Abstract

Persicaria maculosa(Polygonaceae) (known as lady's thumb) is an annual morphologically variable weed that is widely distributed in Chile. The purpose of this study was to investigate the antifeedant potential of methanolic (MeOH), ethanolic (EtOH), and dichloromethane (DCM) extracts from the aerial parts of this plant collected in the Valparaiso and Curico provinces (Chile) and relate this activity to the antioxidant capacity and the presence of phenolic compounds in the extracts. A phenolic profile based on HPLC-ESI-MS/MS allowed the identification of 26 phenolic compounds, most of them glycosyl derivatives of isorhamnetin, quercetin, and kaempferol. In addition, the total phenolic content (TP), total flavonoids (TF), and antioxidant activity measured by 2,2-diphenyl-1-picrylhydrazyl (DPPH), superoxide anion scavenging (O-2(-)), ferric-reducing antioxidant power (FRAP), and cupric-reducing antioxidant capacity (CUPRAC) of the extracts are reported. The antifeedant potentials of the plant extracts were tested againstEpilachna paenulata,Pseudaletia adultera,Macrosiphum euphorbiae, andDiaphorina citriinsects for the first time. The activity against the aphidM. euphorbiaewas significant for the DCM extracts of plants from Valparaiso and Curico (settling % = 23% +/- 4% and 23% +/- 5%, respectively). The antifeedant activities against the beetleE. paenulataand the lepidopteraP. adulterawere significant for Valparaiso extracts, especially when tested againstE. Paenulata(IFP = 1.0 +/- 0.0). Finally, the MeOH and EtOH extracts from Valparaiso plants reduced the diet consumption of the psilidD. citri(p< 0.05). The results showed thatP. maculosais a good source of flavonoids with some antioxidant capacities and has potential interest as botanical eco-friendly alternative with deterrent activity.