Butyrylcholinesterase (BChE) inhibitors were identified from a collection containing cinchonine, cinchonidine and synthetic derivatives, and further characterized using cytotoxicity and molecular docking studies. The most active ones were: (10≡)-10,11-dibromo-10,11-dihydrocinchonidine (11), a competitive inhibitor with Ki, = 3.45±0.39 μM, and IC50 BChE = 9.83±0.30 μM/human (h)BChE = 34.47±4.63 and O-(trimethylsilyl)cinchonine (15), a mixed inhibitor with Kiuc = 1.73±0.46 μM and Kic = 0.85±0.26 μM, and IC50 BChE = 0.56±0.14 μM / hBChE = 0.24±0.04. In cytotoxicity experiments, ≥80% of the cells remained viable when exposed to concentrations of up to 80 μM of both inhibitors in four different cell lines, including neurons. Due to the bulkier trimethylsilyl side group of 15, it covered the active site of hBChE better than 11 with an OH-group while not being able to fit into the active site gorge of hAChE, thus explaining the selectivity of 15 towards hBChE.
van MarumRJ. (2008) Current and future therapy in Alzheimer's disease. Fundamental & Clinical Pharmacology, 22, 265–274.
2.
ArendtT, BrucknerMK, LangeM, BiglV. (1992) Changes in acetylcholinesterase and butyrylcholinesterase in Alzheimer's disease resemble embryonic development—a study of molecular forms. Neurochemistry International, 21, 381–396.
3.
KamalMA, KleinP, LuoW, LiY, HollowayHW, TweedieD, GreigNH. (2008) Kinetics of human serum butyrylcholinesterase inhibition by a novel experimental Alzheimer therapeutic, dihydrobenzodioxepine cymserine. Neurochemical Research, 33, 745–753.
4.
PodolyE, ShalevDE, Shenhar-TsarfatyS, BennettER, Ben AssayagE, WilgusH, LivnahO, SoreqH. (2009) The butyrylcholinesterase K variant confers structurally derived risks for Alzheimer pathology. Journal of Biological Chemistry, 284, 17170–17179.
5.
GreigNH, UtsukiT, IngramDK, WangY, PepeuG, ScaliC, YuQS, MamczarzJ, HollowayHW, GiordanoT, ChenD, FurukawaK, SambamurtiK, BrossiA, LahiriDK. (2005) Selective butyrylcholinesterase inhibition elevates brain acetylcholine, augments learning and lowers Alzheimer beta-amyloid peptide in rodent. Proceedings of the National Academy of Sciences of the United States of America, 102, 17213–17218.
6.
WillcoxM. (2011) Improved traditional phytomedicines in current use for the clinical treatment of malaria. Planta Medica, 77, 662–671.
7.
ChemnitiusJM, HaselmeyerKH, GonskaBD, KreuzerH, ZechR. (1997) Mipafox differential inhibition assay for heart muscle cholinesterases: substrate specificity and inhibition of three isoenzymes by physostigmine and quinidine. General Pharmacology: The Vascular System, 28, 567–575.
8.
KambamJR, FranksJJ, SmithBE. (1987) Inhibitory effect of quinidine on plasma pseudocholinesterase activity in pregnant women. American Journal of Obstetrics and Gynecology, 157, 897–899
9.
BrunhoferG, FallareroA, KarlssonD, Batista-GonzalezA, ShindeP, MohanCG, VuorelaP. (2012) Exploration of natural compounds as sources of new bifunctional scaffolds targeting cholinesterases and beta amyloid aggregation: The case of chelerythrine. Bioorganic & Medicinal Chemistry, 20, 6669–6679
10.
SkogmanME, KujalaJ, BusyginI, LeinobR, VuorelaPM, FallareroA. (2012) Evaluation of antibacterial and anti-biofilm activities of cinchona alkaloid derivatives against Staphylococcus aureus. Natural Product Communications, 7, 1173–1176
11.
ThomsenT, KadenB, FischerJP, BickelU, BarzH, GusztonyG, Cervos-NavarroJ, KewitzH. (1991) Inhibition of acetylcholinesterase activity in human brain tissue and erythrocytes by galanthamine, physostigmine and tacrine. European Journal of Clinical Chemistry and Clinical Biochemistry, 29, 487–492
12.
