INTRODUCTION: Propolis is a complex mixture of natural sticky, gummy and resinous components produced by honeybees (Apis mellifera L.) from plant materials. However, phytochemical data of the Andalusian (southern Spain) propolis are scant. OBJECTIVE: The primary objectives of this study were to chemically characterise the compounds and evaluate the anti-oxidant activity found in 28 Andalusian propolis samples. METHODS: Ethanol extracts of propolis (EEP) were prepared and examined for their anti-oxidant activity by 2,2'-azinobis(3-ethylbenzothiazoline-6-sulphonic acid) and 2,2-diphenyl-1-picrylhydrazyl assays. To characterise the phenolic composition, the presence of 11 compounds was identified by HPLC analysis with photodiode array and mass spectrometric detection. RESULTS: All propolis samples had strong anti-oxidant activity, accompanied by high total phenolic content. The most abundant compounds were flavonoids. Concerning the phenolic compounds content, our results showed that the 75% of the samples analysed contained at least 80 mg/g of flavonoids, primarily pinobanksin 3-acetate, pinocembrin, chrysin, galangin and pinobanksin. Caffeic acid phenethyl ester was detected in almost all EEP samples but in smaller proportions (mean 12.9 ± 2.8 mg/g). CONCLUSION: The present investigation constitutes the first comprehensive report on the phenolics identified in southern Spanish propolis. The results revealed that the samples tested showed a high scavenging activity and therefore indicate the possible use of Andalusian propolis as an important source of natural anti-oxidants.
INTRODUCTION: Propolis is a complex mixture of natural sticky, gummy and resinous components produced by honeybees (Apis mellifera L.) from plant materials. However, phytochemical data of the Andalusian (southern Spain) propolis are scant. OBJECTIVE: The primary objectives of this study were to chemically characterise the compounds and evaluate the anti-oxidant activity found in 28 Andalusian propolis samples. METHODS:Ethanol extracts of propolis (EEP) were prepared and examined for their anti-oxidant activity by 2,2'-azinobis(3-ethylbenzothiazoline-6-sulphonic acid) and 2,2-diphenyl-1-picrylhydrazyl assays. To characterise the phenolic composition, the presence of 11 compounds was identified by HPLC analysis with photodiode array and mass spectrometric detection. RESULTS: All propolis samples had strong anti-oxidant activity, accompanied by high total phenolic content. The most abundant compounds were flavonoids. Concerning the phenolic compounds content, our results showed that the 75% of the samples analysed contained at least 80 mg/g of flavonoids, primarily pinobanksin 3-acetate, pinocembrin, chrysin, galangin and pinobanksin. Caffeic acid phenethyl ester was detected in almost all EEP samples but in smaller proportions (mean 12.9 ± 2.8 mg/g). CONCLUSION: The present investigation constitutes the first comprehensive report on the phenolics identified in southern Spanish propolis. The results revealed that the samples tested showed a high scavenging activity and therefore indicate the possible use of Andalusian propolis as an important source of natural anti-oxidants.
Authors: Ling-Hsiu Liao; Daniel J Pearlstein; Wen-Yen Wu; Allison G Kelley; William M Montag; Edward M Hsieh; May R Berenbaum Journal: PLoS One Date: 2020-12-09 Impact factor: 3.240
Authors: Sandra M Osés; Patricia Marcos; Patricia Azofra; Ana de Pablo; Miguel Ángel Fernández-Muíño; M Teresa Sancho Journal: Antioxidants (Basel) Date: 2020-01-15