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Analysis of phyto-oestrogens in biological matrices

Published online by Cambridge University Press:  26 October 2011

Antti A. Hoikkala ,
Emidio Schiavoni  and
Kristiina Wähälä
Antti A. Hoikkala
Affiliation:
Department of Chemistry, Laboratory of Organic Chemistry, PO Box 55, FIN-00014, University of Helsinki, Finland
Emidio Schiavoni
Affiliation:
National Institute for Research on Food and Nutrition, Via Ardeatina 546, I-00178 Rome, Italy
Kristiina Wähälä*
Affiliation:
Department of Chemistry, Laboratory of Organic Chemistry, PO Box 55, FIN-00014, University of Helsinki, Finland
*
*Corresponding author: Professor K. Wähälä, fax +358 9 191 50357, email kristiina.wahala@helsinki.fi
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A review covering different methods for the analysis of phyto-oestrogens in biological matrices is presented. Sample pretreatment and analysis of isofiavonoids and lignans by HPLC and GC with various detection methods are discussed. The immunoassay method is also briefly presented.

Keywords

Analysis of phyto-oestrogensIsofiavonoidsLignans
Type
Research Article
Information
British Journal of Nutrition , Volume 89 , Issue S1: Effects of Phyto-oestrogens on Bone Health: the VENUS Concerted Action , June 2003 , pp. S5 - S18
Copyright
Copyright © The Nutrition Society 2003

References

Adlercreutz, H, Fotsis, T, Bannwart, C, Wähälä, K, Brunow, G & Hase, T (1991 a) Isotope dilution gas chromatographic-mass spectrometric method for the determination of lignans and isoflavonoids in human urine, including identification of genistein. Clinica Chimica Acta 199, 263–278.CrossRefGoogle ScholarPubMed
Adlercreutz, H, Fotsis, T, Bannwart, C, Wähälä, K, Mäkelä, T, Brunow, G & Hase, T (1986 a) Determination of urinary lignans and phyto-oestrogen metabolites, potential antiestrogens and anticarcinogens, in urine of women on various habitual diets. Journal of Steroid Biochemistry 25, 791–797.Google Scholar
Adlercreutz, H, Fotsis, T, Kurzer, M, Wähälä, K, Mäkelä, T & Hase, T (1995 b) Isotope dilution gas chromatographic-mass spectrometric method for the determination of unconjugated lignans and isoflavonoids in human feces, with preliminary results in omnivorous and vegetarian women. Analytical Biochemistry 225, 101–108.CrossRefGoogle ScholarPubMed
Adlercreutz, H, Fotsis, T, Lampe, J, Wähälä, K, Mäkelä, T, Brunow, G & Hase, T (1993) Quantitative determination of lignans and isoflavonoids in plasma of omnivorous and vegetarian women by isotope dilution gas chromatography–mass spectrometry. Scandinavian Journal of Clinical and Laboratory Investigation 53 Suppl., 5–18.Google Scholar
Adlercreutz, H, Fotsis, T, Watanabe, S, Lampe, J, Wähälä, K, Mäkelä, T & Hase, T (1994) Determination of lignans and isoflavonoids in plasma by isotope dilution gas chromatography–mass spectrometry. Cancer Detection and Prevention 18, 259–271.Google ScholarPubMed
Adlercreutz, H, Honjo, H, Higashi, A, Fotsis, T, Hämäläinen, E, Hasegawa, T & Okada, H (1991 b) Urinary excretion of lignans and isoflavonoid phyto-oestrogens in Japanese men and women consuming a traditional Japanese diet. American Journal of Clinical Nutrition 54, 1093–1100.Google Scholar
