The organo-seleniumdrug ebselen exhibits a wide range of pharmacological effects that are predominantly due to its interference with redox systems catalyzed by seleno enzymes, e.g., glutathione peroxidase and thioredoxin reductase. Moreover, ebselen can covalently interact with thiol groups of several enzymes. According to its pleiotropic mode of action, ebselen has been investigated in clinical trials for the prevention and treatment of different ailments. Fluorescence-labeled probes containing ebselen are expected to be suitable for further biological and medicinal studies. We therefore designed and synthesized two coumarin-tagged activity-based probes bearing the ebselen warhead. The heterodimers differ by the nature of the spacer structure, for which—in the second compound—a PEG/two-amide spacer was introduced. The interaction of this probe and of ebselen with two cysteine proteases was investigated. Full article

Human CK2 is a heterotetrameric constitutively active serine/threonine protein kinase and is an emerging target in current anti-cancer drug discovery. The kinase is composed of two catalytic CK2α subunits and two regulatory CK2β subunits. In order to establish an assay to identify protein-protein-interaction inhibitors (PPI) of the CK2α/CK2β interface, a bioorthogonal click reaction was used to modify the protein kinase α-subunit with a fluorophore. By expanding the genetic code, the unnatural amino acid para azidophenylalanine (pAzF) could be incorporated into CK2α. Performing the SPAAC click reaction (Strain-Promoted Azide-Alkyne Cycloaddition) by the use of a dibenzylcyclooctyne-fluorophore (DBCO-fluorophore) led to a specifically labeled human protein kinase CK2α. This site-specific labeling does not impair the phosphorylation activity of CK2, which was evaluated by capillary electrophoresis. Furthermore a dissociation constant (K_D) of 631 ± 86.2 nM was determined for the substrate α_S1-casein towards CK2α. This labeling strategy was also applied to CK2β subunit on Escherichia coli, indicating the site-specific modifications of proteins on the bacterial cell surface when displayed by Autodisplay. Full article

Novel esters of γ-aminobutyric acid (GABA) with monocyclic terpenes were synthesized via Steglich esterification and characterized by ¹H-NMR, IR and mass spectral studies. Their anticonvulsant, analgesic and anti-inflammatory activities were evaluated by a PTZ-induced convulsion model, AITC-induced hyperalgesia and AITC-induced paw edema, respectively. All studied esters, as well as their parent terpenes, were found to produce antinociceptive effects in the AITC-induced model and attenuate acute pain more than the reference drug benzocaine after their topical application. GABA esters of l-menthol and thymol were also shown to exceed the reference drug ibuprofen in their ability to decrease the inflammatory state induced by intraplantar injection of the TRPA1 activator AITC. The present findings indicate that GABA esters of carvacrol and guaiacol are not a classical prodrug and possess their own pharmacological activity. Prolonged antiseizure action of the ester based on the amino acid and guaiacol (200 mg/kg) was revealed at 24 h after oral administration. Furthermore, orally co-administered gidazepam (1 mg/kg) and GABA esters of l-menthol, thymol and carvacrol produce synergistic seizure prevention effects. Full article

A series of 15 alkanediamide-linked bisbenzamidines and related analogs was synthesized and tested in vitro against two Trypanosoma brucei (T.b.) subspecies: T.b. brucei and T.b. rhodesiense, Trypanosoma cruzi, Leishmania donovani and two Plasmodium falciparum subspecies: a chloroquine-sensitive strain (NF54) and a chloroquine-resistant strain (K1). The in vitro cytotoxicity was determined against rat myoblast cells (L6). Seven compounds (5, 6, 10, 11, 12, 14, 15) showed high potency against both strains of T. brucei and P. falciparum with the inhibitory concentrations for 50% (IC₅₀) in the nanomolar range (IC₅₀ = 1–96 nM). None of the tested derivatives was significantly active against T. cruzi or L. donovani. Three of the more potent compounds (5, 6, 11) were evaluated in vivo in mice infected with the drug-sensitive (Lab 110 EATRO and KETRI 2002) or drug-resistant (KETRI 2538 and KETRI 1992) clinical isolates of T. brucei. Compounds 5 and 6 were highly effective in curing mice infected with the drug-sensitive strains, including a drug-resistant strain KETRI 2538, but were ineffective against KETRI 1992. Thermal melting of DNA and molecular modeling studies indicate AT-rich DNA sequences as possible binding sites for these compounds. Several of the tested compounds are suitable leads for the development of improved antiparasitic agents. Full article

Based on the data for compounds known from the literature to be active against various types of Ser/Thr kinases, a general pharmachophore model for these types of kinases was developed. The search for the molecules fitting to this pharmacophore among the ASINEX proprietary library revealed a number of compounds, which were tested and appeared to possess some activity against Ser/Thr kinases such as Aurora A, Aurora B and Haspin. Our work on the optimization of these molecules against Aurora A kinase allowed us to achieve several hits in a 3–5 nM range of activity with rather good selectivity and Absorption, Distribution, Metabolism, and Excretion (ADME) properties, and cytotoxicity against 16 cancer cell lines. Thus, we showed the possibility to fine-tune the general Ser/Thr pharmacophore to design active and selective compounds against desired types of kinases. Full article

It is well known that plants are important sources for the preparation of natural remedies as they contain many biologically active compounds. In particular, polyphenols, terpenic compounds, organic acids, and vitamins are the most widely occurring groups of phytochemicals. Some endemic species may be used for the production of herbal preparations containing phytochemicals with significant bioactivity, as antioxidant activity and anti-inflammatory capacities, and health benefits. Blackberry sprouts and blackcurrant buds are known to contain appreciable levels of bioactive compounds, including flavonols, phenolic acids, monoterpenes, vitamin C, and catechins, with several clinical effects. The aim of this research was to perform an analytical study of blackcurrant and blackberry bud-preparations, in order to identify and quantify the main biomarkers, obtaining a specific phytochemical fingerprint to evaluate the single botanical class contribution to total phytocomplex and relative bioactivity, using a High Performance Liquid Chromatograph−Diode Array Detector; the same analyses were performed both on the University laboratory and commercial preparations. Different chromatographic methods were used to determine concentrations of biomolecules in the preparations, allowing for quantification of statistically significant differences in their bioactive compound content both in the case of Ribes nigrum and Rubus cultivated varieties at different harvest stages. In blackcurrant bud-extracts the most important class was organic acids (50.98%) followed by monoterpenes (14.05%), while in blackberry preparations the main bioactive classes were catechins (50.06%) and organic acids (27.34%). Chemical, pharmaceutical and agronomic-environmental knowledge could be important for obtaining label certifications for the valorization of specific genotypes, with high clinical and pharmaceutical value: this study allowed to develop an effective tool for the natural preparation quality control and bioactivity evaluation through the chemical fingerprinting of bud preparations. Full article

The first International Electronic Conference on Medicinal Chemistry, organized and sponsored by MDPI AG, publisher, and the Journal Pharmaceuticals, took place in November 2015 on the SciForum website. More than 200 authors from 18 countries participated in the event and was attended by 25,000 visitors who had the opportunity to browse among 55 presentations, keynotes, and videos. A short description of some works presented during that scientific meeting is disclosed in this report. Full article