4-phenylselenyl-7-chloroquinoline, a novel multitarget compound with anxiolytic activity: Contribution of the glutamatergic system

Comprehensive Review on the Synthesis of [1,2,3]Triazolo[1,5-a]Quinolines

This report outlines the evolution and recent progress about the different protocols to synthesize the N-heterocycles fused hybrids, specifically [1,2,3]triazolo[1,5-a]quinoline. This review encompasses a broad range of approaches, describing several reactions for obtaining this since, such as dehydrogenative cyclization, oxidative N-N coupling, Dieckmann condensation, intramolecular Heck, (3+2)-cycloaddition, Ullman-type coupling and direct intramolecular arylation reactions. We divided this review in three section based in the starting materials to synthesize the target [1,2,3]triazolo[1,5-a]quinolines. Starting materials containing quinoline or triazole units previously formed, as well as starting materials which both quinoline and triazole units are formed in situ. Different methods of obtaining are described, such as metal-free or catalyzed conditions, azide-free, using conventional heating or alternative energy sources, such as electrochemical and photochemical methods. Mechanistic insights underlying the reported reactions were also described in this comprehensive review.

Advances in organocatalyzed synthesis of organic compounds

The recent advancements in utilizing organocatalysts for the synthesis of organic compounds have been described in this review by focusing on their simplicity, effectiveness, reproducibility, and high selectivity which lead to excellent product yields. The organocatalytic methods for various derivatives, such as indoles, pyrazolones, anthrone-functionalized benzylic amines, maleimide, polyester, phthalimides, dihydropyrimidin, heteroaryls, N-aryl benzimidazoles, stilbenoids, quinazolines, quinolines, and oxazolidinones have been specifically focused. The review provides more understanding by delving into potential reaction mechanisms. We anticipate that this collection of data and findings on successful synthesis of diverse compound derivatives will serve as valuable resources and stimulating current and future research efforts in organocatalysis and industrial chemistry.

Novel Multi-Target Agents Based on the Privileged Structure of 4-Hydroxy-2-quinolinone

In this work, the privileged scaffold of 4-hydroxy-2quinolinone is investigated through the synthesis of carboxamides and hybrid derivatives, as well as through their bioactivity evaluation, focusing on the ability of the molecules to inhibit the soybean LOX, as an indication of their anti-inflammatory activity. Twenty-one quinolinone carboxamides, seven novel hybrid compounds consisting of the quinolinone moiety and selected cinnamic or benzoic acid derivatives, as well as three reverse amides are synthesized and classified as multi-target agents according to their LOX inhibitory and antioxidant activity. Among all the synthesized analogues, quinolinone-carboxamide compounds 3h and 3s, which are introduced for the first time in the literature, exhibited the best LOX inhibitory activity (IC50 = 10 μM). Furthermore, carboxamide 3g and quinolinone hybrid with acetylated ferulic acid 11e emerged as multi-target agents, revealing combined antioxidant and LOX inhibitory activity (3g: IC50 = 27.5 μM for LOX inhibition, 100% inhibition of lipid peroxidation, 67.7% ability to scavenge hydroxyl radicals and 72.4% in the ABTS radical cation decolorization assay; 11e: IC50 = 52 μM for LOX inhibition and 97% inhibition of lipid peroxidation). The in silico docking results revealed that the synthetic carboxamide analogues 3h and 3s and NDGA (the reference compound) bind at the same alternative binding site in a similar binding mode.

Anxiolytic-like action of 3-((4-methoxyphenyl)selanyl)-2-phenylbenzofuran (SeBZF3) in mice: A possible contribution of the serotonergic system

Anxiety disorders, characterized by high prevalence rates, cause psychiatric disabilities and are related to impairments in serotoninergic system function. Frequent anxiety recurrence, resistance, and drug adverse effects have driven searches for new therapies. We initially evaluated the anxiolytic-like activity of 3-selanyl-benzo[b]furan compounds (SeBZF1-5) (50 mg/kg, i.g.) in male Swiss mice using the light-dark test (LDT). The compound 3-((4-methoxyphenyl)selanyl)-2-phenylbenzofuran (SeBZF3) exhibited anxiolytic-like activity. SeBZF3 anxiolytic-like effects were also observed in the novelty-suppressed feeding test (NSFT) (50 mg/kg) and elevated plus-maze test (EPMT) (25 and 50 mg/kg). In the EPMT, anxiolytic-like effects of SeBZF3 (50 mg/kg) were abolished by pretreatment with p-chlorophenylalanine, a selective tryptophan hydroxylase inhibitor (100 mg/kg, i.p. for 4 days), suggesting the involvement of serotonergic mechanisms. Furthermore, we conducted experiments to investigate the synergistic effects of SeBZF3 subeffective doses (5 mg/kg, i.g.) in combination with fluoxetine (a selective serotonin reuptake inhibitor, 5 mg/kg, i.p.) or buspirone (a partial agonist of the 5-HT1A receptor, 2 mg/kg, i.p.). This coadministration resulted in pronounced synergistic effects. We also examined the effects of repeated oral treatment with SeBZF3 at doses of 1 and 5 mg/kg over 14 days and both reduced anxiety signals. In vitro and ex vivo findings revealed that SeBZF3 inhibited cerebral MAO-A activity. These findings collectively imply the potential involvement of serotonergic mechanisms in the anxiolytic-like activity of SeBZF3 in mice. These data offer contributions to the research field of organoselenium compounds and anxiolytics, encouraging the broadening of the search for new effective drugs while offering improved side effect profiles.