Adlercreutz, H, Musey, PI, Fotsis, T, Bannwart, C, Wähälä, K, Mäkelä, T, Brunow, G & Hase, T (1986 b) Identification of lignans and phyto-oestrogens in urine of chimpanzees. Clinica Chimica Acta 158, 147–154.CrossRefGoogle ScholarPubMed
Adlercreutz, H, van der Wildt, J, Kinzel, J, Attalla, H, Wähälä, K, Mäkelä, T, Hase, T & Fotsis, T (1995 a) Lignan and isoflavonoid conjugates in human urine. Journal of Steroid Biochemistry and Molecular Biology 52, 97–103.CrossRefGoogle ScholarPubMed
Adlercreutz, H, Wang, G, Lapcík, O, Hampl, R, Wähälä, K, Mäkelä, T, Lusa, K, Talme, M & Mikola, H (1998) Time-resolved fluoroimmunoassay for plasma enterolactone. Analytical Biochemistry 265, 208–215.CrossRefGoogle ScholarPubMed
Al-Maharik, NI, Kaltia, SA & Wähälä, K (1999) Regioselective mono-O-carboxymethylation of polyhydroxyisoflavones. Molecules Online 3, 20–24.Google Scholar
Al-Maharik, N, Mutikainen, I & Wähälä, K (2000) An expedient synthesis of 2-(ω-carboxyalky)polyhydroxyisoflavones via cyclisation of 2-hydroxydeoxybenzoins with l,ω-alkanedicarboxylic acid monoesters. Synthesis 411–416.Google Scholar
Andlauer, W, Kolb, J & Furst, P (2000 b) Absorption and metabolism of genistin in the isolated rat small intestine. FEBS Letters 475, 127–130.CrossRefGoogle ScholarPubMed
Andlauer, W, Kolb, J, Stehle, P & Furst, P (2000 a) Absorption and metabolism of genistein in isolated rat small intestine. Journal of Nutrition 130, 843–846.CrossRefGoogle ScholarPubMed
Aramendia, MA, Boráu, V, García, I, Jiménez, C, Lafont, F, Marinas, JM, Porras, A & Urbano, FJ (1995) Determination of isoflavones by capillary electrophoresis/electrospray ionization mass spectrometry. Journal of Mass Spectrometry and Rapid Communications in Mass Spectrometry 9, Suppl., S153–S157.Google Scholar
Aussenac, T, Lacombe, S & Daydé, J (1998) Quantification of isoflavones by capillary zone electrophoresis in soybean seeds: effects of variety and environment. American Journal of Clinical Nutrition 68, Suppl., 1480S–1485S.CrossRefGoogle ScholarPubMed
Bannwart, C, Adlercreutz, H, Wähälä, K, Brunow, G & Hase, T (1989) Detection and identification of the plant lignans lariciresinol, isolariciresinol and secoisolariciresinol in human urine. Clinica Chimica Acta 180, 293–301.Google Scholar
Barnes, S, Coward, L, Kirk, M & Sfakianos, J (1998) HPLC-mass spectrometry analysis of isoflavones. Proceedings of the Society for Experimental Biology and Medicine 217, 254–262.Google Scholar
Bennetau-Pelissero, C, Le Houérou, C, Lamothe, V, Le Menn, F, Babin, P & Bennetau, B (2000) Synthesis of haptens and conjugates for ELISAs of phyto-oestrogens. Development of the immunological tests. Journal of Agricultural and Food Chemistry 48, 305–311.Google Scholar
Chang, HC, Churchwell, MI, Delclos, KB, Newbold, RR & Doerge, DR (2000) Mass spectrometric determination of genistein tissue distribution in diet exposed Sprague-Dawley rats. Journal of Nutrition 130, 1963–1970.Google Scholar
Cimino, CO, Shelnutt, SR, Ronis, MJJ & Badger, TM (1999) An LC-MS method to determine concentrations of isoflavones and their sulfate and glucuronide conjugates in urine. Clinica Chimica Acta 287, 69–82.CrossRefGoogle ScholarPubMed
Coward, L, Kirk, M, Albin, N & Barnes, S (1996) Analysis of plasma isoflavones by reversed-phase HPLC-multiple reaction ion monitoring-mass spectrometry. Clinica Chimica Acta 247, 121–142.Google Scholar
