Journal of Medicinal Chemistry, 2008, Vol. 51, No. 7 2031 Gly 1a277 TYr 33 His 4 -Asp 74 33l288 115 如 48 b d Ligand bond His 53 Non-hgand residues involved in hydrophobic Non-lisand bond Om contact(s) ●-● Hvdrogen bond and its length Figure 4. Representation of 5h colored green) docked into the binding sites of mAChe (a) and hbChe (c). The binding site surfaces are colored according to the vacuum statics protein contact potential, calculated by PyMoL 0.99rc2(DeLano Scientific LLC, San Carlos, CA) Crucial catalytic and peripheral he counterpart)residues are colored yellow. Hydrogen bonds and hydrophobic contacts between 5h and the rotein residues of mAChE (b) I site (or the ChE(d)are shown by Lig Plot 4.4.2. 41 aggregation. These findings agree with the results from enzy-(--)-nor-MEPs 5. Their AChE inhibitory activities were closely natic test and molecular docking, which indicated that a linker related to the length of the alkylene chain, whereas BChE of 9 or 10 methylenes would help to reach the peripheral site inhibition was less influenced. The optimal chain length for of achE AChE and BChE inhibition was achieved with 9 in 5h. which Cell Viability. The toxicity of the most po ent two bis 9(-) showed a 10000-fold and 1500-fold increase in the inhibition nor an neuroblastoma cell line of mice brain AChE and mice serum BChE, respectively SH-SY5Y. Cell viability was not affected for 5h and 5i at compared with(-)-MEP. Molecular docking elucidated that Sh concentrations of 1-100 uM(higher than the ICso values of 5h simultaneously bound to the catalytic and peripheral sites via and 5i against B-amyloid aggregation inhibition(around 80 uM) hydrophobic interactions with Trp86 and Trp286 in mAChE. and 10000 times higher than their AChE inhibiting ICso values) In comparison, it folded in the large aliphatic cavity of hBChE Conclusion The differences were explained by the absence of peripheral We have discovered novel nanomolar ChE inhibitors with site and the enlargement of the active site gorge in BChE h inhibitory potency on AB aggregation, i.e., a series of bis- Furthermore, 5h and 5i markedly prevented the AChE-inducedaggregation. These findings agree with the results from enzy￾matic test and molecular docking, which indicated that a linker of 9 or 10 methylenes would help to reach the peripheral site of AChE. Cell Viability. The toxicity of the most potent two bis-(-)- nor-MEPs was determined in human neuroblastoma cell line SH-SY5Y. Cell viability was not affected for 5h and 5i at concentrations of 1–100 µM (higher than the IC50 values of 5h and 5i against
-amyloid aggregation inhibition (around 80 µM) and 10000 times higher than their AChE inhibiting IC50 values). Conclusion We have discovered novel nanomolar ChE inhibitors with high inhibitory potency on A
aggregation, i.e., a series of bis- (-)-nor-MEPs 5. Their AChE inhibitory activities were closely related to the length of the alkylene chain, whereas BChE inhibition was less influenced. The optimal chain length for AChE and BChE inhibition was achieved with 9 in 5h, which showed a 10000-fold and 1500-fold increase in the inhibition of mice brain AChE and mice serum BChE, respectively, compared with (-)-MEP. Molecular docking elucidated that 5h simultaneously bound to the catalytic and peripheral sites via hydrophobic interactions with Trp86 and Trp286 in mAChE. In comparison, it folded in the large aliphatic cavity of hBChE. The differences were explained by the absence of peripheral site and the enlargement of the active site gorge in BChE. Furthermore, 5h and 5i markedly prevented the AChE-induced Figure 4. Representation of 5h (C atoms colored green) docked into the binding sites of mAChE (a) and hBChE (c). The binding site surfaces are colored according to the vacuum electrostatics protein contact potential, calculated by PyMOL 0.99rc2 (DeLano Scientific LLC, San Carlos, CA). Crucial catalytic and peripheral site (or the counterpart) residues are colored yellow. Hydrogen bonds and hydrophobic contacts between 5h and the protein residues of mAChE (b) and hBChE (d) are shown by LigPlot 4.4.2.41 Bis-(-)-nor-meptazinols as Inhibitors Journal of Medicinal Chemistry, 2008, Vol. 51, No. 7 2031