Effect of extraction solvent on antiradical activity of the obtained propolis extracts

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Total phenolic, flavonoid and mineral contents and antiradical activity are usually used as a measure of propolis extract quality. The purpose of this study was to compare the quality of propolis extracts obtained with different solvents such as water, ethanolic solutions (30, 70, 95%, v/v in water) and edible vegetable oils (canola and soybean). LC-MS was used to identify constituents of the extracts. Antiradical activity was assayed using chemiluminescence from the luminol/hemin/H2O2/CTAB system and the DPPH test. Both antiradical assays were strongly correlated (r = -0.97). Principal Component Analysis indicated positive correlations for phenolics, flavonoid levels and antiradical activity showing that all phenolic compounds are important for the scavenging activity of Brazilian propolis. The extract obtained with ethanol 30% v/v had the highest antiradical activity mainly due to its high content of dicaffeoylquinic acids.53191100Financiadora de Estudos e projetos (FINEP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundacao Araucaria [10908/PPP/2006]Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundacao Araucaria [10908/PPP/2006

Synthesis of vinyl polymers via enzymatic oxidative polymerisation

Enzymatic methods for the polymerisation of vinyl monomers are presented and critically discussed. Vinyl monomers can be polymerised initiated by enzyme-catalysed radical formation. The most widely used initiators for this purpose are β-diketo compounds, which can be transformed into the corresponding radicals via peroxidase- or laccase-catalysed oxidation. For this, peroxidases use hydrogen peroxide as oxidant, while laccases rely on molecular oxygen. Both enzyme classes comprise specific advantages and disadvantages that are discussed in this chapter. Also, parameters to control the polymer properties are introduced and discussedGreen Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.BT/Biocatalysi