Regioselective C-H chalcogenylation and halogenation of arenes and alkenes under metal-free conditions

The reactions of direct Csp²-H chalcogenylation and halogenation of N-arylpyrrolidone under the action of PIFA without a directing group and under metal-free conditions were reported in this paper. Diphenyl selenide/sulfur and selenium phenyl halides were used as reaction reagents to obtain chalcogenylated and halogenated N-arylpyrrolidone products, respectively. The mechanistic studies indicated that a radical pathway was likely involved in these reactions. Preliminary antitumor tests showed that these compounds have moderate to potent activities against human acute leukemia cells K562 in vitro, which may be used as lead compounds for subsequent research.

Interface of Aging and Acute Peripheral Neuropathy Induced by Oxaliplatin in Mice: Target-Directed Approaches for Na+, K+-ATPase, Oxidative Stress, and 7-Chloro-4-(phenylselanyl) quinoline Therapy

Almost 90% of patients develop pain immediately after oxaliplatin (OXA) treatment. Here, the impact of aging on OXA-induced acute peripheral neuropathy and the potential of 7-chloro-4-(phenylselanyl) quinoline (4-PSQ) as a new therapeutic strategy were evaluated. In Swiss mice, the oxidative damage and its influence on Mg²⁺-ATPase and Na⁺, K⁺-ATPase activities were investigated. The relationship between the reactive oxygen species (ROS) and nitrate and nitrite (NOx) levels, the activity of glutathione peroxidase (GPx), and superoxide dismutase (SOD) with the development of OXA-induced acute peripheral neuropathy was also studied. In this study, it was evidenced that OXA-induced acute peripheral neuropathy was exacerbated by aging through increased oxidative damage as well as Na⁺, K⁺-ATPase, and Mg⁺²-ATPase inhibition. 4-PSQ reversed hypersensitivity induced by OXA and aging-aggravated by reducing ROS and NOx levels, through modulation of GPx and SOD activities. 4-PSQ partially reestablish Na⁺, K⁺-ATPase activity, but not Mg ²⁺-ATPase activity. Locomotor and exploratory activities were not affected. This study is the first of its kind, providing new insight into the aging impact on mechanisms involved in OXA-induced acute peripheral neuropathy. Also, it provides evidence on promising 4-PSQ effects on this condition, mainly on aging.

Rodrigues K, Pinz MP, Biondi JV, Becker NP, Blodorn E, Domingues WB, Larroza A, Campos VF, Alves D, Wilhelm EA, Luchese C. Prospecting for a quinoline containing selenium for comorbidities depression and memory impairment induced by restriction stress in mice

RATIONALE

Depression is often associated with memory impairment, a clinical feature of Alzheimer's disease (AD), but no effective treatment is available. 7-Chloro-4-(phenylselanyl) quinoline (4-PSQ) has been studied in experimental models of diseases that affect the central nervous system.

OBJECTIVES

The pharmacological activity of 4-PSQ in depressive-like behavior associated with memory impairment induced by acute restraint stress (ARS) in male Swiss mice was evaluated.

METHODS

ARS is an unavoidable stress model that was applied for a period of 240 min. Ten minutes after ARS, animals were intragastrically treated with canola oil (10 ml/kg) or 4-PSQ (10 mg/kg) or positive controls (paroxetine or donepezil) (10 mg/kg). Then, after 30 min, mice were submitted to behavioral tests. Corticosterone levels were evaluated in plasma and oxidative stress parameters; monoamine oxidase (MAO)-A and MAO -B isoform activity; mRNA expression levels of kappa nuclear factor B (NF-κB); interleukin (IL)-1β, IL-18, and IL-33; phosphatidylinositol-se-kinase (PI3K); protein kinase B (AKT2), as well as acetylcholinesterase activity were evaluated in the prefrontal cortex and hippocampus.

RESULTS

4-PSQ attenuated the depressive-like behavior, self-care, and memory impairment caused by ARS. Based on the evidence, we believe that effects of 4-PSQ may be associated, at least in part, with the attenuation of HPA axis activation, attenuation of alterations in the monoaminergic system, modulation of oxidative stress, reestablishment of AChE activity, modulation of the PI3K/AKT2 pathway, and reduction of neuroinflammation.

CONCLUSIONS

These results suggested that 4-PSQ exhibited an antidepressant-like effect and attenuated the memory impairment induced by ARS, and it is a promising molecule to treat these comorbidities.

4-Phenylselanyl-7-chloroquinoline attenuates hepatic injury triggered by neonatal exposure to monosodium glutamate in rats

AIMS

Obesity is associated with a spectrum of hepatic abnormalities that can be experimentally induced by injections of monosodium glutamate (MSG) in neonatal rodents. We investigated the protective actions of the repeated therapy with 4-phenylselenyl-7-chloroquinoline (4-PSQ), a quinoline derivative containing selenium, on damage to the liver triggered by early postnatal administration of MSG in male Wistar rats.

MAIN METHODS

Neonatal rats received MSG (4 g/kg, subcutaneous route) or saline (1 ml/kg) from 5 to 14 postnatal day (PND) to induce obesity with consequent damages in the liver. 4-PSQ treatment (5 mg/kg) or canola oil (1 ml/kg) was administered from 60 to 76 PND by the intragastric route. On 76 PND, animals were anesthetized for blood and liver collection. Plasma markers of hepatic function, hepatic lipoperoxidation levels and histology analysis of liver tissue were assessed.

KEY FINDINGS

Our data revealed that treatment with 4-PSQ reverted the increase in plasma transaminases activities observed in MSG rats. Treatment with 4-PSQ reduced plasma lactate levels in obese rats. In the liver, MSG elevated the content of lipoperoxidation which was reverted by 4-PSQ administrations. Lastly, 4-PSQ therapy attenuated the histological alterations induced by MSG.

