High-Performance Thin-Layer Chromatographic Analysis of the Phenolic Acid and Flavonoid Content of Croatian propolis Samples

摘要

Propolis is the generic name for the resinous substance collected by honeybees (Apis mellifera L.) from a variety of plant sources. Because of its popularity in folk medicine, it has become the subject of intense pharmacological and chemical studies over the last 30 years. Increased use of propolis preparations necessitates analysis of its composition and identification of its pharmacologically active constituents. In this paper a simple, selective, and sensitive HPTLC method is reported for determination and quantification of three phenolic acids (caffeic acid, p-coumaric acid, and isoferulic acid) and four flavonoids (pinocembrin, pinocembrin-7-methyI ether, chrysin, and tectochrysin) in seven propolis samples collected from different parts of Croatia. Chromatographic analysis was performed on 20 cm x 10 cm glass-backed silica gel F254s HPTLC plates with chloroform-methanol-formic acid, 44:3.5:2.5 (v/v) as mobile phase. Quantification was performed by scanning densitometry at the UV absorption maximum of each compound. The method was found to be simple, reliable, and convenient for analysis of these phenolic compounds in Croatian propolis samples. Its analytical performance (precision, accuracy and robustness) fulfilled the acceptance criteria established for TLC methods in the official literature. The method was also shown to be selective and linear.