Synthesis, In silico and Biological Studies of Thiazolyl-2h-chromen-2-one Derivatives as Potent Antitubercular Agents

Ethionamide and Prothionamide Based Coumarinyl-Thiazole Derivatives: Synthesis, Antitubercular Activity, Toxicity Investigations and Molecular Docking Studies

The goal of this research work was to prepare and evaluate the antitubercular (anti-TB) activity of ethionamide (ETH) and prothionamide (PTH) based coumarinyl-thiazole derivatives. ETH and PTH were reacted with coumarin intermediates (3a-3e) to provide the target compounds (4a-4e and 4f-4j, respectively). Spectral studies confirmed the assigned structures of 4a-4j. The Microplate Alamar Blue Assay was utilized to evaluate the anti-TB activity of compounds 4a-4j against Mycobacterium tuberculosis H37Rv strain in comparison to ETH, PTH, isoniazid (INH), and pyrazinamide (PYZ) as standard drugs. The cytotoxicity studies were carried out versus HepG2 and Vero cell lines. In addition. molecular docking studies of 4a-4j concerning the DprE1 enzyme and the in-silico evaluation of physicochemical and pharmacokinetic parameters were performed. Compounds 4a, 4b, 4f, and 4g displayed equal minimum inhibitory concentration (MIC) values in comparison to INH (3.125 μg/ml) and PYZ (3.125 μg/ml), whereas 4c-4e and 4h-4j displayed better MIC values (1.562 μg/mL) than INH and PYZ. All compounds presented better anti-TB potential than ETH (6.25 μg/mL) and PTH (6.25 μg/mL). The studies of toxicity revealed that 4a-4j were safe up to 300 μg/mL concentration versus Vero and HepG2 cell lines. The molecular docking studies suggested that 4a-4j could possess anti-TB activity through the inhibition of the DprE1 enzyme. The in silico studies showed that 4a-4j followed Lipinski's rule (drug-likeliness) and exhibited better gastrointestinal absorption than BTZ043 and macozinone. In conclusion, the ETH and PTH-based coumarinyl-thiazole template can help developing selective DprE1 enzyme inhibitors as potent anti-TB agents.

Balanced QSAR and Molecular Modeling to Identify Structural Requirements of Imidazopyridine Analogues as Anti-infective Agents Against Trypanosomiases

Human African trypanosomiasis (HAT), a fatal infection caused by Trypanosoma brucei (T. brucei) is considered as a neglected disease in the tropical areas, and newer agents with unique mechanism of action are urgently needed. In this work, 65 Imidazopyridine analogues from known literature were selected for building statistically robust genetic algorithm (GA) based QSAR models. Furthermore, values for the various cross-validation properties supported its statistical robustness (model 1, [Formula: see text], RMSE[Formula: see text], MAE[Formula: see text], CCC[Formula: see text], and [Formula: see text]). Our in silico ADMET analysis revealed that a designed molecule, S10 may act as potent lead (T. brucei, pEC[Formula: see text] ([Formula: see text]M), [Formula: see text]) with better pharmacokinetics, no carcinogenicity, class III acute oral toxicity, minimal OCT1 and OCT2 inhibitions and no eye corrosion profiles. Our molecular docking analysis (on 42 drug targets) for a dataset and designed molecules demonstrated higher binding affinity of Imidazopyridine analogues with T. brucei farnesyl diphosphate synthase (TbFPPS) (PDB id: 2I19). This observation was further supported by 100[Formula: see text]ns molecular dynamics analysis retaining better stability of complex. Thus, imidazopyridine analogues would provide a promising scaffold for the development of anti-HAT agents.

