title: Synthesis, biological activity and HPLC validation of 1,2,3,4-tetrahydroacridine derivatives as acetylcholinesterase inhibitors.
abstract: The synthesis and biochemical evaluation of new hybrids of tacrine (THA) and 4-fluorobenzoic acid (4-FBA) possessing activity towards acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) inhibition are presented. The compounds of interest were obtained from the reaction of activated 4-FBA and diamino derivatives of 1,2,3,4-tetrahydroacridine. The compounds C6-2KW/HCl, C6-4KW/HCl and C6-3KW/HCl have four-fold higher antiacetylcholinesterase activity than THA. All of the acquired compounds present higher selectivity towards AChE than THA and lower selectivity towards BuChE. In addition, a rapid, selective and stability-indicating HPLC method was developed and validated for the determination of C6-2KW/HCl, C6-3KW/HCl and C6-4KW/HCl. THA and 4-FBA were found to be the main impurities. Chromatographic separation was achieved isocratically on a Waters Symmetry C18 150 × 3.9 mm, 4 μm column with a mobile phase of acetonitrile/buffer (17 mM sodium dodecyl sulphate and 8.3 mM sodium dihydrogen phosphate, 50:50 v/v) (overall pH 4). A 1.5 ml/min flow rate and a 247 nm wavelength were chosen for this method. C6-2KW/HCl, C6-3KW/HCl and C6-4KW/HCl were subjected to acidic and basic hydrolysis, chemical oxidation, thermal exposition at 60 °C and intense UV light. The limits of detection (LOD) and quantification (LOQ) were less than 2 μg/ml and 6 μg/ml for C6-2KW/HCl, C6-3KW/HCl and C6-4KW/HCl, 0.04 μg/ml and 0.12 μg/ml for THA, 0.42 μg/ml and 1.41 μg/ml for 4-FBA, respectively.
authors.affiliation: Medical University, Department of Pharmaceutical Chemistry and Drug Analyses, ul. Muszyńskiego 1, 90-151 Lodz, Poland. pawel.szymanski@umed.lodz.pl
authors.forename: Paweł
authors.initials: P
authors.lastname: Szymanski
authors.forename: Adam
authors.initials: A
authors.lastname: Karpiński
authors.forename: Elzbieta
authors.initials: E
authors.lastname: Mikiciuk-Olasik
mesh_terms: D000110:Acetylcholinesterase / Q000378:metabolism*; D000166:Acridines / Q000138:chemical synthesis / Q000494:pharmacology; D000544:Alzheimer Disease / Q000188:drug therapy / Q000503:physiopathology; D001565:Benzoates / Q000737:chemistry; D002091:Butyrylcholinesterase / Q000378:metabolism*; D002800:Cholinesterase Inhibitors / Q000138:chemical synthesis / Q000494:pharmacology; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004355:Drug Stability; D004789:Enzyme Activation / Q000187:drug effects*; D006801:Humans; D006868:Hydrolysis; D007700:Kinetics; D057230:Limit of Detection; D010084:Oxidation-Reduction; D012680:Sensitivity and Specificity; D017550:Spectroscopy, Fourier Transform Infrared; D013329:Structure-Activity Relationship; D013619:Tacrine / Q000737:chemistry
chemical_list: D000166:Acridines; D001565:Benzoates; D002800:Cholinesterase Inhibitors; D013619:Tacrine; D000110:Acetylcholinesterase; D002091:Butyrylcholinesterase; C022893:4-fluorobenzoic acid