Wael A. El-Sayed

Antimicrobial activity of new 4,6-disubstituted pyrimidine, pyrazoline, and pyran derivatives.

A number of new 2,6-didisubstituted pyrimidine, pyrazoline, and pyran derivatives were synthesized starting from their chalcone derivative. The synthesized compounds displayed different degrees of antimicrobial activity against Bscillus subtilis (Gram-positive), Pseudomonas aeruginosa (Gram-negative), and Streptomyces species (Actinomycetes).

Anti-HIV Activity of New Substituted 1,3,4-Oxadiazole Derivatives and their Acyclic Nucleoside Analogues

A number of new 5-[(naphthalen-5-yloxy)methyl]-1,3,4-oxadiazole derivatives, 2 - 5 and 8 - 11, were synthesized. The 2-{5-[(naphthalen-5-yloxy)methyl]-1,3,4-oxadiazol-2-ylthio}acetohydrazones 6a and 6b were synthesized by the reaction of the hydrazide 4 with the corresponding monosaccharides. Cyclization of the sugar hydrazones 6a and 6b with acetic anhydride afforded the substituted oxadiazoline derivatives 7a and 7b. The synthesized compounds were evaluated for their antiviral activity against, the human immunodefi ciency virus (HIV-1) and some of these compounds showed moderate to high antiviral activity.

Synthesis and Anticancer Activity of New 1-Thia-4-azaspiro[4.5]decane, Their Derived Thiazolopyrimidine and 1,3,4-Thiadiazole Thioglycosides

New 1-thia-azaspiro[4.5]decane derivatives, their derived thiazolopyrimidine and 1,3,4-thiadiazole compounds were synthesized. The thioglycoside derivatives of the synthesized (1,3,4-thiadiazolyl)thiaazaspiro[4.5]decane and thiazolopyrimidinethione compounds were synthesized by glycosylation reactions using acetylated glycosyl bromides. The anticancer activity of synthesized compounds was studied against the cell culture of HepG-2 (human liver hepatocellular carcinoma), PC-3 (human prostate adenocarcinoma) and HCT116 (human colorectal carcinoma) cell lines and a number of compounds showed moderate to high inhibition activities.

Anti-Hepatitis B Virus Activity of New N4-β-D-Glycoside Pyrazolo[3,4-d]pyrimidine Derivatives

1 The reaction of 6-hydrazinyl-1,3-dimethylpyrimidine-2,4-(1H,3H)-dione () with ethoxymethylenemalononitrile afforded 5-amino-1-(1,3-dimethyl-2,6-dioxo-1,2,3,6-tetrahydropyrimidin- 6-yl)-1H-pyrazole-4-carbonitrile (2). The latter was reacted with formamide and urea affording the corresponding 4-aminopyrazolo[3,4-d]pyrimidines 3 and 4. The reaction of monosaccharide aldoses with 3 and 4 gave stereoselectively the β-N-glycosides 5a - d and 6a - d which were treated with acetic anhydride in pyridine to afford the corresponding acetylated derivatives 7a - d and 8a - d. The prepared compounds were tested for their antiviral activity against hepatitis B virus (HBV) and showed moderate to high activities

Antimicrobial Activity of New 2,4-Disubstituted Thiazolidinone Derivatives

A number of new disubstituted 2,5-thiazolidinone derivatives were synthesized and tested for their antimicrobial activity against Bacillus subtilis (Gram-positive), Pseudomonas aeruginosa (Gram-negative), and Streptomyces species (Actinomycetes). They displayed different degrees of antimicrobial activities or inhibitory actions

Synthesis and antimicrobial activity of new substituted 1,2,4-triazoles and their acyclic C-nucleoside analogues.

A number of new substituted 1,2,4-triazole {[(1,2,4-triazolyl)ethyl]tetrazolyl} derivatives, their sugar hydrazones, and their acyclic C-nucleoside analogues were synthesized and tested for their antimicrobial activity against Bacillus subtilis (Gram-positive), Pseudomonas aeruginosa (Gram-negative), and Streptomyces species (Actinomycetes). The synthesized compounds displayed different degrees of antimicrobial activities or inhibitory actions.

Copper-catalyzed Synthesis and Antimicrobial Activity of Disubstituted 1,2,3-Triazoles Starting from 1-Propargyluracils and Ethyl (4-Azido- 1,2,3-trihydroxybutyl)furan-3-carboxylate

1,3-Dipolar cycloaddition reactions of 1-propargyluracils 2a - h with the azido derivative 3 afforded the corresponding 1,2,3-triazoles 4a - h. Hydrazinolysis of the esters 4a - h gave the corresponding acid hydrazides 5a - h. Reaction of 5a - h with carbon disulfide in ethanol afforded 6a - h. The antimicrobial activity of compounds 4 - 6 was determined Graphical Abstract Copper-catalyzed Synthesis and Antimicrobial Activity of Disubstituted 1,2,3-Triazoles Starting from 1-Propargyluracils and Ethyl (4-Azido- 1,2,3-trihydroxybutyl)furan-3-carboxylate

Anti-Hepatitis B Virus Activity of New Pyrimidine and Adenine Peptide Nucleic Acid Analogues

A number of N-substituted thymine and adenine derivatives, 2a, b and 3a, b, were synthesized by the coupling reaction of 1-bromo-2,2-diethoxyethane with the corresponding base. The corresponding peptide nucleic acid (PNA) analogues, N-substituted ethylamino-3-hydroxypropanoate derivatives 5a, b and ethylamino-3-hydroxybutanoate derivatives 6a, b, were synthesized from the corresponding 2-[3,4-dihydro-5-methyl-2,4-dioxopyrimidin-1(2H)- yl]-acetaldehyde (3a) and 2-[6-amino-4H-purin-9(5H)-yl]-acetaldehyde (3b), respectively. The synthesized compounds were tested for their antiviral activity against hepatitis B virus (HBV). The plaque reduction infectivity assay was used to determine the virus count reduction as a result of the treatment with the tested compounds.

Anti-Hepatitis B Virus Activity of New Substituted Pyrimidine Acyclic Nucleoside Analogues

A number of N-substituted pyrimidine acyclic nucleosides were synthesized by coupling reaction of 2-(2-chloroethoxy)ethyl acetate or (2,2-dimethyl-1,3-dioxolan-4-yl)methyl 4-methylbenzenesulfonate with the corresponding base followed by deprotection. The synthesized compounds were tested for their antiviral activity against hepatitis B virus (HBV). The plaque reduction infectivity assay was used to determine virus count reduction as a result of treatment with the synthesized compounds which showed moderate to high antiviral activities

Synthesis and anticancer activity of new [(Indolyl)pyrazolyl]-1,3,4-oxadiazole thioglycosides and acyclic nucleoside analogs

ABSTRACT New [(Indolyl)pyrazolyl]-1,3,4-oxadiazole compounds and their derived thioglycosides as well as the corresponding sugar hydrazones were synthesized. The acyclo C-nucleoside analogs of the oxadiazoline base system were also prepared by reaction of acid hydrazides with aldehydo sugars followed by one pot process encompassing acetylation and cyclization of the synthesized hydrazones. The anticancer activity of the newly synthesized compounds was studied against colorectal carcinoma (HCT116), breast adenocarcinoma (MCF7) and prostate cancer (PC3) human tumor cell lines and a number of compounds showed moderate to high activities.