SIGNIFICANCE

Together, the results indicate a hepatoprotective action of repeated treatment with 4-PSQ in obese rats.

Suppressive effect of 1,4-anhydro-4-seleno-D-talitol (SeTal) on atopic dermatitis-like skin lesions in mice through regulation of inflammatory mediators

BACKGROUND

Atopic dermatitis (AD) is a multifactorial chronic inflammatory disease that affects ∼20 % of children and 3% of adults globally and is generally treated by the topical application of steroidal drugs that have undesirable side-effects. The development of alternative therapies is therefore an important objective. The present study investigated the effects of topical treatment with a novel water-soluble selenium-containing carbohydrate derivative (4-anhydro-4-seleno-D-tatitol, SeTal) on the symptoms and inflammatory parameters in an AD mouse model.

METHODS

Mice were sensitized by applying 2,4-dinitrochlorobenzene (DNCB) to their dorsal skin on days 1-3, then further challenged on their ears and dorsal skin on days 14, 17, 20, 23, 26, and 29. SeTal (1 and 2%) or hydrocortisone (1%) was applied topically to the backs of the mice from days 14-29, and skin severity scores and scratching behavior determined on day 30. The mice were euthanized, and their ears and dorsal skin removed to quantify inflammatory parameters, edema, myeloperoxidase (MPO) activity, and AD-associated cytokines (tumor necrosis factor alpha (TNF-α), interleukins (IL)-18, and IL-33).

RESULTS

DNCB treatment induced skin lesions and increased the scratching behavior, ear edema, MPO activity (ear and dorsal skin), and cytokine levels in dorsal skin. Topical application of SeTal improved inflammatory markers (cytokine levels and MPO activity), cutaneous severity scores, and scratching behavior.

CONCLUSION

The efficacy of SeTal was satisfactory in the analyzed parameters, showing similar or better results than hydrocortisone. SeTal appears to be therapeutically advantageous for the treatment and control of AD.

The neurotherapeutic role of a selenium-functionalized quinoline in hypothalamic obese rats

RATIONALE

Obesity is considered one of the major global health problems and increases the risk of several medical complications, such as diabetes and mental illnesses.

OBJECTIVE

The present study investigated the effect of 7-chloro-4-(phenylselanyl) quinoline (4-PSQ) on obesity parameters, behavioral and neurochemical alterations in hypothalamic obese rats.

METHODS

Male Wistar rats received subcutaneous neonatal injections of monosodium glutamate (MSG, 4g/kg) or saline. After the Lee Index evaluation, rats were divided into groups and treated with 4-PSQ (5 mg/kg, intragastric route) or canola oil once a day (post-natal days (PND) 60→76). Open-field, elevated plus-maze, forced swim task, object recognition/location memory, and stepdown inhibitory avoidance tasks were conducted from PND 66 to 74. On PND 76, rats were euthanized and epididymal fat, blood, cerebral cortex, andhippocampus were removed. Blood biochemical parameters and cortical/hippocampal acetylcholinesterase (AChE) and Na /K -ATPase activities were assessed.

RESULTS

MSG increased the Lee Index characterizing the chemically induced hypothalamic obesity model. 4-PSQ reversed the increases of epididymal fat, blood glucose, and triglyceride levels caused by MSG exposure. 4-PSQ attenuated anxiety-like and depression-like behaviors induced by neonatal administrations of MSG. Memory deficits found in MSG-obese rats were reversed by treatment with 4-PSQ. Neurochemical alterations produced by MSG evidenced by stimulation ofNa⁺/K⁺-ATPase and AChE activities in the cerebral cortex and hippocampus of rats were normalized by 4-PSQ treatment.

CONCLUSIONS

In brief, 4-PSQ therapy improved hypothalamic obesity-related parameters, as well as psychiatric symptoms, cognitive impairment, and neurochemical alterations found in obese rats.

7-Chloro-4-(phenylselanyl) quinoline reduces renal oxidative stress induced by oxaliplatin in mice

The object of this study was to evaluate the relationship between oxidative damage induced by oxaliplatin (OXA) and the therapeutic potential of 7-chloro-4-(phenylselanyl) quinoline (4-PSQ) in kidney of mice. Mice received OXA (10 mg/kg) or vehicle intraperitoneally (days 0 and 2). Oral administration of 4-PSQ (1 mg/kg) or vehicle was performed on days 2 to 14. On day 15 the animals were euthanized and the kidneys and blood were collected. The effect of OXA and (or) 4-PSQ on urea, thiobarbituric acid reactive species, nonprotein thiol (NPSH), and protein carbonyl (PC) levels were investigated. Moreover, renal superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR), glutathione S-transferase (GST), δ-aminolevulinic acid dehydratase (δ-ALA-D), and Na⁺,K⁺ ATPase activities were evaluated. Our findings revealed an increase on urea levels and significant renal oxidative damage in OXA-induced mice. OXA exposure increased SOD, GPx, and GST activities and caused a reduction on NPSH levels and CAT and GR activities. Na⁺,K⁺ ATPase and δ-ALA-D activities were reduced by OXA. 4-PSQ decreased plasmatic urea levels and renal oxidative damage. SOD, GPx, CAT, GR, and Na⁺,K⁺ ATPase activities were restored by 4-PSQ. 4-PSQ may be a good prototype for the treatment of OXA-induced renal injury.

