Editorial: Current status and perspective on drug targets in tubercle bacilli and drug design of antituberculous agents based on structure-activity relationship

Synthesis, Molecular Docking Study, and Biological Evaluation of New 4-(2,5-Dimethyl-1H-pyrrol-1-yl)-N'-(2-(substituted)acetyl)benzohydrazides as Dual Enoyl ACP Reductase and DHFR Enzyme Inhibitors

In this study, a new series of 4-(2,5-dimethyl-1H-pyrrol-1-yl)-N'-(2-(substituted)acetyl) benzohydrazides (5a-n) were prepared and new heterocycles underwent thorough characterization and evaluation for antibacterial activity; some of them underwent further testing for in vitro inhibition of enoyl ACP reductase and DHFR enzymes. The majority of the synthesized molecules exhibited appreciable action against DHFR and enoyl ACP reductase enzymes. Some of the synthesized compounds also showed strong antibacterial and antitubercular properties. In order to determine the potential mode of action of the synthesized compounds, a molecular docking investigation was conducted. The results revealed binding interactions with both the dihydrofolate reductase and enoyl ACP reductase active sites. These molecules represent excellent future therapeutic possibilities with potential uses in the biological and medical sciences due to the compounds' pronounced docking properties and biological activity.

Potential therapeutic targets of Klebsiella pneumoniae: a multi-omics review perspective

The multidrug resistance developed in many organisms due to the prolonged use of antibiotics has been an increasing global health crisis. Klebsiella pneumoniae is a causal organism for various infections, including respiratory, urinary tract and biliary diseases. Initially, immunocompromised individuals are primarily affected by K. pneumoniae. Due to the emergence of hypervirulent strains recently, both healthy and immunocompetent individuals are equally susceptible to K. pneumoniae infections. The infections caused by multidrug-resistant and hypervirulent K. pneumoniae strains are complicated to treat, illustrating an urgent need to develop novel and more practical approaches to combat the pathogen. We focused on the previously performed high-throughput analyses by other groups to discover several novel enzymes that may be considered attractive drug targets of K. pneumoniae. These targets qualify most of the selection criteria for drug targeting, including an absence of its homolog's gene in the host. The capsule, lipopolysaccharide, fimbriae, siderophores and essential virulence factors facilitate the pathogen entry, infection and survival inside the host. This review discusses K. pneumoniae pathophysiology, including its virulence determinants and further the potential drug targets that might facilitate the discovery of novel drugs and effective treatment regimens shortly.

Current Pharmaceutical Aspects of Synthetic Quinoline Derivatives

Quinoline derivatives are considered broad-spectrum pharmacological compounds that exhibit a wide range of biological activities. Integration of quinoline moiety can improve its physical and chemical properties and also pharmacological behavior. Due to its wide range of pharmaceutical applications, it is a very popular compound to design new drugs for the treatment of multiple diseases like cancer, dengue fever, malaria, tuberculosis, fungal infections, AIDS, Alzheimer's disease and diabetes. In this review, our major focus is to pay attention to the biological activities of quinoline compounds in the treatment of these diseases such as anti-viral, anti-cancer, anti-malarial, antibacterial, anti-fungal, anti-tubercular and anti-diabetic.

Network pharmacology based high throughput screening for identification of multi targeted anti-diabetic compound from traditionally used plants

The incurable Type 2 diabetes mellitus (T2DM) has now been considered a pandemic with only supportive care in existence. Due to the adverse effects of available anti-diabetic drugs, there arises a great urgency to develop new drug molecules. One of the alternatives that can be considered for the treatment of T2DM are natural compounds from traditionally used herbal medicine. The present study undertakes, an integrated multidisciplinary concept of Network Pharmacology to evaluate the efficacy of potent anti-diabetic compound from traditionally used anti-diabetic plants of north east India and followed by DFT analysis. In the course of the study, 22 plant species were selected on the basis of their use in traditional medicine for the treatment of T2DM by various ethnic groups of the north eastern region of India. Initially, a library of 1053 compounds derived from these plants was generated. This was followed by network preparation between compounds and targets based on the docking result. The compounds having the best network property were considered for DFT analysis. We have identified that auraptene, a monoterpene coumarin for its activity in the management of Type 2 diabetes mellitus and deciphered its unexplored probable mechanisms. Molecular dynamics simulation of the ligand-protein complexes also reveals the stable binding of auraptene with the target proteins namely, Protein Kinase C θ, Glucocorticoid receptor, 11-β hydroxysteroid dehydrogenase 1 and Aldose Reductase, all of which form uniform interactions throughout the MD simulation trajectory. Therefore, this finding could provide new insights for the development of a new anti-diabetic drug.Communicated by Ramaswamy H. Sarma.

