Publications by authors named "S Hakimelahi"

Synthesis of adenine derivative of triphosphono-gamma-(Z)-ethylidene-2,3-dimethoxybutenolide 4 was accomplished by treatment of phosphonate 3 with 5-phosphoribosyl 1-pyrophosphate in the presence of 5-phosphoribosyl 1-pyrophosphate synthetase. It was found that triphosphonate 4 functions as an irreversible stoichiometric inactivator of the Escherichia coli ribonucleoside diphosphate reductase (RDPR). Triphosphonate 4 exhibited potent inhibitory activity against murine leukemias (L1210 and P388), breast carcinoma (MCF7), and human T-lymphoblasts (Molt4/C8 and CEM/0) cell lines.

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Racemic 7-(phenylacetamido)-1-dethia-3-aza-1-carba-2-oxacephem 3 was synthesized and found to possess antibacterial activity against Staphylococcus aureus FDA 209P, Escherichia coli ATCC 39188, Pseudomonas aeruginosa 1101-75 and Klebsiella pneumoniae NCTC 418 as well as the beta-lactamase producing organisms E. coli A9675 and P. aeruginosa 18S-H and the methicillin-resistant organism S.

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By use of pro-dual-drug concept the synthesis of 6-beta-[(R)-2-(clavaminio-9-N-yl)-2-(4-hydroxyphenylacetamido)]penicillanic acid (10), 6-beta-[(R)-2-(amino)-2-(4-(clavulano-9-O-yl)phenylacetamido)]penicillanic acid (13), (Z)-4-[2-(amoxycillin-4-O-yl)ethylidene]-2-(clavulano-9-O-yl)-3-methoxy-Delta(alpha,beta)-butenolide (19), and 3-[(amoxicillin-4-O-yl)methyl]-7-(phenoxyacetamido)-(1-oxo)-3-cephem-4-carboxylic acid (23) was accomplished. Unlike penicillin G, ampicillin, or amoxicillin, these four heretofore undescribed compounds 10, 13, 19, and 23 showed notable activity against beta-lactamase (betaL) producing microorganisms, Staphylococcus aureus A9606, S. aureus A15091, S.

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A novel cephalosporin derivative of monohydroguaiaretic acid (cephem-M(3)N, 7) was synthesized and found to possess anticancer activity against human leukemia (K562), breast carcinoma (MCF7), human lung cancer (A549), human colon cancer (Colo205) and pancreatic cancer cells (Capan2 and MiaPaCa2). A tumor targeting fusion protein (dsFv3-beta-lactamase) was also used in conjunction with cephem-based M(3)N 7 and its potency toward K562, MCF7, A549, Colo205, Capan2, and MiaPaCa2 was found to approach that of the free M(3)N (4). In the presence of dsFv3-beta-lactamase, tumor cells were found to be much more susceptible to conjugate 7 than normal human embryonic lung (HEL) cells and normal fibroblasts (Hef522).

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Thiols are the most reactive nucleophilic reagents among the biological models investigated. The reactivity of butenolides 1a-c, 2-4, and 6-8 toward L-cysteine, a model biological nucleophile, was studied spectrophotometrically. The rates of the reactions were measured and correlated with antitumour activity of these molecules.

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