2 8 3h 3 5 cyclic adenosine monophosphate ammonium salt

All chemicals and reagents used and purchased were of analytical quality. Adenosine monophosphate (AMP) was purchased from Alexis Biochemicals (Lörrach, Germany); barium hydroxide octahydrate (Ba(OH)₂·8H₂O), caffeine, cyclic adenosine monophosphate (cAMP), phosphodiesterase (PDE) 3B (recombinant, EC 3.1.4.17), gallic acid, and ascorbic acid from Sigma Aldrich (St. Louis, MO, USA); [2,8-³H]-3′5′-cyclic adenosine monophosphate ammonium salt, 9.25 MBq/mL, from Hartmann Analytic (Braunschweig, Germany). Tris-(hydroxymethyl)-aminomethane (TRIS), and hydrochloric acid were obtained from Carl Roth (Karlsruhe, Germany). The Folin–Ciocalteu reagent, magnesium chloride hexahydrate (MgCl₂·6H₂O), and zinc sulphate heptahydrate (ZnSO₄·7H₂O) were ordered from Merck (Darmstadt, Germany), and dimethyl sulfoxide (DMSO) was obtained from VWR Int. S.A.S. (Darmstadt, Germany). Peonidin-3-glucoside chloride, cyanidin-3-arabinoside chloride, petunidin-3-glucoside chloride, cyanidin-3-glucoside chloride, cyanidin-3-galactoside chloride, malvidin-3-glucoside chloride, cyanidin-3-rutinoside chloride, cyanidin-3,5-diglucoside chloride, and cyanidin chloride were supplied by PhytoLab (Vestenbergsgreuth, Germany).

All the chemicals and reagents used were purchased in analytical quality. The purity of reference substances was >95%. 3,4-dicaffeoylquinic acid (3,4-DiCQA) was available from earlier studies [64 (link)]. The AMP, arbutin, benzamidine, bovine serum albumin (BSA), caffeine, cAMP, formic acid, [6]-gingerol, luteolin-7-O-glucuronide, 3,4,5-trimethoxycinnamic acid and XAD16N materials were purchased from Sigma Aldrich (Taufkirchen, Germany); apigenin, luteolin and luteolin-7-O-glucoside from Extrasynthese (Genay Cedex, France); leupeptin, pepstatin A and phenylmethylsulfonyl fluoride from Alexis Biochemicals (Loerrach, Germany); rolipram from Calbiochem (La Jolla, CA, USA); and [2,8-³H]-3′5′-cyclic adenosine monophosphate ammonium salt, 9.25 MBq/mL, from Hartmann Analytic (Braunschweig, Germany). The LXFL529L cell line was kindly provided by Prof. Fiebig (Freiburg, Germany).