Antioxidant Activity and ATR-FTIR- based Chemometric of Wild Erechtites Species Leaves Extracts

Erechtites sp. belongs to Asteraceae family. E. valerianifolia (EV) and E. hieraciifolia (EH) are rarely been studied despite the consumption of the leaves as an edible vegetable by local people. Besides, these wild vegetables are being removed and wasted when the habitat was cleaned. In this study, the antioxidant capacity, the phenolics and attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectroscopy analysis of ethanol/water (EW) extracts of both Erechtites were investigated. The leaves were lyophilized, ground and then macerated in EW (4:1) at 50 degrees C ( 15 minutes), sonicated (15 minutes) and centrifugated. The extract was collected, concentrated using a rotary evaporator, and dried. Four antioxidant assays including 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, ABTS(center dot+) ( 2,2azino- bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical cation, ferric reducing antioxidant power (FRAP), and nitric oxide (NO) scavenging were carried out. The results revealed that EVEW exhibited stronger antioxidant activity as well as more total phenolics (TPC) and flavonoids (TFC), compared to EHEW. The EVEW recorded lower IC50 values against DPPH (IC50: 26.32 mu g/mL), ABTS (IC50: 20.42 mu g/mL) and NO (IC50: 712.24 mu g/mL) radicals, whilst higher FRAP level (18.56 mmol Fe2+/g), compared to EHEW. Besides, higher TPC and TFC were determined in EVEW with respective values of 60.00 GAE mg/g gallic acid equivalent and 37.78 mg/g quercetin equivalent. Fourier transform infrared (FTIR) coupled with chemometrics reveals PCA clusters indicating strong chemicals variations infrared signals in area 1 and area 6. Meanwhile, HCA dendrogram classification. Thus, EVEW have potential to be promoted for wider usage besides edible vegetables.