Synthesis and mechanistic study of 2-(trifluoromethyl)-10H-phenoselenazine from double cross coupling reaction.

Phenoselenazines are nitrogen and selenium-based heterocyclic compounds that have important biological activities. However, their preparation methods are scarce and difficult to handle. The synthesis of a phenoselenazine from a simple and robust CuO nanoparticle catalyzed methodology, using bis-aniline-diselenide and 1,2-dihalobenzenes under microwave irradiation. Also, the double-cross-coupling reaction mechanism for C-Se and C-N bond formation, including the observation of a reaction intermediate by mass spectrometry have been studied.

Inhibitory effects against SARSCoV-2 main protease (Mpro) of biflavonoids and benzophenones from the fruit of Platonia insignis.

The SARS-CoV-2 mutation and the limitation of the approved drug against COVID-19 are still a challenge in many country healthcare systems and need to be affronted despite the set of vaccines to prevent this viral infection. To contribute to the identification of new antiviral agents, the present study focused on natural products from an edible fruit with potential inhibitory effects against the SARS-CoV-2 main protease (Mpro). First, LC-ESIMS analysis of Platonia insignis fruits was performed and showed the presence of biflavonoids and benzophenones in the seed and pulp, respectively. Then, maceration and chromatographic purification led to the identification of two triglycerides (1 and 2) alongside chamaejasmine (3) and volkensiflavone (4) from the seed and isogarcinol (5) and cycloxanthochymol (6), from the pulp. Compounds 1-6 after evaluating their inhibitory against Mpro, displayed from no to significant activity. Compound 5 was the most potent with an IC50 value of 0.72 µM and was more active than the positive control, Ebselen (IC50 of 3.4 µM). It displayed weak and no cytotoxicity against THP-1 (CC50 of 116.2 µM) and Vero cell lines, respectively. Other active compounds showed no cytotoxicity against THP-1. and Vero cell lines. Molecular docking studies revealed interactions in the catalytic pocket between compound 5 and amino acid residues that composed the catalytic dyads (His 41 and Cyst 145).

Selenium-Derivative Compounds: A Review of New Perspectives in the Treatment of Alzheimer's Disease.

BACKGROUND: Alzheimer's disease (AD) is one of the most prevalent types of dementia, affecting millions of older people worldwide. AD is stimulating efforts to develop novel molecules targeting its main features associated with a decrease in acetylcholine levels, an increase in oxidative stress and depositions of amyloid-ß (Aß) and tau protein. In this regard, selenium-containing compounds have been demonstrated as potential multi-targeted compounds in the treatment of AD. These compounds are known for their antioxidant and anticholinesterase properties, causing a decrease in Aß aggregation. OBJECTIVE: In this review, we approach structure-activity relationships of each compound, associating the decrease of ROS activity, an increase of tau-like activity and inhibition of AChE with a decrease in the self-aggregation of Aß. METHODS: We also verify that the molecular descriptors apol, nHBAcc and MlogP may be related to optimized pharmacokinetic properties for anti-AD drugs. RESULTS: In our analysis, few selenium-derived compounds presented similar molecular features to FDA-approved drugs. CONCLUSION: We suggest that unknown selenium-derived molecules with apol, nHBAcc and MlogP like FDA-approved drugs may be better successes with optimized pharmacokinetic properties in future studies in AD.

One-pot organocatalytic/multicomponent approach for the preparation of novel enantioenriched non-natural selenium-based peptoids and peptide-peptoid conjugates.

A combined organocatalytic and multicomponent synthetic approach was designed for the preparation of selenium-based peptoids and peptide-peptoid conjugates. This single-step synthetic protocol comprises the organocatalytic asymmetric insertion of phenylselenium in the aldehyde moiety followed by the Ugi four-component reaction which results in obtaining the desired compounds in good-to-moderate yields and with good-to-excellent levels of stereoselectivity.

Synthesis and antitumor activity of selenium-containing quinone-based triazoles possessing two redox centres, and their mechanistic insights.

Selenium-containing quinone-based 1,2,3-triazoles were synthesized using click chemistry, the copper catalyzed azide-alkyne 1,3-dipolar cycloaddition, and evaluated against six types of cancer cell lines: HL-60 (human promyelocytic leukemia cells), HCT-116 (human colon carcinoma cells), PC3 (human prostate cells), SF295 (human glioblastoma cells), MDA-MB-435 (melanoma cells) and OVCAR-8 (human ovarian carcinoma cells). Some compounds showed IC50 values < 0.3 µM. The cytotoxic potential of the quinones evaluated was also assayed using non-tumor cells, exemplified by peripheral blood mononuclear (PBMC), V79 and L929 cells. Mechanistic role for NAD(P)H: Quinone Oxidoreductase 1 (NQO1) was also elucidated. These compounds could provide promising new lead derivatives for more potent anticancer drug development and delivery, and represent one of the most active classes of lapachones reported.

Imidazolium ionic liquids containing selenium: synthesis and antimicrobial activity.

The synthesis and antimicrobial profile of imidazolium ionic liquids containing selenium are described herein. Minimum inhibitory concentration revealed that these compounds are especially active against algae, and their activity is modulated by substituents attached to the selenium moiety as well as by the counterion.

Synthesis of diorganyl selenides mediated by zinc in ionic liquid.

A new approach for the synthesis of diorganyl selenides is described. By using economically attractive zinc dust in BMIM-BF(4), a series of diorganyl selenides were efficiently achieved in excellent yields, under neutral reaction conditions. Compared to the usual organic solvents, BMIM-BF(4) exhibited higher performance with the advantage to be reused up to five successive runs.

Synthesis of telluroamino acid derivatives with remarkable GPx like activity.

A series of modular telluroamino acid derivatives with remarkable GPx-like behavior was prepared in an efficient and short two-step synthesis.

Efficient synthesis of chiral beta-seleno amides via ring-opening reaction of 2-oxazolines and their application in the palladium-catalyzed asymmetric allylic alkylation.

[structure: see text] A set of chiral beta-seleno amides have been efficiently synthesized via the ring-opening reaction of chiral 2-oxazolines by selenium nucleophiles. The present method is applicable to the synthesis of beta-seleno amides containing thioether, alcohol, and ether moieties in good yields. As an application, the synthesis of a selenocysteine derivative has been accomplished. Additionally, these new compounds were evaluated in the palladium-catalyzed asymmetric allylic alkylation, giving the alkylated products in up to 98% ee.