Jia-Jia Wu

Design, synthesis and biological evaluation of novel donepezil–coumarin hybrids as multi-target agents for the treatment of Alzheimer’s disease

Combining N-benzylpiperidine moiety of donepezil and coumarin into in a single molecule, novel hybrids with ChE and MAO-B inhibitory activity were designed and synthesized. The biological screening results indicated that most of compounds displayed potent inhibitory activity for AChE and BuChE, and clearly selective inhibition to MAO-B. Of these compounds, 5m was the most potent inhibitor for eeAChE and eqBuChE (0.87 μM and 0.93 μM, respectively), and it was also a good and balanced inhibitor to hChEs and hMAO-B (1.37 μM for hAChE; 1.98 μM for hBuChE; 2.62 μM for hMAO-B). Molecular modeling and kinetic studies revealed that 5m was a mixed-type inhibitor, which bond simultaneously to CAS, PAS and mid-gorge site of AChE, and it was also a competitive inhibitor, which occupied the active site of MAO-B. In addition, 5m showed good ability to cross the BBB and had no toxicity on SH-SY5Y neuroblastoma cells. Collectively, all these results suggested that 5m might be a promising multi-target lead candidate worthy of further pursuit.

Synthesis and evaluation of multi-target-directed ligands for the treatment of Alzheimer’s disease based on the fusion of donepezil and melatonin

A novel series of compounds obtained by fusing the acetylcholinesterase (AChE) inhibitor donepezil and the antioxidant melatonin were designed as multi-target-directed ligands for the treatment of Alzheimers disease (AD). In vitro assay indicated that most of the target compounds exhibited a significant ability to inhibit acetylcholinesterase (eeAChE and hAChE), butyrylcholinesterase (eqBuChE and hBuChE), and β-amyloid (Aβ) aggregation, and to act as potential antioxidants and biometal chelators. Especially, 4u displayed a good inhibition of AChE (IC50 value of 193nM for eeAChE and 273nM for hAChE), strong inhibition of BuChE (IC50 value of 73nM for eqBuChE and 56nM for hBuChE), moderate inhibition of Aβ aggregation (56.3% at 20μM) and good antioxidant activity (3.28trolox equivalent by ORAC assay). Molecular modeling studies in combination with kinetic analysis revealed that 4u was a mixed-type inhibitor, binding simultaneously to catalytic anionic site (CAS) and the peripheral anionic site (PAS) of AChE. In addition, 4u could chelate metal ions, reduce PC12 cells death induced by oxidative stress and penetrate the blood-brain barrier (BBB). Taken together, these results strongly indicated the hybridization approach is an efficient strategy to identify novel scaffolds with desired bioactivities, and further optimization of 4u may be helpful to develop more potent lead compound for AD treatment.

Synthesis and evaluation of donepezil–ferulic acid hybrids as multi-target-directed ligands against Alzheimer's disease

A novel family of donepezil–ferulic acid hybrids were designed, synthesized and biologically evaluated as multi-target-directed ligands against Alzheimers disease by fusing a fragment of donepezil and ferulic acid. The in vitro assay indicated that some of these molecules exhibited potent cholinesterase inhibitory activities, outstanding radical scavenging activities and good neuroprotective effects on PC12 cells, and could penetrate into the central nervous system. Compound 5c especially showed moderate acetylcholinesterase inhibitory activity (IC50 values of 0.398 μM for electric eel acetylcholinesterase) and butyrylcholinesterase inhibitory activity (IC50 = 0.976 μM for equine serum butyrylcholinesterase). It also showed significant antioxidant activity (1.78 trolox equivalents by the ABTS method, IC50 values of 24.9 μM by the DPPH method). The kinetic study and molecular docking indicated that compound 5c interacted with both the peripheral anionic site and the catalytic binding site of acetylcholinesterase. Overall, these results indicated that compound 5c is a promising drug candidate with balanced properties for the treatment of Alzheimers disease.

Synthesis and pharmacological evaluation of novel chromone derivatives as balanced multifunctional agents against Alzheimer's disease

In a continuing effort to develop multitargeted compounds as potential treatment agents against Alzheimers disease (AD), a series of chromone derivatives were designed, synthesized and evaluated. In vitro assay indicated that most of the target compounds have both MAOs inhibition activities, antioxidant activity and biometal chelating ability. Especially, compound s19 exhibits good inhibitory potency for inhibition of MAOs (IC50 value of 5.12μM for hMAO-A and 0.816μM for hMAO-B), moderate inhibition of Aβ aggregation (75.1% at 20μM), metal chelation, control of ROS generation and antioxidant activity (ORAC=3.62). In addition, s19 could reduce PC12 cells death induced by oxidative stress and penetrate the blood-brain barrier (BBB). Taken together, these results suggested that s19 might be a promising multitargeted compound for AD treatment.

Synthesis and pharmacological evaluation of donepezil-based agents as new cholinesterase/monoamine oxidase inhibitors for the potential application against Alzheimer’s disease

Abstract In a continuing effort to develop multitargeted compounds as potential treatment agents against Alzheimers disease (AD), a series of donepezil-like compounds were designed, synthesized and evaluated. In vitro studies showed that most of the designed compounds displayed potent inhibitory activities toward AChE, BuChE, MAO-B and MAO-A. Among them, w18 was a promising agent with balanced activities, which exhibited a moderate cholinesterase inhibition (IC50, 0.220 μM for eeAChE; 1.23 μM for eqBuChE; 0.454 μM for hAChE) and an acceptable inhibitory activity against monoamine oxidases (IC50, 3.14 μM for MAO-B; 13.4 μM for MAO-A). Moreover, w18 could also be a metal-chelator, and able to cross the blood–brain barrier with low cell toxicity on PC12 cells. Taken together, these results suggested that w18 might be a promising multitargeted compound for AD treatment.

