Kaempferol

Four wampee fruits samples, W1–W4, were collected in July 2020 from South China, including Guangdong, Guangxi, and Hainan provinces, and the varieties were identified by professionals. Detailed information about W1–W4 is shown in Table 1. All the standards, including o-coumaric acid, gallic acid, gentisic acid, chlorogentic acid, DL-catechin, isoquercitrin, caffeic acid, myricetin, quercein, rutin, kaempferol 7-O-glucoside, quercitrin, and kaempferol, were HPLC-grade (>97%) and purchased from Shanghai Macklin Biochemical Co., Ltd. (Shanghai, China). 4-nitrophenyl α-D-glucopyranoside (pNPG), 2,2′-azinobis (3-ethylbenzothiazoline-6-sulfonic acid ammonium salt) (ABTS), 1,1-diphenyl-2-picrylhydrazyl radical (DPPH), 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid (Trolox), 2,4,6-tris(2-pyridyl)-s-triazine (TPTZ), and all mobile phase reagents used for liquid chromatography, including ethanol, acetonitrile, formic acid, and 2-propanol (HPLC-grade), were purchased from Shanghai Aladdin Biochemical Technology Co., Ltd. (Shanghai, China). Folin–Ciocalteu phenol reagent was purchased from Sigma-Aldrich Chemical Co., Ltd. (St. Louis, MO, USA). Other reagents applied in the study were of analytical grade and purchased from Sinopharm Chemical Reagent Co., Ltd. (Shanghai, China).

QCS (Z05170722) was supplied by Longhua Hospital, Shanghai University of Traditional Chinese Medicine. It consisted of the following herbs: Radix Notoginseng, Indigo Naturalis, Gallnut, Herba Portulacae and borneol, in a ratio of 2:2:5:5:1. Sulfasalazine Suppository (SASP) is a yellow suppository which was made of 0.5 g sulfasalazine with fatty matrix. SASP was purchased from Shanxi Tongda Pharmaceutical Co. Ltd. (Shanxi, China). Dextran sulfate sodium salt (DSS) (MW 36,000–50,000) was purchased from MP Biologicals (Santa Ana, CA, USA). Indirubin, Notoginsenoside R1, Ginsenoside Rg1, Ginsenoside Rb1, Ginsenoside Re, and Luteolin were purchased from the National Institutes for Food and Drug Control (Shanghai, China). Kaempferol, Quercetin, Gallic acid, α-Linolenic acid, and Methyl gallate were purchased from Shanghai Macklin Biochemical Co. Ltd. HPLC grade acetonitrile was obtained from Fisher (Geel, Belgium) and HPLC grade formic acid from ANPEL Laboratory Technologies (Shanghai, China). Water was purified using a Milli-Q Academic System (Millipore, Billerica, MA, USA).

The IBM SPSS 26 software was used to analyze the data and compare the differences among groups. Duncan multiple comparison in one-way analysis of variance (ANOVA) was used to detect the significant difference, and the significance level was p < 0.05.
Quercetin (Q817162, MACKLIN, Shanghai, China) and kaempferol (K812226, MACKLIN, China) were mixed with methanol to form the mother liquor of 100 mM, respectively, and UDP-Glc (U850073, MACKLIN, China) was prepared with ddH₂O as the mother liquor of 50 mM. 2 × Hepes (1 L) formula: first dissolve Hepes powder (BS106, BIOSHARP, Shanghai, China) in ddH₂O, adjust the PH to 6.8, add 273.6 g sucrose, then add 20 mL 0.5 M MgCl₂ and MnCl₂, fixed volume to 1 L. The above mother liquids were stored at −20 °C. In addition, when using the Hepes buffer (PH 6.8), one piece of protease inhibitor (BL630B, BIOSHARP, China) should be added to each 50 mL 1 × Hepes solution.