Synthesis of selenated tetracyclic indoloazulenes via iodine and diorganyl diselenides

Herein, we report an efficient protocol for the synthesis of selenated tetracyclic indoloazulenes. The reaction of diorganyl diselenides with molecular iodine in dichloromethane leads to the in situ formation of organo selenenyl iodide. The synthesis of selenylated tetracyclic indoloazulenes through intramolecular cascade cyclization has been achieved via organo selenenyl iodide and bisindole at room temperature under metal-free conditions in good yields. All compounds were fully characterized by the FT-IR, HRMS, and ¹H, ¹³C and ⁷⁷Se NMR spectral data.

Synthesis of 4-Arylselanyl-1H-1,2,3-triazoles from Selenium-Containing Carbinols

In this work, we present a simple way to achieve 4-arylselanyl-1H-1,2,3-triazoles from selenium-containing carbinols in a one-pot strategy. The selenium-containing carbinols were used as starting materials to produce a range of selanyl-triazoles in moderate to good yields, including a quinoline and Zidovudine derivatives. One-pot protocols are crucial to the current concerns about waste production and solvent consumption, avoiding the isolation and purification steps of the reactive terminal selanylalkynes. We could also isolate an interesting and unprecedented by-product with one alkynylselenium moiety connected to the triazole.

Toxicology and pharmacology of synthetic organoselenium compounds: an update

Here, we addressed the pharmacology and toxicology of synthetic organoselenium compounds and some naturally occurring organoselenium amino acids. The use of selenium as a tool in organic synthesis and as a pharmacological agent goes back to the middle of the nineteenth and the beginning of the twentieth centuries. The rediscovery of ebselen and its investigation in clinical trials have motivated the search for new organoselenium molecules with pharmacological properties. Although ebselen and diselenides have some overlapping pharmacological properties, their molecular targets are not identical. However, they have similar anti-inflammatory and antioxidant activities, possibly, via activation of transcription factors, regulating the expression of antioxidant genes. In short, our knowledge about the pharmacological properties of simple organoselenium compounds is still elusive. However, contrary to our early expectations that they could imitate selenoproteins, organoselenium compounds seem to have non-specific modulatory activation of antioxidant pathways and specific inhibitory effects in some thiol-containing proteins. The thiol-oxidizing properties of organoselenium compounds are considered the molecular basis of their chronic toxicity; however, the acute use of organoselenium compounds as inhibitors of specific thiol-containing enzymes can be of therapeutic significance. In summary, the outcomes of the clinical trials of ebselen as a mimetic of lithium or as an inhibitor of SARS-CoV-2 proteases will be important to the field of organoselenium synthesis. The development of computational techniques that could predict rational modifications in the structure of organoselenium compounds to increase their specificity is required to construct a library of thiol-modifying agents with selectivity toward specific target proteins.

Role of 7-chloro-4-(phenylselanyl) quinoline in the treatment of oxaliplatin-induced hepatic toxicity in mice

There is an increasing incidence of hepatotoxicity induced by oxaliplatin (OXA); therefore, researchers' attention has been drawn to therapeutic alternatives that may decrease OXA-induced hepatotoxicity. Studies indicate that oxidative stress plays a major role in OXA-induced liver injury. As several pharmacological effects of 7-chloro-4-(phenylselanyl) quinole (4-PSQ) involve its antioxidant action, the hypothesis that this organoselenium compound could be promising for the treatment or prevention of hepatotoxicity induced by treatment with OXA was investigated. To test this hypothesis, male Swiss mice received OXA (10 mg·kg-1) on days 0 and 2, followed by oral administration of 4-PSQ (1 mg·kg-1) on days 2 to 14. 4-PSQ reduced the plasma aspartate, and alanine aminotransferase activity increased by exposure to OXA. The histopathological examination of the liver showed that 4-PSQ markedly improved OXA-induced hepatic injury. In addition, treatment with 4-PSQ reduced the oxidation of lipids and proteins (thiobarbituric acid reactive species levels and protein carbonyl content) and attenuated the increase of hepatic catalase and glutathione peroxidase activity caused by OXA. The inhibition of hepatic δ-aminolevulinic dehydratase activity induced by OXA was reverted by 4-PSQ. In conclusion, results indicate that 4-PSQ may be a good therapeutic strategy for attenuating OXA-induced liver damage.

Transition-metal-free C-S, C-Se, and C-Te Bond Formation from Organoboron Compounds

The present review describes the successful application of organoboron compounds in transition-metal-free C-S, C-Se, and C-Te bond formations. We presented studies regarding these C-Chalcogen bond formations using organoboron reagents, such as boronic acids, boronic esters, borate anions, and several sources of chalcogen atoms/moieties. Moreover, a broad range of transition-metal-free approaches to synthesize sulfides, selenides, and tellurides were described using conventional heating methods, which are sometimes green since they use green solvents, safe reagents, among others. Furthermore, protocols using alternative energy sources, including ultrasound, microwave irradiation, photocatalysis, and electrolytic processes, were also shown to be suitable. These protocols were applied to prepare a broad scope of functionalized chalcogenides with high molecular diversity. These studies and their proposed mechanisms were also reported herein in addition to the reuse of reaction promoters.

