Neuropharmacology of Organoselenium Compounds in Mental Disorders and Degenerative Diseases.

Neurodegenerative and mental disorders are a public health burden with pharmacological treatments of limited efficacy. Organoselenium compounds are receiving great attention in medicinal chemistry mainly because of their antioxidant and immunomodulatory activities, with a multi-target profile that can favor the treatment of multifactorial diseases. Therefore, the purpose of this review is to discuss recent preclinical studies about organoselenium compounds as therapeutic agents for the management of mental (e.g., depression, anxiety, bipolar disorder, and schizophrenia) and neurodegenerative diseases (e.g., Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, and multiple sclerosis). We have summarized around 70 peer-reviewed articles from 2016 to the present that used in silico, in vitro, and/or in vivo approaches to assess the neuropharmacology of selenium- containing compounds. Among the diversity of organoselenium molecules investigated in the last five years, diaryl diselenides, Ebselen-derivatives, and Se-containing heterocycles are the most representative. Ultimately, this review is expected to provide disease-oriented information regarding the neuropharmacology of organoselenium compounds that can be useful for the design, synthesis, and pharmacological characterization of novel bioactive molecules that can potentially be clinically viable candidates.

Selenium as a Versatile Reagent in Organic Synthesis: More than Allylic Oxidation.

For many years since its discovery, Selenium has played the role of a bad boy who became a hero in organic transformations. Selenium dioxide, for instance, is one of the most remembered reagents in allylic oxidations, having been applied in the synthesis of several naturally occurring products. The main goal of this review is to show the recent advances in the use of classical and new selenium reagents in organic synthesis. As demonstrated through the around 60 references discussed here, selenium can go even forward as a versatile reagent. We bring a collection of selenium reagents and their transformations that still asleep in the eyes of most synthetic organic chemists.

Synthesis of chitosan derivatives with organoselenium and organosulfur compounds: Characterization, antimicrobial properties and application as biomaterials.

In this study, Schiff bases of chitosan (CS) were synthesized using citronellal, citral, and their derivatives containing selenium and sulfur. Organoselenium and organosulfur compounds show attractive biological and pharmaceutical activities, which can be beneficial to CS-based materials. From the characterization analyses, it was found that the CS-derivatives containing organoselenium and organosulfur compounds exhibited the highest conversion degrees (23 and 28%). Biological assays were conducted using films prepared by the blending of CS-derivatives and poly(vinyl alcohol). The antimicrobial evaluation indicated that the film prepared with the sulfur-containing CS was the most active against the tested pathogens (Escherichia coli, Staphylococcus aureus, and Candida albicans) since it reduced considerably their counts (42.5%, 17.4%, and 18.7%). Finally, in vivo assays revealed that this film attenuates atopic dermatitis-like symptoms in mice by suppressing the increase of myeloperoxidase (MPO) activity and reactive species (RS) levels induced by 2,4-dinitrochlorobenzene (DNCB). In summary, CS-derivatives containing chalcogens, mainly organosulfur, are potential candidates for biomedical applications such as for the treatment of chronic skin diseases.

Ultrasound-enhanced Ag-catalyzed decarboxylative coupling between α-keto acids and disulfides for the synthesis of thioesters.

Herein, we described the ultrasound-assisted synthesis of thioesters via the Ag-catalyzed radical oxidative decarboxylation of α-keto acids, in the presence of disulfides. This protocol takes advantage of the sonication to prepare the title compounds in moderate to very good yields, in only 20 min of reaction. The positive effect of ultrasonic irradiation is attributed to both, the high mass transfer efficiency and to the induced radical formation in the reaction medium.