Chemical Properties and Antioxidant Activity of Different Extracts from Purslane (Portulaca Oleracea L.) Semizotunun (Portulaca Oleracea L.) Farklı Ekstraktlarının Kimyasal Özellikleri ve Antioksidan Aktivitesi

Purslane (Portulaca oleracea L.) has been known as a medical herb with valuable nutritional and pharmacological properties. Herein, water, methanol, and acetone extracts were prepared from two morphologically different purslane samples, thereafter their content of β-carotene, chlorophyll a and b, total phenolic compounds (TPC), total flavonoids, and total flavonols was evaluated. Additionally, DPPH• scavenging activity and ferrous iron (Fe+2) chelating activity of these extracts were also measured. The acetone extract had the highest amounts of β-carotene (14.16 mg g-1 DW), chlorophyll a (40.46 mg g-1 DW), chlorophyll b (9.94 mg g-1 DW), TPC (51.01 mg GAE g-1 DW), flavonoids (133.23 mg RE g-1 DW), and flavonols (46.94 mg RE g-1 DW). Whereas the lowest values were observed in the water extract, as 0.03 mg g-1 DW, 0.03 mg g-1 DW, 0.06 mg g-1 DW, (34.24 mg GAE g-1 DW, 10.98 mg RE g-1 DW, 3.28 mg RE g-1 DW, respectively. The acetone extract also showed higher DPPH• scavenging activity (IC50 = 57.23 µg mL-1) compared to methanol (IC50 = 65.80 µg mL-1) and water (IC50 = 71.47 µg mL-1) extracts. Regarding the ferrous iron (Fe+2) chelating activity, methanol extract exhibited the highest value followed by water and acetone extracts, being 12.78, 10.20 and 6.08%, respectively. A positive correlation was detected between the DPPH• scavenging activities of the purslane extracts and their content of TPC, flavonoid, flavonol, β-carotene, chlorophyll a, and chlorophyll b. On the other hand, there was no significant correlation between chelating activity of the extracts and their content of β-carotene, chlorophyll a, TPC, flavonoids, flavonols, and DPPH scavenging activity. Purslane extracts could be suggested as a natural antioxidant substance for many pharmaceutical and food applications.