Searching for new anxiolytic agents among derivatives of 11-dialkylaminoethyl-2,3,4,5-tetrahydrodiazepino[1,2-a]benzimidazole

A study on the anxiolytic activity of the new derivatives of 11-dialkylaminoethyl-2,3,4,5-tetrahydrodiazepino[1,2-a]benzimidazole, containing privileged scaffolds of benzodiazepine and benzimidazole in their structure, was conducted. The cytotoxic properties of low levels of six compounds were preliminary determined in vitro using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide test. The screening of these substances for anxiolytic activity was conducted using elevated plus maze (EPM) test in vivo, and DAB-21 was found to be the most active compound. The acute toxicity of DAB-21 was determined as less toxic than that of diazepam. The dose-dependent effect of the most active compound revealed a minimum dose of 1.26 mg/kg, which resulted in the maximum counterphobic effect. The effect of DAB-21 was superior in a number of tests compared with that of diazepam, which indicated a high level of tranquilizing activity for DAB-21. The results of in silico docking analysis suggest that DAB-21 should have a slightly lower anxiolytic activity than diazepam, but should exhibit greater specific affinity for the benzodiazepine site of the GABA_A receptor, in comparison with its GABA-binding site. The interaction between DAB-21 and flumazenil in terms of EPM verifies the GABAergic mechanism of action of DAB-21. Our results highlight the potential of 11-dialkylaminomethyl-2,3,4,5-tetrahydrodiazepino[1,2-a]benzimidazoles as promising compounds in the search for new highly effective anxiolytics.

7-chloro-4-(phenylselanyl) quinoline co-treatment prevent oxidative stress in diabetic-like phenotype induced by hyperglycidic diet in Drosophila melanogaster

The goals of this work were to evaluate the effects produced by a hyperglycidic diet (HD) on Drosophila melanogaster and to verify the protective effect of 7-chloro-4-(phenylselanyl) quinoline (4-PSQ) on this model. Adult flies were divided into eight groups of 50 flies each: (1) RD, (regular diet) (2) RD + 4-PSQ (25 μM), (3) HD 5%, (4) HD 10%, (5) HD 30% (6) HD 5% + 4-PSQ (25 μM), (7) HD 10% + 4-PSQ (25 μM) and (8) HD 30% + 4-PSQ (25 μM). Flies were exposed to a diet containing sucrose and or 4-PSQ for ten days, according to each group. At the end of treatment survival rate, longevity, hatch rate, food intake, glucose and triglyceride levels, as well as, some markers of oxidative stress, such as thiobarbituric acid reactive substances (TBARS), superoxide dismutase (SOD) and catalase (CAT) activities, protein thiol (PSH) and non-protein levels (NPSH) and cell viability assays (Resazurin and MTT) were evaluated. It was observed that HD's consumption was associated with lower survival of the flies, lower longevity, and increased levels of glucose, triglycerides, TBARS and increased SOD activities and CAT activities. Treatment with 25 μM 4-PSQ increased the satiety of flies, increased survival, reduced glucose, triglyceride and TBARS levels, increased hatching, and normalized SOD and CAT activities. These results suggest that 25 μM 4-PSQ had a potential antioxidant effect and provided greater satiety by attenuating the effects of high HD consumption on this model.

Advances in the Understanding of Oxaliplatin-Induced Peripheral Neuropathy in Mice: 7-Chloro-4-(Phenylselanyl) Quinoline as a Promising Therapeutic Agent

In this study, the deposition of platinum in oxaliplatin (OXA)-exposed mice and the effects of the oxidative damage on the central nervous system were investigated. The relationship between the reactive species (RS) levels as well as the expression and activity of enzymes, such as catalase (CAT), glutathione peroxidase (GPx), superoxide dismutase (SOD) and acetylcholinesterase (AChE), in the development of peripheral neuropathy after OXA exposure, was evidenced. The effects of 7-chloro-4-(phenylselanyl) quinoline (4-PSQ) on OXA-induced peripheral neuropathy was also investigated. Swiss mice received OXA (10 mg kg^-1) or vehicle by intraperitoneal route (days 0 and 2). Oral administration of 4-PSQ (1 mg kg^-1) or vehicle was performed on days 2 to 14. Behavioural tasks started on day 9, after the first OXA administration. It was observed that 4-PSQ reduced the mechanical and thermal hypersensitivity induced by OXA. 4-PSQ and OXA did not affect locomotor and exploratory activities. The results revealed, for the first time, a high concentration of platinum in the spinal cord of mice exposed to OXA. 4-PSQ reversed the increased levels of RS in the spinal cord, cerebral cortex and hippocampus of mice exposed to OXA. The alterations in the activity and expression of the GPx, SOD, CAT and AChE induced by OXA exposure were normalized by 4-PSQ. Therefore, the 4-PSQ might be a good prototype for the development of a more effective drug for the treatment of OXA-induced peripheral neuropathy. The results obtained by the present study expanded the knowledge about the mechanisms involved in the physiopathology of peripheral neuropathy. Graphical abstract.

The anxiolytic effect of a promising quinoline containing selenium with the contribution of the serotonergic and GABAergic pathways: Modulation of parameters associated with anxiety in mice

Recently, we demonstrated the promising anxiolytic action of 7-chloro-4-(phenylselanyl) quinoline (4-PSQ) in mice. For this reason, the objective of this study was to expand our previous findings by investigating the contribution of serotoninergic and GABAergic systems to the anxiolytic action of this compound. Pretreatment with different serotoninergic antagonists (pindolol, WAY100635 and ketanserin) blocked the anxiolytic effect caused by 4-PSQ (50 mg/kg, per oral) in the elevated plus maze (EPM) test. The contribution of the GABAergic system was investigated by pretreatment with pentylenetetrazole (a GABA_A receptor antagonist) (PTZ). 4-PSQ diminished the PTZ-induced anxiety, and did not modify the locomotor, exploratory and motor activities of mice. Later, this group of animals was euthanized and the blood was removed to determine the levels of corticosterone, and cerebral cortex and hippocampus to determine the mRNA expression levels of cAMP response element binding protein (CREB), brain derived neurotrophic factor (BDNF) and nuclear factor kappa B (NF-κB), as well as the Na⁺, K⁺ ATPase activity and reactive species (RS) levels. 4-PSQ was able to significantly reverse the increase in RS and corticosterone levels, as well as the decrease of CREB and BDNF expression in the cerebral structures and increase of NF-κB expression in the hippocampus. Finally, 4-PSQ restored the Na⁺, K⁺ ATPase activity in the cerebral structures evaluated. Here, we showed that the modulation of serotonergic and GABAergic systems, factors related to neurogenesis, oxidative status and Na⁺, K⁺ ATPase activity contributes to the anxiolytic effect of 4-PSQ and reinforces the therapeutical potential of this compound for the treatment of anxiety.

