Yehya M. Elkholy

Phenolic compounds from Foeniculum vulgare (Subsp. Piperitum) (Apiaceae) herb and evaluation of hepatoprotective antioxidant activity

Objective: The study was designed to evaluate the antioxidant and hepatoprotective activities of the 80% methanolic extract as well as the ethyl acetate (EtOAc) and butanol (BuOH) fractions of the wild fennel (Foeniculum vulgare (Subsp; Piperitum)) and cultivated fennel (F. vulgare var. azoricum). In addition, quantification of the total phenolic content in the 80% methanol extract of fennel wild and cultivated herbs is measured. Materials and Methods: An amount of 400 g of air dried powdered herb of wild and cultivated fennel were sonicated with aqueous methanol (80%), successively extracted with Hexane, EtOAc, and n-BuOH. The EtOAc and n-BuOH were subjected to repeated column chromatography on silica gel and Sephadex LH-20. The antioxidant effect was determined in vitro using 1,1-diphenyl-2-picrylhydrazyl (DPPH). Hepatoprotective activity was carried out using a Wistar male rat (250–300 g). Total phenolic and flavonoid contents were determined as chlorogenic acid and rutin equivalents, respectively. Results: Two phenolic compounds, i.e., 3,4-dihydroxy-phenethylalchohol-6-O-caffeoyl-β-D-glucopyranoside and 3΄,8΄-binaringenin were isolated from the fennel wild herb, their structures were elucidated by spectral methods including 1D NMR, 2D NMR, and UV. The EtOAc and BuOH fractions of wild fennel were found to exhibit a radical scavenging activity higher than those of cultivated fennel. An in vitro method of rat hepatocytes monolayer culture was used for the investigation of hepatotoxic effects of the 80% methanol extract on the wild and cultivated fennel, which were >1000 and 1000 μg/mL, respectively. As well as, their hepatoprotective effect against the toxic effect of paracetamol (25 mM) was exerted at 12.5 μg/mL concentration. Conclusions: Fennel (F. Vulgare) is a widespread plant species commonly used as a spice and flavoring. The results obtained in this study indicated that the fennel (F. vulgare) herb is a potential source of natural antioxidant. Two phenolic compounds, i.e. 3,4-dihydroxy-phenethylalchohol-6-O-caffeoyl-β-D-glucopyranoside (A) and 3΄,8΄-binaringenin (B) were isolated from the fennel wild herb for the first time.

Chemical composition and biological activity of ripe pumpkin fruits (Cucurbita pepo L.) cultivated in Egyptian habitats.

The chemical composition and biological activity of three parts (rind, flesh and seeds) of pumpkin fruits (Cucurbita pepo L.) cultivated in Egypt were studied. Chemical analysis of fibre, protein, β-carotene, carbohydrates, minerals and fatty acids present in the rind, flesh, seeds and defatted seeds meal was conducted. Chemical, GC-MS and biological assays of organic extracts of the main fruit parts, rind and flesh established their unique constituents. Chromatographic purification of the extracts afforded triglyceride fatty acid mixture (1), tetrahydro-thiophene (2), linoleic acid (3), calotropoleanly ester (4), cholesterol (5) and 13(18)-oleanen-3-ol (6). GC-MS analysis of the extracts unpolar fraction revealed the existence of dodecane and tetradecane. Structures of the isolated compounds (1–6) were confirmed by NMR and EI-MS spectrometry. Antimicrobial, antiviral and antitumour activities of the fruit parts were discussed. The promising combined extract of rind and flesh was biologically studied for microbial and cytotoxic activities in comparison with the whole isolated components.

ENAMINONES AS BUILDING BLOCKS IN ORGANIC SYNTHESIS: SYNTHESIS OF NEW POLYFUNCTIONAL PYRIDINES, CONDENSED PYRIDINES, AND PENTA SUBSTITUTED BENZENE

ABSTRACT Several new thienopyridine and methylthioether derivatives have been synthesized. New synthesis of pyrido[2,3-b]-thieno[3,2-d]pyrimidine and penta substituted benzene were achieved.

β-enaminonitriles in heterocyclic synthesis: A novel synthesis and transformations of α-substituted-β-enaminonitriles

Abstract Novel synthesis of α-substituted-β-enaminonitriles could be obtained from reaction of β-enaminonitriles with paraformaldehyde and dimethylamine. Such compounds reacted readily with a wide variety of reagents to give unique heterocyclic systems.

Novel Synthesis of Pyrido[2,1-B]Benzothiazoles and 1,3-Benzothiazole Derivatives

Abstract A variety of new pyrido[2,1-b]benzothiazole and benzothiazoles, have been prepared via the reaction of 2-substituted methylthiazole with α,β-unsaturated nitriles and activated methylene compounds. The structures of the reaction products were established based on the elemental analyses and spectral data (IR, 1H-, 13C-NMR, MS).

SYNTHETIC POTENTIALITIES OF THIOPHENE SYSTEMS IN HETEROCYCLIC SYNTHESIS: A NOVEL SYNTHESIS OF THIENO[2,3-b]PYRIDINE DERIVATIVES

Abstract The reactivity of thiophene derivatives 1,2 and 3 towards active methylene reagents, aryledenernalononitriles were studied to afford several new thieno[2,3-b]pyridine derivatives. The biological activities of the synthesized products showed interesting results.

Synthesis and antimicrobial activity of new polyfunctionally substituted pyridazines and their fused derivatives

Aminoacetonitrilehydrogensulfate was reacted with aldehydes to give the schiff bases 3. The latter were reacted with dimethyl acetylenedicarboxylate to afford the pyridine derivative 4, which reacted with hydrazine hydrate and aromatic amine respectively to give pyridopyridazine and pyrrolopyridine. The antimicrobial activity of the prepared compounds was tested.

Studies With Pyridinethiones: A Convenient Synthesis of Polyfunctionally Substituted Pyridine Ring Systems

Abstract 1-Benzoyl-1-phenylsulfone-2-ethoxyethene 3 has been prepared via reaction of phenacyl sulfone 1 with triethylorthoformate. Compound 3 can be used for prepration of pyridinethione, which could be annulated into fused various heterocyclic ring systems.

Design, Synthesis and Antitumor Activity of Novel D-Glucuronic Acid Derivatives

A series of D-glucuronic acid derivatives were chemically synthesized including acetylated and deacetylated glucuronamides, as well as N-glucuronides starting from the D-glucuronic acid itself by means of protection/deprotection, activation and condensation protocols. Structure elucidation of all products along with optimization of the synthetic steps is described. The synthesized compounds were evaluated for their in vitro antitumor activity against MCF-7, TK-10 and UACC-62 cell lines. The compounds 4, 5, 7, 8, 14, 16 and 18 were the most active against TK-10 cell line. On the other hand, the most active compounds against the MCF-7 cell line were 9, 18 and 20. However, compounds 7-10 13-15 and 17 were the most active against the UACC-62 cell line.

Studies With Pyrazol-3-Carboxylic Acid Hydrazide: The Synthesis of New Pyrazolyloxadiazole and Pyrazolyltriazole Derivatives

A simple and versatile method for the synthesis of pyrazol-3-yl-1,3,4-oxadiazole, pyrazol-3-yl-1,2,4-triazole, (1,5-diphenylpyrazol-3-yl)-(3,5-dimethyl-1-carbonyl)pyrazole, and (1,5-diphenylpyrazol-3-yl)-(5-hydroxy-3-metheyl-1-carbonyl)pyrazole derivatives from 1,5-diphenylpyrazole-3-carboxylic acid hydrazide has been developed.