Isoflavone glucuronide

Clarke, D.B., Lloyd, A.S., Botting, N.P., Oldfield, M.F., Needs, P.W., and Wiseman, H., Measurement of intact sulfate and glucuronide phytoestrogen conjugates in human urine using isotope dilution liquid chromatography-tandem mass spectrometry with [13C(3)]isoflavone internal standards, Anal. Biochem., 309, 158, 2002. 

Figure 4.3 Chemical structures of Isoflavone glycosides. In soy foods, Isoflavones form 7-0-P-glucosIde conjugates. A Is the simple glucoside commonly found In soy milk, B Is the 6"-0-malonyl-7-0-p-glucoslde from the soybean, and C Is the 6"-0-acetyl-7-O-p-glucoside, a product of toasting of soy flour. D is the 7-0-P-glucuronide that is the principal conjugate in the blood.

Isoflavone metabolites are more potent antioxidants than parent compounds in vitro, but sulfation and glucuronidation suppress this effect. 

Figure 7.15 The isoflavone daidzein is found in soyabeans along with its 7-O-glucoside and malonyDglucoside. Genistein and its 7-O-glucoside and 7-0-(6"-malonyl)glucoside are also present. French beans contain quercetin-3-O-glucuronide in high amounts while caffeoyl-l-malic acid is present in pods of Vida faba.

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