Compound 8, a free radical scavenger, exhibits an IC50 value of 43.39 μg/ml in neutralizing the DPPH radical [1].

Echinatin (Retrochalcone) disturb the mitochondrial energy transfer reactions and membrane permeability, at a low concentration cause deterioration of respiratory control and oxidative phosphorylation of isolated rat liver mitochondria, inhibits DNP-ATPase activity while stimulating range latent ATPase activity. Echinatin has significant antioxidant activities, it shows strong scavenging activity toward the ABTS + radical, it also dose-dependently inhibits LPS induced reactive oxygen species (ROS) production in RAW 264.7 cells and inhibits the production of nitric oxide (NO), interleukin-6 (IL-6) and prostaglandin E2 (PGE2) in LPS-induced macrophage cells.

Matairesinol has radical and superoxide scavenging activities,; it also has anti-angiogenic activity by suppressing mROS signaling , can decrease hypoxia-inducible factor-1α± in hypoxic HeLa cells.

RV01 is a novel quinoline-substituted analogue of resveratrol that inhibits DNA damage, reduces ethanol-induced acetaldehyde dehydrogenase (ALDH2) mRNA expression, and has hydroxyl radical scavenging activity. rV01 reduces iNOS expression and has anti-neuroinflammatory effects. rV01 reduces tumor necrosis factor-a (TNF-a) and interleukin-6 (IL-6) mRNA levels and secretion. RV01 reduced tumor necrosis factor-a (TNF-a) and interleukin-6 (IL-6) mRNA levels and secretion, inhibited lps-induced ROS production and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activation, decreased toll-like receptor 4 (TLR4) protein expression, and inhibited lps-induced activation of mitogen-activated protein kinase (MAPK) and nuclear transcription factor-кB (NF-кB) signaling pathways.

Spermine tetrahydrochloride (Musculamine tetrahydrochloride) is a polyamine involved in cellular metabolism found in all eukaryotic cells. It is a major natural intracellular compound capable of protecting DNA from free radical attack.

Echinacoside is a natural polyphenolic compound with various kinds of pharmacological activities, such as anti-inflammatory, antioxidative, hepatoprotective, neuroprotective, nitric oxide radical-scavenging and vasodilative ones.

DL-5-Hydroxylysine hydrochloride (5-hydroxylysine hydrochloride) is a racemic mixture of D- and L- enantiomers of 5-hydroxylysine which may be used as potential target markers for radical-induced protein oxidation.

Naringenin (NSC-11855) is a flavanone that is considered to have a bioactive effect on human health as antioxidant, free radical scavenger, antiinflammatory, carbohydrate metabolism promoter, immunity system modulater. This substance has also been shown to repair DNA.

PTZ-343 is a potent enhancer of Luminol, acts as an electron transfer mediator, reacting with HRP-II to release HRP and a PTZ-343 radical, which oxidizes luminol anions to induce light emission.

Azelaic acid (Anchoic acid) is a component of hair and skin conditioners and is produced by the ozonolysis of oleic acid. Azelaic acid has bacteriostatic activity against Propionibacterium acnes and Staphylococcus epidermidis by inhibiting protoprotein synthesis in microbial cells. Azelaic acid also has the ability to inhibit pigmentation due to its free radical scavenging action.

Gallic acid (Benzoic acid) is found in almost all plants. Plants known for their high gallic acid content include gallnuts,grapes,tea,hops and oak bark.

1-IODOADAMANTANE (1-Adamantyl Iodide) is employed in the free-radical carbonylation reactions with alkenes.

1. Bergaptol (4-Hydroxybergapten) shows very good radical scavenging activity. 2. Bergaptol is a potent inhibitor of debenzylation activity of CYP3A4 enzyme.

(±)-Taxifolin ((±)-Dihydroquercetin) is the racemate of Taxifolin, a flavonoid commonly found in onion, silymarin, French maritime pine bark, and Douglas fir bark, with anti-tyrosinase and anti-fibrotic activity.Taxifolin is an inhibitor of collagenase, with an IC 50 value of 193.3 μM. Taxifolin is a free radical scavenger with antioxidant capacity.

α-Vitamin E (Dexrabeprazole Sodium) is a naturally-occurring form of vitamin E, a fat-soluble vitamin with potent antioxidant properties.

β-Carotene (Provitamin A) is a naturally-occurring retinol (vitamin A) precursor obtained from certain fruits and vegetables with potential antineoplastic and chemopreventive activities. As an anti-oxidant, beta carotene inhibits free-radical damage to DNA.

Chromotrope 2B (C.I. Acid Red 176) is a reagent for analytical determination of boric acid and borates, and is also used to produce a highly colored radical anion in conjuction with Chromotrope 2R.

