Clindamycin phosphate

Clindamycin phosphate, Penicillin/Streptomycin (P/S), 0.25% trypsin/EDTA, Veratrine alkaloid, RPMI-1640, Fetal bovine serum (FBS), Bismuth III nitrate, atropine, quercetin, andrographolide, Folin-Ciocalteus, and MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) reagents were purchased from Sigma Aldrich, USA. Other chemicals such as dimethyl sulphoxide (DMSO), bromocresol green, and gallic acid were purchased from Biobasic, Canada, while absolute ethanol was from VWR Chemicals, France.

Native human AAG (#SLCD7253) and drug compounds (clindamycin phosphate, diltiazem hydrochloride and lidocaine) were purchased from Sigma–Aldrich (Darmstadt, Germany). Warfarin sodium salt was a gift from the Department of Medicinal Chemistry, Faculty of Pharmacy and Biochemistry, Zagreb, Croatia. All chemicals were used without further purification. Immobilized SialEXO^® (derived from Akkermansia muciniphilla and expressed in E. Coli) was obtained from Smart Enzymes™ Genovis (Lund, Sweden), and HEPES buffer was obtained from VWR International (Leuven, Belgium). All other reagents were of analytical grade or better. All solutions were prepared immediately before the experiments in order to minimize contamination and/or impair the stability of solutions. The solutions for microcalorimetric titrations were prepared in 25 mM HEPES at pH 7.40 containing 150 mM NaCl (Kemika, Zagreb, Croatia), using doubly distilled water and 5 M NaOH (Kemika, Zagreb, Croatia) for adjusting the pH value. AAG and drug solutions were prepared by dissolving the appropriate amount of solid in the given solvent.