Newly Identified COVID-19 Drug Candidates Based on Computational Strategies

The COVID-19 has raised a public health catastrophe in early 2020 worldwide. Despite several approved vaccines that have repressed the pandemic and decreased the mortality rate since then, attempts to discover an effective antiviral drug have not indicated reliable results. In this research, in silico studies (virtual screening and molecular docking) were performed based on quinoline structure to identify novel drug candidates against SARS-CoV-2 before laboratory evaluations. A chemical library consisting of 548 compounds was collected from literature mining of five databases to select the best ligands interacting with three target proteins of SARS-CoV-2, including the main protease, spike protein, and chimeric receptor-binding domain in a complex of human angiotensin-converting enzyme 2. The top five compounds that presented suitable binding energy against each target protein are reported in detail for the first time. Notably, new compound N-4-(6-methyl-3-pyridinyl) phenyl)-9-acridinamine showed high affinity to all selected proteins. These identified compounds will help in speeding up the drug development against COVID-19.

Synthesis, In silico and In vitro Analysis of Hydrazones as Potential Antituberculosis Agents

Tuberculosis (TB) is a major cause of mortality and illness as reported by the W.H.O in 2019. The WHO report also mentioned the fact that about 10.0 million people fell ill with tuberculosis in the year 2018. Hydrazide-hydrazones having azomethine group (-NH-N=CH-) connected with carbonyl group is reported for the number of bioactivities like anti-inflammatory, anticonvulsant, anticancer, antiviral and antiprotozoal.

OBJECTIVE

The objective of our current study is to design and synthesise more potent hydrazide- hydrazones, containing anti-tubercular agents.

METHODS

In the current study, we synthesized 10 hydrazones (3a-3j) by stirring corresponding benzohydrazides (2) with substituted aldehydes (1a-j) in ethanol as a solvent and acetic acid as a catalyst at room temperature. All synthesized compounds were characterized by various spectroscopic techniques including elemental analysis, ultraviolet-visible spectroscopy, fluorescence, fourier- transform infrared spectroscopy and nuclear magnetic resonance spectroscopy. Compounds (3a-3j) were tested for in vitro anti-TB activity using Microplate Alamar Blue Assay (MABA).

RESULTS

All our synthesized compounds (3a-3j) were found to be potent against Mycobacteria tuberculosis (H37RV strain) with MIC (minimum inhibitory concentrations) values of 3.125-50 μg/mL. The hydrazide CO-NH protons in (3a-j) compounds are highly deshielded and showed broad singlet at 9.520-9.168 ppm. All the compounds were found to have more intense emission in the 416 - 429 nm regions and strong absorption in the regions of 316 - 327 nm. Synthesized compounds were also tested for in silico analysis using different software for their Absorption, Distribution, Metabolism, Excretion and Toxicity (ADMET) analysis. All the compounds were found to be in silico non-carcinogenic.

CONCLUSION

It will be worth saying that our in silico and in vitro approaches used in the current study will become a guide for medicinal chemists to make structural modifications and synthesize more effective and potent hydrazone containing anti-tubercular agents.

An Insight Into the Anxiolytic Effects of Lignans (Phyllanthin and Hypophyllanthin) and Tannin (Corilagin) Rich Extracts of Phyllanthus amarus : An In-Silico and In-vivo approaches

The extracts and the compounds isolated from Phyllanthus amarus Schumm and Thonn (Family: Euphorbiaceae) have shown a wide spectrum of pharmacological activities including antiviral, antibacterial, antiplasmodial, antimalarial, antimicrobial, anticancer, antidiabetic, hypolipidemic, antioxidant, hepatoprotective, nephroprotective and diurectic properties.

BACKGROUND

This investigation was aimed at exploring the anxiolytic potential of Phyllanthus amarus standardized extracts and predict probable role of marker phyto constitutents.

OBJECTIVE AND METHODS

Three standardized extracts of Phyllanthus amarus plant viz. standardized aqueous extract of Phyllanthus amarus whole plant (PAAE), standardized methanolic extract of P. amarus leaf (PAME) and the standardized hydro-methanolic extract of P. amarus leaf (PAHME) were tested in the classical animal models of anxiety: Elevated plus-maze model and Light & Dark Exploration test.

RESULTS

The lower doses of the tannin rich extract (PAHME) of the P. amarus possess significant anxiolytic activity compared to lignin rich (PAME) and aqueous extracts (PAAE), while at a higher dose (400mg/kg) the results of all three extracts appears to be potentially sedative. While the molecular docking studies support these probable anxiolytic, the sedative effects of the Phyllanthus amarus extracts could be due to the interaction of tannins and lignans with the GABAbenzodiazepine receptor complex.

