Platelet antiaggregant methoxyphenylthienyl ketoxime ethers: synthesis and structure-activity relationships

A Review of Biologically Active Oxime Ethers

Oxime ethers are a class of compounds containing the >C=N-O-R moiety. The presence of this moiety affects the biological activity of the compounds. In this review, the structures of oxime ethers with specific biological activity have been collected and presented, and bactericidal, fungicidal, antidepressant, anticancer and herbicidal activities, among others, are described. The review includes both those substances that are currently used as drugs (e.g., fluvoxamine, mayzent, ridogrel, oxiconazole), as well as non-drug structures for which various biological activity studies have been conducted. To the best of our knowledge, this is the first review of the biological activity of compounds containing such a moiety. The authors hope that this review will inspire scientists to take a greater interest in this group of compounds, as it constitutes an interesting research area.

The Oxime Ethers with Heterocyclic, Alicyclic and Aromatic Moiety as Potential Anti-Cancer Agents

Chemotherapy is one of the most commonly used methods of cancer disease treatment. Due to the acquisition of drug resistance and the possibility of cancer recurrence, there is an urgent need to search for new molecules that would be more effective in destroying cancer cells. In this study, 1-(benzofuran-2-yl)ethan-1-one oxime and 26 oxime ethers containing heterocyclic, alicyclic or aromatic moiety were screened for their cytotoxicity against HeLa cancer cell line. The most promising derivatives with potential antitumor activity were 2-(cyclohexylideneaminoxy)acetic acid (18) and (E)-acetophenone O-2-morpholinoethyl oxime (22), which reduced the viability of HeLa cells below 20% of control at concentrations of 100-250 μg/mL. Some oxime ethers, namely thiazole and benzothiophene derivatives (24-27), also reduced HeLa cell viability at similar concentrations but with lower efficiency. Further cytotoxicity evaluation confirmed the specific toxicity of (E)-acetophenone O-2-morpholinoethyl oxime (22) against A-549, Caco-2, and HeLa cancer cells, with an EC50 around 7 μg/mL (30 μM). The most potent and specific compound was (E)-1-(benzothiophene-2-yl)ethanone O-4-methoxybenzyl oxime (27), which was selective for Caco-2 (with EC50 116 μg/mL) and HeLa (with EC50 28 μg/mL) cells. Considering the bioavailability parameters, the tested derivatives meet the criteria for good absorption and permeation. The presented results allow us to conclude that oxime ethers deserve more scientific attention and further research on their chemotherapeutic activity.

Study of the Room-Temperature Synthesis of Oxime Ethers by using a Super Base

In this study, we present a convenient method for the synthesis of oxime ethers by reacting oximes with various chlorides (alkyl, functionalized alkyl, and benzyl) and with the subsequent use of a super base-pulverized potassium hydroxide in DMSO. The reactions take place at room temperature and the products are obtained in high yields. The final products were received within 2 min to 3 h. In addition, the compounds do not require chromatographic separation. The structure elucidation of the titled compounds was performed by using 1H NMR and 13C NMR spectroscopy as well as mass spectrometry. The presented method of synthesis for oxime ethers is environmentally friendly, because neither water cooling or heating of the reaction mixture/solvents (necessary for chromatographic purification) is required. The synthesis can be carried out very easily on a large scale.