Figure 1.

Fingerprint analysis of the ethanol extract of propolis. Chromatograms were plotted at 275 nm with reverse-phase high-performance liquid chromatography on a C18 column (4.6 mm × 250 mm; particle diameter, 5 µm; pore diameter, 100 Å) and gradient elution with methanol and acidic water (pH 2.7). The chromatographic profile includes the following compounds: (1) caffeic acid phenethyl ester (in approximately 15 min); (2) p-coumaric acid (in approximately 20 min); (3) trans-Cinnamic acid (in 35–36 min); (4) aromadendrin (in 38 min); and (5) artepillin C (in 61–62 min).