Publications by authors named "Mohamed M Azaam"

3 Publications

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New functionalized mercaptoundecahydrododecaborate derivatives for potential application in boron neutron capture therapy: synthesis, characterization and dynamic visualization in cells.

Eur J Med Chem 2015 Mar 20;93:574-83. Epub 2015 Feb 20.

Department of Chemistry, Faculty of Science, University of Tanta, 31527 Tanta, Egypt.

A series of mercaptoundecahydrododecaborate (B12H11SH(2-), BSH) bearing mono- and dicarboxyalkyl derivatives was prepared, characterized, and their reactivity towards amidation and esterification in DMF was evaluated. Symmetrical alkylation of BSH was achieved by treatment with primary haloalkyl carboxylic acids in aqueous acetonitrile to produce S,S-bis(carboxyalkyl)sulfonium-undecahydro-closo-dodecaborate tetramethylammonium salts. Unsymmetrically substituted sulfonium salts were obtained through a similar treatment of cyanoethylthioether-undecahydro-closo-dodecaborate tetramethylammonium salt with haloalkyl carboxylic acid. Selective removal of the remaining cyanoethyl group upon treatment with tetramethylammonium hydroxide yielded S-carboxyalkyl-thioether-undecahydro-closo-dodecaborate ditetramethylammonium salts. N,N'-dicyclohexylcarbodiimide (DCC) activated amidation of S,S-bis(carboxyalkyl)sulfonium-undecahydro-closo-dodecaborate or S-carboxyalkyl-thioether-undecahydro-closo-dodecaborate tetramethylammonium salts with propargylamine provided the opportunity to install terminal acetylene groups for further conjugation. These compounds acted as powerful building blocks for the synthesis of a broad range of 1,4-disubstituted 1,2,3-triazole products in high yields, utilizing the Cu(I)-mediated click cycloaddition reaction. The synthesis of BSH-lipid with a two-tailed moiety was also achieved, by esterification of S,S-bis(carboxyethyl)sulfoniumundecahydro-closo-dodecaborate(1-) tetramethylammonium salt with 1,2-O-distearoyl-sn-3-glycerol, which may prove useful in the liposomal boron delivery system. The bio-compatibility of the azide-alkyne click reaction was then utilized by performing this reaction in cell culture. The distribution of BSH in HeLa cells could be visualized by treating the cells first with a BSH-alkyne compound and then with Alexa Fluor 488(®) azide dye. The BSH-dye conjugate, which did not wash out, revealed the distribution of boron in the HeLa cells. Cytotoxicity assays of these BSH derivatives revealed that the synthesized BSH-conjugated triazoles possessed low cytotoxicity in HeLa cancer cells. Of these compounds, BSH conjugated triazole 15 induced a significant increase in the level of boron accumulation in HeLa cells.
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http://dx.doi.org/10.1016/j.ejmech.2015.02.033DOI Listing
March 2015

Synthesis and antimicrobial activities of a novel series of heterocyclic α-aminophosphonates.

Arch Pharm (Weinheim) 2012 Oct 24;345(10):784-9. Epub 2012 Jul 24.

Faculty of Science, Department of Chemistry, Tanta University, Tanta, Egypt.

Two series of novel α-aminophosphonates having heterocyclic moieties were synthesized in high yields. The structures of the newly synthesized compounds were confirmed by their elemental analyses, IR, (1)H NMR and MS spectral data. These compounds were screened for their antibacterial activities against Escherichia coli (NCIM2065) as a Gram-negative bacterium, Bacillus subtilis (PC1219) and Staphylococcus aureus (ATCC25292) as Gram-positive bacteria, and Candida albicans and Saccharomyces cerevisiae as fungi. The minimum inhibitory concentrations (MICs) of the synthesized compounds show high antibacterial and antifungal activities at low concentrations (10-1000 µg/mL). Furthermore, their lethal doses indicated that such compounds are safe for use as antimicrobial agents.
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http://dx.doi.org/10.1002/ardp.201200109DOI Listing
October 2012

Synthesis, antimicrobial and anticancer activities of a novel series of diphenyl 1-(pyridin-3-yl)ethylphosphonates.

Bioorg Med Chem 2012 Apr 13;20(7):2252-8. Epub 2012 Feb 13.

Department of Chemistry, Faculty of Science, Tanta University, Tanta 31527, Egypt.

A novel series of diphenyl 1-(arylamino)-1-(pyridin-3-yl)ethylphosphonates 1-5 was obtained in high yields from reactions of 3-acetyl pyridine with aromatic amines and triphenylphosphite in the presence of lithium perchlorate as a catalyst. The structures of the synthesized compounds were confirmed by IR, (1)H NMR spectral data and microanalyses. Compounds 1-5 showed high antimicrobial activities against Escherichia coli (NCIM2065) as a Gram-negative bacterium, Bacillus subtilis (PC1219) and Staphylococcus aureus (ATCC25292) as Gram-positive bacteria and Candidaalbicans and Saccharomyces cerevisiae as fungi, at low concentrations (10-100 μg/mL). Also, the synthesized compounds showed significant cytotoxicity anticancer activities against liver carcinoma cell line (HepG2) and human breast adenocarcinoma cell line (MCF7). The lethal dose of the synthesized compounds was also determined and indicated that most compounds are safe to use.
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http://dx.doi.org/10.1016/j.bmc.2012.02.015DOI Listing
April 2012