Doerge, DR, Churchwell, MI & Delclos, KB (2000) On-line sample preparation using restricted-access media in the analysis of the soy isoflavones, genistein and daidzein, in rat serum using liquid chromatography electrospray mass spectrometry. Rapid Communications in Mass Spectrometry 14, 673–678.3.0.CO;2-F>CrossRefGoogle ScholarPubMed
Duncan, AM, Merz-Demlow, BE, Xu, X, Phipps, WR & Kurzer, MS (2000) Premenopausal equol excretors show plasma hormone profiles associated with lowered risk of breast cancer. Cancer Epidemiology, Biomarkers & Prevention 9, 581–586.Google ScholarPubMed
Franke, AA & Custer, LJ (1996) Daidzein and genistein concentrations in human milk after soy consumption. Clinical Chemistry 42, 955–964.Google Scholar
Franke, AA, Custer, LJ, Carmencita, MC & Narala, K (1995) Rapid analysis of dietary phyto-oestrogens from legumes and from human urine. Proceedings of the Society for Experimental Biology and Medicine 208, 18–26.Google Scholar
Franke, AA, Custer, LJ & Tanaka, Y (1998 a) Isoflavones in human breast milk and other biological fluids. American Journal of Clinical Nutrition 68, Suppl., 1466S–1473S.Google Scholar
Franke, AA, Custer, LJ, Wang, W & Shi, CY (1998 b) HPLC analysis of isoflavonoids and other phenolic agents from foods and from human fluids. Proceedings of the Society for Experimental Biology and Medicine 217, 263–273.Google Scholar
Gamache, PH & Acworth, IN (1998) Analysis of phyto-oestrogens and polyphenols in plasma, tissue and urine using HPLC with coulometric array detection. Proceedings of the Society for Experimental Biology and Medicine 217, 274–280.Google Scholar
Heinonen, S, Wähälä, K & Adlercreutz, H (1999) Identification of isoflavone metabolites dihydrodaidzein, dihydrogenistein, 6′-OH-O-DMA and cis-4-OH-equol in human urine by gas chromatography-mass spectroscopy using authentic reference compounds. Analytical Biochemistry 274, 211–219.CrossRefGoogle Scholar
Holder, CL, Churchwell, MI & Doerge, DR (1999) Quantification of soy isoflavones, genistein and daidzein, and conjugates in rat blood using LC/ES-MS. Journal of Agricultural and Food Science 47, 3764–3770.Google Scholar
Horn-Ross, PL, Barnes, S, Kirk, M, Coward, L, Parsonnet, J & Hiatt, RA (1997) Urinary phyto-oestrogen levels in young women from a multiethnic population. Cancer Epidemiology, Biomarkers & Prevention 6, 339–345.Google Scholar
Hutchins, AM, Lampe, JW, Martini, MC, Campbell, DR & Slavin, JL (1995) Vegetables, fruits, and legumes: effect on urinary isoflavonoid and lignan excretrion. Journal of the American Dietetic Association 95, 769–774.CrossRefGoogle Scholar
Jacobs, E, Kulling, SE & Metzler, M (1999) Novel metabolites of the mammalian lignans enterolactone and enterodiol in human urine. Journal of Steroid Biochemistry and Molecular Biology 68, 211–218.Google Scholar
Jenab, M & Thompson, LU (1996) The influence of flaxseed and lignans on colon carcinogenesis and β-glucuronidase activity. Carcinogenesis 17, 1343–1348.Google Scholar
Joannou, GE, Kelly, GE, Reeder, AY, Waring, M & Nelson, C (1995) A urinary profile study of dietary phyto-oestrogens. The identification and mode of metabolism of new isoflavonoids. Journal of Steroid Biochemistry and Molecular Biology 54, 167–184.Google Scholar
