Hplc grade solvents

The chemicals used as substrates or standards were catechol, propanoic acid, benzoic acid, phenyllactic acid, phenylacetic acid, 2-phenylpropanoic acid, 3-phenylpropanoic acid (3PPA), m-tolylacetic acid, p-tolylacetic acid, ibuprofen as sodium salt, diclofenac, ibufenac, naproxen, and ketoprofen, and were all obtained from Sigma-Aldrich (Steinheim, Germany). Other chemicals used were 3-fluorocatechol (Alfa Aesar, Karlsruhe, Germany), and cinnamic acid (Fluka, Buchs, Switzerland). HPLC-grade solvents were supplied by Scharlau (Barcelona, Spain); all other chemicals were of analytical purity.

The berberine and palmatine in the total extract and the alkaloid enrichment of M. bealei were quantitated using the HPLC-DAD method. HPLC-grade solvents were purchased from Scharlau (Barcelona, Spain) and Merck Millipore (Darmstadt, Germany). HPLC-DAD data were generated using a Thermo Ultimate 3000 system consisting of a quaternary pump, an autosampler, a column oven, and a diode array detector. A Hypersil GOLD HPLC column (250 mm × 4.6 mm, 5 µm) was used at 40 °C, while 0.1% (v/v) acetic acid in water and acetonitrile (ACN, Concord, NC, USA) were set as solvent channel A and B, respectively. A flow rate of 1.0 mL per min was selected, with a linear gradient from 25% to 50% ACN over 20 min, followed by 5 min washing with 100% methanol and 5 min of the initial condition. The injection volume for each sample was 2 µL. The UV detector was set at 345 nm (for the simultaneous determination of berberine and palmatine). Calibration solutions for each standard compound were prepared in a concentration range of 10–200 µg/mL and analyzed under the same conditions as the samples. Berberine and palmatine were purchased as standard compounds from Sigma-Aldrich (St. Louis, MI, USA).

Ring-labeled [3H]-benzophenone-2 (2,2′,4,4′-tetrahydroxybenzophenone; radiochemical purity: 99%, specific activity: 740 GBq/mmol) was purchased from American Radiolabeled Chemicals, Inc. (Saint-Louis, MO, USA). Ring-radiolabeled [3H]-bisphenol-S (4,4′-sulfonyldiphenol; radiochemical purity: 99.7%, specific activity 62.9 GBq/mmol) was supplied by Moravek Biochemicals, Inc. (Brea, CA, USA). Unlabeled benzophenone-2 (BP2, CAS #131-55-5, chemical purity: 97%) and bisphenol S (BPS, CAS #80-09-1, chemical purity: 98%) were purchased from Sigma–Aldrich (Saint Quentin Fallavier, France). Flo-Scint II and Ultima Gold liquid scintillation cocktails were purchased from PerkinElmer Life and Analytical Sciences (Courtaboeuf, France). HPLC-grade solvents (ethanol, methanol, dichloromethane, acetonitrile) were purchased from Scharlau (Barcelona, Spain). Ammonium acetate was purchased from Merck KGaA (Darmstadt, Germany). Ultrapure water produced with the Milli-Q system (Millipore, Saint Quentin En Yvelines, France) was used for preparing HPLC mobile phases.