2 4 6 tri 2 pyridyl 1 3 5 triazine tptz

The extraction solvents ethanol, petroleum ether, ethyl acetate n-butanol and the dimethyl sulfoxide (DMSO) were supplied by Shanghai Chemical Reagent Corp. (Shanghai, China). The different standards used for the assays comprising gallic acid, rutin, ascorbic acid (Vit C), butylated hydroxytoluene (BHT), Trolox, 2,2-diphenyl-1-picrylhdrazyl (DPPH), 2,2′-azinobis-(3-ethyl-benzthiazoline-6-sulfonic acid) diammonium salt (ABTS), 2,4,6-Tri (2-pyridyl)-1,3,5-triazine (TPTZ), and indomethacin with a purity ≥99.5% were purchased from Sigma-Aldrich Corp (Shanghai, China). The HPLC grade solvents acetonitrile (ACN), methanol, and formic acid (FA) were obtained from TEDIA Company Inc. (Fairfield, OH, United States). The p-nitrophenyl α-D-glucopyranoside (p-NPG) substrate was acquired from Aladdin Bio-Chem Technology Corp. The COX-2 inhibitor screening assay kit (No: S0168) was purchased from Beyotime Biotechnology (Shanghai, China). The α-glucosidase enzyme was bought from Sigma Aldrich (St Louis, MO, United States) whereas Wuhan Antgene Biotechnology Co., Ltd. (Wuhan, China) supplied the COX-2 enzyme. The centrifugal ultrafiltration membranes 10 kDa Cut-off (YM-10) were purchased from Millipore Co. Ltd. (Bedford, MA, United States). Finally, Shanghai Macklin Biochemical Co. (Shanghai, China) supplied the phytochemical standards vitexin and astragalin (≥98%).

Fresh and mature persimmons of three cultivars were purchased in Beijing market (shown in Figure 1). The “Gongcheng” cultivar was yellowish and crispy, which was harvested in Guangxi, China; the “Mopan” cultivar was orange-red with a thick peel and soft flesh, which was harvested in Beijing, China; and the “Yangfeng” cultivar was a deep orange-red with moderate hardness, which was harvested in Shanxi, China.
The 2,2-diphenyl-1-picrylhydrazyl (DPPH), (±)-6-hydroxy-2,5,7,8-tetramethyl-chroman-2-carboxylic acid (Trolox), and 2,4,6-tri-2-pyridyl-1,3,5-triazine (TPTZ) were obtained from Sigma Aldrich (St. Louis, USA). High performance liquid chromatography (HPLC)-grade acetonitrile, methanol and formic acid were purchased from Thermo Fisher Scientific (MA, USA). Other chemicals were obtained from Solarbio (Beijing, China).

Leaves of Biqi, the major cultivar used in the industry, were hand-harvested randomly in October 29, 2011 in Cixi, Zhejiang Province, Southeastern China. Sephadex LH-20 was purchased from GE Healthcare Bio-Sciences AB (Sweden). Methanol, hexane, and ethyl acetate for HPLC analysis and preparation were of HPLC grade. All other reagents and solvents used were of analytical grade, unless stated otherwise. 2,5-Dihydroxybenzoic acid (DHB), trifluoroacetic acid (TFA), 6-hydroxy-2,5,7,8-tetramethyl-choman-2-carboxylic acid (Trolox), 2,2′-azobis(2-methylpropionamidine)dihydrochloride (AAPH), (1,1-diphenyl-2-picryl-hydrazyl) (DPPH), 2,4,6-tri(2-pyridyl)-1,3,5-triazine (TPTZ), 2′,7′-dichlorofluorescin diacetate, and fluorescein disodium salt were purchased from Sigma-Aldrich (St. Louis, MO, USA). Myricetin was purchased from J&K Scientific Ltd. (Beijing, China). Sodium chloride and L-ascorbic acid were purchased from Sinopharm Chemical Reagent Co., Ltd. (Shanghai, China). Gallocatechin (GC), epicatechin gallate (ECG), gallocatechin gallate (GCG), and epigallocatechin gallate (EGCG) were purchased from Yuanye Bio-Technology Co., Ltd. (Shanghai, China).