Kelly, GE, Nelson, C, Waring, MA, Joannou, GE & Reeder, AY (1993) Metabolites of dietary (soya) isoflavones in human urine. Clinica Chimica Acta 223, 9–22.Google Scholar
Kirkman, LM, Lampe, JW, Campbell, DR, Martini, MC & Slavin, JL (1995) Urinary lignan and isoflavonoid excretion in men and women consuming vegetable and soy diets. Nutirition and Cancer 24, 1–12.Google Scholar
Kohen, F, Lichter, S, Gayer, B, DeBoever, J & Lu, LJW (1998) The measurement of the isoflavone daidzein by time resolved fluorescent immunoassay: a method for assessment of dietary soya exposure. Journal of Steroid Biochemistry and Molecular Biology 64, 217–222.Google Scholar
Lampe, JW, Gustafson, DR, Hutchins, AM, Martini, MC, Li, S, Wähälä, K, Grandits, GA, Potter, JD & Slavin, JL (1999) Urinary isoflavonoid and lignan excretion on a western diet: relation to soy, vegetable, and fruit intake. Cancer Epidemiology, Biomarkers & Prevention 8, 699–707.Google ScholarPubMed
Lampe, JW, Skor, HE, Li, S, Wähälä, K, Howald, WN & Chen, C (2001) Wheat bran and soy protein feeding do not alter urinary excretion of the isoflavan equol in premenopausal women. Journal of Nutrition 131, 740–744.Google Scholar
Lapcík, O, Hampl, R, Al-Maharik, N, Salakka, A, Wähälä, K & Adlercreutz, H (1997) A novel radioimmunoassay for daidzein. Steroids 62, 315–320.Google Scholar
Lapcík, O, Hampl, R, Hill, M, Wähälä, K, Al-Maharik, N & Adlercreutz, H (1998) Radioimmunoassay of free genistein in human serum. Journal of Steroid Biochemistry and Molecular Biology 64, 261–268.Google Scholar
Lapcík, O, Hampl, R, Stárka, L, Wähälä, K, Al-Maharik, N & Adlercreutz, H (1999) Radioimmunoassay of phyto-oestrogens of isoflavone series. Journal of Medicinal Food 2, 207–208.Google Scholar
Le Houérou, C, Bennetau-Pelissero, C, Lamothe, V, Le Menn, F, Babin, P & Bennetau, B (2000) Synthesis of novel hapten-protein conjugates for production of highly specific antibodies to formononetin, daidzein and genistein. Tetrahedron 56, 295–301.Google Scholar
Liggins, J, Grimwood, R & Bingham, S (2000) Extraction and quantification of lignan phyto-oestrogens in food and human samples. Analytical Biochemistry 287, 102–109.Google Scholar
Lu, L-JW, Broemeling, LD, Marshall, MV & Ramanujam, VMS (1995 a) A simplified method to quantify isoflavones in commercial soybean diets and human urine after legume consumption. Cancer Epidemiology, Biomarkers & Prevention 4, 497–503.Google ScholarPubMed
Lu, L-JW, Grady, JJ, Marshall, MV, Ramanujam, VMS & Anderson, KE (1995 b) Altered time course of urinary daidzein and genistein excretion during chronic soya diet in healthy male subjects. Nutrition and Cancer 24, 311–323.Google Scholar
Lu, L-JW, Lin, S-N, Grady, JJ, Nagamani, M & Anderson, KE (1996) Altered kinetics and extent of urinary daidzein and genistein excretion in women during chronic soya exposure. Nutrition and Cancer 26, 290–302.Google Scholar
Mäkelä, T, Matikainen, J, Wähälä, K & Hase, T (2000) Development of a novel hapten for radioimmunoassay of the lignan, enterolactone in plasma (serum). Total synthesis of (±)-trans-5-carboxymethoxyenterolactone and several analogues. Tetrahedron 56, 1873–1882.CrossRefGoogle Scholar
