P nitrophenyl β d glucoside

Rutin (quercetin 3-O-rutinoside) (2) was purchased from Alchimica s.r.o. (Czech Republic). Hesperidin (hesperetin 7-O-rutinoside) (3), narcissin (isorhamnetin 3-O-rutinoside) (4), diosmin (diosmetin 7-O-rutinoside) (5), and p-nitrophenyl β-d-glucoside (7) were purchased from Sigma-Aldrich. Isoquercitrin (quercetin 3-O-β-d-glucopyranoside) (1) and p-nitrophenyl rutinoside (8) were prepared as previously described (Weignerová et al. 2012 (link); Šimčíková et al. 2015 (link)).

Naringinase from Aspergillus aculeatus/Aspergillus niger (Novozyme NS 33117) was kindly donated by Novozyme. Naringin (≥95% HPLC), limonin (>90% HPLC), p-nitrophenyl-α-l-rhamnopyranoside (pNPR), and p-nitrophenyl-β-d-glucoside (pNPG) were purchased from Sigma-Aldrich, Santiago, Chile. Acetonitrile, octyl-sepharose 4 Fast Flow, butyl-sepharose 4 Fast Flow, and sodium metaperiodate were purchased from Merck, Santiago, Chile. All other chemicals were of analytical grade. Grapefruits were purchased from the local market.

In August 2021, Ribes meyeri fruits were collected in Manasi County South Mountain Forestry, Xinjiang, China, and identified by Associate Prof. Wenbin XU. Then they were stored at −20 °C. The Ribes meyeri fruit specimen (RML210811) was coded and maintained in the botany laboratory of Shihezi University.
Four standards of anthocyanin, cyanidin-3-O-rutinoside, delphinidin-3-O-rutinoside, cyanidin-3-O-glucoside, and delphinidin-3-O-glucoside, were purchased from Chengdu Durst Biotechnology Co. (Chengdu, China). Formic acid, acetonitrile, and methanol (Optima™ LC/MS Grade) were purchased from Fisher Scientific (Waltham, MA, USA). The following analytical purity chemicals were provided by Adamas Co. (Shanghai, China): methanol, hydrochloric acid, potassium chloride, ethanol, potassium persulfate, and sodium potassium tartrate. A macroporous resin, AB-8, was obtained from Cangzhou Bao’en Adsorption Material Technology Co. (Cangzhou, China).
Protein tyrosine phosphatase 1B (PTP1B, EC 3.1.3.48) from human recombinant protein, α-glucosidase (EC 3.2.1.20) from Saccharomyces cerevisiae, α-amylase (EC 3.2.1.1) from porcine pancreas, p-nitrophenyl-β-D-glucoside (pNPG), Na₃VO₄, ascorbic acid, acarbose, 2,2′-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) (ABTS), and 2,2-diphenyl-1-picrylhydrazyl (DPPH) were provided by Sigma-Aldrich Chemical Co. (St Louis, MO, USA).