Sodium nitrite

The following chemicals and reagents were purchased from Shanghai Yuanye Bio-Technology Co., Ltd. (Shanghai, China): Folin–Ciocalteu reagent, 2,2-diphenyl-1-picrylhydrazyl (DPPH), aluminum nitrate, 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), sodium carbonate, sodium nitrite, aluminum chloride, sodium hydroxide, ascorbic acid, gallic acid, rutin, and Trolox. Analytical grade ethanol was purchased from Sichuan Xilong Science Co., Ltd. (Chengdu, China). Pure water was prepared using a secondary reverse osmosis system (JYS-500L; Shanghai Juyuan Automation Technology Co., Ltd., Shanghai, China).

Vine tea was purchased from Guilin Paradise Lijiang Specialty Products Co., Ltd. (Guangxi Zhuang Autonomous Region, China).
Yeast-extract-powder peptone glucose (YPG) medium, man-rogosa-sharpe (MRS), malt extract powder liquid medium, and LB medium were purchased from Shanghai YSRIBIO Industrial Co., Ltd. (Shanghai, China). Standard flavonoids (rutin, ethanol, sodium nitrite, aluminum nitrate, sodium hydroxide), standard polyphenols (gallic acid, ferrous tartrate, phosphate buffer), and standard polysaccharides (glucose, phenol) were bought from Shanghai Yuanye Bio-Technology Co., Ltd. (Shanghai, China). Dimethyl sulfoxide (DMSO), Roswell Park Memorial Institutefoetal-1640 (RPMI-1640), α-melanocyte-stimulating hormone (α-MSH), fatal bovine serun (FBS), and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) were synthesized by Procell Life Science & Technology Co., Ltd. (Wuhan, China). 1,1-Diphenyl-2-trinitrophenylhydrazine (DPPH), tris(hydroxymethyl)aminomethane (TRIS), hydrogen peroxide, o-triphenol, ferrous ethylenediaminetetraacetic acid (Fe²⁺-EDTA) solution, methylene blue, hydrogen peroxide, and 2,2′amino-bis (3-ethyl-benzothiazolinesulfonic acid-6) ammonium salt (ABTS) were provided by Tianjin Kemiou Chemical Reagent Co., Ltd. (Tianjin, China).

All mass spectrometric grade reagents (methanol, acetonitrile, and formic acid) were bought from Sigma-Aldrich Trading Co., Ltd. (Shanghai, China), while chromatographic grade reagents (rutin, gallic acid, and acarbose) and analytical grade reagents, including sodium nitrite, aluminum chloride, sodium hydroxide, sodium carbonate, ascorbic acid, Folin–Ciocalteu reagent, 2,2-diphenyl-1-picrylhydrazyl (DPPH), diammonium 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonate) (ABTS+•), potassium persulfate, phosphate-buffered saline (PBS), salicylic acid, ferrous sulfate, tripyridine triazine (TPTZ), ferric chloride, sodium acetate, potassium ferricyanide, hydrogen peroxide solution, hydrochloric acid, acetic acid, trichloroacetic acid, α-glucosidase, p-nitrophenyl-β-d-glucopyranoside (pNPG), and 4′,6-diamidino-2-phenylindole (DAPI), were purchased from Yuanye Bio-Technology Co., Ltd. (Shanghai, China). Mouse mononuclear macrophage leukemia cells (RAW 264.7 cells), human hepatoma cells (HepG2 cells), and human esophageal carcinoma cells (TE-1) were provided by Wanwu Bio-Technology Co., Ltd. (Hefei, Anhui, China).