Pharmacological modulation of Na+, K+-ATPase as a potential target for OXA-induced neurotoxicity: Correlation between anxiety and cognitive decline and beneficial effects of 7-chloro-4-(phenylselanyl) quinoline

Growing evidence demonstrates that Oxaliplatin (OXA) is commonly associated with neurotoxicity that leads to emotional and cognitive impairments. The aim of the present study was to evaluate the OXA and Na⁺, K⁺-ATPase interaction and to correlate anxious behavior and cognitive impairment induced by this chemotherapeutic in Swiss mice. Also, considering the pharmacological modulation of Na⁺, K⁺-ATPase as a potential target for OXA-induced neurotoxicity, the therapeutic potential of 7-chloro-4-(phenylselanyl) quinoline (4-PSQ) was evaluated. Mice received OXA (10 mg kg^-1) or vehicle by intraperitoneal route (days 0 and 2). Oral administration of 4-PSQ (1 mg kg^-1) or vehicle was performed from days 2-14. Behavioral tasks started from day 12 onwards. On day 15, the animals were sacrificed, and the tissues collected. The effects of OXA and 4-PSQ on activity and expression level of Na⁺, K⁺-ATPase in the hippocampus and cerebral cortex, and the plasmatic corticosterone levels were determined. The findings demonstrated a significant positive correlation between anxious behavior and cognitive impairment induced by OXA. OXA caused an increase on the plasmatic corticosterone levels and reduced activity and expression level of Na⁺, K⁺-ATPase. 4-PSQ reduced both anxious behavior and cognitive impairment induced by OXA. 4-PSQ effect seems to be due to the modulation of Na⁺, K⁺-ATPase and reduction of corticosterone levels. Our results helped to expand knowledge about the mechanisms involved in the physiopathology of the OXA-induced neurotoxicity and strongly indicated that 4-PSQ may be a good prototype for the treatment of anxious behavior and cognitive impairment induced by OXA exposure.

Synthesis and antioxidant activity of new selenium-containing quinolines

Background:

Quinoline derivatives have been attracted much attention in drug discovery and synthetic derivatives of these scaffolds present a range of pharmacological activities. Therefore, organoselenium compounds are valuable scaffolds in organic synthesis because their pharmacological activities and their use as versatile building blocks for regio-, chemio-and stereoselective reactions. Thus, the synthesis of selenium-containing quinolines has great significance, and their applicability range from simple antioxidant agents, to selective DNA-binding and photocleaving agents.

Objective:

In the present study we describe the synthesis and antioxidant activity in vitro of new 7-chloroN(arylselanyl)quinolin-4-amines 5 by the reaction of 4,7-dichloroquinoline 4 with (arylselanyl)-amines 3.

Methods:

For the synthesis of 7-chloro-N(arylselanyl)quinolin-4-amines 5, we performed the reaction of (arylselanyl)- amines 3 with 4,7-dichloroquinoline 4 in the presence of Et3N at 120 °C in a sealed tube. The antioxidant activities of the compounds 5 were evaluated by the following in vitro assays: 2,2- diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, 2,2-azinobis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS), ferric ion reducing antioxidant power (FRAP), nitric oxide (NO) scavenging and superoxide dismutase-like activity (SOD-Like).

Results:

7-Chloro-N(arylselanyl)quinolin-4-amines 5a-d has been synthesized in yields ranging from 68% to 82% by the reaction of 4,7-dichloroquinoline 4 with arylselanyl-amines 3a-d using Et3N as base, at 120 °C, in a sealed tube for 24 hours and tolerates different substituents, such as -OMe and -Cl, in the arylselanyl moiety. The obtained compounds 5a-d presented significant results with respect to the antioxidant potential, which had effect in the tests of inhibition of radical’s DPPH, ABTS+ and NO, as well as in the test that evaluates the capacity (FRAP) and in the superoxide dismutase-like activity assay (SOD-Like). It is worth mentioning that 7-chloro-N(arylselanyl)quinolin-4-amine 5b presented excellent results, demonstrating a better antioxidant capacity when compared to the others.

Conclusion:

According to the obtained results 7-chloro-N(arylselanyl)quinolin-4-amines 5 were synthesized in good yields by the reaction of 4,7-dichloroquinoline with arylselanyl-amines and tolerates different substituents in the arylselanyl moiety. The tested compounds presented significant antioxidant potential in the tests of inhibition of DPPH, ABTS+ and NO radicals, as well as in the FRAP and superoxide dismutase-like activity assays (SOD-Like).

Synthesis, photophysics and biomolecule interactive studies of new hybrid benzo-2,1,3-thiadiazoles

New hybrid molecules containing benzo-2,1,3-thiadiazole, benzofuran and arylselanyl moieties were synthesized and their photophysics and biomolecule interactive studies were performed.

