Mohamed F. Abdel-Megeed

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

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.

Studies on antiretroviral drug concentrations in breast milk: validation of a liquid chromatography-tandem mass spectrometric method for the determination of 7 anti-human immunodeficiency virus medications.

Studying the pharmacokinetics of antiretroviral drugs in breast milk has important implications for the health of both the mother and the infant, particularly in resource-poor countries. Breast milk is a highly complex biological matrix, yet it is necessary to develop and validate methods in this matrix, which simultaneously measure multiple analytes, as women may be taking any number of drug combinations to combat human immunodeficiency virus infection. Here, we report a novel extraction method coupled to high-performance liquid chromatography and tandem mass spectrometry for the accurate, precise, and specific measurement of 7 antiretroviral drugs currently prescribed to infected mothers. Using 200 μL of human breast milk, simultaneous quantification of lamivudine (3TC), stavudine (d4T), zidovudine (ZDV), nevirapine (NVP), nelfinavir (NFV), ritonavir, and lopinavir was validated over the range of 10-10,000 ng/mL. Intraday accuracy and precision for all analytes were 99.3% and 5.0 %, respectively. Interday accuracy and precision were 99.4 % and 7.8%, respectively. Cross-assay validation with UV detection was performed using clinical breast milk samples, and the results of the 2 assays were in good agreement (P = 0.0001, r = 0.97). Breast milk to plasma concentration ratios for the different antiretroviral drugs were determined as follows: 3TC = 2.96, d4T = 1.73, ZDV = 1.17, NVP = 0.82, and NFV = 0.21.

Synthesis of Novel 3H-Quinazolin-4-ones Containing Pyrazolinone, Pyrazole and Pyrimidinone Moieties

The diazonium salt of 3-(4-aminophenyl)-2-methyl-3H-quinazolin-4-one (2a) and its 6-bromo derivative 2b reacted with some active methylene compounds, namely ethyl acetoacetate (3), ethyl cyanoacetate (4) and acetylacetone (5), to afford the corresponding hydrazono quinazolinone derivatives 6-8. Treatment of 6a,b with hydrazine hydrate or phenyl hydrazine in refluxing ethanol afforded the corresponding pyrazolin-5-one derivatives of 3H-quinazolin-4-one 9a-d. Cyclization of 7a,b with hydrazine hydrate yielded the corresponding products 10a,b. Reaction of 8a,b with phenyl hydrazine or with urea afforded the corresponding derivatives 11a,b and 12a,b, respectively. Compounds 6-12 were identified by C,H,N analysis, IR, 1H-NMR, 13C-NMR and mass spectroscopy.

Synthesis, Conformational and Configurational Studies of Some New Acetylated Glycosides of 2-Thio-3-aryl-4(3H)-quinazolinones, Their Thiono and 3,1-Benzothiazin-2,4-dithione

Abstract A series of some new acetylated S-glycosides of 2-thioxoquinazolin-4-ones, their thiono analogues and 3,1-benzothazin-2,4-dithione derivatives, including a D-glucose and a D-galactose derivatives and a D-xylose, and an L-arabinose derivatives have been synthesized. The conformation and configuration of these carbohydrate derivatives were determined by analysing their 1H and 13C NMR chemical shifts and coupling constants. The biological activity of these compounds has been studied.

Synthesis of Glycosides Containing Quinazolin-4(3H)-one Ring System

Reactions of various aminoquinazolin-4(3H)-ones with monosaccharides in the presence of a catalytic amount of glacial acetic acid afforded the corresponding N-glycosylamines as a mixture of b- and a-anomers. Acetylation of this mixture gave the corresponding b-glycoside acetates. However, b-glycoside acetates could be obtained directly from reactions of per-O-acetyl-b-D-glucosyl bromides with quinazolin-4(3H)-one derivatives which deacetyalted to the corresponding b-glycosides. A series of S-glycosides have been synthesised from reaction of per-O-acetyl-b-D-glucosyl bromides with quinazolinethiones.

Synthesis and Antimicrobial Activities of Diphenyl(Arylamino)(1-Phenyl-3-(Pyridin-2-Yl)-1H-Pyrazol-4-Yl)Methylphosphonates

Abstract A series of novel diphenyl(arylamino)(1-phenyl-3-(pyridin-2-yl)-1H-pyrazol-4-yl)methylphosphonates have been synthesized in high yields. They 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 Schccaromycies cerevisiae as a fungus. The minimum inhibitory concentrations (MICs) of the synthetic compounds showed moderate antibacterial and antifungal activities at low concentrations (10–1000 μg/mL). Supplemental materials are available for this article. Go to the publishers online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file. GRAPHICAL ABSTRACT

Synthesis of a Series of Diphenyl (Arylamino)(Pyridin-3-yl)Methylphosphonates as Potential Antimicrobial Agents

Abstract Diphenyl 1-(arylamino)(pyridin-3-yl)methylphosphonates were obtained in high yields from the reactions of nicotinaldehyde with aromatic amines and triphenylphosphite in the presence of titanium tetrachloride (TiCl4) as a catalyst. The structures of the synthesized compounds were confirmed by IR, 1H NMR and mass spectral data and their purities were confirmed by elemental analyses. The synthesized α-aminophosphonates showed moderate to high antimicrobial 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 Schccaromycies cerevisiae as fungi, at various concentrations (10–100 μg/mL).The lethal dose of the synthesized compounds was also determined and indicated that most compounds are safe to use. Supplemental materials are available for this article. Go to the publishers online edition of Phosphorus, Sulfur, and Silicon and the related elements to view the free supplemental file. GRAPHICAL ABSTRACT

Regiospecific electrophilic substitution of aminoquinazolinones: directed lithiation of 3-(pivaloylamino)- and 3-(acetylamino)-2-methylquinazolin-4(3H)-ones

The 2-methyl group in 3-(pivaloylamino)- and in 3-(acetylamino)-2-methyIquinazolin-4(3H)-ones has been lithiated with butyllithium. The lithium reagents thus obtained react with a variety of electrophiles (benzophenone, methyl iodide, D2O, cyclohexanone, acetophenone, phenyl isocyanate) to give the corresponding substituted derivatives in very good yields. The amide group has been cleaved in good yield under basic conditions for one model case to provide convenient access to 3-amino-2-ethylquinazolin-4(3H)- one. The NMR spectra of the 2-substituted 3-acylaminoquinazolin-4(3H)-ones show diastereotopism of the CH2 group at position 2.

Unexpected Products from Carbonylation of Lithiated Quinazolin-4(3H)-one Derivatives

Doubly lithiated 3-pivaloylaminoquinazolin-4(3H)-one reacts with carbon(II) oxide at 0°C to give 77% of a mixture of azetidinone and indole derivatives, each incorporating a diisopropylamide unit from lithium diisopropylamide used for lithiation. No analogous reaction occurs with doubly lithiated 3-acetylaminoquinazolin-4(3H)-one and 3-acyl-2-alkylquinazolin-4(3H)-one. Carbonylation of doubly lithiated 2-alkyl-3-aminoquinazolin-4(3H)-ones at 0°C results in deamination to give 2-alkylquinazolin-4(3H)-ones in good yields.

Synthesis and Antimicrobial Activities of a Novel Series of Heterocyclic α-Aminophosphonates

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, 1H 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.