The influence of extraction method and extraction time on phenolic compounds content and antioxidant activity of palisota hirsuta roots (k.schum, commelinaceae)

The influences of different extraction methods and the extraction time of total phenols, flavonoids, condensed tannins, and the antioxidant activity of the ethanolic extracts obtained from the roots of Palisota hirsuta were studied. The extractions were performed by maceration, decoction and Soxhlet method, with absolute ethanol every 30 min (30 min, 1h,1h30 min, 2h and 2h 30). For each extract it was determined the total phenolic content (TPC), the total flavonoid content (TFC), the total condensed tannins (TC), the ability to scavenge DPPH, and Fe3+ reducing power. Soxhlet extraction showed the highest yield extraction. Maceration method led to the highest concentration of phenolics and flavonoids, and also the highest DPPH scavenging activity. However, the highest concentration of condensed tannin and the highest Fe3+ reducing power were obtained by Soxhlet used. Beside in general, the TPC, TC, TFC and antioxidant activity increased when extraction time was increased from 30 min to 2h, but their decreased after 1h30 min for using as decoction and Soxhlet methods.