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Biomedical subjects

R M Shafik

Publications and source records attributed to R M Shafik.

At least 19 recordsLinked to original sources
PubMed2004

Synthesis of novel 2-[2-(substituted amino)phenethyl]-1 H-benzimidazoles; 3,4-dihydro and 1,2,3,4,-tetrahydropyrimido[1,6-a]-benzimidazoles as potential antiulcer agents.

In an effort to establish new antiulcer agents a series of 2-(2-substituted amino)-1 H-benzimidazoles 8, 9, 14; 1,3-disubstituted-3,4-dihydropyrimido[1,6-a]benzimidazoles 4, 7, 11, 12; 3-substituted-3,4-dihydropyrimido[1,6-a]benzimidazol-1 (2H)-thiones (or (2H)-ones) 10, 17 and 3-substituted-1,2,3,4-tetrahydropyrimido[1,6-a]benzimidazoles 15 were synthesized. Representative members were selected to evaluate their gastric antisecretory activity using an in vivo pylorus ligated rat method. Omeprazole was used as reference. The results indicated that the test compounds exhibit gastric antisecretory activity. The percent inhibition+/-SEM at the indicated dose level was demonstrated as omeprazole (59%+/-0.16 at 3 mg/kg) > 15a (53%+/-1.39 at 3 mg/kg) > 7a (51%+/-1.04 at 1 mg/kg) > 10a (50%+/-1.36 at 3 mg/kg).

Animals↗
PubMed1995

Synthesis and biochemical evaluation of N-(1-substituted-cycloalkyl)-beta-(3,4-dimethoxy; or dihydroxy) phenethylamines: potential dopaminergic agents.

The design and synthesis of some hybrid-structures comprising the dopamine framework on one hand and an N-(1-substituted-cycloalkyl) moiety on the other have been elaborated. Selective members of the new series were biochemically assayed to determine their effects on the levels of dopamine and its metabolite norepinephrine in brains of Albino-rats. The brain MAO activity was also estimated. The results were compared with those displayed by apomorphine, metoclopramide and PCP.

Dopamine Agents↗
PubMed1987

(+/-)alpha-Phenyl-beta-(3,4-dimethoxy)- and (+/-)alpha-phenyl-beta -(3,4-dihydroxy)phenethylamines: potential probes for nicotinic acetylcholine receptor-ion channel molecule from torpedo electric organ.

The synthesis of some N-methyl, N-alkyl derivatives of (+/-)alpha-phenyl-beta-(3,4-dimethoxy)- and (+/-)alpha-phenyl-beta-(3,4-dihydroxy)-phenethylamines was achieved. These compounds were shown to bear certain structural features of acetylcholine (ACh), as well as phencyclidine (PCP). The latter was reported to act as a specific probe for the nicotinic ACh receptor-ion channel molecule from Torpedo electric organ. Biochemical binding studies revealed that for the nicotinic ACh receptor, the 3,4-dimethoxy derivatives behaved as blockers for the binding interaction of [3H]ACh, whereas the 3,4-dihydroxy analogues stimulated such binding. On the other hand, all of the tested phenethylamines exhibited potent blockade towards [3H]PCP binding interactions. The results indicated that the tested compounds might be applied as potential probes for the ACh receptor-ion channel molecule.

Acetylcholine↗
PubMed1984

alpha-Phenyl-beta-(3,4-dimethoxy)phenethylamines: novel inhibitors of choline acetyltransferase from Torpedo electric organ.

Some derivatives of alpha-phenyl-beta-(3,4-dimethoxy)phenethylamine that might bear a certain conformational resemblance to choline were prepared. The in vitro inhibition of choline acetyltransferase from Torpedo electric organ was investigated. These compounds gave variable degrees of inhibition; the most potent inhibitor was, N,N,N,-trimethyl-alpha-phenyl-beta-(3,4-dimethoxy)phenethylammonium++ + iodide, with an I50 of 1.3 X 10(-5) M. The inhibition of choline acetyltransferase from Spodoptera littoralis larval brains was also determined for comparative study. The aforementioned compound has an I50 of 9 X 10(-6) M on choline acetyltransferase from this source.

Animals↗
PubMed1982

Synthesis and biological investigations of some 5H-1,3,4-oxadiazolo[3,2-a]pyrimidin-5-ones.

The synthesis of some substituted 7-hydroxy-5H-1,3,4-oxadiazolo [3,2-a]pyrimidin-5-ones, a class of bicyclics with unexplored pharmacotoxicological properties, is described. Reacting the 2-phenyl derivative with bis(2,4,5-trichlorophenyl)benzylmalonate afforded a linear pyrano-oxadiazolopyrimidinedione. The assigned structures were verified by IR, 1H-NMR, and mass spectral studies. Six compounds of the series were screened for in vitro antibacterial and antifungal activities. The effect of four compounds on alkaline phosphatase enzyme was also examined.

Alkaline Phosphatase↗
PubMed1979

New biphenyl derivatives II: 1-(4-Biphenylyl)-1-hydroxy-2-aminoethanes and 1-(4-biphenylyl)-1-chloro-2-aminoethanes as potential beta-adrenoceptor blocking agents.

Series of 1-(4-biphenylyl)-1-hydroxy-2-aminoethanes and 1-(4-biphenylyl)-1-chloro-2-aminoethanes were synthesized. Newly developed reaction conditions for aryl aminomethyl ketone reduction and reductive alkylation, using sodium borohydride, are described. The prepared compounds were examined for adrenergic blocking activity on an anesthetized dog blood pressure preparation and on isolated toad hearts. beta-Adrenergic blockade was investigated using isoproterenol as the agonist. The benzylamino and cyclohexylamino analogs exhibited marked beta-adrenoceptor blocking activity, for which the latter derivatives were more potent.

Adrenergic beta-Antagonists↗
PubMed1978

Synthesis of methaqualone and its diphasic titration in pure and tablet forms.

A one-step synthesis of methaqualone from N-acetylanthranilic acid and o-toluidine in the absence of a catalyst is described. A rapid diphasic titration procedure for its microestimation in pure and tablet forms, using dioctyl sodium sulfosuccinate and dimethyl yellow screened with oracet blue B, is proposed. The data were compared with those obtained from nonaqueous titration methods.

Methaqualone↗
PubMed1975

Polysubstituted pyrazoles. Part 2: Sulphonamidophenylhydrazone-2-pyrazolin-4-ones and sulphonamidophenylazopyrazoles as potential anticancer agents.

The synthesis of some new derivatives of 1-[4-nitrophenyl]-5-[4-substituted sulphonamidophenylhydrazono]-2-pyrazolin-4-ones and 3,5-dimethyl-4-[4-substituted sulphonamidophenylazo]-pyrazoles is described. Bromination of ethyl 2-[nitrophenylhydrazono]-3-oxobutyrates in dry benzene afforded the 4-bromo derivatives which upon cyclization gave high yields of the 4-hydroxpyrazoles. Many other new intermediates were prepared and the results of the UV and IR spectral studies are discussed.

Antineoplastic Agents↗