[Prevalence of equol producer phenotype and its relations to lifestyle factors and dietary intakes among lifestyle factors and dietary intakes among healthy Chinese adults in Beijing].

OBJECTIVE: To investigate the prevalence of equol producers and the physiological range of urinary equol excretion, and also to evaluate relations between equol phenotype and lifestyle among Chinese adults in Beijing. METHODS: 100 male and 100 female adults participated in a cross-sectional study and provided twice 1d urine samples on regular diet and after 3d soy isoflavone challenge respectively. A health and demographics questionnaire, and 2d food record were completed before the urine collections. Isoflavones and their metabolites in urine were measured to determine equol phenotype by HPLC. RESULTS: The physiological range of 24h urinary equol excretion was 0-76.56 micromol/24h, and the percentage of the equol producer phenotype was 26.8% on regular diet and 60.4% after soy isofavone challenge, respectively. There was no indication that habitual consumption of soy foods is associated with the equol producer phenotype. The correlations of isoflavone intake from 2d food record with those from urinary isoflavone levels were 0.58 for total isoflavones, 0.49 for daidzein, 0.56 for genistein, and 0.50 for glycitein (P < 0.01). CONCLUSION: About one fourth of Chinese adults in Beijing were detected equol excretion in urine under the usually lifestyle. However, equol_producing potential was higher.

[Determination of sennosides and degraded products in the process of sennoside metabolism by HPLC].

A method for the separation and determination of sennosides A and B and the main composition (sennidins A and B) in degraded products of sennosides by linear gradient high performance liquid chromatography has been developed. Separation conditions were as follows: column, a Spherisorb C18 column (250 mm x 4.6 mm i.d., 10 microm); column temperature, 40 degrees C; detection wavelength, 360 nm; mobile phase A, 1.25% acetic acid aqueous solution; mobile phase B, methanol; linear gradient, 100% A --> (20 min) 100% B. The method is effective, quick, accurate and reproducible. The satisfactory results show that this new method has certain practical values as an approach of real-time analysis in the process of sennoside metabolism.