Screening Non-colored Phenolics in Red Wines using Liquid Chromatography/Ultraviolet and Mass Spectrometry/Mass Spectrometry Libraries

Abstract

Liquid chromatography/ultraviolet (LC/UV) and mass spectrometry/mass spectrometry (MS/MS) libraries containing 39 phenolic compounds were established by coupling a LC and an ion trap MS with an electrospray ionization (ESI) source, operated in negative ion mode. As a result, the deprotonated [M-H] -molecule was observed for all the analyzed compounds. Using MS/MS hydroxybenzoic acid and hydroxycinnamic acids showed a loss of CO 2 and production of a [M-H-44] -fragment and as expected, the UV spectra of these two compounds were affected by their chemical structures. For flavonol and flavonol glycosides, the spectra of their glycosides and aglycones produced deprotonated [M-H] -and [A-H] -species, respectively, and their UV spectra each presented two major absorption peaks. The UV spectra and MS/MS data of flavan-3-ols and stilbenes were also investigated. Using the optimized LC/MS/MS analytical conditions, the phenolic extracts from six representative wine samples were analyzed and 31 phenolic compounds were detected, 26 of which were identified by searching the LC/UV and MS/MS libraries. Finally, the presence of phenolic compounds was confirmed in different wine samples using the LC/UV and LC/MS/MS libraries. Molecules, 2007, 12 680

Contribution of Major Hydrophilic and Lipophilic Antioxidants from Papaya Fruit to Total Antioxidant Capacity

“…Research done in other fruits have indicated that hydroxicinnamic acids are generally more abundant than hydroxibenzoic acids, and that skins have greater concentration of phenolic compounds than pulp [20,21], that their concentration decreased during ripening stages [22], and influenced by geography, variety and ripeness stages [23]. Later, an evaluation was performed of the individual contribution to TAC of phenolic compounds of papaya fruit skin in the hydrophilic extract.…”

Atividade antioxidante, antimicrobiana e caracterização de compostos bioativos da casca interna de Kielmeyera coriacea Mart. & Zucc

“…A banda em 280 nm é característica das proantocianidinas (SUN et al, 2007;WHYREPKWSKI, 2016), compostos conhecidos como taninos condensados ou catecóicos. …”

“…Devido a essa ligação éter as PAs do tipo A tem 2 unidades a menos que as do tipo B em seus compostos (SARNOSKI et al, 2012). As proantocianidinas do tipo B são, portanto, epi-catequinas homo-oligoméricas com dois grupos hidroxilas no anel B (RUE et al, 2017;SIMÕES et al, 2004a Devido aos vários estereoisômeros da catequina e da epicatequina suas identificações e a identificação de seus polímeros somente por espectrometria de massas tornam-se difíceis (HELLSTRÖM et al, 2007;RUE et al, 2017;SUN et al, 2007 unidades (GE et al, 2017;MAGRINI, 2016 (LIN et al, 2015). O extrato etanólico da casca interna apresentou, no geral, atividade antibacteriana moderada.…”

“…8,25 291,0875 291,0884 3,1 273, 207, 165, 139, 123 C15H14O6 (290) SHUYI et al, 2012SHUYI et al, . 9,07 9,07 577,1351SHUYI et al, 579,1499SHUYI et al, 577,1370SHUYI et al, 579,1522 EE, PDM, PAE, PBU, RMA EE, PDM, PAE, PBU, RMA PA-B: trímero PA-B: trímero Ge et al, 2017;Rodrigues et al, 2007;Sun et al, 2007;Stefova et al, 2017Stefova et al, . 9,90 561,1402Stefova et al, 561,1400 EE, PAE, RMA (E)Afz--(E)Cat Epiafzelequinaepicatequina Gu et al, 2003;Ge et al, 2016;Souza, 2008Souza, .…”

“…6,72 867,2131Rockenbach et al, 867,2143 EE, PDM, PAE, Fraser, Collette, Hancock, 2016;Souza, 2008Souza, . 5,89 577,1351Souza, 577,1371 EE, PDM, PAE, PBU PA-B (E)Cat-(E)Cat Ge et al, 2017;Rodrigues et al, 2007;Sun et al, 2007;Stefova et al, 2017Stefova et al, . 5,97 579,1548Stefova et al, 579,1529 EE, PDM, PAE, PBU PA-B (E)Cat-(E)Cat Fraser, Collette, Hancock, 2016;Souza, 2008Souza, .…”