Phenolic characterization of Northeast Portuguese propolis: usual and unusual compounds

• Published in: Analytical and bioanalytical chemistry Vol. 396; no. 2; pp. 887 - 897
• Main Authors: Falcão, Soraia I, Vilas-Boas, Miguel, Estevinho, Letícia M, Barros, Cristina, Domingues, Maria R. M, Cardoso, Susana M
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Berlin/Heidelberg : Springer-Verlag 01.01.2010; Springer-Verlag; Springer
• Subjects: Analysis; Analytical Chemistry; Biochemistry; Characterization and Evaluation of Materials; Chemical properties; Chemistry; Chemistry and Materials Science; Chromatographic methods and physical methods associated with chromatography; Chromatography, High Pressure Liquid; Derivatives; Dimers; Esters; Exact sciences and technology; Flavonoids; Flavonoids - analysis; Food Science; Isoflavones; Laboratory Medicine; Liquid chromatography; Mathematical analysis; Monitoring/Environmental Analysis; Original Paper; Other chromatographic methods; Phenolic acids; Phenols; Phenols - analysis; Plant Extracts - analysis; Poplar; Portugal; Propolis; Propolis - chemistry; Spectrometric and optical methods; Spectrometry, Mass, Electrospray Ionization; Portugal; Flavonoids; Phenolic compounds; Mass spectrometry; Electrospray ionization; Phenolic acids; Fractionation; Phenolic acid; Sample; HPLC chromatography; Identification; Flavonoid; Electrospray; Chemical ionization; Characterization; Ester; Sample preparation; Phenols; Dimer
• ISSN: 1618-2642; 1618-2650
• DOI: 10.1007/s00216-009-3232-8

In this study, an ethanolic extract from Portuguese propolis was prepared, fractionated by high-performance liquid chromatography, and the identification of the phenolic compounds was done by electrospray mass spectrometry in the negative mode. This technical approach allowed the identification of 37 phenolic compounds, which included not only the typical phenolic acids and flavonoids found in propolis from temperate zones but also several compounds in which its occurrence have never been referred to in the literature. Four of the novel phenolic compounds were methylated and/or esterified or hydroxylated derivatives of common poplar flavonoids, although six peculiar derivatives of pinocembrin/pinobanksin, containing a phenylpropanoic acid derivative moiety in their structure, were also identified. Furthermore, the Portuguese propolis sample was shown to contain a p-coumaric ester derivative dimer.