Showing papers by "Wafaa S. Hamama published in 2014"

Vistas in the domain of organoselenocyanates

Abstract: In this review we compile and update recent developments in the synthesis, chemical properties, and biological importance of organic selenocyanates. The diverse synthetic routes to organoselenocyanates are described in the first part, including direct and indirect cyanoselenation. In the second part, the chemical reactions of organoselenocyanate are discussed. These included oxidation-reduction reactions. Further reactions included addition to the selenocyanate carbonitrile group, and reactions accompanied with cyanide group loss. These compounds exhibit anticancer, antioxidative, antileishmanial, antimutagenic and chemopreventive properties. The reported biological properties of this group of compounds are summarized in the last part.

Synthesis and Antioxidant Activities of Novel Chiral Ebselen Analogues

Abstract: Novel chiral analogues of the antioxidant, anti-inflammatory organoselenium drug ebselen were synthesized. The reaction proceeded readily from 2-(chloroseleno)benzoyl chloride with chiral amino compounds. The chiral substituent on the nitrogen atom did not provide a substantial increase in activities and the newly synthesized compounds showed similar activities to ebselen.

New synthetic approach to coumarino[4,3-b]pyridine systems and potential cytotoxic evaluation

Abstract: The reaction of 4-aminocoumarin (2) with appropriate α,β-unsaturated ketones gave the corresponding coumarin [4,3-b]pyridines. Thus, treatment of 2 with (E)-3-(4-nitrophenyl)-1-phenylprop-2-en-1-one, (1E,4E)-1,5-diphenylpenta-1,4-dien-3-one, (Z)-ethyl 3-(4-chlorophenyl)-2-cyanoacrylate, and (2E,6E)-2,6-dibenzylidenecyclohexanone (3, 6 and 12) afforded the corresponding coumarino[4,3-b]pyridines 5, 7 and coumarino[4,3-b]quinoline derivatives 13, respectively. Heterocyclic annulations of coumarino [5,4-b]pyridine system were achieved via reaction of 2 (in situ) with benzylidene derivatives of indandione to give 15 which was also obtained by multicomponent condensation reaction of 2 (in situ) with indandione and benzaldehyde. A representative sample of new synthesized compounds was evaluated as cytotoxic agents.

Synthesis and anti-tumor evaluation of novel organoselenocyanates and symmetrical diselenides dyestuffs

Abstract: A convenient procedure for the synthesis of novel organoselenium compounds was developed from simple aniline selenocyanate 1 and its corresponding diselenide 2. Their chemical reactivity was investigated towards azo coupling type reactions and their corresponding diazo derivatives 3a,b and 5a,b were sequentially obtained. Besides, heterocyclic selenocyanates 7-9 and diselenocyanate 10 were obtained by the subsequent reaction of hydrazines diazo 3a,b and 5b compounds, respectively. Furthermore, condensation of 1 and 2 with phthalic anhydride afforded the phthalimide selenocyanates 4a,b and 6, alternately. Moreover, some representatives of the new synthesized compounds were evaluated for their antitumor activity and were found to be more cytotoxic compared to their corresponding analogues without selenium. It is worth mentioning that the dying characteristic of these compounds was also evaluated and found to exhibit good dying properties.

In vivo anti-inflammatory and in vitro antioxidant activities of Genista quadriflora Munby extracts

Abstract: The present study aims to investigate in vivo anti-inflammatory and in vitro antioxidant activities of Genista quadriflora extracts. The n-butanol extract of this plant was evaluated in Wistar Albinos rats for anti-inflammatory activity using carrageenan-induced hind paw edema model. Antioxidant properties of n-butanol and ethyl acetate extracts were assayed by scavenging abilities on 1, 1-diphenyl-2-picrylhydrazyl (DPPH), lipid peroxidation and total phenolic content (TPC) using spectrophotometric method. Oral treatment with n- butanol extract of Genista quadriflora elicited an inhibitory activity on the development of the paw edema induced by carrageen. This extract showed a significant reduction (p < 0.001; p < 0.01) in the paw edema volume in a dose-dependent with a maximum that reaches 100 and 200 mg/kg. The n-butanol extract showed anti-inflammatory activity, while all the extracts showed significant antioxidant activity in vitro.

Studies on Quinolinedione: Synthesis, Reactions, and Applications

Abstract: In this account we present the rapidly expanding bibliography of published research concerning the progress in the area of quioline-2,4-dione chemistry, including synthetic strategies.

Developments in the Chemistry of 2‐Pyridone

Abstract: The focus of our review is on the methods of synthesis and chemical reactivity of 2-pyridone and some derivatives as 2-chloro-3-nicotinonitrile in addition to the biological activity of the 2-pyridone moiety.