CONCLUSION

The results of the present study indicate that the tannin-rich extract of the P. amarus may have potential clinical applications in the management of anxiety. It can be further studied for optimum dosage to be used as a future of anti-anxiety drug development or as a standardized Phytomedicine.

Synthesis, Antitumor Activity and Molecular Docking Studies on Seven Novel Thiazacridine Derivatives

AIM AND OBJECTIVE

In the last decades, cancer has become a major problem in public health all around the globe. Chimeric chemical structures have been established as an important trend on medicinal chemistry in the last years. Thiazacridines are hybrid molecules composed of a thiazolidine and acridine nucleus, both pharmacophores that act on important biological targets for cancer. By the fact it is a serious disease, seven new 3-acridin-9-ylmethyl-thiazolidine-2,4-dione derivatives were synthesized, characterized, analyzed by computer simulation and tested in tumor cells. In order to find out if the compounds have therapeutic potential.

MATERIALS AND METHODS

Seven new 3-acridin-9-ylmethyl-thiazolidine-2,4-dione derivatives were synthesized through Michael addition and Knoevenagel condensation strategies. Characterization was performed by NMR and Infrared spectroscopy techniques. Regarding biological activity, thiazacridines were tested against solid and hematopoietic tumoral cell lines, namely Jurkat (acute T-cell leukemia); HL-60 (acute promyelocytic leukemia); DU 145 (prostate cancer); MOLT-4 (acute lymphoblastic leukemia); RAJI (Burkitt's lymphoma); K562 (chronic myelogenous leukemia) and normal cells PBMC (healthy volunteers). Molecular docking analysis was also performed in order to assess major targets of these new compounds. Cell cycle and clonogenic assay were also performed.

RESULTS

Compound LPSF/AA-62 (9f) exhibited the most potent anticancer activity against HL-60 (IC50 3,7±1,7 μM), MOLT-4 (IC50 5,7±1,1 μM), Jurkat (IC50 18,6 μM), Du-145 (IC50 20±5 μM) and Raji (IC50 52,3±9,2 μM). While the compound LPSF/AA-57 (9b) exhibited anticancer activity against the K562 cell line (IC50 51,8±7,8 μM). Derivative LPSF/AA-62 (9f) did not interfere in the cell cycle phases of the Molt-4 lineage. However, the LPSF/AA-62 (9f) derivative significantly reduced the formation of prostate cancer cell clones. The compound LPSF/AA-62 (9f) has shown strong anchorage stability with enzymes topoisomerases 1 and 2, in particular due the presence of chlorine favored hydrogen bonds with topoisomerase 1.

CONCLUSION

The 3-(acridin-9-ylmethyl)-5-((10-chloroanthracen-9-yl)methylene)thiazolidine-2,4-dione (LPSF/AA-62) presented the most promising results, showing anti-tumor activity in 5 of the 6 cell types tested, especially inhibiting the formation of colonies of prostate tumor cells (DU-145).

Synthesis and Anti-mycobacterium Study on Halo-substituted 2-aryl oxyacetohydrazones

BACKGROUND

The treatment of multiple-drug-resistant tuberculosis (MDR-TB) with currently available marketed drugs remains a global health concern. The cases of resistant tuberculosis patients are increasing day by day.

OBJECTIVE

The objective of this study is to highlight the need of developing shorter, simpler and tolerable drug regimens.

METHODS

In the present study, we synthesized various halo-substituted 2-aryloxyacetohydrazones via a series of reactions from halo-substituted phenols. All the compounds were characterized by using various spectroscopic methods, such as NMR, FT-IR, UV spectroscopy, etc. Results: All the synthesized hydrazones showed theoretically good interactions with enzyme enoyl reductase (pdb id: 4tzk). All the synthesized compounds (5a-5o) showed moderate to good activity (3.125-100 μg/mL) against Mycobacteria tuberculosis, H37RV strain.

CONCLUSION

Our results would pave a new way for the development of more effective Anti-TB agents in the future.