Mazur, W, Fotsis, T, Wähälä, K, Ojala, S, Salakka, A & Adlercreutz, H (1996) Isotope dilution gas chromatographic-mass spectrometric method for the determination of isoflavonoids, coumestrol, and lignans in food samples. Analytical Biochemistry 233, 169–180.Google Scholar
Morton, M, Arisaka, O, Miyake, A & Evans, B (1999) Analysis of phyto-oestrogens by gas chromatography-mass spectrometry. Environmental Toxicology and Pharmacology 7, 221–225.CrossRefGoogle ScholarPubMed
Morton, MS, Chan, PSF, Cheng, C, Blacklock, N, Matos-Ferreira, A, Abranches-Monteiro, L, Correia, R, Lloyd, S & Griffiths, K (1997 b) Lignans and isoflavonoids in plasma and prostatic fluid in men: samples from Portugal, Hong Kong and the United Kingdom. Prostate 32, 122–128.Google Scholar
Morton, MS, Matos-Ferreira, A, Abranches-Monteiro, L, Correia, R, Blacklock, N, Chan, PSF, Cheng, C, Lloyd, S, Wu, C-P & Griffiths, K (1997 a) Measurement and metabolism of isoflavonoids and lignans in the human male. Cancer Letters 114, 145–151.Google Scholar
Morton, MS, Wilcox, G, Wahlqvist, ML & Griffiths, K (1994) Determination of lignans and isoflavonoids in human female plasma following dietary supplementation. Journal of Endocrinology 142, 251–259.Google Scholar
Nesbitt, PD, Lam, Y & Thompson, LU (1999) Human metabolism of mammalian lignan precursors in raw and processed flaxseed. American Journal of Clinical Nutrition 69, 549–555.CrossRefGoogle ScholarPubMed
Niemeyer, HB, Honig, D, Lange-Böhmer, A, Jacobs, E, Kulling, SE & Metzler, M (2000) Oxidative metabolites of the mammalian lignans enterodiol and enterolactone in rat bile and urine. Journal of Agricultural and Food Chemistry 48, 2910–2919.Google Scholar
Nose, M, Fujimoto, T, Nishibe, S & Ogihara, Y (1993) Structural transformation of lignan compounds in rat gastrointestinal tract; II. Serum concentration of lignans and their metabolites. Planta Medica 59, 131–134.Google Scholar
Nose, M, Fujimoto, T, Takeda, T, Nishibe, S & Ogihara, Y (1992) Structural transformation of lignan compounds in rat gastrointestinal tract. Planta Medica 58, 520–523.Google Scholar
Nurmi, T & Adlercreutz, H (1999) Sensitive high-performance liquid chromatographic method for profiling phyto-oestrogens using coulometric electrode array detection: application to plasma analysis. Analytical Biochemistry 274, 110–117.CrossRefGoogle ScholarPubMed
Peterson, TR, Ji, G-PJ, Kirk, M, Coward, L, Falany, CN & Barnes, S (1998) Metabolism of the isofiavones genistein and biochanin A in human breast cancer cells. American Journal of Clinical Nutrition 68, Suppl., 1505S–1511S.Google Scholar
Piskula, MK (2000) Soy isoflavone conjugation differs in fed and food-deprived rats. Journal of Nutrition 130, 1766–1771.Google Scholar
Piskula, MK, Yamakoshi, J & Iwai, Y (1999) Daidzein and genistein but not their glucosides are absorbed from the rat stomach. FEBS Letters 447, 287–291.Google Scholar
Rasku, S, Mazur, W, Adlercreutz, H & Wähälä, K (1999 a) Synthesis of deuterated plant lignans for gas chromatography-mass spectrometry analysis. Journal of Medicinal Food 2, 103–105.CrossRefGoogle ScholarPubMed
Rasku, S, Wähälä, K, Koskimies, J & Hase, T (1999 b) Synthesis of isoflavonoid deuterium labeled polyphenolic phyto-oestrogens. Tetrahedron 55, 3445–3454.Google Scholar
