Synthesis and biological evaluation of novel 3-(5-substituted-1H-indol-3-yl)pyrrolidine-2,5-dione derivatives with a dual affinity for serotonin 5-HT1A receptor and SERT.

The serotonin 1A (5-HT1A) receptors and serotonin transporter (SERT) are important biological targets in the treatment of diseases of the central nervous system, especially for depression. In this study, new 3-(1H-indol-3-yl)pyrrolidine-2,5-dione derivatives linked with the 3-(1,2,3,6-tetrahydropyridin-4-yl)-1H-indole moiety were synthesised and evaluated for their affinity for 5-HT1A receptor and serotonin reuptake inhibition. Selected compounds were then tested for their affinity for D2, 5-HT2A, 5-HT6 and 5-HT7 receptors, and also in in vitro metabolic stability assays in human microsomes. Finally, in vivo assays allowed us to evaluate the agonist-antagonist properties of pre- and postsynaptic 5-HT1A receptors. 3-(1-(4-(3-(5-methoxy-1H-indol-3-yl)-2,5-dioxopyrrolidin-1-yl)butyl)-1,2,3,6-tetrahydropyridin-4-yl)-1H-indole-5-carbonitrile (4f) emerged as the most promising compound from the series, due to its favourable receptor binding profile (Ki(5-HT1A) = 10.0 nM; Ki(SERT) = 2.8 nM), good microsomal stability and 5-HT1A receptor agonistic activity.

Novel multi-target ligands of dopamine and serotonin receptors for the treatment of schizophrenia based on indazole and piperazine scaffolds-synthesis, biological activity, and structural evaluation.

Schizophrenia is a chronic mental disorder that is not satisfactorily treated with available antipsychotics. The presented study focuses on the search for new antipsychotics by optimising the compound D2AAK3, a multi-target ligand of G-protein-coupled receptors (GPCRs), in particular D2, 5-HT1A, and 5-HT2A receptors. Such receptor profile may be beneficial for the treatment of schizophrenia. Compounds 1-16 were designed, synthesised, and subjected to further evaluation. Their affinities for the above-mentioned receptors were assessed in radioligand binding assays and efficacy towards them in functional assays. Compounds 1 and 10, selected based on their receptor profile, were subjected to in vivo tests to evaluate their antipsychotic activity, and effect on memory and anxiety processes. Molecular modelling was performed to investigate the interactions of the studied compounds with D2, 5-HT1A, and 5-HT2A receptors on the molecular level. Finally, X-ray study was conducted for compound 1, which revealed its stable conformation in the solid state.

Immunomodulatory Properties of Polysaccharides from Lentinula edodes.

Lentinula edodes (Berk.) Pegler, also known as shiitake mushroom, is a popular edible macrofungus and a source of numerous bioactive substances with multiple beneficial health effects. L. edodes-derived polysaccharides are the most valuable compounds, with anticancer, antioxidant, antimicrobial, and immunomodulatory properties. It has been demonstrated that their biological activity depends on the extraction method, which affects monosaccharide composition, molecular weight, branching degrees, and helical conformation. In this review, we discuss the immunomodulatory properties of various polysaccharides from L. edodes in animal models and in humans.

5-HT Receptors and the Development of New Antidepressants.

Serotonin modulates several physiological and cognitive pathways throughout the human body that affect emotions, memory, sleep, and thermal regulation. The complex nature of the serotonergic system and interactions with other neurochemical systems indicate that the development of depression may be mediated by various pathomechanisms, the common denominator of which is undoubtedly the disturbed transmission in central 5-HT synapses. Therefore, the deliberate pharmacological modulation of serotonergic transmission in the brain seems to be one of the most appropriate strategies for the search for new antidepressants. As discussed in this review, the serotonergic system offers great potential for the development of new antidepressant therapies based on the combination of SERT inhibition with different pharmacological activity towards the 5-HT system. The aim of this article is to summarize the search for new antidepressants in recent years, focusing primarily on the possibility of benefiting from interactions with various 5-HT receptors in the pharmacotherapy of depression.

