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Updated: Dec 27, 2025

Biosynthesis of a Flavonol from a Flavanone by Establishing a One-pot Bienzymatic Cascade
Published on: August 14, 2019
Flavonoids interference in common protein assays: Effect of position and degree of hydroxyl substitution
Rashim Singh1, Rong Lu2, Ming Hu1
1Department of Pharmacological and Pharmaceutical Science, College of Pharmacy, University of Houston, Houston, TX, USA.
Abstract:
Flavonoids interfere with colorimetric protein assays in a concentration- and structure-dependent manner. Degree (≥3) and position (C3) of -OH substitution was associated with intensified interference (p < 0.05). Significant overestimation of protein (~3-5 folds) could occur at higher flavonoid concentrations (>5 μM) and is particularly evident at lower protein concentrations (25-250 μg/ml). Since, healthy human urinary protein (<200 μg/ml) and flavonoids urinary excretion (0.5-2 μg/ml) levels fall in this range, overestimation of protein concentration with flavonoids consumption in diet, including natural supplements, remains relevant issue for diagnostic and research labs. Protein precipitation by acetone to remove interfering flavonoid successfully resolves the problem.
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