Quantitative Analysis of Flavonoids and Phenolic Acids in Propolis by Two-Dimensional Thin Layer Chromatography

摘要

Flavonoids are polyphenolic compounds present in a wide variety of plants. They are benzo-gamma-pyrone derivatives, which resemble coumarin. Flavonoids (with other polyphenols, e.g. phenolic acids) are believed to have a variety of physiological activity. One of the most concentrated sources of those compounds is propolis, a resinous substance collected by the honeybees from various plant sources. Its composition, and thus its content of pharmacologically active compounds, depends on geographic origin.We have developed a new TLC method suitable for analysis of complex mixtures such as propolis. Two-dimensional TLC with densito-metric evaluation seemed an appropriate method for rapid screening of active compounds and quantifying the concentration of flavonoid aglycones and phenolic acids present in propolis extracts. After developing the method we tested it by analyzing and comparing the composition of three raw propolis samples from different geographic regions of Croatia.