The Development of S-Equol Diastereoisomer Specific ELISA
| Autor: | Akira Kambegawa, Takayuki Minekawa, Shizuka Takehara, Hidetoshi Arakawa, Kumiko Shindome |
|---|---|
| Rok vydání: | 2012 |
| Předmět: | |
| Zdroj: | American Journal of Analytical Chemistry. :448-454 |
| ISSN: | 2156-8278 2156-8251 |
| Popis: | Equol is a metabolite of soybean isoflavone, daidzein, and many health benefits are expected. Endogenous equol in urine is S-equol and mostly exists as glucuronate or sulfate conjugate. In this study we preliminary established the simple enzyme-linked immunosorbent assay (ELISA) without deconjugation, then developed the S-equol specific ELISA involves deconjugation showing high stereospecificity to S-equol without using stereospecific antibody. For the simple ELISA, we used a polyclonal antibody that targets the regions not influenced by inhibition by conjugation of glucuronate and sulfate and achieved the correlation coefficient; r = 0.975, but the value was 30 % lower than high performance liquid chromatography (HPLC). Developing upon this we invented the specific ELISA established from S-equol homogeneous combination for the standard and enzyme-labeled antigen to enhance stereospecificity. The correlation with HPLC was favorable: r = 0.986, y = 0.996x – 6. Compared to the previous method using (R,S)-equol combination, cross-reactivity with R-equol was reduced from 65 to 13 %, and that with daidzein from 0.31% to 0.08%, markedly increased in the specificity. This study is expected to be applied for both simple clinical researches, and stereospecific immunoassays in which specific antibody preparation is difficult. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|