A New Method For The Determination Of Antioxidant Activity Of Drug

In this paper a new method for determining drug antioxidant activity was Studied and established. It can be applied in related research of drug anti-oxidation activity and chemical structure. Because Escherichia coli has a short growth cycle and fast breeding and other characteristics, Experimental models was established by E. coli standard strains for Model organisms. H2O2is free radical initiator and it handles the logarithmic phase cells of E. coli, so that the cells are in a state of oxidative stress. Using phototurbidometry (OD600) determined bacterial growth curves. Compared with the bacteria without added antioxidants, dormancy stage of bacteria with added antioxidants became shorter and Bacteria quick accessed to a logarithmic growth state. To assess antioxidant activity of the antioxidants by this.The paper study protective effect when bacterial was oxidative stress status come from compounds of cinnamic acid series with the chemical structure similar to:caffeic acid, Ferulic acid, p-coumaric acid, and cinnamic acid, and the correlation is revealed between antioxidant activity and chemical structure by preliminary exploration. Their antioxidant activity order derived from the above model is accordant with report in the literature, and therefore it verified the validity of the model. The method can be used with screening antioxidant activity of drug and herbal extracts, and structure-activity relationship studies.In this study,9kinds of Tibetan medicine carried out by preparation of extracts, and content of total phenolics and total flavonoids of the extracts were determined. Nine kinds of Tibetan medicine are Lagotis brevituba Maxim. Herba Gentianae Uunulae. Dracocephalum hetrophyllum Benth. Cuminum cyminum L. Fructus Terminaliae Billericae. Herba Ephedrae Sinicae. Torularia humilis(C.A.Meyer)O.E.Schulz. Dracocephalum tanguticum. Swertia bimaculata (Sieb.et Zucc.)Hook.f.et Thoms.ex Clarke. Then E. coli model screening Antioxidant activity of these nine kinds of Tibetan medicine. In these nine kinds of Tibetan medicine, we founded that ethanol extract of Tibetan medicine except for Fructus Terminaliae Billericae.and Swertia bimaculata (Sieb.et Zucc., the rest of the alcohol extract of Tibetan medicine has antioxidant activity:The water extract of Tibetan medicine all has antioxidant activity. This method can service for development and using of Tibetan medicine. The method is simple in operation and equipment. It requires lower cost, and has certain use value.