Sayed A. Ahmed

Synthesis and anti-tumor activities of some new pyridines and pyrazolo (1,5-a)pyrimidines

Cyclocondensation of cyanoacetamide, cyanothioacetamide and 3-aminopyrazols with sodium salt of 3-hydroxy-1-(2-naphthyl)prop-2-en-1-one gives pyridin-2-one, pyridin-2(1H)-thione, and pyrazolo[1,5-a]pyrimidine derivatives. These derivatives showed potent anti-tumor cytotoxic activity in vitro using different human cancer cell lines.

Synthesis and Antimicrobial Activity of Some New 5-Arylazothiazole, Pyrazolo[1,5-a] Pyrimidine, [1,2,4]Triazolo[4,3-a]Pyrimidine, and Pyrimido[1,2-a]Benzimidazole Derivatives Containing the Thiazole Moiety

1-(2-(4,5-Dihydro-3-(4-methyl-2-phenylthiazol-5-yl)-5-phenylpyrazol-1-yl)-4-substituted thiazol-5-yl)-2-phenyldiazene were synthesized from hydrazonoyl halides and 3-(4-methyl-2-phenyl-1,3-thiazol-5-yl)-5-phenyl-4,5-dihydro-1H-pyrazole-1-carbothioamide in ethanolic triethylamine. Also, pyrazolo[5,1-a]pyrimidines, 2,3,6-trisubstituted pyridines, and pyrazolo[3,4-d]pyridazines were obtained from sodium salt of 3-hydroxy-1-(4-methyl-2-phenylthiazol-5-yl)prop-2-en-1-one and different heterocyclic amines. All structures of the newly synthesized compounds were elucidated by elemental analysis, spectral data, and alternative synthetic route whenever possible. The newly synthesized compounds were tested towards different microorganisms. Supplemental materials are available for this article. Go to the publishers online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.

Reaction of hydrazonoyl halides 49 1: Synthesis and antimicrobial activity of some new pyrimido[1,2-b][1,2,4,5]tetrazin-6-one, tetrazino[3,2-b]quinazolin-5-one, pyrimidino[1,2-b]1,2,4,5-tetrazin-5-one and triazolo[4,3-a]pyrimidine derivatives

Pyrimido[1,2-b][1,2,4,5]tetrazin-6-one, tetrazino[3,2-b]quinazolin-5-one, pyrimidino[1,2-b]1,2,4,5-tetrazin-5-one and triazolo[4,3-a]pyrimidine derivatives were synthesized from C-(4-methyl-2-phenyl)thiazol-5-oyl-N-phenyl-hydrazonoyl bromide and different pyrimidine-2-thiones. New compounds had their structures confirmed by elemental and spectral analysis and were screened antimicrobial activity.

Cytotoxic Activities of Flavonoids from Centaurea scoparia

Phytochemical studies on the ethanolic extract of the aerial parts of Centaurea scoparia led to the isolation of two new flavonoids, 3′,4′-dihydroxy-(3′′,4′′-dihydro-3′′-hydroxy-4′′-acetoxy)-2′′,2′′-dimethylpyrano-(5′′,6′′:7,8)-flavone-3-O-β-D-glucopyranoside (1) and 3,3′,4′-trihydroxy-(3′′,4′′-dihydro-3′′,4′′-dihydroxy)-2′′,2′′-dimethylpyrano-(5′′,6′′:7,8)-flavone (2), along with eight known flavonoids isolated for the first time from this plant, cynaroside (3), Apigetrin (4), centaureidin (5), oroxylin A (6), 5,7-dihydroxy-3′,4′,5′-trimethoxyflavone (7), atalantoflavone (8), 5-hydroxy-3′,4′,8-trimethoxy-2′′,2′′-dimethylpyrano (5′′,6′′:6,7)-flavone (9), and 3′,4′,5,8-tetramethoxy-2′′,2′′-dimethylpyrano (5′′,6′′:6,7)-flavone (10). The structures of the isolated compounds were elucidated by means of spectroscopic tools including 1D and 2D NMR, UV, IR, and mass spectroscopy. Cytotoxic activities of the isolated compounds were evaluated against human cervical carcinoma HeLa, human hepatocellular carcinoma HepG2, and human breast carcinoma MCF-7. Compound 2 was the most potent cytotoxic agent against HeLa cells with an IC50 0.079 μM.