Quercetin dihydrate

Ammonium formate, 98% crystalline (Alfa Aesar, United States), EDTA ≥ 98.5% w/w (Sigma-Aldrich, United States), methanol HPLC-grade (Thermo Fisher Scientific, United States), ultrapure grade water purified to 18.1 MΩ⋅cm using a Barnstead water filtration system (Thermo Fisher Scientific, United States), potato starch (Sigma; 102954), and quercetin dihydrate, 97% w/w (Alfa Aesar, United States).

Kyoto Green was synthesized following the procedure described in Ojida et al.^{23 (link)}. Magnesium chloride (MgCl₂), zinc nitrate (Zn(NO₃)₂), HEPES minimum 99.5% titration (C₈H₁₈N₂O₄S), p-nitrophynyl thymidine 5′-monophosphate (pNph-5′-TMP), sodium pyrophosphate decahydrate (NaPPi), adenosine 5′-triphosphate disodium salt (ATP), and adenosine 5′-monophosphate disodium salt (AMP) were products of Sigma-Aldrich (St. Louis, MO, USA) or Merck (Darmstadt, Germany). Cordycepin, uridine, cytidine, inosine, thymidine, kaempferol, 2′-deoxyadenosine, 2′-deoxyinosine, 2′-deoxyuridine, and 2′-deoxyguanosine were purchased from Fujifilm Wako Pure Chemical Corporation (Japan). Myricetin, quercetin dihydrate and guanosine were commercially available from Alfa Aesar (UK). Recombinant human ENPP1 was purchased from R&D systems (Minneapolis, USA).