5-Hydroxy-1-methylhydantoin (HD-003) is an antioxidant potentially for the treatment of renal failure. A creatinine metabolite, 5-Hydroxy-1-methylhydantoin , a hydroxyl radical scavenger, has previously been shown to confer renoprotection by inhibiting the progression of chronic kidney disease in rats. 5-Hydroxy-1-methylhydantoin is a novel anti-oxidant drug completely suppressed the expression of B2-kinin receptors (B2KR) in response to high glucose (25 mM) stimulation in VSMC and was also shown to attenuate the effects of BK on VSMC remodeling. 5-Hydroxy-1-methylhydantoin inhibited the BK-induced increase in MAPK phosphorylation and attenuated the increase in connective tissue growth factor (CTGF) protein levels in VSMC. These findings suggest that 5-Hydroxy-1-methylhydantoin may confer vascular protection against high glucose concentrations and BK-stimulation to ameliorate vascular injury and remodeling through its anti-oxidant properties.

Magnoloside B, a phenylethanol glycoside from the fruit of Magnolia officinalis, is an α-glucosidase inhibitor with protective effects against free radical-induced oxidative damage and can be used in cancer research.

4-Chloro-4'-hydroxybenzophenone inhibits tyrosinase and also acts as a free radical scavenger or antioxidant, reducing lipid and protein oxidation.

Baihuaqianhuoside (Praeroside) is a coumarin glycoside. Baihuaqianhuoside can be isolated from the roots of Passiflora and Hindenia solanacea and was first isolated from P. japonicum. Baihuaqianhuoside has anti-inflammatory activity in vitro and can be used in studies of inflammation. Baihuaqianhuoside has been shown to be effective against 1,1- scavenging effect of diphenyl-2-propenyl hydrazide radical and inhibition of 2,2'-azobis(2-amidinopropane) dihydrochloride-induced liposome oxidation.

1,5-diphenylpyrazole-3-carboxylic acid (1H-PYRAZOLE-3-CARBOXYLIC ACID, 1,5-DIPHENYL-) is a plant-physiologically tolerable salt radical or any desired ester radical.

AD 0261 is a radical scavenger. It has a strong inhibitory action on the generation of lipid peroxides and superoxide anions.

AFMK (Formyl-N-acetyl-5-methoxykynurenamine) is an active metabolite of Melatonin with antioxidant and free radical scavenging activity. AFMK is a modulator of apoptosis and improves the anti-tumor effect of Gemcitabine in PANC-1 cells.

Samwirin A is a promising radical scavenger in aqueous media at physiological pH.

1. Loganic acid (Loganate) and geniposide exhibit both sides effect on superoxide generation.

(-)-Gallocatechin ((−)-GC) has free radical scavenging ability and moderate affinity to the human cannabinoid receptor.

DPPH (2,2-Diphenyl-1-picrylhydrazyl) is a cell-permeable, stable free radical that is commonly used to evaluate the ability of compounds to act as free radical scavengers or hydrogen donors and to measure the antioxidant activity of tissue extracts

Edaravone (MCI-186)(MCI-186) is a potent new free radical scavenger used for the therapy of patients with acute brain infarction.

(+)-Gallocatechin (Gallocatechol) possesses free radical scavenging ability. (+)-Gallocatechin has moderate affinity to the human cannabinoid receptor.

Nordihydroguaiaretic acid (NDGA) (NDGA) is a phenolic antioxidant found in the leaves and twigs of the evergreen desert shrub, Larrea tridentata (Sesse and Moc. ex DC) Coville (creosote bush). It is a recognized inhibitor of lipoxygenase (LOX) and has antioxidant and free radical scavenging properties.

Corchoionoside C has antioxidant activity, shows strong scavenging activities on DPPH radical, it also shows weak antifungal activity. Corchoionosides A, B, and C inhibit the histamine release from rat peritoneal exudate cells induced by antigen-antibody reaction.

Thymolphthalexon (tetrasodium) is an organic thioxanthone derivative utilized as a biochemical assay reagent due to its potent antioxidant properties. It plays a significant role in researching free radical response, oxidative stress, and aging. Furthermore, Thymolphthalexon serves as a photosensitizer in photodynamic therapy, contributing to the treatment of cancer and various other diseases.

MHLWAAK, an antioxidant peptide derived from pancreatin hydrolysate of C-phycocyanin, exhibits potent DPPH and ABTS radical scavenging capabilities. It effectively shields zebrafish larvae against H2O2-induced oxidative damage [1].

Cyanidin, an antioxidant, exhibits protective effects against DNA cleavage, demonstrates free radical scavenging activity, and significantly inhibits xanthine oxidase (XO) activity [1].

