Sodium hydrogen phosphate

All chemicals were analytical grade. Methanol (MeOH), iron (II)-sulfate-7-hydrate and trichloroacetic acid were obtained from Riedel-de Haën™ (Seelze, Germany) and formic acid, water and acetonitrile (ACN) from Fisher Scientific, OptimaTM (Hampton, NH, USA). Trifluoroacetic acid (TFA), potassium dihydrogen phosphate, tris(hydroxymethyl)aminomethane (Tris) and sodium chloride were bought from Merck (Darmstadt, Germany). Ethanol 96% was bought from Carlo Erba (Peypin, France), gentiopicroside from TransMIT (Hesse, Germany) and potassium chloride from Fluka (Seelze, Germany). Acetylcholinesterase (AChE), acetylcholine iodide (AChI), 5-5′-dithiobis (2-nitrobenzoic acid) (DTNB), HMG-CoA Reductase assay kit, gallic acid, 2,2-diphenyl-1-picrylhydrazyl (DPPH), butylated hydroxytoluene (BHT), quercetin, rutin and galantamine were obtained from Sigma (Barcelona, Spain). Magnesium chloride hexahydrate, thiobarbituric acid, hydrogen peroxide, sodium hydrogen phosphate and 1-butanol were bought to PanReac (Barcelona, Spain). Sodium hydroxide was obtained from JT Baker, UK and sodium nitroprusside and Griess reagent from VWR Chemicals PL.

Methacrylic acid (MAA,
99.5%), IA (99%), and ethylene glycol dimethylacrylate (EGDMA, 98%)
were purchased from Acros Organics. Methyl methacrylate (MMA, 99%),
styrene (St, 99%), N-isopropylacrylamide (NIPAM,
97%), and CDCl₃ (99.8%) used to record ¹H NMR
spectra were purchased from Sigma-Aldrich. Azobisisobutyronitrile
(AIBN, 98%) was purchased from Fluka. Absolute ethanol (EtOH, 99.8%),
hydrochloric acid (HCl) 37% aqueous solution, EtOAc (99.8%), dichloromethane
(DCM, 99.8%), methanol (MeOH, 99.8%), and acetonitrile (MeCN, 99.9%)
of HPLC grade were purchased from Fisher Scientific. Methyl tert-butyl ether (MTBE, 99.9%) was purchased from Lab Scan.
Potassium hydroxide (KOH, 85.8%) pellets and sodium hydrogenphosphate
(Na₂HPO₄, 99%) were purchased from Panreac.
1,3,5-Trimethoxybenzene 99% was purchased from Alfa Aesar. Soxhlet
thimbles were purchased from Merck. Lupanine, with 82% purity, determined
by ¹H NMR, was obtained following a published procedure.^{31 (link)}