Emtithal A. El-Sawi

Pharmacological performance of novel poly-(ionic liquid)-grafted chitosan-N-salicylidene Schiff bases and their complexes.

In our endeavor to develop a new class of pharmacological candidates with antimicrobial and anticancer efficacy, a series of biopolymeric chitosan Schiff bases bearing salicylidene ionic liquid (IL-Sal) brushes (ILCSB1-3, poly-(GlcNHAc-GlcNH2-(GlcN-Sal-IL)) was successfully synthesized by adopting efficient synthetic routes. Unfortunately, metalation trials of these biopolymeric Schiff bases afford the corresponding Ag(I)/M(II) complexes (where M=Co, Pd). These designed architectures were structurally characterized and pharmacologically evaluated for their in vitro antimicrobial, against common bacterial and fungal pathogens, and anticancer activities against human colon carcinoma (HCT-116) cell line. In conclusion functionalization of chitosan with IL-Sal brushes coupled with metalation of formed ILCSBs were synergistically enhanced its antimicrobial and antitumor properties to a great extent. Noteworthy, Ag-ILCSB2 (IC50=9.13μg/mL) was ca. 5-fold more cytotoxic against HCT-116 cell line than ILCSB2 (IC50=43.30μg/mL).

Ionic Sal-SG Schiff bases as new synergetic chemotherapeutic candidates: synthesis, metalation with Pd(II) and in vitro pharmacological evaluation

A series of novel N-(salicylidene)-sulfaguanidines (Sal-SG) bearing ionic liquid (IL) terminals (ILSSGH, 4a–f) have been synthesized by Schiff base condensation of IL-functionalized salicylaldehydes (ILSal, 3a–g) and sulfaguanidine (SG). Metalation trials of these ionic Schiff bases with palladium(II) chloride affords the corresponding Pd(II) complexes, [Pd(II)(ILSSG)Cl(H2O)] (5a–g). Further, the antimicrobial profiles of the new compounds against a set of common pathogens have been described. Zone of inhibition (ZOI) and minimal inhibitory concentration (MIC) values revealed that most of the new compounds exhibited significant antibacterial and potential inhibitory activity against Staphylococcus aureus (S. aureus), and this activity is modulated by substituents attached to the ionic liquid core as well as the counter-ion.

A New Type of Synthesis of 1,2,3-Thiadiazole and 1,2,3-Diazaphosphole Derivatives Via-Hurd-Mori Cyclization

We present a short and efficient synthesis of the title compounds starting with cheap and readily available camphor and derivatives of acetophenone. The optimized sequence allows the large-scale preparation of this new type of synthesis in a few steps. New 1,2,3-thiadiazole and 1,2,3-diazaphosphole derivatives 11-20, were prepared from the ketones 1-5 via the corresponding semicarbazones 6-10. The Hurd-Mori and Lalezari methods were used, respectively, for the preparation of these 1,2,3-thiadiazole and 1,2,3-diazaphospholene derivatives. These derivatives exhibit anticancer effect due to their high potential biological activity.

Synthesis and Anticancer Activity of Some New Derivatives of Coumarin and Quinolinyl Mercaptotriazoles

Pechmann condensation of ethylacetoacetate with derivatives of phenol by heating in absence of solvent and with montmorillonite clays K-10 afforded coumarin derivatives (1a-e) in good yields which on reaction with thiosemicarbazide in anhydrous pyridine yielded coumarin-quinolinyl mercaptotriazole (2a-e). The latter compounds were evaluated for their antimicrobial and anticancer activities. The newly synthesized compounds were characterized by IR, 1HNMR and mass spectra.

Synthesis, Characterization of Poly (4-vinyl Pyridine/Vinyl Acetate) Organo Montmorillonite Clay Composites Prepared by Chemical Initiation and their Metallated Products

The nanocomposite of different ratios of (4-vinyl pyridine (VP) vinyl acetate (VAc) copolymers), with montmorillonite (Bent), was prepared by direct interaction of sodium montmorillonite (Bent). It was found that the interaction occurred, through ion exchange between sodium cations in Bent and pyridinium ions, in the copolymers. The structure of the prepared composite was confirmed via X-ray diffraction, thermal stability via thermogravimetric analysis and scanning electron microscope. Also, the formation of metallo composites with Cu+2, Hg+2, and Co+2 cations, and their antimicrobial activities were investigated. The results indicated that the prepared composite exhibited antibacterial activities.

Friendly Synthesis, Metallation, and Phosphorylation of Schiff Base as a Potential Pharmacological Interest

In view of the broad physiological activity of organometallic and organophosphorus compounds, the present paper deals with the synthesis of 2-(4-methoxybenzylidene amino) benzene-thiol, its metallation with mercury (II), nickel (II), palladium (II), and phosphorylation. The antimicrobial activities of all products were investigated. The palladated product displays a significant anticancer activity against human breast carcinoma cell. All the new products were investigated and their structures were elucidated using elemental analyses, thermal analysis, and spectroscopic data.

Metallation of Some New Imines and Evaluation of Their Antimicrobial and Anticancer Activity

Metallation of new imines 2-(4-(Dimethylamino)benzylidene- amino)benzenethiol (1) and 2-(4-nitrobenzylideneamino)-benz- enethiol(5) with Hg(II), Ni(II) acetate, and palladium chloride afforded metallated products (2), (3), and (4) in the form of monomercurated, dinickel nickel bis-, monopalladated products and monometallated products of Hg++ and Ni++ (6) and (7), and monopalladated cyclized product (8), respectively. Compounds (1) and (5) were prepared from the reaction of o-aminothiophenol with N,N-dimethylaminobenzaldehyde and p-nitrobenzaldehyde in ethyl alcohol. Elemental analyses, IR, 1HNMR, and mass spectral elucidated the structures. All the newly synthesized compounds have been evaluated for their antimicrobial activity against gram positive and gram negative bacteria and fungi. Compounds (4) and (8) exhibited in vitro anticancer activity toward breast cancer.

Novel Organometallic Compounds Via Metallation of Some New Schiff Bases

Isatin reacts with N-(2-aminoethyl)-1,3-propanediamine in a 1:1 molar ratio in ethyl alcohol to give new Schiff base, 4-[2-(2-oxoindolin-3-ylideneamino)ethylamino.-3,4-dihydro-2H-pyrido[3,2-b]indole. When the reaction is carried out by fusion, two new Schiff bases, 3-(vinylimino)indolin-2-one and 3-(allylimino)indolin-2-one, are obtained with the liberation of ammonia gas. The synthesis, characterization, and the reactivity of the Schiff bases with mercury(II) acetate and palladium(II) chloride are studied. Elucidation of the structures are based on elemental analyses and infrared (IR), ultraviolet (UV), 1H-nuclear magnetic resonance (NMR), and mass spectroscopic (MS) spectra.