Table 2.

Analysis of the ethanolic extract of propolis by the HPLC.

Compound	Rt [min]	Concentration [mg/L of EEP]
Gallic acid	6.0	n.d
Caffeic acid	21.2	65 ± 11
Vanillin	23.4	65 ± 11
p-Coumaric acid	27.5	231 ± 10
t-Ferulic acid	28.9	514 ± 15
Benzoic acid	33.6	n.d
Quercetin	42.3	n.d
t-Cinnamic acid	42.7	29 ± 1
Naringenin	43.2	n.d.
Luteolin	44.7	n.d
Genistein	45.6	n.d
Kaempferol	51.3	101 ± 45
Apigenin	53.4	73 ± 8
Chrysin	70.0	36 ± 5
Pinocembrin	65.1	n.d.
Galangin	73.1	n.d.
CAPE	71.4	n.d.

(n.d. = nondetected; CAPE = caffeic acid phenethyl ester).