Synthesis and Molecular Modeling Studies of 2-[2-(3-nitrophenyl)-1h-benzimidazol-1-yl]-acetamide Derivatives as Anthelmintic

Benzimidazole derivatives of substituted 2 [2-(3-nitrophenyl)-1H-benzimidazole-1-yl] acetamide analogues were synthesized and studied for antihelminthic activity. Compounds 3a–o were obtained in three steps, starting with the Oxidative Condensation of the appropriate 3-nitrobenzaldeyde, o-phenylenediamine and sodium hydrogen sulfite to form 2-(3-nitrophenyl)-1H-benzimidazole (1a). In second step Nucleophilic substitution, Chlorine atom of ethylchloroacetate will attach on nitrogen of benzimidazole by replacing hydrogen with elimination of hydrochloric acid to form ethyl [2-(3-nitrophenyl)-1H-benzimidazole-1-Yl acetate (2a).In third step amide formation from ester takes place by substitution of electrophilic with loss of ethanol to form substituted 2 [2-(3-nitrophenyl)-1H-benzimidazole-1-yl] acetamide 3a–o The antihelminthic activity showed that compounds 3f, 3h, 3i, 3j and 3k good activity against Indian earthworms (Pheretima posthuma) in comparison to albendazole.

Synthesis, Molecular Docking and Antiplasmodial Activities of New Tetrahydro-β-Carbolines

Malaria is still one of the most dangerous infectious diseases and the emergence of drug resistant parasites only worsens the situation. A series of new tetrahydro-β-carbolines were designed, synthesized by the Pictet–Spengler reaction, and characterized. Further, the compounds were screened for their in vitro antiplasmodial activity against chloroquine-sensitive (D10) and chloroquine-resistant (W2) strains of Plasmodium falciparum. Moreover, molecular modeling studies were performed to assess the potential action of the designed molecules and toxicity assays were conducted on the human microvascular endothelial (HMEC-1) cell line and human red blood cells. Our studies identified N-(3,3-dimethylbutyl)-1-octyl-2,3,4,9-tetrahydro-1H-pyrido[3,4-b] indole-3-carboxamide (7) (a mixture of diastereomers) as the most promising compound endowed with the highest antiplasmodial activity, highest selectivity, and lack of cytotoxicity. In silico simulations carried out for (1S,3R)-7 provided useful insights into its possible interactions with enzymes essential for parasite metabolism. Further studies are underway to develop the optimal nanosized lipid-based delivery system for this compound and to determine its precise mechanism of action.

Synthesis, molecular modeling and cholinesterase inhibitory effects of 2-indolinone-based hydrazinecarbothioamides

Background: 2-Indolinone-based hydrazinecarbothioamides carrying a 3-phenylsulfonamide moiety (7–9) were designed by replacement of donepezil's pharmacophore group indanone with a 2-indolinone ring. Method: Compounds 7–9 were synthesized by reaction of N-(3-sulfamoylphenyl)hydrazinecarbothioamide (6) with 1 H-indolin-2,3-diones (1–3). Acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) inhibitory effects of compounds 7–9 were assayed. Molecular modeling studies of 5-chloro-1,7-dimethyl-substituted compound 8e were carried out to determine the possible binding interactions at the active site of AChE. Results: Compound 8e showed the strongest inhibition against AChE ( Ki = 0.52 ± 0.11 μM) as well as the highest selectivity (SI = 37.69). The selectivity for AChE over BuChE of compound 8e was approximately 17-times higher than donepezil and 26-times higher than galantamine. Conclusion: Further development of compounds 7–9 may present new promising agents for Alzheimer's treatment.