Doutoramento em Bioquímica
Bichemical mechanisms and target drugs in neurodegenerative diseases
Patrícia Bacalhau

Orientação:  Maria do Rosário Martins & Ana Teresa Caldeira & Anthony Joseph Burke

Neurodegenerative diseases, namely Alzheimer’s and Parkinson’s diseases are a major challenge for medicine and public health due to their prevalence in developed countries. Thus, the research for therapies for neurodegenerative diseases, such as Parkinson’s and Alzheimer’s diseases, should be based on understanding their molecular and biochemical pathogenesis.The research conducted in this thesis involves screening of different families of compounds (isoquinolinones, azepanones, indolinones, diether-esters, chromanones, chromanols and rivastigmine derivatives) based on their ability to inhibit the activity of the therapeutic targets acetylcholinesterase, butyrylcholinesterase and monoamine oxidase B. These targets were chosen for their importance in the neuropathology of Alzheimer’s and Parkinson’s diseases. The most promising compounds were then selected, and the determination of their action at the molecular level was studied via STD-NMR. These studies allow us to understand the importance of different functionalities within the inhibitor molecule on the inhibition of the selected targets, and thus direct the investigation in the sense of developing compounds that can be better inhibitors. Toxicological and pharmacological evaluation of the most promising synthesized compounds was performed using two different biological models, A. salina and Swiss mouse model. Compound 4-((3-hydroxy-2-oxo-3-phenylindolin-1-yl)methyl)piperidin-1-ium chloride was tested ex vivo against hepatic AChE and BuChE, showing IC50 values of 594.64 μM and 434.51 μM, respectively. This compound was also assayed in vivo after intraperitoneal administration of 3 mg kg-1 and 6 mg kg-1 in Swiss mice, using donepezil (3 mg kg-1) as a benchmark. This synthetic compound gave better brain AChE inhibition than donepezil, indicating that this compound might have a similar brain uptake mechanism to that of donepezil.

Neurodegenerative diseases, namely Alzheimer’s and Parkinson’s diseases are a major challenge for medicine and public health due to their prevalence in developed countries. Thus, the research for therapies for neurodegenerative diseases, such as Parkinson’s and Alzheimer’s diseases, should be based on understanding their molecular and biochemical pathogenesis.The research conducted in this thesis involves screening of different families of compounds (isoquinolinones, azepanones, indolinones, diether-esters, chromanones, chromanols and rivastigmine derivatives) based on their ability to inhibit the activity of the therapeutic targets acetylcholinesterase, butyrylcholinesterase and monoamine oxidase B. These targets were chosen for their importance in the neuropathology of Alzheimer’s and Parkinson’s diseases. The most promising compounds were then selected, and the determination of their action at the molecular level was studied via STD-NMR. These studies allow us to understand the importance of different functionalities within the inhibitor molecule on the inhibition of the selected targets, and thus direct the investigation in the sense of developing compounds that can be better inhibitors. Toxicological and pharmacological evaluation of the most promising synthesized compounds was performed using two different biological models, A. salina and Swiss mouse model. Compound 4-((3-hydroxy-2-oxo-3-phenylindolin-1-yl)methyl)piperidin-1-ium chloride was tested ex vivo against hepatic AChE and BuChE, showing IC50 values of 594.64 μM and 434.51 μM, respectively. This compound was also assayed in vivo after intraperitoneal administration of 3 mg kg-1 and 6 mg kg-1 in Swiss mice, using donepezil (3 mg kg-1) as a benchmark. This synthetic compound gave better brain AChE inhibition than donepezil, indicating that this compound might have a similar brain uptake mechanism to that of donepezil.

Key words: Alzheimer, Parkinson, acetylcholinesterase, butyrylcholinesterase, monoamine oxidase B, spectrometry, flourometry, STD-NMR, inhibitors.