Synthesis and biological evaluation of novel aliphatic amido-quaternary ammonium salts for anticancer chemotherapy: Part I

Facile synthesis, larvicidal activity, biological effects, and molecular docking of sulfonamide-incorporating quaternary ammonium iodides as acetylcholinesterase inhibitors against Culex pipiens L

Insecticides participate with a vital role in our lives especially in preventing the spread of human diseases via controlling the dangerous pests. It is a challenge to identify alternatives to the ordinary insecticides with new mode of action to be used for mosquitoes' control in an environmentally sustainable manner. Using a facile two-step procedure, three novel series of sulfonamide-incorporating quaternary ammonium iodides (3a-i, 4a-i and 5a-i) were synthesized and their chemical structures were successfully characterized. The uncharged sulfonamide intermediates (2a-i) were constructed through simple amidation of the corresponding (hetero)aryl sulfonyl chlorides then the cationic target molecules were formed by quaternizing the tertiary nitrogen with methyl, ethyl, and allyl iodides. The larvicidal activities and biological effects of most synthesized compounds against Culex pipiens L. were extensively investigated and they exhibited good and comparable activities to temephos. Among these hybrids, 4a showed the most potent activity with LC₅₀ = 26.71 ppm. Additionally, the developmental durations of larval and pupal stages were significantly prolonged after treatment with all concentrations of 4h. At high concentration (160 ppm) of 4a and 4b, no adults emerged due to the complete death of pupae, and consequently zero growth index. Moreover, the results of the molecular docking demonstrated that the activities of compounds correlate partially to their binding with acetylcholinesterase (AChE) and it is not the sole parameter for determining the activity.

Anticancer activities of fatty acids and their heterocyclic derivatives

Traditional chemotherapy relies on the premise that rapidly proliferating cancer cells are more likely to be killed by a cytotoxic agent, but in reality, the long-standing problem of chemotherapy is the lack of tumor-specific treatments. Apart from the impact on tumor cells, the drugs' major limitation is their severe adverse side effects on normal cells and tissues. Nutritional and epidemiological studies have indicated that cancer progression is correlated with the consumption of fatty acids, but the exact mechanisms still remain unknown. In the first part of our review, we discussed the beneficial effects of free fatty acids (saturated and unsaturated) on the progress of carcinogenesis in different tumor cell lines. We presented various mechanisms proposed in the literature, which explain the possible impact on the cells metabolism. The second part describes modifications of different fatty acids with existing anticancer drugs and heterocyclic moieties by condensation reactions. Such conjugations increased the tissue selectivity and made chemotherapy potentially more effective and less toxic in in vivo and in vitro studies. This fatty acid modifications, which change the activity of compounds, their uptake selectivity and alter drug delivery methods, may be the key to unlocking true medical potential of fatty acids.

In vivo studies of the effectiveness of novel N-halomethylated and non-halomethylated quaternary ammonium salts in the topical treatment of cutaneous leishmaniasis

The physicochemical properties of four N-halomethylated and one non-halomethylated ammonium salts, with proven in vitro antileishmanial activity, were determined according to pharmaceutical standard procedures. The effectiveness and toxicity of these compounds were assessed in hamsters infected with Leishmania (Viannia) braziliensis and compared to that showed by meglumine antimoniate. Animals were followed during 90 days after the completion of treatment. Therapeutic response was determined according to the reduction of size of skin lesions. Toxicity was determined by the effect of compounds on body weight changes and serum levels of renal and hepatic metabolites. The effectiveness of compound 4 was similar to that showed by intralesional administration of meglumine antimoniate and better than that of the other ammonium salts. Levels of creatinine, alanine amino transferase, and blood urea nitrogen in serum were not significantly different between treatment groups, including healthy or untreated hamsters. Results imply that compound 4 has potential as a pharmaceutical active ingredient in the development of new and better formulations for the treatment of cutaneous leishmaniasis.

Novel 1-(2-aryl-2-adamantyl)piperazine derivatives with antiproliferative activity

Novel 1-(2-aryl-2-adamantyl)piperazine derivatives have been synthesized and evaluated in vitro for their antitumor properties against HeLa cervical carcinoma, MDA MB 231 breast cancer, MIA PaCa2 pancreatic cancer, and NCI H1975 non-small cell lung cancer. The parent piperazine 6 was found to exhibit a reasonable activity toward the HeLa and MDA MB 231 tumor cell lines (IC50= 9.2 and 8.4 μΜ, respectively). Concurrent benzene ring C4-fluorination and piperidine acetylation of the piperazino NH of compound 6 resulted in the most active compound 13 of the series in both of the above cell lines (IC50=8.4 and 6.8 μΜ, respectively). Noticeably, compounds 6 and 13 exhibited a significantly low cytotoxicity level over the normal human cells HUVEC (Human Umbilical Vein Endothelial Cells) and NHDF (Normal Human Dermal Fibroblasts).

4-Benzyl-N-methyl-piperazine-1-carbothio-amide

The asymmetric unit in the title thio­urea derivative, C₁₃H₁₉N₃S, comprises three independent mol­ecules (A, B and C). The thio­urea groups are superimposable for the three mol­ecules, but there are significant conformational differences. Mol­ecules A and B are approximate mirror images of each other, and mol­ecule C has an inter­mediate conformation. The dihedral angles between the thio­urea groups and the phenyl rings are 52.10 (5), 63.29 (5) and 66.46 (6)° in mol­ecules A, B and C, respectively. Each independent mol­ecule self-associates into a supra­molecular chain along [100] via N—H⋯S hydrogen bonds. Mol­ecules of A and B assemble into layers four mol­ecules thick in the ac plane via C—H⋯S and C—H⋯π inter­actions. Mol­ecules of C self-assemble into layers in the ac plane via C—H⋯S inter­actions. The layers stack along the b axis with no specific inter­actions between them.