Synthesis of Isoxazolines by the Electrophilic Chalcogenation of β,γ-Unsaturated Oximes: Fishing Novel Anti-Inflammatory Agents

Herein, we describe a new strategy to prepare chalcogen-functionalized isoxazolines. The strategy involves the reaction of β,γ-unsaturated oximes with electrophilic selenium and tellurium species, affording 19 new selenium- and tellurium-containing isoxazolines in good yields after 1 h at room temperature. The method was efficiently extended to the synthesis of 5 new (bis)isoxazoline ditellurides. One of the prepared compounds, 3-phenyl-5-((phenylselanyl)methyl)-isoxazoline, demonstrated better anti-inflammatory and antiedematogenic effects than the reference drug Celecoxib.

7-chloro-4-(phenylselanyl) quinoline prevents dopamine depletion in a Drosophila melanogaster model of Parkinson's-like disease

Neurodegeneration in Parkinson's disease appears to be caused by multiple factors, including oxidative damage and an increase in acetylcholinesterase expression that can culminate in loss of dopaminergic neurons. A selenium-containing quinoline derivative, 7-chloro-4-(phenylselanyl) quinoline (4-PSQ), shows important pharmacological actions mainly attributed to its antioxidant and anticholinesterase properties. Thus, this study investigated the neuroprotective effect of 4-PSQ in a model of Parkinson's-like disease induced by rotenone (ROT) in Drosophila melanogaster and verified whether these effects are related to selenium levels. Adult flies were divided into: [1] control, [2] 4-PSQ (25 μM), [3] ROT (500 μM), and [4] 4-PSQ (25 μM) + ROT (500 μM) groups and exposed to a diet containing ROT and/or 4-PSQ for 7 days, according to their respective groups. Survival, behavioral, and ex vivo analyses were performed. Dopamine levels, reactive species levels (RS), lipid peroxidation (LPO), superoxide dismutase (SOD) and catalase (CAT) activity, and proteic thiol (PSH) and non-proteic thiol (NPSH) content in the head region were analyzed, while acetylcholinesterase (AChE) activity and selenium levels in the head and body regions were analyzed. 4-PSQ was able to reverse the ROT-induced deficits in flies, reestablish dopamine and selenium levels, reverse cholinergic deficits, improve motor function, and ameliorate mortality. Furthermore, 4-PSQ also reduced RS levels and LPO, and restored the activities of the antioxidant enzymes, SOD and CAT. Interestingly, a positive relationship between dopamine and selenium levels could be seen. Our results demonstrate the neuroprotective effect of 4-PSQ, and we suggest that the compound may act via different mechanisms, such as improving antioxidant defenses and consequently reducing oxidative damages, as well as having an anticholinesterase action, which together can prevent dopamine depletion, as these actions were correlated with the presence of selenium in the 4-PSQ molecule.

7-Chloro-4-(Phenylselanyl) Quinoline with Memory Enhancer Action in Aging Rats: Modulation of Neuroplasticity, Acetylcholinesterase Activity, and Cholesterol Levels

This study investigated the effect of 7-chloro-4-(phenylselanyl) quinoline (4-PSQ) to restore the cognitive impairment caused by aging in male Wistar rats. Moreover, modulation of neuroplasticity markers, acetylcholinesterase (AChE) activity, and cholesterol levels was performed. Aged rats were intragastrically treated with 4-PSQ (5 mg/kg) for 7 days. Animals were tested in behavioral tasks, and then plasma (to determine cholesterol levels), hippocampus, and cerebral cortex (to determine neural cell adhesion molecule (NCAM) and polysialyltransferase (PST) levels, and AChE activity) were removed. Our findings demonstrated that treatment of aged rats with 4-PSQ restored short-term and long-term memories in the object recognition tests. 4-PSQ treatment did not restore exploratory activity (rearings) but partially restored locomotor activity (crossings) reduced by aging in the open-field test. Moreover, the compound restored the reduction in the NCAM and PST levels, and AChE activity in cerebral structures, as well as the increase in the plasma cholesterol levels, caused by aging in rats. In conclusion, 4-PSQ restored cognitive impairment caused by aging in rats by modulating synaptic plasticity, cholinergic system, and cholesterol levels.

Iodine mediated in situ generation of R-Se–I: application towards the construction of pyrano[4,3-b]quinoline heterocycles and fluorescence properties

Iodine mediated in situ generation of R-Se–I and its application towards the construction of pyrano[4,3-b]quinolin-1-one derivatives.

Current advances of pharmacological properties of 7-chloro-4-(phenylselanyl) quinoline: Prevention of cognitive deficit and anxiety in Alzheimer's disease model

This study investigated the effect of 7-chloro-4-(phenylselanyl) quinoline (4-PSQ) at a dose of 1 mg/kg in memory impairment and anxiety in an Alzheimer's disease (AD) model induced by amyloid β-peptide (Aβ) (fragment 25-35) in mice. The involvement of acetylcholinesterase (AChE) activity and lipid peroxidation in hippocampus and cerebral cortex was evaluated. Male Swiss mice were pretreated with 4-PSQ (1 mg/kg, intragastrically (i.g.), daily) for fourteen days. Thirty minutes after the first treatment with 4-PSQ, the animals received a single injection of Aβ (3 nmol/3 μl/per site, intracerebroventricular (i.c.v.)). Mice were submitted to the behavioral tasks (open-field, elevated plus maze, Barnes maze, object recognition and location, and step-down inhibitory avoidance tests) from the fifth day onwards. On the fifteenth day, blood was removed for analysis of biochemical markers (glucose, triglycerides, urea, aspartate (AST) and alanine (ALT) aminotrasferases), and cerebral cortex and hippocampus for determination of AChE activity and thiobarbituric acid reactive species (TBARS) levels. Aβ caused memory impairment, anxiogenic behavior, increased AChE activity in the cerebral structures and TBARS levels in the cerebral cortex. 4-PSQ was effective to protect against behavioral changes, AChE activity and TBARS levels. In conclusion, 4-PSQ protected against learning and memory impairment and anxiety in a mouse model of AD induced by Aβ, and anticholinesterase and antioxidant actions are involved in the pharmacological effect of the compound.