KhoranaN, ChangwichitK, IngkaninanK, UtsintongM. (2012) Prospective acetylcholinesterase inhibitory activity of indole and its analogs. Bioorganic & Medicinal Chemistry Letters, 22, 2885–2888.
13.
MellonPL, WindleJJ, GoldsmithPC, PadulaCA, RobertsJL, WeinerRI. (1990) Immortalization of hypothalamic GnRH neurons by genetically targeted tumorigenesis. Neuron, 5, 1–10
14.
KarlssonD, FallareroA, BrunhoferG, MayerC, PrakashO, MohanCG, VuorelaP, ErkerT. (2012) The exploration of thienothiazines as selective butyrylcholinesterase inhibitors. European Journal of Pharmaceutical Sciences, 47, 190–205.
15.
JarvinenP, VuorelaP, HatakkaA, FallareroA. (2011) Potency determinations of acetylcholinesterase inhibitors using Ellman's reaction-based assay in screening: Effect of assay variants. Analytical Biochemistry, 408, 166–168
16.
RishtonGM. (2003) Nonleadlikeness and leadlikeness in biochemical screening. Drug Discovery Today, 8, 86–96
17.
RosénJ, LövgrenA, KogejT, MuresanS, GottfriesJ, BacklundA. (2009) ChemGPS-NP(Web): chemical space navigation online. Journal of Computer-Aided Molecular Design, 23, 253–259
18.
LarssonJ, GottfriesJ, MuresanS, BacklundA. (2007) ChemGPS-NP: tuned for navigation in biologically relevant chemical space. Journal of Natural Products, 70, 789–794.
19.
NawazSA, AyazM, BrandtW, WessjohannLA, WestermannB. (2011) Cation-π and π-π stacking interactions allow selective inhibition of butyrylcholinesterase by modified quinine and cinchonidine alkaloids. Biochemical and Biophysical Research Communications, 404, 935–940.
20.
KarlssonD, FallareroA, BrunhoferG, GuzikP, PrinzM, HolzgrabeU, ErkerT, VuorelaP. (2012) Identification and characterization of diarylimi-dazoles as hybrid inhibitors of butyrylcholinesterase and amyloid beta fibril formation. European Journal of Pharmaceutical Sciences, 45, 169–183.
21.
NicoletY, LockridgeO, MassonP, Fontecilla-CampsJ, NachonF. (2003) Crystal structure of human butyrylcholinesterase and of its complexes with substrate and products. Journal of Biological Chemistry, 278, 41141–41147
22.
CheungJ, RudolphMJ, BurshteynF, CassidyMS, GaryEN, LoveJ, FranklinMC, HeightJJ. (2012) Structures of human acetylcholinesterase in complex with pharmacologically important ligands. Journal of Medicinal Chemistry, 55, 10282–10286
23.
BrajeWM, FrackenpohlJ, SchrakeO, WartchowR, BeilW, HoffmannHMR. (2000) Synthesis of 10,11-didehydro Cinchona alkaloids and key derivatives. Helvetica Chimica Acta, 83, 777–792
24.
BlaserH, JalettH, LottenbachW, StuderM. (2000) Heterogeneous enantioselective hydrogenation of ethyl pyruvate catalyzed by cinchona-modified Pt catalyst: effect of modifier structure. Journal of the American Chemical Society, 122, 12675–12682.
25.
BusyginI, NieminenV, TaskinenA, SinkkonenJ, ToukoniittyE, SillanpääR, MurzinDY, LeinoR. (2008) A combined NMR, DFT, and X-ray investigation of some cinchona alkaloid O-ethers. Journal of Organic Chemistry, 73, 6559–6569
26.
EllmanG, CourtneyK, AndresVJ, Feather-StoneR. (1961) A new and rapid colorimetric determination of acetylcholinesterase activity. Biochemical Pharmacology, 7, 88–95.
27.
Schrödinger Suite 2011 Protein Preparation Wizard; Epik version 2.2, Ligprep 2.5, Glide 5.7. LLC, New York, NY; 2011.
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