Ferroptosis-IN-3 (Compound 25), a ferroptosis inhibitor, demonstrates potent activity by inhibiting RSL3-induced ferroptosis in HT-1080 cells (EC50: 8.6 nM). It exhibits radical scavenging abilities against DPPH and ABTS (EC50: 3.94 and 6.3 μM, respectively), and effectively reduces lipid peroxidation [1].

8-Prenyldaidzein has cytotoxic properties against P-388 cells, its IC 50 values 5.82 ug/mL, it also exhibits very high antioxidant activity against DPPH radical scavenging.

Antimycin A4 is an active component of the antimycin A antibiotic complex that is more polar than antimycin A1 , antimycin A2 , and antimycin A3 . Antimycin A4 inhibits ATP-citrate lyase with a Ki value of 64.8 μM. The antimycin A complex is a mixture of antimycins A1, A2, A3, and A4 that demonstrates antifungal, insecticidal, nematocidal, and piscicidal properties. It blocks mitochondrial respiration and can deplete cellular levels of ATP via inhibition of complex III of the mitochondrial electron transport chain (ETC). Antimycin A prevents the transfer of electrons between the b-cytochromes and ubiquinone at the Q(inner) site of complex III. This results in the stabilization of the ubisemiquinone radical at the Q(outer) site of complex III, leading to increased production of superoxide. Antimycin A is widely used in research to shunt electron flow through the ETC to study the chemical details of oxygen respiration. Additionally, antimycin A has been shown to inhibit Bcl-2 and Bcl-xL proteins, inducing apoptosis.

7,4'-Dihydroxy-8-methylflavan can significantly promote mesenchymal stem cells (MSCs) osteogenic differentiation by increasing the levels of alkaline phosphatase (ALP) activity. 7,4'-Dihydroxy-8-methylflavan also has free radical scavenging properties.

Ophiopogonanone E has oxygen free radicals(OFRs) scavenging effects, it can scavenge hydroxyl radical(·OH) and hydrogen peroxide(H2O2) in vitro.

Myzodendrone is a highly effective as free radical scavenger.

Cistanoside F shows vasorelaxant, and antioxidative effects, it shows a strong free radical scavenging activity on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and xanthine/xanthine oxidase (XOD) generated superoxide anion radical (O2-.).

Neonuezhenide is a phenolic compound isolated from Ligustrum officinale, which has strong antioxidant effects on free radical-induced hemolysis of red blood cells.

Quercetin-3-o-rutinose has antioxidative activity, it exerts strong DPPH radical-scavenging activity.

Methyl brevifolincarboxylate (Brevifolincarboxylic acid methyl ester) is a potent influenza virus PB2 cap-binding inhibitor. Methyl brevifolincarboxylate exhibits inhibitory activity against influenza virus A/Puerto Rico/8/34 (H1N1) and A/Aichi/2/68 (H3N2) with IC50s of 27.16 μM and 33.41 μM. Anti-oxidant activity[1][2]. Methyl brevifolincarboxylate exhibits significant DPPH radical scavenging activity with an IC50 value of 8.9 μM. [1]. Wu QY, et al. Chromatographic fingerprint and the simultaneous determination of five bioactive components of geranium carolinianum L. water extract by high performance liquid chromatography. Int J Mol Sci. 2011;12(12):8740-8749. [2]. Fang SH, et al. Anti-oxidant and inflammatory mediator's growth inhibitory effects of compounds isolated from Phyllanthus urinaria. J Ethnopharmacol. 2008;116(2):333-340.

(+)-Afzelechin has a neuroprotective effect on the glutamate-induced neurotoxicity in HT22 cells, it has ABTS cation radical scavenging effects with IC50 values of 23.7 microM

Isoscoparin-2''-Beta-D-glucopyranoside shows prominent free radical scavenging activity in DPPH assay.

Diquat is a bipyridylium herbicide that, as a stable radical, acts as an electron acceptor in the electron transport chain and is reoxidized by molecular oxygen, producing reactive oxygen species (ROS).1Diquat administration has been used to induce oxidative stressin vitroand in animal models.2,3,4It increases the production of ROS and decreases the mitochondrial membrane potential in mitochondria isolated from porcine intestine leading to mitophagy when administered at a dose of 100 mg/kg.2Formulations containing diquat have been used in agriculture for crop desiccation and defoliation.

Glabranin has antimicrobial activity, it shows significant activities on DPPH free radical with the IC50 value of 240.20 ug/ml. Glabranin or a derivative thereof could be used to stimulate hair growth. Glabranine exerts a dose-dependent inhibitory effect

1. Aloenin (Aloenin A) and aloe-emodin are active principles for inhibition of c-ADH and c-ALDH activities in vitro.