Ultrasound-promoted synthesis of 2-organoselanyl-naphthalenes using Oxone® in aqueous medium as an oxidizing agent

A green methodology to synthesize 2-organoselanyl-naphthalenes based on the reaction of alkynols with diaryl diselenides is described. The electrophilic species of selenium were generated in situ, by the oxidative cleavage of the Se–Se bond of diaryl diselenides by Oxone^® using water as the solvent. The reactions proceeded efficiently under ultrasonic irradiation as an alternative energy source, using a range of alkynols and diorganyl diselenides as starting materials. Through this methodology, the corresponding 2-organoselanyl-naphthalenes were obtained in moderate to good yields (56–94%) and in short reaction times (0.25–2.3 h).

Organoselenium group is critical for antioxidant activity of 7-chloro-4-phenylselenyl-quinoline

The quinolone compounds have been reported for many biological properties, especially as potent antioxidants. This study investigated the antioxidant effect of 7-chloro-4-phenylselenyl-quinoline (PSQ), a quinolone derivative with organoselenium group, against oxidative stress induced by sodium nitroprusside (SNP) in brains of mice. A second objective was to verify the importance of phenylselenyl group presents at position 4 of the quinoline structure to antioxidant effect of compound. So, it was compared the antioxidant effect of PSQ with a quinoline without organoseleniun group (7-chloroquinoline [QN]). Swiss mice were used and received SNP (0.335 μmol/site, intracerebroventricular) 30 min after treatment with PSQ or QN, at the doses of 50 mg/kg (intragastrically). After 1 h, animals were sacrificed and the brains were removed to biochemistry analysis. Thiobarbituric acid reactive species (TBARS), protein carbonyl (PC) and non-protein thiol (NPSH) levels, as well as catalase (CAT), glutathione S transferase (GST) and δ -aminolevulinic acid (δ-ALA-D) activities were determined. SNP increased TBARS and PC levels, and reduced the enzymatic (CAT and GST activity) and non-enzymatic (NPSH levels) antioxidant defenses and inhibited the δ-ALA-D activity. PSQ avoided the increase in the lipid peroxidation and PC levels, as well as the decrease in the NPSH levels, CAT, GST and δ-ALA-D activities QN partially avoided the increase in lipid peroxidation, but it not protected against alterations induced by SNP. In conclusion, phenylselenyl group present in quinoline structure is critical for antioxidant activity of PSQ.

Modulating Neuroinflammation to Treat Neuropsychiatric Disorders

Neuroinflammation is recognised as one of the potential mechanisms mediating the onset of a broad range of psychiatric disorders and may contribute to nonresponsiveness to current therapies. Both preclinical and clinical studies have indicated that aberrant inflammatory responses can result in altered behavioral responses and cognitive deficits. In this review, we discuss the role of inflammation in the pathogenesis of neuropsychiatric disorders and ask the question if certain genetic copy-number variants (CNVs) associated with psychiatric disorders might play a role in modulating inflammation. Furthermore, we detail some of the potential treatment strategies for psychiatric disorders that may operate by altering inflammatory responses.

Further analysis of acute antinociceptive and anti-inflammatory actions of 4-phenylselenyl-7-chloroquinoline in mice

A new quinoline containing selenium, 4-phenylselenyl-7-chloroquinoline (4-PSQ), was described and synthetized by our research group. Recently, we demonstrated the potential antinociceptive and anti-inflammatory of 4-PSQ. For this reason, the first objective of this study was to expand our previous findings by investigating the contribution of glutamatergic, serotonergic, and nitrergic systems to the acute antinociceptive action of this compound. Pretreatment with 4-PSQ (0.01-25 mg/kg, p.o.) reduced the nociception induced by glutamate. MK-801 (an uncompetitive antagonist of the N-Methyl-d-aspartate (NMDA) receptor) blocked the antinociceptive effect exerted by 4-PSQ (25 mg/kg, p.o.) in the acetic acid-induced abdominal writhing test. The pretreatment with WAY100635 (a selective antagonist of 5-HT_1A receptor), ketanserin (a selective antagonist of 5-HT_2A/2C receptor), and pindolol (a nonselective antagonist of 5-HT_1A/1B receptors) partially blocked the antinociceptive effect caused by 4-PSQ (25 mg/kg, per oral, p.o.) in the acetic acid-induced abdominal writhing test. Nitric oxide precursor, l-arginine hydrochloride, partially reversed antinociception caused by 4-PSQ or ω-nitro-l-arginine (l-NOARG). Treatments did not modify the locomotor and exploratory activities of mice. Additionally, the acute anti-inflammatory effect of 4-PSQ in a model of pleurisy induced by carrageenan in mice was investigated. 4-PSQ reduced the cellular migration, pleural exudate accumulation, and myeloperoxidase activity induced by carrageenan exposure. 4-PSQ protected against the increase in reactive species levels and reduction of nonprotein thiol levels induced by carrageenan. Data presented here showed that the modulation of serotonergic, nitrergic, and glutamatergic systems contributed to the antinociceptive effect of 4-PSQ and it reinforced the therapeutic potential of this quinolinic compound for acute inflammation.