DPPH (2,2-Diphenyl-1-picrylhydrazyl) is a stable free radical that may be utilized to measure the free radical scavenging activity of antioxidants. The odd electrons of the nitrogen atoms in DPPH are reduced to the corresponding hydrazines by absorbing hydrogen atoms from the antioxidant. The DPPH method may be utilized in aqueous and non-polar organic solvents and may be utilized to examine hydrophilic and lipophilic antioxidants.

Physicochemical Properties

Molecular Formula	C18H12N5O6
Molecular Weight	394.32
Exact Mass	394.078
CAS #	1898-66-4
PubChem CID	2735032
Appearance	Brown to black solid powder
Melting Point	136-138ºC
LogP	5.97
Hydrogen Bond Donor Count	0
Hydrogen Bond Acceptor Count	7
Rotatable Bond Count	4
Heavy Atom Count	29
Complexity	549
Defined Atom Stereocenter Count	0
SMILES	C1=CC=C(C=C1)N(C2=CC=CC=C2)[N]C3=C(C=C(C=C3[N+](=O)[O-])[N+](=O)[O-])[N+](=O)[O-]
InChi Key	HHEAADYXPMHMCT-UHFFFAOYSA-N
InChi Code	InChI=1S/C18H12N5O6/c24-21(25)15-11-16(22(26)27)18(17(12-15)23(28)29)19-20(13-7-3-1-4-8-13)14-9-5-2-6-10-14/h1-12H
Chemical Name	1,1-Diphenyl-2-picrylhydrazyl (free radical)
Synonyms	2,2-Diphenyl-1-picrylhydrazyl; UNII-DFD3H4VGDH; DFD3H4VGDH; 1,1-Diphenyl-2-picrylhydrazyl (free radical); EINECS 217-591-8; Hydrazyl, 2,2-diphenyl-1-picryl-; NSC 12562; ...; 1898-66-4;
HS Tariff Code	2934.99.9001
Storage	Powder-20°C 3 years 4°C 2 years In solvent -80°C 6 months -20°C 1 month Note: Please store this product in a sealed and protected environment (e.g. under nitrogen), avoid exposure to moisture and light.
Shipping Condition	Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

Biological Activity

Targets	Free radicals (scavenges DPPH• radicals via hydrogen donation)[1]
ln Vitro	- Antioxidant activity: DPPH (0.1 mM) in ethanol solution was used to evaluate the free radical scavenging capacity of plant extracts and pure compounds. The reaction was monitored by measuring absorbance at 517 nm, with a decrease in absorbance indicating radical scavenging activity. The method was validated for reproducibility and sensitivity across different sample matrices[1] Because it has an odd number of electrons, DPPH exhibits a strong absorption band at 517 nm. The solution takes on a dark purple color, and the absorption vanishes as the electron pairs vanish. The decolorization that follows is stoichiometric with respect to the quantity of electrons absorbed. Over the relevant absorption range, alcohol solutions at 0.5 mM exhibit a strong color and follow the Lambert-Beer law [1]. The DPPH assay is a quick, easy, affordable, and popular way to gauge a substance's capacity to donate hydrogen or scavenge free radicals, as well as to evaluate the antioxidant activity of food. Additionally, in complicated biological systems, it can be utilized to quantify antioxidants in liquid or solid sample types. Fruit and vegetable juices can have their total antioxidant capacity and free radical scavenging activity determined using this straightforward and user-friendly approach. The oxidation of wheat grains and bran, vegetables, conjugated linoleic acid, herbs, edible seed oils, and flour in a variety of solvent systems, such as ethanol, aqueous acetone, methanol, hydrous alcohol, and benzene, has all been effectively studied with this assay. characteristics of an antioxidant. Antioxidants include cysteine, glutathione, ascorbic acid, tocopherols, and polyhydroxyaromatic compounds in olive oil, fruits, juices, and wines can be easily measured using this straightforward method [1].
Enzyme Assay	DPPH radical scavenging assay: A solution of DPPH (0.1 mM in ethanol) was mixed with sample extracts or compounds. After 30 minutes of incubation in the dark, absorbance was measured at 517 nm. Antioxidant activity was calculated as the percentage decrease in absorbance relative to a control without sample[1]
Toxicity/Toxicokinetics	2735032 mouse LD50 intravenous 1800 ug/kg U.S. Army Armament Research & Development Command, Chemical Systems Laboratory, NIOSH Exchange Chemicals., NX#06207
References	[1]. Genesis and development of DPPH method of antioxidant assay. J Food Sci Technol. 2011 Aug;48(4):412-22.
Additional Infomation	- Methodological development: The DPPH assay was optimized for accuracy and precision, with recommendations for standardization of reaction conditions (e.g., solvent choice, incubation time, and wavelength selection). The method was shown to effectively quantify antioxidant activity in food, plant, and biological samples[1] - Mechanism of action: DPPH acts as a stable free radical, accepting an electron or hydrogen atom from antioxidants to form the non-radical DPPH-H. The extent of color fading (from purple to yellow) correlates with antioxidant potency[1] - Applications: Widely used in food science, pharmacology, and cosmetics to screen natural antioxidants, evaluate dietary supplements, and assess oxidative stress in biological systems[1]

Solubility Data

Solubility (In Vitro)

DMSO: 25 mg/mL (63.40 mM) Ethanol: 1 mg/mL (2.54 mM)

Solubility (In Vivo)

Solubility in Formulation 1: ≥ 2.08 mg/mL (5.27 mM) (saturation unknown) in 10% DMSO + 40% PEG300 +5% Tween-80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), clear solution. For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 20.8 mg/mL clear DMSO stock solution to 400 μL PEG300 and mix evenly; then add 50 μL Tween-80 + to the above solution and mix evenly; then add 450 μL normal saline to adjust the volume to 1 mL. Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution.  (Please use freshly prepared in vivo formulations for optimal results.)

Preparing Stock Solutions		1 mg	5 mg	10 mg
	1 mM	2.5360 mL	12.6801 mL	25.3601 mL
	5 mM	0.5072 mL	2.5360 mL	5.0720 mL
	10 mM	0.2536 mL	1.2680 mL	2.5360 mL

*Note: Please select an appropriate solvent for the preparation of stock solution based on your experiment needs. For most products, DMSO can be used for preparing stock solutions (e.g. 5 mM, 10 mM, or 20 mM concentration); some products with high aqueous solubility may be dissolved in water directly. Solubility information is available at the above Solubility Data section. Once the stock solution is prepared, aliquot it to routine usage volumes and store at -20°C or -80°C. Avoid repeated freeze and thaw cycles.