Selenium-Containing Exopolysaccharides Isolated from the Culture Medium of Lentinula edodes: Structure and Biological Activity.

In continuation of our research on the influence of selenium incorporation on the biosynthesis, structure, and immunomodulatory and antioxidant activities of polysaccharides of fungal origin, we have isolated from a post-culture medium of Lentinula edodes a selenium (Se)-containing exopolysaccharide fraction composed mainly of a highly branched 1-6-α-mannoprotein of molecular weight 4.5 × 106 Da, with 15% protein component. The structure of this fraction resembled mannoproteins isolated from yeast and other mushroom cultures, but it was characterized by a significantly higher molecular weight. X-ray absorption fine structure spectral analysis in the near edge region (XANES) suggested that selenium in the Se-exopolysaccharide structure was present mainly at the IV oxidation state. The simulation analysis in the EXAFS region suggested the presence of two oxygen atoms in the region surrounding the selenium. On the grounds of our previous studies, we hypothesized that selenium-enriched exopolysaccharides would possess higher biological activity than the non-Se-enriched reference fraction. To perform structure-activity studies, we conducted the same tests of biological activity as for previously obtained mycelial Se-polyglucans. The Se-enriched exopolysaccharide fraction significantly enhanced cell viability when incubated with normal (human umbilical vein endothelial cells (HUVEC)) cells (but this effect was absent for malignant human cervical HeLa cells) and this fraction also protected the cells from oxidative stress conditions. The results of tests on the proliferation of human peripheral blood mononuclear cells suggested a selective immunosuppressive activity, like previously tested Se-polyglucans isolated from L. edodes mycelium. The Se-exopolysaccharide fraction, in concentrations of 10-100 µg/mL, inhibited human T lymphocyte proliferation induced by mitogens, without significant effects on B lymphocytes. As with previously obtained Se-polyglucans, in the currently tested Se-polymannans, the selenium content increased the biological activity. However, the activity of selenium exopolysaccharides in all tests was significantly lower than that of previously tested mycelial isolates, most likely due to a different mode of selenium binding and its higher degree of oxidation.

Identification of the Primary Structure of Selenium-Containing Polysaccharides Selectively Inhibiting T-Cell Proliferation.

We previously described the biosynthesis, isolation, and immunosuppressive activity of the selenium-containing polysaccharide fraction isolated from the mycelial culture of Lentinula edodes. Structural studies have shown that the fraction was a protein-containing mixture of high molar mass polysaccharides α- and ß-glucans. However, which of the components of the complex fraction is responsible for the immunosuppressive activity non-typical for polysaccharides of fungal origin has not been explained. In the current study, we defined four-polysaccharide components of the Se-containing polysaccharide fraction determined their primary structure and examined the effect on T- and B-cell proliferation. The isolated Se-polysaccharides, α-1,4-glucan (Mw 2.25 × 106 g/mol), unbranched ß-1,6-d-glucan, unbranched ß-1,3-d-glucan and ß-1,3-branched ß-1,6-d-glucan (Mw 1.10 × 105 g/mol), are not typical as components of the cell wall of L. edodes. All are biologically active, but the inhibitory effect of the isolated polysaccharides on lymphocyte proliferation was weaker, though more selective than that of the crude fraction.

Identification of bacteria and fungi inhabiting fruiting bodies of Burgundy truffle (Tuber aestivum Vittad.).

