β glucuronidase type h 2

The following reagents were obtained from Sigma Co. (St. Louis, MO, USA): catechin, kaempferol, isorhamnetin, naringenin, quercetin, butylated hydroxytoluene (BHT), Folin–Ciocalteu’s phenol reagent, copper sulfate, ethylenediaminetetraacetic acid (EDTA), β-glucuronidase type H-2 (containing sulfatase from Helix pomatia), glutathione reductase (type III), nicotinamide adenine dinucleotide phosphate (NADP), sodium 1-octanesulfonate monohydrate, reduced glutathione, oxidized glutathione, sodium azide, sodium chloride, sodium phosphate monobasic, sodium phosphate dibasic, 1,1,3,3-tetraethoxypropane, 2’,3’,4’-trihydroxyacetophenone, Tris buffer, magnesium chloride, triphenylphosine, and α-tocopherol. Diisopropylethylamine (DIPEA), O-bis (trimethylsilyl) trifluoroacetamide (BSTFA), and pentafluorobenzyl bromide (PFBBr) were purchased from Thermo (Boston, MA, USA). Deuterated prostaglandin (PG) F_2α (internal standard), PGF_2β, and 8-iso-PGF_2α were purchased from Cayman (Ann Arbor, MI, USA). All organic solvents, glacial acetic acid, and potassium bromide were purchased from Fisher Co. (Fair Lawn, NJ, USA).

The reference standards of quercetin, kaempferol, rutin, kaempferol-3-O-rutinoside, isoquercitrin, hyperoside, N-trans-Feruloyltyramine, and astragalin were purchased from the National Institute for the Control of Pharmaceutical and Biological Products (Beijing, China). Internal standard (IS) d3-quercetin was obtained from Toronto Research Chemicals (North York, ON, Canada). Sulfatase (type H-1) and β-glucuronidase (type H-2) were obtained from Sigma-Aldrich (St Louis, MO, USA). Deionized water was freshly prepared using a Milli-Q purification system (Millipore, Billerica, MA, USA). HPLC-grade acetonitrile and methanol were purchased from Fisher Scientific (Fair Lawn, NJ, USA). EDTA-K₂ containing vacutainer tubes (5 mL) and 22 G IV catheters (0.9 × 25 mm) were obtained from BD Biosciences (Franklin Lakes, NJ, USA). Formic acid, methyl tert-butyl ether (MTBE), and other chemical reagents were of analytical grade. The tartary buckwheat extracts were produced by Jing Brand Co. Ltd. (Daye, China). The contents of rutin, quercetin, kaempferol and, kaempferol-3-O-rutinoside were 61.2%, 4.5%, 0.15%, and 4.84% respectively, which was quantified by HPLC.

4- Nonylphenol (p-isomers >85%) was obtained from Fluka (Buchs, Switzerland). Methanol, n-hexane, acetone, acetonitrile, hydrochloric acid, acetic acid, and ammonium acetate were LC grade, and all were obtained from Merck (Darmstadt, Germany). β-Glucuronidase (type H-2) was purchased from Sigma-Aldrich (USA). Deionized water, obtained using a Millipore water purification system (Bedford, MA, USA), was prepared before use and was collected in a glass container.