ETHANOLIC AND HYDROALCOHOLIC EXTRACTS OF PITANGA LEAVES (Eugenia uniflora L.) AND THEIR FRACTIONATION BY SUPERCRITICAL TECHNOLOGY

Abstract

Hydroalcoholic extracts prepared by conventional methods (in stirred vessel at 25 °C and 1 bar) and, hydroalcoholic and supercritical carbon dioxide (scCO 2) extracts prepared in fixed bed extractors (60 ºC and 400 bar) were obtained from pitanga leaves (Eugenia uniflora L.) in order to recover phenolic compounds. Hydroalcoholic and ethanolic extracts obtained in fixed bed were further fractionated in four separators by gradual pressure reduction, using scCO 2 as an antisolvent. All extracts and fractions were characterized in terms of extraction yield and the presence of total phenolics and flavonoids. Solvents were found to significantly influence the extraction yields and composition. Yields increased as a function of polarity, whereas the hydroalcoholic extractions displayed the highest yields and the highest amounts of extracted phenols and flavonoids.

In Vitro Antioxidant, Anti-Inflammatory, and Digestive Enzymes Inhibition Activities of Hydro-Ethanolic Leaf and Bark Extracts of Psychotria densinervia (K. Krause) Verdc

“…Terpenoids are involved in hypolipidemic activity by inhibiting pancreatic lipase [30]. Tannins have antioxidant and antilipase activities [31]. Both leaf and bark extracts of P. densinervia contain these bioactive components and may be responsible in one way or the other for the biological activities of the plant.…”

The effect of black barberry hydroalcoholic extract on immune mediators in patients with active rheumatoid arthritis: A randomized, double–blind, controlled clinical trial

“…In order to prepare the barberry extract, 10 g of dried, mixed black barberry and l liter of 70% ethanol (with a proportion of 1 to 4) were mixed together. Extraction was performed in a fixed bed and the extract was collected in the collector (Garmus et al, 2019). The intervention group received two black barberry capsules per day, each containing 1,000 mg black barberry extract, and the placebo group received two identical placebo capsules containing maltodextrin (Green plants of life pharmaceutical co.) with or after their meal for 12 weeks.…”

Phytochemical profile, in vitro activities, and toxicity of optimized Eugenia uniflora extracts

“…Therefore, extractions using more than one solvent provide better separation and isolation of phenolic compounds (Stojiljković et al, 2016). Garmus et al (2019) evaluated E. uniflora leaf extracts using different solvents and extractive methods; he identified an increase in the extraction yield as a function of the polarity of the solvents, with hydroethanolic extracts showing the greatest yields of phenols and flavonoids. Although hydroethanolic solvents are supported in the literature as efficient extractors of tannins and flavonoids (Nešić et al, 2019), we observed that the addition of PROP to this system significantly increased the levels of gallic acid and ellagic acid (tannins) and myricitrin (flavonoid).…”