Tuber species may be regarded as complex microhabitats hosting diverse microorganisms inside their fruiting bodies. Here, we investigated the structure of microbial communities inhabiting the gleba of wild growing (in stands) T. aestivum, using Illumina sequencing and culture-based methods. The two methods used in combination allowed to extract more information on complex microbiota of Tuber aestivum gleba. Analysis of the V3-V4 region of 16S rDNA identified nine phyla of bacteria present in the gleba of T. aestivum ascomata, mostly Proteobacteria from the family Bradyrhizobiaceae. Our results ideally match the earlier data for other Tuber species where the family Bradyrhizobiaceae was the most represented. The ITS1 region of fungal rDNA represented six alien fungal species belonging to three phyla. To complement the metagenomic analysis, cultivable fungi and bacteria were obtained from the gleba of the same T. aestivum fruiting bodies. The identified fungi mostly belong to the phylum Basidiomycota and same to Ascomycota. Analysis of cultivable bacteria revealed that all the specimens were colonized by different strains of Bacillus. Fungal community inhabiting T. aestivum fruiting bodies was never shown before.

Synthesis of new 4-butyl-arylpiperazine-3-(1H-indol-3-yl)pyrrolidine-2,5-dione derivatives and evaluation for their 5-HT1A and D2 receptor affinity and serotonin transporter inhibition.

A series of novel 4-butyl-arylpiperazine-3-(1H-indol-3-yl)pyrrolidine-2,5-dione derivatives were synthesized and evaluated for their 5-HT1A/D2 receptor affinity and serotonin reuptake inhibition. The compounds exhibited high affinity for the 5-HT1A receptor, (especially 4dKi = 0.4 nM) which depended on the substitution pattern at the phenylpiperazine moiety. From this series screen, compound 4c emerged with promising mixed receptor profiles for the 5-HT1A/D2 receptors and the serotonin transporter (Ki = 1.3 nM, 182 nM and 64 nM, respectively).

Structure-activity relationship and cardiac safety of 2-aryl-2-(pyridin-2-yl)acetamides as a new class of broad-spectrum anticonvulsants derived from Disopyramide.

A series of 2-aryl-2-(pyridin-2-yl)acetamides were synthesized and screened for their anticonvulsant activity in animal models of epilepsy. The compounds were broadly active in the 'classical' maximal electroshock seizure (MES) and subcutaneous Metrazol (scMET) tests as well as in the 6 Hz and kindling models of pharmacoresistant seizures. Furthermore, the compounds showed good therapeutic indices between anticonvulsant activity and motor impairment. Structure-activity relationship (SAR) trends clearly showed the highest activity resides in unsubstituted phenyl derivatives or compounds having ortho- and meta- substituents on the phenyl ring. The 2-aryl-2-(pyridin-2-yl)acetamides were derived by redesign of the cardiotoxic sodium channel blocker Disopyramide (DISO). Our results show that the compounds preserve the capability of the parent compound to inhibit voltage gated sodium currents in patch-clamp experiments; however, in contrast to DISO, a representative compound from the series 1 displays high levels of cardiac safety in a panel of in vitro and in vivo experiments.

Application of Pleurotus ostreatus to efficient removal of selected antidepressants and immunosuppressant.

Disposed pharmaceuticals constitute a significant threat to the environment due to the high consumption of drugs and inefficient treatment of wastewater. In this paper, we first described the efficient removal of a series of antidepressants and immunosuppressant from a cultivation medium carried out by white-rot fungus, Pleurotus ostreatus. We determined the removal efficiency of pharmaceuticals and the activity of fungal ligninolytic enzymes over time, as well as the toxicity of pre- and post-cultivation medium to Spirostomum ambiguum. We showed that P. ostreatus can remove from the model medium most of the pharmaceuticals studied, including clomipramine, mianserin, paroxetine, sertraline, and mycophenolic acid. Pharmaceuticals containing phenolic or benzene moieties, likewise in the natural monolignols, were removed in a high efficiency within a short time. The activity of the fungal ligninolytic enzymes, laccase, and lignin peroxidase, in the cultivation medium, was three times higher in the presence of the pharmaceuticals, which justifies their contribution to the degradation. The post-cultivation medium showed lower toxicity than pre-cultivation medium and toxic units were 7- and 2-fold lower for the sublethal and lethal response, respectively. Over twenty metabolites we detected resulted mostly from oxygenation or demethylation of parent pharmaceuticals. The biological treatment we developed using P. ostreatus-based system should be convenient and effective in mycoremediation of environmental wastewater polluted with emerging contaminants including monolignol-like antidepressants and immunosuppressant.

