ABSTRACT
N.M. Emanuel Institute of Biochemical Physics, 4, Kosygin street, Moscow, 119334, Russian Federation; E-mail: vl.volkov@mail.ru
CONTENTS
Abstract ................................................................................................. 405 16.1 Introduction ................................................................................ 406 16.2 Materials and Methods ............................................................... 408 16.3 Results and Discussion .............................................................. 409 16.4 Conclusions ................................................................................ 419 Keywords .............................................................................................. 420 References ............................................................................................. 420
ABSTRACT
In this study, a kinetic method of analysis of compounds from edible and medicinal plant extracts activity against stable radical 2,2-diphenyl1-picrylhydrazyl (DPPH) is developed. The initial rate of DPPH’s decay in standard conditions is suggested and theoretically explained as a kinetic
parameter to compare the extract antiradical activity. A 10-150-fold decrease of the DPPH’s reaction rate with plant extract antioxidants is achieved by the addition of acids into the reaction medium. Such results were explained by changes of input of different mechanisms into the whole process of scavenge of DPPH radical. A decrease of the reaction rate for the optimum of added acid’s concentration with the acid strength increasing is also observed. The influence of the acids extracted from plant material on the results is excluded by this method because of the stronger acid addition. It is found that the linear interval of the dependence of DPPH’s conversion degree after the first 30 min from the start of the reaction vs. the initial antioxidant concentration lies from 0 to 60%.
