Isolation of phenolic compounds from hop extracts using polyvinylpolypyrrolidone: Characterization by high-performance liquid chromatography–diode array detection–electrospray tandem mass spectrometry

The root extract of the medicinal plant Pelargonium sidoides is a potent HIV-1 attachment inhibitor

Global HIV-1 treatment would benefit greatly from safe herbal medicines with scientifically validated novel anti-HIV-1 activities. The root extract from the medicinal plant Pelargonium sidoides (PS) is licensed in Germany as the herbal medicine EPs®7630, with numerous clinical trials supporting its safety in humans. Here we provide evidence from multiple cell culture experiments that PS extract displays potent anti-HIV-1 activity. We show that PS extract protects peripheral blood mononuclear cells and macrophages from infection with various X4 and R5 tropic HIV-1 strains, including clinical isolates. Functional studies revealed that the extract from PS has a novel mode-of-action. It interferes directly with viral infectivity and blocks the attachment of HIV-1 particles to target cells, protecting them from virus entry. Analysis of the chemical footprint of anti-HIV activity indicates that HIV-1 inhibition is mediated by multiple polyphenolic compounds with low cytotoxicity and can be separated from other extract components with higher cytotoxicity. Based on our data and its excellent safety profile, we propose that PS extract represents a lead candidate for the development of a scientifically validated herbal medicine for anti-HIV-1 therapy with a mode-of-action different from and complementary to current single-molecule drugs.

Obtenção de extratos de guaraná ricos em cafeína por processo enzimático e adsorção de taninos

As bebidas sabor guaraná são muito populares no Brasil e têm apresentado um excelente potencial de vendas no mercado externo. De acordo com as leis brasileiras, bebidas sabor guaraná devem conter entre 0,02 g a 0,2 g de semente de guaraná ou equivalente, para cada 100 mL de produto. Tais teores são usualmente obtidos pela adição de um extrato concentrado hidroalcoólico ou xarope de açúcar contendo extrato de guaraná diretamente à bebida. A utilização desses extratos em concentrações mais elevadas, entretanto, é limitada pela presença dos taninos, que conferem adstringência e coloração escura ao produto final. Neste trabalho, foi estudado o desenvolvimento de um processo enzimático para obtenção de extratos não alcoólicos de guaraná, de forma a produzir um extrato contendo baixas concentrações de taninos e teores elevados de cafeína, utilizando-se planejamento experimental e processos de adsorção. Por meio de um planejamento fatorial fracionário, foram determinadas as quantidades de 0,25% (v/v) de pectinase e 0,1% (v/v) de glucoamilase, sendo mantidas no planejamento composto central, que obteve como condições ótimas: 0,23% (v/v) de celulase, 0,86% (v/v) de hemicelulase e 1% (v/v) de alfa-amilase durante 5,5 h de extração a 200 rpm e 50 °C, obtendo-se uma relação cafeína/tanino de 1,65. Com o processo de adsorção com óxido de magnésio a 10% (p/v), foi alcançada uma relação de cafeína-tanino de 7,3.

Extraction and isolation of phenolic compounds

Phenolic compounds constitute a major class of plant secondary metabolites that are widely distributed in the plant kingdom and show a large structural diversity. These compounds occur as aglycones or glycosides, as monomers or constituting highly polymerized structures, or as free or matrix-bound compounds. Furthermore, they are not uniformly distributed in the plant and their stability varies significantly. This greatly complicates their extraction and isolation processes, which means that a single standardized procedure cannot be recommended for all phenolics and/or plant materials; procedures have to be optimized depending on the nature of the sample and the target analytes, and also on the object of the study. In this chapter, the main techniques for sample preparation, and extraction and isolation of phenolic compounds have been reviewed-from classical solvent extraction procedures to more modern approaches, such as the use of molecularly imprinted polymers or counter-current chromatography.