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Diverse plants of ethnobotanic interest in Amazonia are commonly used in traditional medicine. We determined the antioxidant potential against lipid peroxidation, the antimicrobial activity, and the polyphenol composition of several Amazonian plants (Brownea rosademonte, Piper glandulosissimum, Piper krukoffii, Piper putumayoense, Solanum grandiflorum, and Vismia baccifera). Extracts from the plant leaf, bark, and stem were prepared as aqueous infusions, as used in folk medicine, and added to rat liver microsomes exposed to iron. The polyphenolic composition was detected by reverse-phase HPLC coupled to diode-array detector and MS/MS analysis. The antimicrobial activity was tested by the spot-on-a-lawn method against several indicator microorganisms. All the extracts inhibited lipid oxidation, except the P. glandulosissimum stem. The plant extracts exhibiting high antioxidant potential (V. baccifera and B. rosademonte) contained high levels of flavanols (particularly, catechin and epicatechin). By contrast, S. grandiflorum leaf, which exhibited very low antioxidant activity, was rich in hydroxycinnamic acids. None of the extracts showed antimicrobial activity. This study demonstrates for the first time the presence of bioactive polyphenolic compounds in several Amazonian plants, and highlights the importance of flavanols as major phenolic contributors to antioxidant activity.

Background and Aims:During wine ageing, a great variety of reactions take place, resulting in an immense variety of products whose structure sometimes remains unknown. The aim of this work is the study of different fragmentation patterns of flavanol-anthocyanin derivatives formed along the wine ageing; these patterns are useful for elucidating the different structures of these compounds and other new related ones. Methods and Results: Several wines from the Protected Denomination of Origin Rioja have been studied by an analytical method that combines column chromatography and high-performance liquid chromatography with diode array and mass and tandem mass spectrometric detections. Thirty-five coloured flavanol-anthocyanin compounds formed by direct reaction or by acetaldehyde-mediated condensation have been identified. For direct reaction derivatives, two different fragmentation patterns (one of them not previously reported) have been observed depending on the position of flavanol in the coloured derivative. Several compounds have been identified in aged wines for the first time to the authors' knowledge, like (+)-gallocatechin-cyanidin-3-glucoside and (+)-catechincyanidin-3-glucoside Conclusions: The developed analytical procedure has allowed the identification of some compounds for the first time, and two different fragmentation patterns have been observed depending on the position of flavanol in the pigment. Significance of the Study: The establishment of different fragmentation patterns allows the structural elucidation of unknown compounds.

Background and Aims:Pyranoanthocyanins are a type of derivative formed by the cycloaddition reaction of different compounds with anthocyanins during wine maturation and ageing, and show a characteristic pyranic ring. This ring provides a high stability to the pigment, and the ring does not fragment in mass spectrometric experiments. Thus, aglycone ions of these derivatives in tandem mass spectrometry show the same fragmentation pattern as that of the corresponding precursor anthocyanin. The aim of this work was the identification of pyranoanthocyanins present in Rioja aged wines using mass spectrometric features to differentiate among isomeric compounds. Methods and Results: The application to three Rioja aged red wines of a methodology that combines column chromatography, solid-phase extraction and high-performance liquid chromatography-diode array detectionelectrospray ionisation collision-induced dissociation-tandem mass spectrometry has allowed the identification of 72 pyranoanthocyanin derivatives. Conclusions: This paper provides an overview of pyranoanthocyanin derivatives present in aged red wines with the identification of 72 compounds, some of them derivatives that appear in low concentration, and it assesses the importance of mass spectrometric analysis in the differentiation among isomeric derivatives. Significance of the Study: The methodology described allows the identification of derivatives at low concentration and the establishment of characteristic fingerprints of native anthocyanins, which provide an effective tool for pyranoanthocyanin identification, allowing the differentiation among isomeric derivatives.