is a new extraction technique for organic compounds in aqueous samples, in which analytes are extracted from the sample directly into an open tubular capillary by repeated draw/eject cycles of sample solution. Daidzein, genistein and their glucosides tested in this study were clearly separated within 8 min by HPLC using an XDB-C 8 column with diode array detection. In order to optimize the extraction of these compounds, several in-tube SPME parameters were examined. The glucosides daidzin and genistin were analyzed as aglycones after hydrolysis because the glucosides were not concentrated by in-tube SPME. The optimum extraction conditions for daidzein and genistein were obtained with 20 draw/eject cycles of 40 μl of sample using a Supel-Q porous layer open tubular capillary column. The extracted compounds were easily desorbed from the capillary by mobile phase flow, and carryover was not observed. Using the in-tube SPME–HPLC method, the calibration curves of these compounds were linear in the range 5–200 ng/ml, with a correlation coefficient above 0.9999 ( n=18), and the detection limits ( S/ N=3) were 0.4–0.5 ng/ml. This method was successfully applied to the analysis of soybean foods without interference peaks. The recoveries of aglycones and glucosides spiked into food samples were above 97%.

A simultaneous determination of daidzin and puerarin and determination of daidzein in Oriental pharmaceutical decoctions containing puerariae radix by ion-pair high-performance liquid chromatography

A simple and precise method was established for the simultaneous determination of daidzin and puerarin and the determination of daidzein in oriental pharmaceutical decoctions containing Puerariae Radix using high-performance liquid chromatography with tetra-n-heptylammonium bromide (THA) as an ion-pair reagent. Daidzin and puerarin were eluted within 45 min without interference with co-existing components using an ODS column and a mixture of 10 mM phosphate buffer (pH 6.5)-methanol (68:32) containing 5 mM THA as a mobile phase. Daidzein was eluted within 35 min without interference with co-existing components using an ODS column and a mixture of 10 mM phosphate buffer (pH 6.5)-acetonitrile (72:28 or 68:32) containing 5 mM THA as a mobile phase.