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In this contribution, a metal- and base-free protocol has been developed for the synthesis of phosphorochalcogenoates (Se and Te) by using DMSO as solvent at 50 °C. A variety of phosphorochalcogenoates were prepared from diorganyl dichalcogenides and H-phosphonates, leading to the formation of a Chal-P(O) bond, in a rapid procedure with good to excellent yields. A full structural elucidation of products was accessed by 1D and 2D NMR, IR, CGMS, and HRMS analyses, and a stability evaluation of the phosphorochalcogenoates was performed for an effective operational description of this simple and feasible method. Typical 77 Se{ 1 H} (δ Se  = 866.0 ppm), 125 Te{ 1 H} (δ Te  = 422.0 ppm) and 31 P{ 1 H} (δ P  = -1.0, -13.0 and -15.0 ppm) NMR chemical shifts were imperative to confirm the byproducts, in which this stability study was also important to select some products for pharmacological screening. The phosphorochalcogenoates were screened in vitro and ex vivo tests for the antioxidant potential and free radical scavenging activity, as well as to investigation toxicity in mice through of the plasma levels of markers of renal and hepatic damage. The pharmacological screening of phosphorochalcogenoates indicated that compounds have antioxidant propriety in different assays and not changes plasma levels of markers of renal and hepatic damage, with excision of 3g compound that increased plasma creatinine levels and decreased plasma urea levels when compared to control group in the blood mice. Thus, these compounds can be promising synthetic antioxidants that provide protection against oxidative diseases., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Masson SAS. All rights reserved.)

An alternative method to prepare 2-organylchalcogenopheno[2,3-b]pyridines was developed by the insertion of chalcogen species (selenium, sulfur or tellurium), generated in situ, into 2-chloro-3-(organylethynyl)pyridines by using the NaBH 4 /PEG-400 reducing system, followed by an intramolecular cyclization. It was possible to obtain a series of compounds with up to 93 % yield in short reaction times. Among the synthesized products, 2-organyltelluropheno[2,3-b]pyridines have not been described in the literature so far. Moreover, the compounds 2-phenylthieno[2,3-b]pyridine (3 b) and 2-phenyltelluropheno[2,3-b]pyridine (3 c) exhibited significant antioxidant potential in different in vitro assays. Further studies demonstrated that compound 3 b exerted an antinociceptive effect in acute inflammatory and non-inflammatory pain models, thus indicating the involvement of the central and peripheral nervous systems on its pharmacological action. More specifically, our results suggest that the intrinsic antioxidant property of compound 3 b might contribute to attenuating the nociception and inflammatory process on local injury induced by complete Freund's adjuvant (CFA)., (© 2020 Wiley-VCH GmbH.)

We describe here a simple method for the synthesis of 6-arylselanylpurines with antioxidant and anticholinesterase activities, and memory improvement effect. This class of compounds was synthesized in good yields by a reaction of 6-chloropurine with diaryl diselenides using NaBH 4 as reducing agent and PEG-400 as solvent. Furthermore, the synthesized compounds were evaluated for their in vitro antioxidant and acetylcholinesterase (AChE) inhibitor activities. The best AChE inhibitor was assessed on the in vivo memory improvement. Our results demonstrated that the 6-((4-chlorophenyl)selanyl)-9H-purine and 6-(p-tolylselanyl)-9H-purine presented in vitro antioxidant effect. In addition, 6-((4-fluorophenyl)selanyl)-9H-purine inhibited the AChE activity and improved memory, being a promising therapeutic agent for the treatment of Alzheimer's disease., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

We describe here a simple method for the synthesis of glycerol derivatives containing an organochalcogen unit (Se, Te and S) using NaBH4 and PEG-400 as a solvent. The new methodology was used to synthesize a range of new organochalcogen compounds in good yields. Furthermore, four of synthesized compounds were evaluated for their antioxidant activity using different assays, such as 2-azinobis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS), 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical, nitric oxide (NO) and hydroxyl radical (OH) scavenging, ferric ion reducing antioxidant power (FRAP), ferrous ion chelating, superoxide dismutase-like activity and inhibition of linoleic acid lipid peroxidation. The new organotellurium 2,2-dimethyl-4-(phenyltellanylmethyl)-1,3-dioxolane 3 j showed antioxidant activity and was more effective in inhibition of induced lipid peroxidation compared to solketal 4. Selenium and sulfur analogs 3a and 3m and solketal 4 did not present antioxidant effect. These findings suggest that 2,2-dimethyl-4-(phenyltellanylmethyl)-1,3-dioxolane 3 j is a promising antioxidant and that its activity is influenced by the presence of the tellurium atom on the structure., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

We describe herein our results on the synthesis and biological properties in Caenorhabditis elegans of a range of 4-organylsulfenyl-7-chloroquinolines. This class of compounds have been easily synthesized in high yields by direct reaction of 4,7-dichloroquinoline with organylthiols using DMSO as solvent at room temperature under air atmosphere and tolerates a range of substituents in the organylsulfenyl moiety. We have performed a toxicological and pharmacological screening of the synthesized 4-organylsulfenyl-7-chloroquinolines in vivo in C. elegans acutely exposed to these compounds, under per se and stress conditions. Hence, we determined the lethal dose 50% (LD50), in order to choose a nonlethal concentration (10 μM) and verified that at that concentration some of the compounds depicted protective action against the induced damage inflicted by paraquat, a superoxide generator. Two compounds (3c and 3h) reduced the toxicity inflicted by paraquat above survival, reproduction and longevity of the worms, at least in part, by reducing the reactive oxygen species (ROS) generated by the toxicant exposure. Besides, these compounds increased the quantities of superoxide dismutase (SOD-3::GFP) and catalase (CTL-1,2,3::GFP), antioxidant enzymes. We concluded that the protective effects of the compounds observed in this study might have been a hormetic response dependent of the transcriptional factor DAF-16/FOXO, causing a non-lethal oxidative stress that protects against the subsequently damage induced by paraquat., (Copyright © 2014 Elsevier Masson SAS. All rights reserved.)

Essential oil (EO) of the leaves of Eugenia uniflora L. (Brazilian cherry tree) was evaluated for its antioxidant, antibacterial and antifungal properties. The acute toxicity of the EO administered by oral route was also evaluated in mice. The EO exhibited antioxidant activity in the DPPH, ABTS and FRAP assays and reduced lipid peroxidation in the kidney of mice. The EO also showed antimicrobial activity against two important pathogenic bacteria, Staphylococcus aureus and Listeria monocytogenes, and against two fungi of the Candida species, C. lipolytica and C. guilliermondii. Acute administration of the EO by the oral route did not cause lethality or toxicological effects in mice. These findings suggest that the EO of the leaves of E. uniflora may have the potential for use in the pharmaceutical industry., (Copyright © 2012 Elsevier Ltd. All rights reserved.)