engleski

Analysis of propolis from continental and Adriatic region of Croatia

Thin-layer chromatography of ethanolic extract of propolis (EEP) from continental and Adriatic region of Croatia showed that 72.2% of propolis samples contain galangin, 88.8% of samples contain kaempferol, naringenin and apigenin and 66.6% of samples contain caffeic acid. Caffeic acid, pinocembrin, galangin, chrysin and naringenin were analyzed by HPLC. In all samples dominant flavonoid was pinocembrin. In samples from Adriatic region concentration of pinocembrin ranged from 0.03 to 6.14% ( =2.87%) and in continental region samples from 0 to 4.74% ( =2.84%). Chrysin was found in all propolis samples with concentration ranging from 0.22 to 5.32% ( =1.86%) in continental region samples and from 0.03 and 3.64% ( =1.96%) in samples from Adriatic region. Chrysin was followed by naringenin ranging from 0 to 1.14% ( =0.42%) in samples from Adriatic region and from 0.22 to 5.32% ( =1.86%) in continental region samples. Concentration of caffeic acid ranged from 0 to 10.11% ( =2.69%) in Adriatic region samples and from 0.27 to 2.67% ( = 1.37%) in samples from continental region of Croatia. All EEPs significantly inhibited growth of Bacillus subtilis in comparison with control (80% ethanol) (p<0.05), showing inhibition zones of 16&plusmn ; ; ; 2 mm for samples from continental region, and of 18&plusmn ; ; ; 3 mm for samples from Adriatic region. Results of HPLC suggest that propolis samples collected from various part of Croatia not differ markedly in content of investigated flavonoids and caffeic acid. There is no significant difference in antimicrobial activity of EEPs from continental and Adriatic parts of Croatia, suggesting that bactericidal activity depend on synergism of all phenolic compounds.

propolis; galangin; pinocembrin; chrysin; Adriatic; flavonoids; TLC; HPLC

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