Selenium-enriched Coriolus versicolor mushroom biomass: potential novel food supplement with improved selenium bioavailability.

BACKGROUND: The ability of Coriolus versicolor medicinal mushroom to accumulate and transform selenium from selenourea and sodium selenite into an organic form - l-selenomethionine - during growth in liquid medium is examined in this paper. Additionally, the impact of supplementation on biological activity of the selenated mushroom methanol extracts, as well as their chemical composition, is studied. RESULTS: Selenium accumulation was more efficient with sodium selenite application, but biomass yield was significantly lower (1.89 g DW L-1 ) compared to samples enriched with selenourea (4.48 g DW L-1 ). Mushroom sample obtained after growing in liquid medium with selenourea had significantly higher l-selenomethionine content compared to the sample grown in medium with sodium selenite. Selenium-enriched methanol extracts of C. versicolor mushroom showed improved antimicrobial and antioxidant activities compared to non-enriched extract. CONCLUSION: Our results suggest that C. versicolor mushroom cultivated in liquid culture enriched with selenourea can be used for the production of novel food supplements with improved selenium bioavailability. More than 30% of total accumulated selenium from selenourea is transformed into l-selenomethionine. Differences in biological activity of methanol extracts can be explained not only by different selenium content but also by the differences in chemical composition of extracts. © 2019 Society of Chemical Industry.

Colonic indole, gut bacteria metabolite of tryptophan, increases portal blood pressure in rats.

Portal hypertension (PH) is a potentially life-threatening condition. We investigated the effects of indole and dietary tryptophan, a substrate for gut bacterial production of indole, on portal blood pressure (PBP), portal blood flow (PBF), and arterial blood pressure (ABP) in Sprague-Dawley rats (SD) and SD with PH induced by liver cirrhosis (SD-PH). Hemodynamics were recorded in anesthetized male 28-wk-old SD and SD-PH at baseline and after the administration of either a vehicle or indole into the colon. Blood levels of tryptophan and its bacterial metabolites were evaluated using chromatography coupled with mass spectrometry. Indole at lower doses increased PBP and PBF. Indole at higher doses produced a transient increase in PBP, which was accompanied by a decrease in ABP. Portal blood levels of indole, indole-3-propionic, indole-3-lactic, and indole-3-acetic acids were higher in SD-PH, suggesting an increased gut-blood barrier permeability. Rats on a tryptophan-rich diet showed a significantly higher PBP and portal blood level of indoles than rats on a tryptophan-free diet. In conclusion, a tryptophan-rich diet and intracolonic indole increase PBP and portal blood level of indole. Rats with PH show an increased penetration of indoles from the colon to the circulation. Intracolonic indole production may be of therapeutic importance in PH.

Synthesis and biological investigations of 3ß-aminotropane arylamide derivatives with atypical antipsychotic profile.

This work is a continuation of our previous research, concentrating this time on lead structure modification to increase the 5-HT1A receptor affinity and water solubility of designed compounds. Therefore, the compounds synthesised within the present project included structural analogues of 3ß-acylamine derivatives of tropane with the introduction of a methyl substituent in the benzyl ring and a 2-quinoline, 3-quinoline, or 6-quinoline moiety. A series of novel 3ß-aminotropane derivatives was evaluated for their affinity for 5-HT1A, 5-HT2A, and D2 receptors, which allowed for the identification of compounds 12e, 12i, and 19a as ligands with highest affinity for the tested receptors; they were then subjected to further evaluation in preliminary in vivo studies. Selected compounds 12i and 19a displayed antipsychotic properties in the d-amphetamine-induced and MK-801-induced hyperlocomotor activity test in mice. Moreover, compound 19a showed significant antidepressant-like activity in the forced swim test in mice.

