Azaanalogues of ebselen as antimicrobial and antiviral agents: synthesis and properties

The different analogues of ebselen-unsubstituted benzisoselenazol-3(2H)-one (2a) 2-pyridylbenzisoselenazol-3(2H)-ones (2b-h) and 7-azabenzisoselenazol-3(2H)-ones (3a-j) were designed as new selenium-containing antiviral and antimicrobial agents and synthesized. Some of them were found in the antiviral assay in vitro to be strong inhibitors of cythopatic activity of herpes simplex virus type 1--HSV-1 (compounds 2a,b,f,h, 3a-j) and encephalomyocarditis virus--EMCV (compounds 2a,h, 3a-f,k,l). The compounds 2a,h and 3a-e,j were found to have an appreciable activity against Gram-positive bacteria (Staphylococcus aureus and Bacillus) in vitro, some of them inhibited growth of pathogenic yeasts (Candida albicans) (3a,b) and filamentous fungi (3a-e,f).

Functionalized alkyl and aryl diselenides as antimicrobial and antiviral agents: synthesis and properties

The different dialkyl and diaryl diselenides with carbamoyl and sulfamoyl moieties 2, 3, 5 and other substituents in the ortho position of benzene ring 4, 7, 8 as well as derivatives of 1,2,4-benzoselenadiazine (6) were designed as antiviral and antimicrobial agents and synthesized. Some of them, particularly 8a and 8b, were found in the antiviral assay in vitro to be strong inhibitors of cytopathic activity encephalomyocarditis virus (EMCV). The compound 4a and 8a were found to have a broad spectrum of acivity against bacteria, yeasts and pathogenic fungi in vitro.

Antifungal activity of 2-(4-chlorophenyl)-1,2-benzisoselenazol-3(2H)-one, the analog of Ebselen

The antimicrobial activity of 8 selenoorganic compounds (3-benzisoselenazoles, 1-benzisoselenazolone oxide and 4-disaryl diselenides) was investigated. It was found that selenoorganic compounds from benzisoselenazolone group suppress growth of some fungi and bacteria. The growth of Saccharomyces cerevisiae sigma 127-8b and Candida albicans 258 strains was strongly inhibited by the 2-(4-chlorophenyl)-1,2-benzisoselenazol-3(2H)-one. Also Ebselen and 2-acetyl-1,2-benzisoselenazol-3(2H)-one caused strong inhibition of Saccharomyces cerevisiae sigma 127-8b growth but a lower effect was observed in assays with Candida sp. strains. Benzisoselenazolones were also found to have antibacterial activities. They significantly reduced the growth of Gram-negative Escherichia coli K-12 ROW and Gram-positive Staphylococcus aureus 209P (Oxford) bacteria strains.

Carboxyebselen a potent and selective inhibitor of endothelial nitric oxide synthase

Ebselen (Ebs) a glutathione peroxidase like agent has been recently described as an inhibitor of nitric oxide synthase (NOS). Presently, we report that carboxyebselen (HOOC-Ebs), a hydrophyllic derivative of Ebs inhibits NOS present in enzymatic preparations from bovine endothelium, porcine cerebella, and murine spleen, however, it is both more potent and more selective for the constitutive endothelial NOS than Ebs. Unlike Ebs, HOOC-Ebs (0.1-30 microM) causes a concentration-dependent endothelium-independent relaxations of rings of rabbit aorta. The mechanism of this relaxation remains unknown and it is attenuated by glutathione (GSH, 30-300 microM) and N-acetyl-L-cysteine (NAC, 30-300 microM). The vasorelaxant activity of acetylcholine (Ach, 0.1-1 microM) in aortic rings exposed to low concentrations of HOOC-Ebs (0.1-1 microM) or rings exposed to 10 microM HOOC-Ebs after their pretreatment with GSH or NAC (30-300 microM) remained unchanged. The lack of activity of HOOC-Ebs as a NOS inhibitor in intact endothelial cells contrasts the effectiveness of Ebs in this respect.

Organoselenides as potential immunostimulants and inducers of interferon gamma and other cytokines in human peripheral blood leukocytes

A number of organoselenium compounds have been described as anti-inflammatory, antioxidant, glutathione peroxidase-like agents and inhibitors of prostaglandin synthesis. Here we report that bis [2-(N-phenyl-carboxamido)]phenyl diselenide, 2-phenyl-1,2-benzisoselenazol-3(2H)-one (Ebselen) and related compounds are inducers of interferon gamma (IFN-gamma) and tumor necrosis factor (TNF) in human peripheral blood leukocytes. The IFN and TNF response was rapid, occurring within 20 h, and high--up to 1000 and 2000 units ml-1--and was clearly related to the dosage and the structure of the compounds. The action of the compounds and phytohemagglutinin was synergistic. The IFN gamma and TNF production was reduced after removing adherent cells. Although the mode of action of the compounds is not known, they appear to interact directly or indirectly with both adherent and non-adherent leukocytes, and stimulate the synthesis of a set of different cytokines including factors controlling the cell proliferation. Therefore, organoselenides may be regarded as the biological response modifiers.