Abstract:
The objectives of this work were to study the quantity of total phenolic compounds and antioxidant
activities which were existed in four types of Thai herbal plants extracts such as Vietnamese Coriander
(Polygonum odoratum Lour.), Butterfly Pea (Clitoria ternatea L.), Kaffir lime (Citrus hystrix DC.) and
Perilla(Perilla frutescens (L.) Britton). The quantitative analysis of phenolic compounds was investigated via
Folin-Ciocalteu method using butylated hydroxytoluene (BHT) and gallic acid (GA) as the reference standards.
As obtained results, the highest amounts of phenolic compounds (129.93±2.50 mgBHT/g and 68.17±1.53
mgGA/g) were found in the extract part of Vietnamese Coriander. For analysis of antioxidant activity, the 2,2-
diphenyl-1-picrylhydrazyl (DPPH) method was applied with vitamin C as a reference standard. The result was
found that extract from Vietnamese Coriander exhibited IC50 of 44.08±6.223 mg/L.