Novel Schiff bases–based thiophenes: Design, synthesis and biological evaluation

Abstract

Abstract2‐amino‐5‐(3‐fluoro‐4‐methoxyphenyl)thiophene‐3‐carbonitrile derivatives have been synthesized from 1‐(3‐fluoro‐4‐methoxyphenyl)ethanone, malononitrile, mild base, and sulfur powder using the Gewald method through a multistep reaction sequence. The structures of newly synthesized compounds were established on the basis of their elemental analyses, IR, 1H NMR, 13C NMR, and mass spectral data, and then synthesized compounds were screened for their in vitro antimicrobial activity. Among them, derivatives 3b (thiphene), 3f (pyrazole), and 3d (halogen) showed good activity and remaining derivatives exhibited moderate activity.

Synthesis, Biological, and Molecular Docking Studies on 4,5,6,7-Tetrahydrobenzo[b]thiophene Derivatives and Their Nanoparticles Targeting Colorectal Cancer

“…Therefore, to investigate the process of the formation of the nanosystem to examine its effect on the various biological activities, we have designed one compound as a representative example for future work. In this regard, Schiff bases have been acknowledged as excellent capping agents capable of inhibiting the overgrowth of NPs and preventing their aggregation/coagulation in colloidal synthesis . In addition, Schiff bases have gained importance in medicinal and pharmaceutical fields due to their broad spectrum of biological activities like antimicrobial, anticancer, and antioxidant …”

“…In this regard, Schiff bases have been acknowledged as excellent capping agents capable of inhibiting the overgrowth of NPs and preventing their aggregation/ coagulation in colloidal synthesis. 40 In addition, Schiff bases have gained importance in medicinal and pharmaceutical fields due to their broad spectrum of biological activities like antimicrobial, anticancer, and antioxidant. 41 Thus, in this study, the Schiff base 2-((3-hydroxy-4methoxybenzylidene)amino)-4,5,6,7-tetrahydrobenzo [b]thiophene-3-carbonitrile 11 was designed and prepared to be used as a coating shell for the new NPs, which will be evaluated for their efficacy as preventive or therapeutic agents against CRC.…”

Thiophene‐containing compounds with antimicrobial activity

“…thiophene-3-carbonitrile with 1,3-diarylpyrazole-4-carboxaldehydes gave azomethines 136 (Figure 14), whose antimicrobial activity was tested using agar well diffusion assay, while serial microdilution assay was employed to determine MICs for the most potent compounds that have been identified in the preliminary test. [123] While none of these azomethines had any significant antimicrobial activity when In a follow-up article, [124] another series of Schiff bases 137 (Figure 14), which were obtained through the condensation of the been also disclosed. [125] The generally superior results in antimicrobial activity of this series should presumably be due to the re- chromen-2-yl) (Figure 14) had a modest anti-B.…”

“…The most potent thiophenes were 136 (Ar = 4‐BrC 6 H 4 , R = Cl, which was eightfold weaker against E. coli and 32 times weaker against S. aureus than ciprofloxacin), 136 (Ar = 4‐ClC 6 H 4 , R = Cl; Ar = 4‐CH 3 OC 6 H 4 , R = Cl, which were 16 times weaker than ciprofloxacin against B. subtilis ) and 136 (Ar = 4‐FC 6 H 4 , R = Cl, which was 32 times weaker than fluconazole against C. albicans ). In a follow‐up article, [ 124 ] another series of Schiff bases 137 (Figure 14), which were obtained through the condensation of the same 2‐aminothiophene with (hetero)aromatic aldehydes were evaluated as antimicrobial agents employing the same protocol. The most potent azomethines 137 against E. coli were derived from thiophene‐2‐carboxaldehyde and 3‐(4‐nitrophenyl)pyrazole‐4‐carboxaldehyde and were eightfold weaker than ciprofloxacin.…”

Exploring Novel Schiff Base Compounds Derived from Benzothiophene-3- carboxaldehyde Hydrazones: In vitro and In silico Evaluation as Potential Inhibitors of Cholinesterases and Carbonic Anhydrases I-II

“…The synthesis of benzothiophene-derived Schiff bases has been made by some researchers and antimicrobial, antioxidant, antileishmanial activities of them have been examined. (17)(18)(19)(20). Activity studies of such compounds, especially against cholinesterase and carbonic anhydrase enzymes, have not been found more in the literature.…”