A set of 25 novel, silicon-based carbamate derivatives as potential acetyl- and butyrylcholinesterase (AChE/BChE) inhibitors was synthesized and characterized by their in vitro inhibition profiles and the selectivity indexes (SIs). The prepared compounds were also tested for their inhibition potential on photosynthetic electron transport (PET) in spinach (Spinacia oleracea L.) chloroplasts. In fact, some of the newly prepared molecules revealed comparable or even better inhibitory activities compared to the marketed drugs (rivastigmine or galanthamine) and commercially applied pesticide Diuron®, respectively. Generally, most compounds exhibited better inhibition potency towards AChE; however, a wider activity span was observed for BChE. Notably, benzyl N-[(1S)-2-[(tert-butyldimethylsilyl)oxy]-1-[(2-hydroxyphenyl)carbamoyl]ethyl]-carbamate (2) and benzyl N-[(1S)-2-[(tert-butyldimethylsilyl)oxy]-1-[(3-hydroxyphenyl)carbamoyl]ethyl]-carbamate (3) were characterized by fairly high selective indexes. Specifically, compound 2 was prescribed with the lowest IC50 value that corresponds quite well with galanthamine inhibition activity, while the inhibitory profiles of molecules 3 and benzyl-N-[(1S)-2-[(tert-butyldimethylsilyl)oxy]-1-[(4-hydroxyphenyl)carbamoyl]ethyl]carbamate (4) are in line with rivastigmine activity. Moreover, a structure-activity relationship (SAR)-driven similarity evaluation of the physicochemical properties for the carbamates examined appeared to have foreseen the activity cliffs using a similarity-activity landscape index for BChE inhibitory response values. The 'indirect' ligand-based and 'direct' protein-mediated in silico approaches were applied to specify electronic/steric/lipophilic factors that are potentially valid for quantitative (Q)SAR modeling of the carbamate analogues. The stochastic model validation was used to generate an 'average' 3D-QSAR pharmacophore pattern. Finally, the target-oriented molecular docking was employed to (re)arrange the spatial distribution of the ligand property space for BChE and photosystem II (PSII).

Department of Biological and Biochemical Sciences Faculty of Chemical Technology University of Pardubice Studentska 573 532 10 Pardubice Czech Republic

Department of Chemical Drugs Faculty of Pharmacy University of Veterinary and Pharmaceutical Sciences Palackeho 1 612 42 Brno Czech Republic

Department of Energy Saving and Air Protection Central Mining Institute Plac Gwarkow 1 40 166 Katowice Poland

Department of Molecular Biology and Pharmaceutical Biotechnology Faculty of Pharmacy University of Veterinary and Pharmaceutical Sciences Palackeho 1 612 42 Brno Czech Republic

Division of Biologically Active Complexes and Molecular Magnets Regional Centre of Advanced Technologies and Materials Faculty of Science Palacky University Slechtitelu 27 783 71 Olomouc Czech Republic

Global Change Research Institute CAS Belidla 986 4a 60300 Brno Czech Republic

Institute of Chemistry University of Silesia Szkolna 9 40 007 Katowice Poland

Institute of Organic Chemistry and Technology Faculty of Chemical Technology University of Pardubice Studentska 573 532 10 Pardubice Czech Republic

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