1,1 -Diphenyl-2-picrylhydrazyl radical-scavenging activity

Famesylhydroquinone 335, which exhibited DPPH (1, l-diphenyl-2-picrylhydrazyl) radical scavenging activity, was separated from Penicillium sp. marine fiingi and the method of the preparation of this compound was described. 

Chen, Y., Wang, M., Rosen, R.T., and Ho, C.-T., 2,2-Diphenyl-l-picrylhydrazyl radical-scavenging active components from Polygonum multiflorum Thnnb, J. Agric. Food Chem., 47, 2226-2228, 1999. 

Y2. Yamaguchi, T., Takamura, H., Matoba, T., and Terao, J., HPLC method for evalution of the free radical-scavenging activity of foods by using 1, l-diphenyl-2-picrylhydrazyl. Biosci. Biotechnol. Biochem. 62, 1201-1204 (1998). 

As an assay for antioxidant activity, we examined the inhibition of lipoxygenase activity and radical scavenging activity using the a, a-diphenyl-P-picrylhydrazyl (DPPH) decolorization test. Aqueous, ethanolic and methanolic extracts of microalgae were used in the assays. 

The hybrid molecules, comprised of sydnones and other heterocyclic compounds, constitute one of the more promising approaches for the design of bioactive compounds. 3-Aryl-4-formylsydnones (22) are attractive starting compounds for several 4-heterocycle-substituted sydnones, such as thiazo-lidinone (23) and thiazoline (24, 25) [14,15], imidazoles (26) [16], thiadia-zolines (27), thiadiazoles (28) [17], and indoles (29) [18]. Some sydnonyl-substituted thiazolidinone (23) and thiazoline (30) derivatives exhibited a potent l,l-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, comparable to that of vitamin E [14,15]. 

In the DPPH (l,l-diphenyl-2-picrylhydrazyl) assay, garcinol exhibited potent radical scavenging activity at an extent almost 3 times higher than a-tocopherol and comparable to 85% of the activity of ascorbic acid [84],... 

Fiedler and collaborators isolated three new pigmented phenazine compounds, dermacozines li-J (94—96), from Dermacoccus abyssi sp. nov. strains MTl.l and MT1.2 (Figure 14) (14JNP416).When these compounds were tested for l,l-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity, it was found that dermacozine li (94) was the most active with an IC50 value of 18.8 pM. 

Hirota, A., Taki, S., Kawaii, S., Yano, M., Abe, N. (2000). l,l-Diphenyl-2-picrylhydrazyl radical-scavenging compounds from soybean miso and antiproliferative activity of isoflavones from soybean miso toward the cancer cell lines. Bioscience, Biotechnology, and Biochemistry, 64, 1038-1040. 

Brisdelli et al. (2013) investigated the effects of six lichen metabolites (diffractaic acid, lobaric acid, usnic acid, vicanicin, variolaric acid, protolichesterinic acid) on reactive oxygen species (ROS) level towards three human cancer cell lines, MCF-7 (breast adenocarcinoma), HeLa (cervix adenocarcinoma) and HCT-116 (colon carcinoma). AU tested lichen compounds did not exhibit free radical scavenging activity using the l,l-diphenyl-2-picrylhydrazyl (DPPH) assay. The lichen metabolites did not significantly increase the intracellular ROS level and did not prevent oxidative injury induced by t-butyl hydroperoxide in tested cells. 

Atranorin, protolichesterinic acid, usnic acid, 2-hydroxy-4-methoxy-6-propyl benzoic acid, homosekikaic acid, sekikaic acid, benzoic acid, 2,4-dihydroxy-6-propyl and 2,4-dihydroxy-3,6-dimethyl benzoate isolated from the hexane extract from Ramalina roesleri were assayed for antioxidant activity by l,l-diphenyl-2-picrylhydrazyl (Sisodia et al. 2013). Maximum DPPH radical scavenging activity was exhibited by sekikaic acid followed by homosekikaic acid. 

Com oil phenols have been studied with respect to their potential to scavenge the free radicals, the peroxyl radicals, the superoxide radicals, etc. The free radical scavenging activity of the phenolic acids using model free radicals such as l,7-diphenyl-2-picrylhydrazyl radical (DPPH ), or ABTS (2,2 -azinobis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt cation radical) is often measured. TEAC (Trolox equivalent antioxidant capacity), FRAP (Ferric-reducing antioxidant capacity) and TRAP (total-radical-trapping antioxidant parameter) of the com oil are also used in order to obtain additional information, necessary to investigate the relation between the antioxidant intake and the oxidative stress related diseases (Stratil et al., 2008 Ceto et al., 2014 Apak et al., 2007). 

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