2 2 diphenyl 1 picrylhydrazyl dpph 2 2 azinobis 3 ethylbenzothiazoline 6 sulfonic acid abts

2,2-Diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and 3-(2-pyridyl)-5,6-diphenyl-1,2,4-triazine-4′,4″-disulphonic acid sodium salt (Ferrozine) were purchased from Sigma-Aldrich Chemical Co., St Louis, MO. Other chemicals were laboratory reagent grade and obtained from Merck Co. (Darmstadt, Germany).

All chemicals used in the present study were of analytical, HPLC and/or molecular biology grade and were purchased from Himedia, India, Merck, India and Sigma-Aldrich, United States and used without further purification. Standard compounds, such as 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS), gallic acid, caffeic acid, syringic acid, p-coumaric acid, ferulic acid, rutin, myricetin, quercetin, kaempferol, ascorbic acid, and antidiuretic drug furosemide were purchased from Sigma-Aldrich, United States. Solvents were procured from Merck, India. Potassium ferricyanide, trichloroacetic acid (TCA), ferric chloride, hydrogen peroxide, phosphomolybdenum, potassium persulfate etc were obtained from SRL, India. Microbiological media were obtained from HiMedia laboratory, India.

The phenolic standards (gallic acid, cinnamic acid, chlorogenic acid, caffeic acid, coumaric acid, ferulic acid, 2,4-dihydroxybenzoic acid), quercetin, caffein, trigonelline, 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and Folin–Ciocalteu’s reagent were purchased from Sigma–Aldrich (St. Louis, MO, USA). Chemicals used for the physicochemical analysis were purchased from Merck (Darmstadt, Germany). All chemicals used were analytical grade unless specified. All samples were stored in sealed glass jars and at room temperature (20–30 °C) until analysis