2-aminothiophene-3-carboxylic acid ester derivatives as novel highly selective cytostatic agents

2D QSAR, Design, and in Silico Analysis of Thiophene-Tethered Lactam Derivatives as Antimicrobial Agents

BACKGROUND

A very high rate of resistance causes health-care-associated and community-acquired infections. E. coli is one of the nine pathogens of highest concern to most of the antibiotics and other class of antimicrobials.

OBJECTIVE

The objective of the present study is to develop novel thiophene derivatives using 2D QSAR and in silico approach for E. coli resistance.

METHODS

Substituted thiophene series reported by Nishu Singla et al., were taken for QSAR analysis. From the results, a set of 15 new compounds were designed. A complete in silico analysis has been done using PADEL, Autodock vina, Swiss ADME, Protox II software.

RESULTS

The designed compounds obey the Lipinski's rule of five and were known to have excellent inhibitory action (pIC50 values -0.87 to -1.46) which is similar to the most active compound of the data set (pIC50 -0.69) taken for the study. The bioavailability score (0.65) with no toxicity representing that the designed compounds are suitable for oral administration.

CONCLUSION

The designed compounds are inactive for mutagenicity and cytotoxicity and ADMET studies states that these molecules are likely to be orally bioavailable and could be easily transported, diffused, and absorbed. So, the designed compounds will definitely serve as a lead antibacterial agent for E. coli resistance.

Design, synthesis and antimicrobial activity of novel 2-aminothiophene containing cyclic and heterocyclic moieties

One of the major challenges in the community and healthcare was an impedance of pathogenic bacteria to antibiotics. This work developed 2-aminothiophene derivatives as novel antimicrobial agents. Various 2-aminothiophene derivatives (3a-f, 5a-c, 6a, b, 7, 8a, b and 9) with cyclic and heterocyclic moieties at 5-position were synthesized, and characterized using NMR, IR, and mass spectroscopic techniques. The newly synthesized compounds were evaluated for their antimicrobial activity against bacteria S. pneumoniae, B. subtilis, P. aeruginosa, E. coli, and fungi A. fumigatus, S. mracemosum, G. candidum, C. albicans. Compound 3a with OH group at para position of phenyl ring exhibited significant antibacterial activity stronger than that of the drug standards Ampicillin and Gentamicin. Compound 6b possess pyrazole ring and compound 9 bearing pyridine ring showed promising antifungal activity compare to the standard drug Amphotericin B. The remaining compounds exhibited good to moderate inhibitory activities. In summary, the results suggest that the compounds from 2-aminothiophene derivatives can be used as antimicrobial agents.

2-Amino-3-methylcarboxy-5-heptyl-thiophene (TJ191) is a selective anti-cancer small molecule that targets low TβRIII-expressing malignant T-cell leukemia/lymphoma cells

Current chemotherapy regimens often include non-specific cytostatic/cytotoxic drugs, which do not distinguish between normal and tumor cells, therefore causing considerable systemic toxicity. We previously reported the synthesis and anti-proliferative activity of a novel synthetic 2-aminothiophene-3-carboxylic acid ester derivative TJ191 that selectively targets certain cancer cells without affecting the proliferation of other cancer cells or normal fibroblasts or immune cells (over 600-fold selectivity). In a panel of ten human T-cell leukemia/lymphoma cell lines and peripheral blood mononuclear cells (PBMCs), we now found that transforming growth factor β type III receptor (TβRIII) expression correlates inversely with TJ191 sensitivity, but not with sensitivity against classical chemotherapeutic drugs, thus serving as a predictive marker for TJ191 sensitivity. Accordingly, CRISPR/Cas9-mediated knock-out of TβRIII partially restored the susceptibility of TJ191-resistant cells to this novel compound. Our findings highlight TJ191 as a potent and selective anti-cancer molecule with pronounced activity against human malignant T-cells expressing low levels of TβRIII.

2-Aminothiophene scaffolds: Diverse biological and pharmacological attributes in medicinal chemistry

2-Aminothiophenes are important five-membered heterocyclic building blocks in organic synthesis, and the chemistry of these small molecules is still developing based on the discovery of cyclization by Gewald. Another attractive feature of 2-aminothiophene scaffolds is their ability to act as synthons for the synthesis of biological active thiophene-containing heterocycles, conjugates and hybrids. Currently, the biological actions of 2-aminothiophenes or their 2-N-substituted analogues are still being investigated because of their various mechanisms of action (e.g., pharmacophore and pharmacokinetic properties). Likewise, the 2-aminothiophene family is used as diverse promising selective inhibitors, receptors, and modulators in medicinal chemistry, and these compounds even exhibit effective pharmacological properties in the various clinical phases of appropriate diseases. In this review, major biological and pharmacological reports on 2-aminothiophenes and related compounds have been highlighted; most perspective drug-candidate hits were selected for discussion and described, along with additional synthetic pathways. In addition, we focused on the literature dedicated to 2-aminothiophenes and 2-N-substituted derivatives, which have been published from 2010 to 2017.

A new four-component reaction involving the Michael addition and the Gewald reaction, leading to diverse biologically active 2-aminothiophenes

A Gewald-four component reaction has been successfully developed for the synthesis of a series of compounds containing an indole and a 2-aminothiophene moiety separated by a methylene spacer having anti-proliferative activity.

Evaluation of the toxicity of 5-aryl-2-aminoimidazole-based biofilm inhibitors against eukaryotic cell lines, bone cells and the nematode Caenorhabditis elegans

Previously, we have synthesized several series of compounds based on the 5-aryl-2-aminoimidazole scaffold, which showed a preventive activity against microbial biofilms. We here studied the cytotoxicity of the most active compounds of each series. First, the cytostatic activity was investigated against a number of tumor cell lines (L1210, CEM and HeLa). A subset of monosubstituted 5-aryl-2-aminoimidazoles showed a moderate safety window, with therapeutic indices (TIs) ranging between 3 and 20. Whereas introduction of a (cyclo-)alkyl chain at the N1-position strongly reduced the TI, introduction of a (cyclo-)alkyl chain or a triazole moiety at the 2N-position increased the TI up to 370. Since a promising application of preventive anti-biofilm agents is their use in anti-biofilm coatings for orthopedic implants, their effects on cell viability and functional behavior of human osteoblasts and bone marrow derived mesenchymal stem cells were tested. The 2N-substituted 5-aryl-2-aminoimidazoles consistently showed the lowest toxicity and allowed survival of the bone cells for up to 4 weeks. Moreover they did not negatively affect the osteogenic differentiation potential of the bone cells. Finally, we examined the effect of the compounds on the survival of Caenorhabditis elegans, which confirmed the higher safety window of 2N-substituted 5-aryl-2-aminoimidazoles.