α cyclodextrin α cd

For whole-cell recordings, HEK-293 cells were transfected with the different K2P wild type or chimeric channels, using a PC-501A patch clamp amplifier (Warner Instruments) and borosilicate glass pipettes as previously described by Zúñiga et al. [23 (link)]. The cells were superfused with a solution containing 135 mM NaCl, 10 mM HEPES, 10 mM Sucrose, 5 mM KCl, 1 mM MgCl₂, and 1 mM CaCl₂ and adjusted to pH 7.4 with NaOH. The pipette was filled with a solution of 145 mM KCl, 10 mM HEPES, 5 mM EGTA, and 2 MgCl₂, pH 7.4 adjusted with KOH. Methyl-β-cyclodextrin (MβCD), α-cyclodextrin (αCD) (Sigma-Aldrich, St. Louis, MO, USA), and filipin III (Cayman chemical, Ann Arbor, MI, USA) were dissolved in water or DMSO to obtain 100 mM and 500 µg/mL stock solutions. Working concentrations of 5 mM MβCD, 5 mM αCD, and 5 μg/mL filipin III were then prepared by diluting stock solutions with the bath solutions obtaining the desired concentrations. Cells were held at −80 mV, then currents were recorded using a protocol of 500 ms of duration from −100 to +100 mV with increments of 10 mV. Patch-clamp acquisition and analysis was conducted with pClamp 10 Software (Molecular Devices). Data analysis was performed using SigmaPlot version 12.0 (Systat Software Inc., San Jose, CA, USA).

α-cyclodextrin (α-CD) (≥98%, Sigma-Aldrich), β-cyclodextrin (β-CD) (≥97%, Sigma-Aldrich), γ-cyclodextrin (γ-CD) (≥98%, Sigma-Aldrich), 4-sulfocalix[4]arene sodium salt (SC[4]A) (≥98%, Tokyo Chemical Industry Ltd), ethylenediamine (EDA) (ReagentPlus, ≥99%, Sigma-Aldrich), 1,1′-carbonyldiimidazole (CDI) (≥97%, Sigma-Aldrich), TPC (≥98%, Sigma-Aldrich) and TMC (≥98%, Sigma-Aldrich) were used as received without further purification. Pure chlorophyll a and cannabidiol (CBD) solution (10 mg ml⁻¹ in ethanol) were purchased from Sigma-Aldrich. (+)-Limonene (>99%) was purchased from Tokyo Chemical Industry Ltd. Single crystal silicon wafers (phosphorous doped, (100) polished) from Si-Mat Germany were used as a substrate to deposit the free-standing nanofilms for AFM measurement. PLATYPUS silicon wafers with 100-nm-thick gold coating from Agar Scientific were used to deposit the free-standing nanofilms for X-ray photoemission spectroscopy (XPS) measurements. PAN (230,000 g mol⁻¹) powder was obtained from Goodfellow. All solvents used for phase inversion, interfacial polymerization and nanofiltration experiments were purchased from VWR. Commercial membranes DuraMem500 and DuraMem200 manufactured by Evonik were purchased from Sterlitech.

Standards of the determined substances: acarbose, chlorogenic acid, epicatechin, quercetin, kaempferol, and rutin, were obtained from Sigma-Aldrich (St. Louis, MO, USA).
The reagents used in the conducted studies are as follows: α-D-glucopyranoside (pNPG), α-glucosidase, acarbose, 2,2-Diphenyl-1-picrylhydrazyl, TPTZ (2,4,6-tripyridyl-S-triazine) and Iron (III) chloride hexahydrate (FeCl₃x6H₂O), Folin–Ciocalteu’s phenol reagent, sodium carbonate, 2,4,6-tris(2-pyridyl)-1,3,5-triazine (TPTZ, C₁₈H₁₂N₆), iron(III) chloride hexahydrate (FeCl₃·6H₂O), Trolox, α-cyclodextrin (α-CD), β-cyclodextrin (β-CD), and γ-cyclodextrin (γ-CD) were supplied by Sigma-Aldrich, St. Louis, MO, USA. Methanol, isopropanol, and acetone (Super Purity Solvent, Methanol 215 SPS) were supplied by ROMIL Ltd., Cambridge, England.
High-quality pure and ultra-high-quality pure water were prepared using a Direct-Q 3 UV Merck Millipore (Burlington, MA, USA) purification system.

All chemicals were of analytical grade and applied without further purification. DA, A, NA, l-Trp, l-Tyr, 5-HT, l-DOPA, HVA, VMA, and 1-ethyl-3-methylimidazolium tetrafluoroborate (IL) were purchased from Sigma (St. Louis, MO, USA). MeOH, NH₄OH, ethanol, and acetone were delivered by POCh (Gliwice, Poland). Sodium dodecyl sulfate (SDS) was supplied by Bio-Rad (Hercules, CA, USA). Reagents: PCA, FA, dichloromethane (DCM), α-cyclodextrin (α-CD), and sodium tetraborate decahydrate (borax) were obtained from Merck (Darmstadt, Germany). Capillary Regenerator Basic Wash sodium hydroxide was purchased from Beckman Coulter (Brea, CA, USA). The water used in all experiments was obtained from Milli-Q equipment (Bedford, MA, USA).

HPβCD was purchased from Wacker Chemie, and α-cyclodextrin (αCD) was purchased from Merck KGaA, Darmstadt, Germany. HPβCD and αCD solutions were freshly prepared and dissolved in HEK293T-ACE^hi cell medium (vehicle).