Synthesis and biological investigation of new equatorial (ß) stereoisomers of 3-aminotropane arylamides with atypical antipsychotic profile.

A series of novel 3ß-aminotropane derivatives containing a 2-naphthalene or a 2-quinoline moiety was synthesised and evaluated for their affinity for 5-HT1A, 5-HT2A and D2 receptors. Their affinity for the receptors was in the nanomolar to micromolar range. p-Substitution (6c, 6f, 6i, 6l, 6o), as well as substitution with chlorine atoms (6g, 6h, 6i), led to a significant increase in binding affinity for D2 receptors with compounds 6f (Ki=0.6nM), 6c and 6i (Ki=0.4nM), having the highest binding affinities. m-Substituted derivatives were the most promising ligands in terms of 5-HT2A receptor binding affinity whereas 2-quinoline derivatives (10a, 10b) displayed the highest affinity for 5-HT1AR and were the most selective ligands with Ki=62.7nM and Ki=30.5nM, respectively. Finally, the selected ligands 6b, 6d, 6e, 6g, 6h, 6k, 6n and 6o, with triple binding activity for the D2, 5-HT1A and 5-HT2A receptors, were subjected to in vivo tests, such as those for induced hypothermia, climbing behaviour and the head twitch response, in order to determine their pharmacological profile. The tested ligands presented neither agonist nor antagonist properties for the 5-HT1A receptors in the induced hypothermia and lower lip retraction (LLR) tests. All tested compounds displayed antagonistic activity against 5-HT2A, with 6n and 6o being the most active. Four (6b, 6k, 6n and 6o) out of eight tested compounds could be classified as D2 antagonists. Additionally, evaluation of metabolic stability was performed for selected ligands, and introduction of halogen atoms into the benzene ring of 6h, 6k, 6n and 6o improved their metabolic stability. The project resulted in the selection of the lead compounds 6n and 6o, which had antipsychotic profiles, combining dopamine D2-receptor and 5-HT2A antagonism and metabolic stability.

Comparison of Chemical Composition in Tuber aestivum Vittad. of Different Geographical Origin.

Truffles are prized and nutrition-rich edible hypogeous fungi. The aim of this study was a comprehensive investigation of chemical composition of Burgundy truffle (Tuber aestivum Vittad.). We tried to answer the question: what is the impact of the environment on the truffle quality. To know the nutritional value of Burgundy truffle we compared lipids, proteins, saccharides, polyphenolics, flavonoids, total sterols, ergosterol, volatile flavour and aroma compounds content in fruit bodies of the fungus collected in three different geographical regions, i.e., Poland, Slovakia, and Italy. A comparison of the above mentioned compounds is especially interesting due to environmental and climatic differences among the studied geographical regions. Results revealed that fruit bodies of T. aestivum from Poland and Slovakia possessed nearly similar content of proteins, total sterols, and saccharides. The fruiting bodies from Italy contained significantly larger amounts of most of the investigated compounds. In turn, Polish specimens had higher content of lipids and polyphenolics than Slovak and Italian ones. We have found higher similarity of volatile compounds composition between Polish and Italian specimens than those of Polish and Slovak origin.

Novel fluorinated pyrrolo[1,2-a]pyrazine-2,6-dione derivatives: synthesis and anticonvulsant evaluation in animal models of epilepsy.