Rickard, SE, Orcheson, LJ, Seidl, MM, Luyengi, L, Fong, HHS & Thompson, LU (1996) Dose-dependent production of mammalian lignans in rats and in vitro from the purified precursor secoisolariciresinol diglycoside in flaxseed. Journal of Nutrition 126, 2012–2019.Google ScholarPubMed
Rowland, IR, Wiseman, H, Sanders, TAB, Adlercreutz, H & Bowey, EA (2000) Interindividual variation in metabolism of soy isoflavones and lignans: influence of habitual diet on equol production by the gut microflora. Nutrition and Cancer 36, 27–32.Google Scholar
Salakka, A & Wähälä, K (2000) Synthesis of D4-6′-hydroxy-O-demethylangolensin, a deuterium labelled metabolite of genistein. Journal of Labelled Compounds and Radiopharmacy 43, 1145–1147.Google Scholar
Serraino, M & Thompson, LU (1992) Flaxseed supplementation and early markers of colon carcinogenesis. Cancer Letters 63, 159–165.Google Scholar
Setchell, KDR & Adlercreutz, H (1979) The excretion of two new phenolic compounds (180/442 and 180/410) during human menstrual cycle and in pregnancy. Journal of Steroid Biochemistry 11, xv–xvi.Google Scholar
Setchell, KDR, Alme, B, Axelson, M & Sjövall, J (1976) The multicomponent analysis of conjugates of neutral steroids in urine by lipophilic ion exchange chromatography and computerised gas chromatography-mass spectrometry. Journal of Steroid Biochemistry 7, 615–629.CrossRefGoogle ScholarPubMed
Setchell, KDR, Brown, NM, Desai, P, Zimmer-Nechemias, L, Wolfe, BE, Brashear, WT, Kirschner, AS, Cassidy, A & Heubi, JE (2001) Bioavailability of pure isoflavones in healthy humans and analysis of commercial soy isoflavone supplements. Journal of Nutrition 131, Suppl., 1362S–1375S.Google Scholar
Setchell, KDR & Cassidy, A (1999) Dietary isoflavones: biological effects and relevance to human health. Journal of Nutrition 129, Suppl., 758S–767S.Google Scholar
Setchell, KDR, Lawson, AM & Conway, E (1981) The definitive identification of the lignans trans-2,3-bis-(3-hydroxybenzyl)-γ-butyrolactone and 2,3-bis(3-hydroxybenzyl)butane-l,4-diol in human animal urine. Biochemical Journal 197, 447–458.CrossRefGoogle Scholar
Setchell, KDR, Zimmer-Nechemias, L, Cai, J & Heubi, JE (1997) Exposure of infants to phyto-oestrogens from soy-based infant formula. Lancet 350, 23–27.Google Scholar
Sfakianos, J, Coward, L, Kirk, M & Barnes, S (1997) Intestinal uptake and biliary excretion of the isoflavone genistein in rats. Journal of Nutrition 127, 1260–1268.CrossRefGoogle ScholarPubMed
Slavin, JL, Karr, SC, Hutchins, AM & Lampe, JW (1998) Influence of soybean processing, habitual diet, and soy dose on urinary isoflavonoid excretion. American Journal of Clinical Nutrition 68, Suppl., 1492S–1495S.Google Scholar
Stumpf, K, Uehara, M, Nurmi, T & Adlercreutz, H (2000) Changes in the time-resolved fluoroimmunoassay of plasma enterolactone. Analytical Biochemistry 284, 153–157.Google Scholar
Supko, JG & Phillips, LR (1995) High-performance liquid chromatographic assay for genistein in biological fluids. Journal of Chromatography B 666, 157–167.Google Scholar
Tekel, J, Daeseleire, E, Heeremans, A & van Petegham, C (1999) Development of a simple method for the determination of genistein, daidzein, biochanin A, and formononetin (biochanin B) in human urine. Journal of Agricultural and Food Chemistry 47, 3489–3494.Google Scholar
