Design and synthesis of S-citalopram-imprinted polymeric sorbent: Characterization and application in enantioselective separation.

The current work describes the efficient creation and employment of a new S-citalopram selective polymeric sorbent, made from poly(divinylbenzene-maleic anhydride-styrene). The process began by using suspension polymerization technique in the synthesis of poly(styrene-maleic anhydride-divinylbenzene) microparticles. These were then modified with ethylenediamine, developing an amido-succinic acid-based polymer derivative. The S-citalopram, a cationic molecule, was loaded onto these developed anionic polymer particles. Subsequently, the particles were post-crosslinked using glyoxal, which reacts with the amino group residues of ethylenediamine. S-citalopram was extracted from this matrix using an acidic solution, which also left behind stereo-selective cavities in the S-citalopram imprinted polymer, allowing for the selective re-adsorption of S-citalopram. The attributes of the polymer were examined through methods such as 13C NMR, FTIR, thermogravemetric and elemental analyses. SEM was used to observe the shapes and structures of the particles. The imprinted polymers demonstrated a significant ability to adsorb S-citalopram, achieving a capacity of 878 mmol/g at a preferred pH level of 8. It proved efficient in separating enantiomers of (±)-citalopram via column methods, achieving an enantiomeric purity of 97 % for R-citalopram upon introduction and 92 % for S-citalopram upon release.

Synthesis of novel cyanine dyes as antitumor agents.

In this study, some novel cyanine dyes, 1, 3, and 5-15, were synthesized by a one-pot step reaction of pyridinium salts 2 and/or 4 with benzenaminium salt 1. N-{[1-Chloro-3,4-dihydronaphthalen-2-yl)methylene]benzenaminium} chloride 1 was obtained by the reaction of α-tetralone with Vilsmeier-Haack reagent, followed by a mixture of an equimolar ratio of anilin/ethanol (1:1). All new cyanine dyes were evaluated in vitro for their anticancer activity against two cell lines, that is, HepG2 (human hepatocellular liver carcinoma) and MCF-7 (breast cancer). The obtained results were compared with human lung fibroblasts (WI-38) and Vero cells (derived from the kidney of an African green monkey) as normal cells. In particular, some of these compounds, 6, 9, 13, and 14, were found to be the most potent derivatives against all the cancer cell lines, without effect on the normal cells. According to the structure-activity relationship, compound 13 (IC50 = 8.8 µg/ml) exhibited a higher activity against HepG2 cells, as it contains the azo group and two phenyl rings and due to the presence of the π-conjugated system attached to the two pyridine rings. Compound 6 (IC50 = 8 µg/ml) exhibited a higher activity against MCF-7 cells, as it contains two chlorine atoms and the π-conjugated system of the pyridine rings.

Synthesis, Characterization and Cytotoxicity Evaluation of Some Novel Pyridine Derivatives.

Reaction of isonicotinaldehyde with 2-cyanoacetohydrazide afforded (E)-2-cyano-N'-(pyridin-4-ylmethylene)acetohydrazide (1). Compound 1 was used as the precursor for the synthesis of novel pyridine derivatives by reaction with different arylidene malononitriles, malononitrile and acetylacetone to give pyridine derivatives 5a-e, 6 and 7, respectively. 4,4'-Bipyridine derivatives 9a-d were synthesized by a three-component reaction of isonicotinaldehyde, 2-cyanoacetohydrazide and activated nitriles 8a-d. Treatment of compound 9a with different aromatic aldehydes gave [1,2,4]triazolo[1,5-a]pyridine derivatives 11a-c. All reaction products were characterized by analytical and spectral data. For the novel compounds their bioactivity as antitumor agents was examined for in vitro cytotoxicity against HepG-2 and MCF-7. It was found that compounds 9a and 9b have high cytotoxic activity against both HepG-2 and MCF-7.