Synthesis of oxathiolane imidazole nucleosides

Nucleosides have been of great interest since their strong antiviral activities were discovered. 1,3-Oxathiolane ring system has been known for many years, but it is in recent years that the ring has been used as the sugar ring in nucleoside analogs (Synthesis (1991) 1046; J. Am. Chem. Soc. 113 (1991) 9377; Tetrahedron Lett. 35 (1994) 4739). Besides, bredinin is a natural nucleoside antibiotic with imidazole moiety and there are some other studies reported on nucleosides with the imidazole group (Biorg. Med. Chem. 7 (1999) 48 1; Biorg. Med. Chem. 7 (1999) 1617; Nucleosides Nucleotides 18 (1099) 3 3 1). These findings make the imidazole group interesting as the base of a nucleoside. In this study, in order to find out the structure-activity relationships Of L-oxathiolanyl nucleosides, L-oxathiolanyl imidazole nucleosides 7 and 8 were synthesized, via novel intermediates 2-6, which were then tested for anti-HIV activity (Antivir. Res. 1-11 (1994) 25) in human peripheral blood mononuclear (PBM) cells, the synthesized nucleosides did not show significant activity up to 100 muM against HIV-1. (C) 2002 Editions scientifiques et medicales Elsevier SAS. All rights reserved

Synthesis and evaluation of antibacterial activity of some 2-[[alpha-(4-substituted benzoyloxy)-alpha-phenylacetyl or methylacetyl]amino]-5-(4-methoxyphenyl)-1,3,4-oxadiazoles

In this study, a new series of 2-[[alpha-(4-substitutedbenzoyloxy)-alpha-phenylacetyl or methylacetyl]amino]-5-(4-methoxyphenyl)-1,3,4-oxadiazoles were obtained by condensation of 2-[(alpha-chloro-alpha-phenylacetyl or alpha-bromopropionyl)amino]-5-(4-methoxyphenyl)1,3,4-oxadiazoles with sodium salts of 4-substituted benzoic acids. Structures of the compounds were assigned on the basis of spectral data (UV, IR, H-1 NMR, EI MS) and elemental analyses. The antibacterial activities of the novel compounds against Staphylococcus aureus ATCC 6538, Staphylococcus epidermidis ATCC 12228, Escherichia coli ATCC 8739, Klebsiella pneumoniae ATCC 4352, Pseudomonas aeruginosa ATCC 1539, Salmonella typhi, Shigella flexneri and Proteus mirabilis and antifungal activity against Candida albicans ATCC 10231 were tested using disk diffusion method. Compounds 4a, 4d and 4g were found to be active against S. aureus ATCC 6538 (MIC, 78, 39 and 78 mug ml(-1), respectively) and compound 4e against S. epidermidis ATCC 12228 (MIC, 156 mug ml(-1)). (C) 2001 Elsevier Science S.A. All rights reserved

Synthesis and antitubercular activity of 4-(3-coumarinyl)-3-cyclohexyl-4-thiazolin-2-one benzylidenehydrazones

In this study, a new series of 4-(3-coumarinyl)-3-cyclohexyl-4-thiazoline-2-one benzylidene hydrazones (3a-p) were synthesized. Structures of the title compounds were determined by analytical and spectral methods. 3a-p were evaluated for antituberculosis activity against Mycobacterium tuberculosis H37Rv. (C) 2002 Editions scientifiques et medicales Elsevier SAS. All rights reserved

Synthesis and antibacterial activity of 5-aryl-2-[(alpha-chloro-alpha-phenylacetyl/alpha-bromopropionyl)amino]-1,3,4-oxadiazoles and 2-[(5-aryl-1,3,4-oxadiazol-2-yl)imino]-5-phenyl/methyl-4-thiazolidinoes

Reaction of 5-aryl-2-amino-1,3,4-oxadiazoles (BI-VI), obtained by the oxydative cyclization of aromatic aldehyde semicarbazones (A(I-VI)), with alpha-chloro-alpha-phenylacetyl chloride and alpha-bromopropionyl bromide yielded 5-aryl-2-[(alpha-chloro-alpha-phenylacetyl)amino]- 1,3,4-oxadiazoles (Ia-VIa) and 5-aryl-2-[(alpha-bromopropionyl)amino]-1,3,4-oxadiazoles (VIIa-XIIa), respectively. Furthermore, Ia-XIIa were refluxed with ammonium thiocyanate to give 5-phenyl/methyl-2-[(5-aryl-1,3,4-oxadiazol-2-yl)imino]-4-thiazolidinones (It-XIIt)

Synthesis and antimicrobial activity of some 5-aryl-2-[(N,N-disubstituted thiocarbamoylthio)acylamino]-1,3,4-oxadiazoles

In this study, a number of novel 5-aryl-2-[(N,N-disubstituted thiocarbamoylthio)acylamino]-1,3,4-oxadiazole derivatives were synthesized by the reaction of potassium salts of N,N-disubstituted dithiocarbamoic acids with 2-[(alpha-chloro-alpha-phenylacetyl/alpha-bromopropionyl)-amino]-5-aryl-1,3,4-oxadiazoles. Structures of the compounds were confirmed by the spectral data (IR, H-1 NMR, EIMS) and elemental analyses. Most of the compounds were tested against various microorganisms and four of them were found to be weakly active against Staphylococcus aureus and Staphylococcus epidermidis. (C) 1998 Elsevier Science S.A. All rights reserved