Synthesis of novel morpholine, thiomorpholine and N-substituted piperazine coupled 2-(thiophen-2-yl)dihydroquinolines as potent inhibitors of Mycobacterium tuberculosis

A series of novel morpholine, thiomorpholine and N-substituted piperazine coupled 2-(thiophen-2-yl)dihydroquinolines 7a-p was designed and synthesized from 2-acetyl thiophene in six step reaction sequence involving modified Bohlmann-Rahtz and Vilsmeier-Haack-Arnold reactions as key transformations. 2-(Thiophen-2-yl)dihydroquinoline was formylated and subsequently chlorinated using DMF-POCl₃. The resulting aldehyde was reduced to give an alcohol and then converted to bromide using PBr_3. Further coupling of bromide with morpholine, thiomorpholine and N-substituted piperazines resulted in the desired quinolines 7a-p in very good yields. All the new derivatives 7a-p were characterized by their NMR and mass spectral analysis. In vitro screening of new compounds for antimycobacterial activity against Mycobacterium tuberculosis H37Rv (MTB), resulted in two derivatives 7f and 7p as most potent antitubercular agents (MIC:1.56 μg/mL) with lower cytotoxicity profiles.

Dibenzofuran, dibenzothiophene and N-methyl carbazole tethered 2-aminothiazoles and their cinnamamides as potent inhibitors of Mycobacterium tuberculosis

Herein described the design, synthesis and antitubercular evaluation of novel series of dibenzofuran, dibenzothiophene and N-methyl carbazole tethered 2-aminothiazoles and their cinnamamide analogs. One pot condensation of N-methyl carbazole, dibenzofuran and dibenzothiophene methyl ketones with thiourea in the presence of Iodine and CuO gave respective 2-aminothiazoles 4-6 in very good yields. Aminothiazoles were further coupled with substituted cinnamic acids using acid-amine coupling conditions to give desired cinnamamide analogs 8a-e, 9a-e and 10a-e. All the newly synthesized compounds were fully characterized by their NMR and mass spectral analysis. In vitro screening of new derivatives against Mycobacterium tuberculosis H37Rv (Mtb) resulted 8c, 10d and 10e (MIC: 0.78 µg/mL) and 2-aminothiazoles 5 and 6 (MIC: 1.56 µg/mL) as potent compounds with lower cytotoxicity profile.

Docking-based Design of Galantamine Derivatives with Dual-site Binding to Acetylcholinesterase

The enzyme acetylcholinesterase is a key target in the treatment of Alzheimer's disease because of its ability to hydrolyze acetylcholine via the catalytic binding site and to accelerate the aggregation of amyloid-β peptide via the peripheral anionic site (PAS). Using docking-based predictions, in the present study we design 20 novel galantamine derivatives with alkylamide spacers of different length ending with aromatic fragments. The galantamine moiety blocks the catalytic site, while the terminal aromatic fragments bind in PAS. The best predicted compounds are synthesized and tested for acetylcholinesterase inhibitory activity. The experimental results confirm the predictions and show that the heptylamide spacer is of optimal length to bridge the galantamine moiety bound in the catalytic site and the aromatic fragments interacting with PAS. Among the tested terminal aromatic fragments, the phenethyl substituent is the most suitable for binding in PAS.

Newer patents in antimycobacterial therapy

Tuberculosis caused by Mycobacterium tuberculosis is a global health emergency. This deadly disease has far-reaching social and economic implications. Diseased individuals need prolonged polypharmacy which is not without ill effects. Treatment compliance is often compromised contributing to rising resistance. HIV co-infection has further worsened the scenario. On the other hand, no new anti-TB drug has hit the market in last 4–5 decades. After a long latency, only the last few years have witnessed growing research in this direction and a widening anti-TB drug clinical pipeline. The compounds in preclinical stage of development have also shown a heartening increase. The present review is an attempt to discuss novel promising patents in this field.