2,2'-DIPHENYL-1-PICRYLHYDRAZYL RADICAL- SCAVENGING ACTIVITY OF DIFFERENT Teucrium montanum L. EXTRACTS

The sequential extraction of Teucrium montanum L. was realized with five solvents of different polarities (70% methanol, petroleum ether, chloroform, ethyl acetate, n-butanol). The scavenging activity (SA) of obtained extracts was tested by measuring their ability to scavenge stable 2,2`-diphenyl-1-picrylhydrazyl (DPPH) free radical using electron spin resonance (ESR) spectroscopy. The results demonstrated that the SA depended on the type and concentration of applied extracts. In investigated range of concentrations (0.10-0.15 mg/mL) petroleum ether and chloroform extracts did not show any SA. Other extracts exhibited SA in the following order: n-butanol > methanol > ethyl acetate > water extracts. The antioxidant properties were in correlation with the contents of total phenolic compounds (0-296 mg/g) in investigated extracts. The investigated Teucrium montanum L. extracts probably had the SA due to the hydrogen donor ability of the flavonoids (quercetin, rutin) and phenolic acids (chlorogenic, caffeic, gallic, ellagic) which were identified by TLC. Another mechanism is “scavenging” activity (one DPPH molecule forms complex with one aryl radical formed from phenolic compounds).