6 hydroxyl 2 5 7 8 tetramethlychromane 2 carboxylic acid trolox

Sprague-Dawley (SD) rats of four weeks of age were obtained from the Animal Centre at the Guangzhou University of Chinese Medicine, China. Quercitrin (C₂₁H₂₀O₁₁, CAS number: 522-12-3, 98%) and isoquercitrin (Q3G, C₂₁H₂₀O₁₂, CAS number: 482-35-9, 98%) were obtained from Sichuan Weikeqi Biological Technology Co., Ltd. (Chengdu, China). Pyrogallol, 2,4,6-tripyridyl triazine (TPTZ), (±)-6-hydroxyl-2,5,7,8-tetramethlychromane-2-carboxylic acid (Trolox), and butylated hydroxyanisole (BHA) were obtained from Sigma-Aldrich (Shanghai, China). MTT was from, Duchefa (Haarlem, The Netherlands). 1,1-Diphenyl-2-picrylhydrazyl radical (DPPH•) was obtained from Aladdin Chemical, Ltd. (Shanghai, China). 2,9-Dimethyl-1,10-phenanthroline hemihydrate (neocuproine) was obtained from J & K Scientific, Ltd. (Beijing, China). Tris-hydroxymethyl amino methane (Tris) was obtained from Dinggguo Biotechnology, Ltd. (Beijing, China). Dulbecco’s modified Eagle’s medium (DMEM) and fetal bovine serum (FBS) were purchased from Gibco (Grand Island, NY, USA). CD44 was purchased from Boster, Ltd. (Wuhan, China). H₂O₂, FeCl₂·4H₂O, CH₃COONH₄, FeCl₃·6H₂O, Na₂EDTA, CuSO₄, hydrochloric acid, and all of the other reagents were purchased as the analytical grade from Guangdong Guanghua Chemical Plants Co., Ltd. (Shantou, China).

Scutellarein (C₁₈H₁₀O₆, CAS number: 529-53-5, M.W 286.2, purity 98%) and scutellarin (C₂₁H₁₈O₁₂, CAS number: 27740-01-8, M.W 462.4, purity 98%) were obtained from BioBioPha Co., Ltd. (Kunming, China). The molecule 1,1-Diphenyl-2-picrylhydrazyl radical (DPPH^•, C₁₈H₁₂N₅O₆) was obtained from Aladdin Chemical, Ltd. (Shanghai, China), (NH₄)₂ABTS [2,2′-azino-bis (3-ethylbenzo-thiazoline-6-sulfonic acid diammonium salt)] was obtained from Amresco Chemical Co (Solon, OH, USA), 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide radical (PTIO^•) was purchased from TCI Chemical Co. (Shanghai, China), 2,9-Dimethyl-1,10-phenanthroline (neocuproine), pyrogallol, and (±)-6-hydroxyl-2,5,7,8-tetramethlychromane-2-carboxylic acid (Trolox) were obtained from Sigma-Aldrich (Shanghai, China). Tris-hydroxymethyl amino methane (Tris) was obtained from Dingguo Biotechnology, Ltd. (Beijing, China). Water and acetonitrile were of HPLC grade. Analytical-grade FeCl₃·6H₂O and other reagents were purchased from Guangdong Guanghua Chemical Plants Co., Ltd. (Shantou, China).

Acacetin (C₁₆H₁₂O₅, CAS number 480-44-4, MW 284.2, purity 98%; Supplementary 5 Figures S5.1 and S5.2) and isoginkgetin (C₃₂H₂₂O₁₀, CAS number 548-19-6, MW 566.5, purity 98%; Supplementary 6 Figures S6.1 and S6.2) were obtained from Chengdu Biopurify Phytochemicals, Ltd. (Chengdu, China). 4-Methoxy-TEMPO· (C₁₈H₁₂N₅O₆, CAS number 95407-69-5) was purchased from TCI Shanghai Ltd. (Shanghai, China). 2,9-Dimethyl-1,10-phenanthroline (neocuproine), pyrogallol (2,3-dihydroxyphenol), and (±)-6-hydroxyl-2,5,7,8-tetramethlychromane-2-carboxylic acid (Trolox) were obtained from Sigma-Aldrich (Shanghai, China). (NH₄)₂ABTS [2,2′-azino-bis (3-ethylbenzo-thiazoline-6-sulfonic acid diammonium salt)] was obtained from the Amresco Chemical Co. (Solon, OH, USA). Tris-hydroxymethyl amino methane (Tris) was obtained from Dingguo Biotechnology, Ltd (Beijing, China). Water, methanol, and acetonitrile were of HPLC grade and the other reagents were purchased as analytical grade from Guangdong Guanghua Chemical Plants Co. Ltd (Shantou, China).