Escape from adamantane: Scaffold optimization of novel P2X7 antagonists featuring complex polycycles

The adamantane scaffold, despite being widely used in medicinal chemistry, is not devoid of problems. In the recent years we have developed new polycyclic scaffolds as surrogates of the adamantane group with encouraging results in multiple targets. As an adamantane scaffold is a common structural feature in several P2X7 receptor antagonists, herein we report the synthesis and pharmacological evaluation of multiple replacement options of adamantane that maintain a good activity profile. Molecular modeling studies support the binding of the compounds to a site close to the central pore, rather than to the ATP-binding site and shed light on the structural requirements for novel P2X7 antagonists

Azapeptide activity-based probes for the SARS-CoV-2 main protease enable visualization of inhibition in infected cells

The COVID-19 pandemic has revealed the vulnerability of the modern, global society. With expected waves of future infections by SARS-CoV-2, treatment options for infected individuals will be crucial in order to decrease mortality and hospitalizations. The SARS-CoV-2 main protease is a validated drug target, for which the first inhibitor has been approved for use in patients. To facilitate future work on this drug target, we designed a solid-phase synthesis route towards azapeptide activity-based probes that are capped with a cysteine-reactive electrophile for covalent modification of the active site of Mpro. This design led to the most potent ABP for Mpro and one of the most potent inhibitors reported thus far. We demonstrate that this ABP can be used to visualize Mpro activity and target engagement by drugs in infected cells

Depressive mood ratings are reduced by MDMA in female polydrug ecstasy users homozygous for the l-allele of the serotonin transporter

Altres ajuts: Dutch Organisation for Scientifc Research, 400-07-213, 400-05-096, 400-07-2013MDMA exerts its main effects via the serotonergic system and the serotonin transporter. The gene coding for this transporter determines the expression rate of the transporter. Previously it was shown that healthy individuals with the short allelic variant ('s-group') of the 5-HTTLPR-polymorphism displayed more anxiety and negative mood, and had a lower transcriptional efficiency compared to individuals who are homozygous for the l-allele ('l-group'). The present study aimed to investigate the role of the 5-HTTLPR polymorphism in MDMA-induced mood effects. Four placebo-controlled, within-subject studies were pooled, including in total 63 polydrug ecstasy users (N = 48; N = 15) receiving MDMA 75 mg and placebo on two test days, separated by minimally 7 days. Mood was assessed by means of the Profile of Mood States. Findings showed that MDMA induced -independent of sex- a positive mood state, and as a side effect also increased two negative affect states, anxiety and confusion. Anxiety ratings were higher in the l-group and independent of treatment or sex. Depression ratings were lowered by MDMA in the female l-group. Findings indicate that the MDMA-induced reduction in self-rated depressive feelings is sex- and genotype-dependent, with females homozygous for the l-allele showing this beneficial effect

Synthesis, in Vitro Profiling, and in Vivo Evaluation of Benzohomoadamantane-Based Ureas for Visceral Pain: A New Indication for Soluble Epoxide Hydrolase Inhibitors

The soluble epoxide hydrolase (sEH) has been suggested as a pharmacological target for the treatment of several diseases, including pain-related disorders. Herein, we report further medicinal chemistry around new benzohomoadamantane-based sEH inhibitors (sEHI) in order to improve the drug metabolism and pharmacokinetics properties of a previous hit. After an extensive in vitro screening cascade, molecular modeling, and in vivo pharmacokinetics studies, two candidates were evaluated in vivo in a murine model of capsaicin-induced allodynia. The two compounds showed an anti-allodynic effect in a dose-dependent manner. Moreover, the most potent compound presented robust analgesic efficacy in the cyclophosphamide-induced murine model of cystitis, a well-established model of visceral pain. Overall, these results suggest painful bladder syndrome as a new possible indication for sEHI, opening a new range of applications for them in the visceral pain field

A novel class of multitarget anti-Alzheimer benzohomoadamantane‒chlorotacrine hybrids modulating cholinesterases and glutamate NMDA receptors

The development of multitarget compounds against multifactorial diseases, such as Alzheimer's disease, is an area of very intensive research, due to the expected superior therapeutic efficacy that should arise from the simultaneous modulation of several key targets of the complex pathological network. Here we describe the synthesis and multitarget biological profiling of a new class of compounds designed by molecular hybridization of an NMDA receptor antagonist fluorobenzohomoadamantanamine with the potent acetylcholinesterase (AChE) inhibitor 6-chlorotacrine, using two different linker lengths and linkage positions, to preserve or not the memantine-like polycyclic unsubstituted primary amine. The best hybrids exhibit greater potencies than parent compounds against AChE (IC50 0.33 nM in the best case, 44-fold increased potency over 6-chlorotacrine), butyrylcholinesterase (IC50 21 nM in the best case, 24-fold increased potency over 6-chlorotacrine), and NMDA receptors (IC50 0.89 µM in the best case, 2-fold increased potency over the parent benzohomoadamantanamine and memantine), which suggests an additive effect of both pharmacophoric moieties in the interaction with the primary targets. Moreover, most of these compounds have been predicted to be brain permeable. This set of biological properties makes them promising leads for further anti-Alzheimer drug development

MDMA-induced indifference to negative sounds is mediated by the 5-HT receptor

Altres ajuts: This research was funded by the Netherlands Organization for Scientific Research (NWO), Grant Number: 400-07-2013, awarded to JR and KK.MDMA has been shown to induce feelings of sociability, a positive emotional bias and enhanced empathy. While previous research has used only visual emotional stimuli, communication entails more than that single dimension and it is known that auditory information is also crucial in this process. In addition, it is, however, unclear what the neurobiological mechanism underlying these MDMA effects on social behaviour is. Previously, studies have shown that MDMA-induced emotional excitability and positive mood are linked to the action on the serotonin (5-HT) 2A receptor. The present study aimed at investigating the effect of MDMA on processing of sounds (Processing of Affective Sounds Task (PAST)) and cognitive biases (Approach-Avoidance Task (AAT)) towards emotional and social stimuli and the role of 5-HT receptor in these effects. Twenty healthy recreational users entered a 2 × 2, placebo-controlled, within-subject study with ketanserin (40 mg) as pre-treatment and MDMA (75 mg) as treatment. Behavioural (PAST, AAT) measures were conducted 90 min after treatment with MDMA, respectively, 120 min after ketanserin. Self-report mood measures and oxytocin concentrations were taken at baseline and before and after behavioural tests. Findings showed that MDMA reduced arousal elicited by negative sounds. This effect was counteracted by ketanserin pre-treatment, indicating involvement of the 5-HT receptor in this process. MDMA did not seem to induce a bias towards emotional and social stimuli. It increased positive and negative mood ratings and elevated oxytocin plasma concentrations. The reduction in arousal levels when listening to negative sounds was not related to the elevated subjective arousal. It is suggested that this decrease in arousal to negative stimuli reflects potentially a lowering of defences, a process that might play a role in the therapeutic process

Palladium-catalyzed cocyclotrimerization of arynes with a pyramidalized alkene

A pyramidalized alkene and diverse arynes are generated in the presence of a Pd-catalyst to afford [2+2+2] cocycloaddition products. The metal-catalyzed 2+2+2] cocycloaddition of arynes with pyramidalized alkenes is presented. The generation of a highly reactive pyramidalized alkene in the presence of a large excess of in situ-produced arynes led to the corresponding cocyclotrimerization (1 : 2)-adducts in good yields, establishing the first example of a palladium-based reaction of a pyramidalized alkene.Depto. de Química OrgánicaFac. de Ciencias QuímicasTRUEpu