Tham, DM, Gardner, CD & Haskell, WL (1998) Potential health benefits of dietary phyto-oestrogens: a review of the clinical, epidemiological, and mechanistic evidence. Journal of Clinical Endocrinology and Metabolism 83, 2223–2235.Google Scholar
Thompson, LU, Robb, P, Serraino, M & Cheung, F (1991) Mammalian lignan production from various foods. Nutrition and Cancer 16, 43–52.Google Scholar
Thompson, LU, Seidl, MM, Rickard, SE, Orcheson, LJ & Fong, HHS (1996) Antitumorigenic effect of a mammalian lignan precursor from flaxseed. Nutrition and Cancer 26, 159–165.Google Scholar
Tou, JCL, Chen, J & Thompson, LU (1998) Flaxseed and its lignan precursor, secoisolariciresinol diglycoside, affect pregnancy outcome and reproductive development in rats. Journal of Nutrition 128, 1861–1868.Google Scholar
Uehara, M, Lapcík, O, Hampl, R, Al-Maharik, N, Mäkelä, T, Wähälä, K, Mikola, H & Adlercreutz, H (2000) Rapid analysis of phyto-oestrogens in human urine by time-resolved fluoroimmunoassay. Journal of Steroid Biochemistry and Molecular Biology 72, 273–282.Google Scholar
Wähälä, K, Koskimies, JK, Mesilaakso, M, Salakka, AK, Leino, TK & Adlercreutz, H (1997) The synthesis, structure, and anticancer activity of cis- and trans-4′,7-dihydroxyisoflavan-4-ols. Journal of Organic Chemistry 62, 7690–7693.Google Scholar
Wähälä, K & Rasku, S (1997) Synthesis of D4-genistein, a stable deutero labeled isoflavone, by a perdeuteration — selective dedeuteration approach. Tetrahedron Letters 38, 7287–7290.CrossRefGoogle Scholar
Wähälä, K, Salakka, A & Adlercreutz, H (1998) Synthesis of novel mammalian metabolites of the isoflavonoid phyto-oestrogens daidzein and genistein. Proceedings of the Society for Experimental Biology and Medicine 217, 293–299.Google Scholar
Wang, GJ, Lapcík, O, Hampl, R, Uehara, M, Al-Maharik, N, Stumpf, K, Mikola, H, Wähälä, K & Adlercreutz, H (2000) Time-resolved fluoroimmunoassay of plasma daidzein and genistein. Steroids 65, 339–348.Google Scholar
Wang, J & Sporns, P (2000) MALDI-TOF MS analysis of isoflavones in soy products. Journal of Agricultural and Food Chemistry 48, 5887–5892.Google Scholar
Wang, W (1998) Radioimmunoassay determination of formononetin in murine plasma and mammary glandular tissue. Proceedings of the Society for Experimental Biology and Medicine 217, 281–287.CrossRefGoogle ScholarPubMed
Xu, X, Duncan, AM, Merz, BE & Kurzer, MS (1998) Effects of soy isoflavones on oestrogen and phyto-oestrogen metabolism in premenopausal women. Cancer Epidemiology, Biomarkers & Prevention 7, 1101–1108.Google Scholar
Xu, X, Duncan, AM, Wangen, KE & Kurzer, MS (2000 a) Soy consumption alters endogenous oestrogen metabolism in postmenopausal women. Cancer Epidemiology, Biomarkers & Prevention 9, 781–786.Google Scholar
Xu, X, Wang, H-J, Murphy, PA & Hendrich, S (2000 b) Neither background nor type of soy food affects short-term isoflavone bioavailability in women. Journal of Nutrition 130, 798–801.Google Scholar
Yamakoshi, J, Piskula, M, Izumi, T, Tobe, K, Saito, M, Kataoka, S, Obata, A & Kikuchi, M (2000) Isoflavone aglycone-rich extract without soy protein attenuates atherosclerosis development in cholesterol-fed rabbits. Journal of Nutrition 130, 1887–1893.Google Scholar
Yasuda, T & Oshawa, K (1998) Urinary metabolites of daidzein orally administered in rats. Biological and Pharmaceutical Bulletin 21, 953–957.Google Scholar