A series of fluorinated analogs of the potent investigative anticonvulsant agent (4S,8aS)-4-phenylperhydropyrrolo[1,2-a]pyrazine-2,6-dione 1 was prepared and characterized by IR, 1H, 13C NMR and mass spectral data. The compounds have been evaluated in the in vivo rodent models of epilepsy. They displayed high activity in the 'classical' maximal electroshock seizure (MES) and subcutaneous Metrazol (scMET) tests as well as in the 6Hz model of pharmacoresistant limbic seizures. The results showed that incorporating fluorine atoms into the phenyl ring of 1 can be beneficial for the anticonvulsant potency. The most promising meta-trifluoromethyl and meta-trifluoromethoxy derivatives (4S,8aS)-5h and (4S,8aS)-5l, respectively, displayed very broad spectra of activity across the preclinical seizure models.

Expanding the substrate scope of Ugi five-center, four-component reaction U-5C-4CR): ketones as coupling partners for secondary amino acids.

Various symmetrical and unsymmetrical ketones were successfully coupled with secondary amino acids in the course of Ugi five-center, four-component reaction (U-5C-4CR), thus expanding the molecular diversity possible to be achieved by the reaction. The chemical yields depended on the degree of hindrance of the components employed and were satisfactory in view of possible steric interactions in the U-5C-4CR zwitterionic intermediate. The sense of diastereoinduction for reactions employing unsymmetrical ketones was examined by converting the resulting Ugi adducts into the corresponding rigid 2,6-diketopiperazine derivatives.

Synthesis of new perhydropyrrolo[1,2-a]pyrazine derivatives and their evaluation in animal models of epilepsy.

A series of novel stereochemically pure derivatives of the investigative broad-spectrum anticonvulsant ADD408003 was designed and synthesized. Five-center four-component (U-5C-4CR) and four-center three-component (U-4C-3CR) variants of Ugi reaction were used in the key step of the synthetic pathways. The compounds obtained were evaluated for the anticonvulsant activitiy in the maximal electroshock seizure (MES), subcutaneous Metrazole (scMET) and minimal clonic seizure (6 Hz) animal models of epilepsy. The efficacies of most derivatives in the 6 Hz model of pharmacoresistant partial seizures were markedly higher than in the 'classical' MES and scMET models. The most active compounds, (4R,8aR)-3a, and (4S,8aS)-6 displayed median effective doses (ED50) of 47.90 and 126.19 mg/kg, respectively, for the 6 Hz test.

Multicomponent synthesis and anticonvulsant activity of monocyclic 2,6-diketopiperazine derivatives.

In this study, a series of diastereomerically pure monocyclic 2,6-diketopiperazine (2,6-DKP) derivatives were synthesized. The key synthetic step involved a multicomponent Ugi five-center, four-component reaction which was used to generate the convertible tert-butylamidoesters with both good yields and high diastereoselectivity toward the desired bioactive (S,S) absolute configuration. In subsequent steps, selective tertbutyl cleavage by use of BF3·CH3COOH and base-induced intramolecular cyclocondensation gave the final 2,6-DKP derivatives. The relative stereochemistry of the target molecules was confirmed by 1H NMR experiments. The compounds obtained were submitted to in vivo screening in animal models of epilepsy. Some of them displayed good activity in maximal electroshock seizure and 6 Hz tests.

Structure-activity relationships of the aromatic site in novel anticonvulsant pyrrolo[1,2-a]pyrazine derivatives.

Novel, chiral derivatives of pyrrolo[1,2-a]pyrazine with aromatic substituents at carbon C-4 were synthesized by a short synthetic sequence involving Ugi multicomponent reaction. The compounds were evaluated for their in vivo efficacy in animal models of epilepsy within the Anticonvulsant Screening Program (ASP). High activity in 'classical' maximal electroshock seizure (MES) and subcutaneous Metrazol (scMET) tests was characteristic for meta-substituted analogs. On the other hand, efficacy of compounds in the 6 Hz model of pharmacoresistant limbic seizures was only marginally affected by the orientation of substituents in the phenyl moiety. The most active derivative, 5a, displayed an ED50 value of 32.24 mg/kg and a protective index of 6.6 (PI) in the 6 Hz test. It was also active in a pilocarpine-induced status prevention model of pharmacoresistant status epilepticus.