Novel inhibitors of cholinesterases, especially butyrylcholinesterase (BuChE), were obtained by coupling melatonin-tacrine heterodimers via the carbamate bond. Compounds 14a-i possessed potent cholinesterase inhibitory activity (with IC50 values as low as 1.18 nM for acetylcholinesterase (AChE) and 0.24 nM for butyrylcholinesterase (BuChE)). These heterodimers exhibit selectivity toward BuChE, being from 4- to 256-fold more active toward BuChE than AChE, but still acting as better AChE inhibitors than tacrine 4.

Isoprenoids, as common constituents of all living cells, are exposed to oxidative agents—reactive oxygen species, for example, singlet oxygen or hydroxyl radicals. Despite this fact, products of oxidation of polyisoprenoids have never been characterized. In this study, chemical oxidation of isoprenoid alcohols (Prenol-2 and -10) was performed using singlet oxygen (generated in the presence of hydrogen peroxide/molybdate or upon photochemical reaction in the presence of porphyrin), oxygen (formed upon hydrogen peroxide dismutation) or hydroxyl radical (generated by the hydrogen peroxide/sonication, UV/titanium dioxide or UV/hydrogen peroxide) systems. The structure of the obtained products, hydroxy-, peroxy- and heterocyclic derivatives, was studied with the aid of mass spectrometry (MS) and nuclear magnetic resonance (NMR) methods. Furthermore, mass spectrometry with electrospray ionization appeared to be a useful analytical tool to detect the products of oxidation of isoprenoids (ESI–MS analysis), as well as to establish their structure on the basis of the fragmentation spectra of selected ions (ESI–MS/MS analysis). Taken together, susceptibility of polyisoprenoid alcohols to various oxidizing agents was shown for the first time.Electronic supplementary materialThe online version of this article (doi:10.1007/s11745-015-4104-y) contains supplementary material, which is available to authorized users.

Adenosine is the key immunometabolite responsible for immune tolerance in tumors. It is present in normal tissue in low concentrations, having various physiological functions. In the tumor, its concentration increases rapidly, as a result of overexpression of enzymes producing adenosine, additionally enhanced by hypoxia and inflammation. Adenosine inhibits the biological functions of T lymphocytes infiltrating the cancer tissue by binding to the A2A receptor. The affinity to A2B receptor is believed to attenuate the response of dendritic cells and other parts of innate system. Thus blocking simultaneously the effects mediated by both receptor subtypes with dual inhibitor seems to be a viable approach to a single agent cancer immunotherapy or a combination with current immunotherapeutic agents. We have discovered a novel series of potent and selective A2A/A2B inhibitors. Best compounds present subnanomolar activity in both in vitro recombinant cellular model and in primary human cells. Our antagonists dose-dependently restore the adenosine agonist-impaired functional activity of CD4+ and CD8+ human T-lymphocytes (cytokine release assays). We observe also the relieve of adenosine-related suppression in NK cells cytotoxicity. Most importantly tested compounds present improved primary pharmacological profile in comparison to A2A inhibitors currently tested in clinical trials. Further validation in in vivo models showed efficacy standalone and in combination with checkpoint inhibitors. Citation Format: Michal Galezowski, Paulina Wegrzyn, Aneta Bobowska, Claude Commandeur, Katarzyna Dziedzic, Marcin Nowogrodzki, Alicja Obara, Joanna Szeremeta-Spisak, Anna Dzielak, Iwona Lozinska, Marcelina Dudek, Anita Janiga, Jacek Reus, Marek Wronowski, Mateusz Swirski, Adam Radzimierski, Magdalena Ziembik, Joanna Mierzwicka, Katarzyna Wojcik-Jaszczynska, Elzbieta Gocek, Karolina Grycuk, Aniela Golas, Olga Pierzchala, Julian Zachmann, Mateusz Nowak. Characterization of novel dual A2A/A2B adenosine receptor antagonists for cancer immunotherapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3770.

Hybrid inhibitors of acetyl-and butyrylcholinesterase are compounds that combine structural motifs of two different classical inhibitors, leading to a dual binding ligand. A rapidly growing collection of those compounds involves a wide diversity of structural motifs, but the way of linking two active fragments and its impact on the affinity toward cholinesterases usually remains beyond the extent of investigation. We present hereby a detailed analysis of this aspect using melatonin-donepezil hybrids. A new series of compounds, in which two fragments are connected using a carbamate linker, exhibits excellent activity and selectivity toward butyrylcholinesterase. K E Y W O R D S biological activity, drug design, hydrolases, medicinal chemistry, structure-activity relationship Arch Pharm Chem Life Sci. 2018;351:e1800194.wileyonlinelibrary.com/journal/ardp

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