Screening for Antioxidant Activity in Eighteen Local Northeastern Vegetables using Silica Gel Thin-layer Chromatography Followed by Spraying with DPPH

Abstract

Antioxidant has been used as protection of autoxidation. In order to search for antioxidant activity, 18 types of vegetable from Northeastern Thailand, i.e. Strychnos minor Dennst., Asparagus racemosus willd., Blumea napifolia DC., Stephania erecta Linn., Momordica sp., Aganosma marginata G. Don, Cassia tora Linn., Pluchea indica Less, Ottelia alismoides (L.) Pers., Blumea sp., Solanum nigrum Linn, Phyllanthus amarus Schumach & Thonn., Emilia sonchifolia (Linn.) DC., Droogmansia godefroyana (Kuntze) Schindl, Scoparia dulcis Linn., Kaempferia galanga Linn., Monordica cochinchinensis (Lour) Spreng., and Monihoty esculenta Crantz, were collected. The methanolic extracts were screened for antioxidant activity using silica gel thin-layer chromatography followed by spraying with 2,2???diphenyl-1-picrylhydrazyl hydrate (DPPH). The results showed that 17 types of vegetable from Northeastern Thailand exhibited positive antioxidant but only methanolic extracts of Ottelia alismoides (L.) Pers. showed negative antioxidant activity. Moreover, antioxidant components of methanolic extracts of 17 types of vegetable from Northeastern Thailand have the different Rf values with mobile phase acetone, acetone: methanol, and acetone: methanol with the ratio of 1:0, 4:1, and 1:1, respectively.

Keywords: antioxidant, autoxidation, vegetables from Northeastern Thailand