Estimation of total flavonoid content in propolis by two complementary colometric methods
Estimation of total flavonoid content in propolis by two complementary colometric methods
ChiaFu Chang,Ming-Hua Yang,H.-M. Wen,J. Chern
TLDR
Results suggested that the sum of flavonoid contents determined by the above two individual methods represent the real content of total flavonoids.
Abstract
Flavonoids, with various biological activities, are considered as key compounds in propolis. In this study, quantitative deter minations of flavonoids in propolis were conducted by two complementary colorimetric methods, aluminum chloride method and 2,4-dini trophenylhydrazine method. Results suggested that the sum of flavonoid contents determined by the above two individual methods ma y represent the real content of total flavonoids. In this work, six raw propolis samples were investigated and the total content s of flavonoids ranged from 10.38 ± 0.14% to 24.91 ± 0.53%. As for the 12 commercial propolis products examined, the levels of total flavonoids in tinctures were all below 7% and those in powdery products varied from 2.97 ± 0.05% to 22.73 ± 0.72%.