Multifunctional 3-Schiff base-4-hydroxycoumarin derivatives with monoamine oxidase inhibition, anti-β-amyloid aggregation, metal chelation, antioxidant and neuroprotection properties against Alzheimer's disease

A series of 3-Schiff base-4-hydroxycoumarin derivatives (1–20) have been designed, synthesized and evaluated as multifunctional agents against Alzheimers disease. In vitro studies indicated that most of the derivatives exhibited significant abilities to inhibit monoamine oxidase (MAO), self-induced and Cu2+-induced β-amyloid (Aβ1–42) aggregati006Fn, as well acting as potential biometal chelators and antioxidants. Moreover, these derivatives were capable of decreasing reactive oxygen species (ROS) and showed good neuroprotective effects in PC12 cells and could penetrate the central nervous system (CNS). In particular, compound 4 exhibited high potency to monoamine oxidase (IC50, 0.673 μM for hMAO-A, 0.711 μM for hMAO-B), good antioxidant activity (1.34 trolox equivalents by ABTS method, 45.8 μM of IC50 by DPPH method), and it also displayed a significant ability to inhibit self-induced and Cu2+-induced Aβ1–42 aggregation (60.1%, 20 μM and 45.7%, 50 μM). Taken together, these results suggested that compound 4 might be a promising lead compound with balanced properties for AD treatment.

Novel 8-hydroxyquinoline derivatives targeting β-amyloid aggregation, metal chelation and oxidative stress against Alzheimer’s disease

A series of multitargeted 8-hydroxyquinoline derivatives were designed and synthesized for the treatment of Alzheimers disease (AD). In vitro studies indicated that most of the prepared compounds exhibited significant inhibitory effects against self-induced Aβ1-42 aggregation and potential antioxidant properties especially compound 5b (IC50 = 5.64 μM for self-induced Aβ aggregation; the oxygen radical absorbance capacity using fluorescein (ORAC-FL) value is 2.63 Trolox equivalents). Notably, 5b can chelate biometals and inhibit Cu2+/Zn2+-induced Aβ1-42 aggregation. The cell assays showed that 5b had excellent protective effects against oxidative toxin H2O2 and presented low neurotoxicity in PC12 cells. Furthermore, 5b could penetrate the blood-brain barrier (BBB) in vitro and did not show any acute toxicity in mice at doses up to 2000 mg/kg in vivo. Our findings provide a rationale for the potential application of compound 5b as a lead compound in AD therapy.

Rational Design and Multibiological Profiling of Novel Donepezil–Trolox Hybrids against Alzheimer’s Disease, with Cholinergic, Antioxidant, Neuroprotective, and Cognition Enhancing Properties

A novel series of donepezil-trolox hybrids were designed, synthesized, and evaluated as multifunctional ligands against Alzheimers disease (AD). Biological assays showed that these derivatives possessed moderate to good inhibitory activities against acetylcholinesterase (AChE) and monoamine oxidase B (MAO-B) as well as remarkable antioxidant effects. The optimal compound 6d exhibited balanced functions with good inhibition against hAChE (IC50 = 0.54 μM) and hMAO-B (IC50 = 4.3 μM), significant antioxidant activity (41.33 μM IC50 by DPPH method, 1.72 and 1.79 trolox equivalent by ABTS and ORAC methods), excellent copper chelation, and Aβ1-42 aggregation inhibition effect. Furthermore, cellular tests indicated that 6d has very low toxicity and is capable of combating oxidative toxin (H2O2, rotenone, and oligomycin-A) induced neurotoxicity. Most importantly, oral administration of 6d demonstrated notable improvements on cognition and spatial memory against scopolamine-induced acute memory deficit as well as d-galactose (d-gal) and AlCl3 induced chronic oxidative stress in a mouse model without acute toxicity and hepatotoxicity. In summary, both in vitro and in vivo results suggested that 6d is a valuable candidate for the development of a safe and effective anti-Alzheimers drug.

Neuroprotective effects of benzyloxy substituted small molecule monoamine oxidase B inhibitors in Parkinson's disease.

The benzyloxy substituted small molecules are well-known highly potent monoamine oxidase B inhibitors, but their therapeutic potential against Parkinsons disease have not been investigated in detail. In this paper, a series of representative benzyloxy substituted derivatives were synthesized and evaluated for MAO-A/B inhibition. In addition, their neuroprotective effects were investigated in 6-OHDA- and rotenone-treated PC12 cells. It was observed that most of the compounds exhibited a marked increase in survival of PC12 cells which treated with the neurotoxins. Among them, 13 exhibited remarkable and balanced neuroprotective potency. The protective effects of 13 against neurotoxins-induced apoptosis were confirmed with flow cytometry and staining methods. Furthermore, 13 also showed good BBB permeability and low toxicity according to in vitro BBB prediction and in vivo acute toxicity test. The results indicated that 13 is an effective and promising candidate to be further developed as disease-modifying drug for Parkinsons disease therapy.