Designing novel anti-plasmodial quinoline-furanone hybrids: computational insights, synthesis, and biological evaluation targeting Plasmodium falciparum lactate dehydrogenase.

To combat resistance against current antimalarials, modifying key pharmacophores and exploring novel parasite-specific drug targets remained one of the key drug design strategies. The resistance to quinoline-based antimalarials arises often due to the efflux of the drug. Hence, the development of newer agents containing bulkier pharmacophores will enable medicinal chemists to counteract drug resistance. In view of this, herein we designed bulkier quinoline-furanone hybrids. Initially, virtual drug-likeness and ADMET screening were conducted to optimize physicochemical properties followed by docking of the hybrids against the Plasmodium falciparum lactate dehydrogenase (PfLDH) enzyme. The most potent hybrids that emerged from the computational screening were synthesized and screened for their bioactivity against the resistant strain of Plasmodium through Schizont Maturation Inhibition assays. Among the compounds tested, 5g and 6e demonstrated the best activity, with IC50 values similar to chloroquine (CQ), and 5g exhibited superior LDH inhibition compared to CQ. Compounds 5f, 7a, and 7f showed IC50 values comparable to CQ and moderate LDH inhibition. Structure-activity relationship (SAR) analysis revealed that halogen substitutions, particularly Br and Cl, enhanced antimalarial activity, while strong electron-withdrawing (-NO2) or -donating (-OH) groups led to diminished activity. Additionally, bulkier aromatic substitutions were favoured for antimalarial activity and LDH inhibition. The investigation successfully found potent anti-plasmodial quinoline-furanone hybrids, demonstrating promising prospects for combating malaria.

Design, synthesis, biological and computational screening of novel pyridine-based thiadiazole derivatives as prospective anti-inflammatory agents.

In this study, a novel series of pyridine-based thiadiazole derivatives (NTD1-NTD5) were synthesized as prospective anti-inflammatory agents by combining substituted carboxylic acid derivatives of 5-substituted-2-amino-1,3,4-thiadiazole with nicotinoyl isothiocyanate in the presence of acetone. The newly synthesized compounds were characterized by FTIR, 1H NMR, 13C NMR, and mass spectrometry. First, the compounds underwent rigorous in vivo testing for acute toxicity and anti-inflammatory activity and the results revealed that three compounds-NTD1, NTD2, and NTD3, displayed no acute toxicity and significant anti-inflammatory activity, surpassing the efficacy of the standard drug, diclofenac. Notably, NTD3, which featured benzoic acid substitution, emerged as the most potent anti-inflammatory agent among the screened compounds. To further validate these findings, an in silico docking study was carried out against COX-2 bound to diclofenac (PDB ID: 1pxx). The computational analysis demonstrated that NTD2, and NTD3, exhibited substantial binding affinity, with the lowest binding energies (-8.5 and -8.4, kcal/mol) compared to diclofenac (-8.4 kcal/mol). This alignment between in vivo and in silico data supported the robust anti-inflammatory potential of these derivatives. Moreover, molecular dynamics simulations were conducted, extending over 100 ns, to examine the dynamic interactions between the ligands and the target protein. The results solidified NTD3's position as a leading candidate, showing potent inhibitory activity through strong and sustained interactions, including stable hydrogen bond formations. This was further confirmed by RMSD values of 2-2.5 Å and 2-3Ǻ, reinforcing NTD3's potential as a useful anti-inflammatory agent. The drug likeness analysis of NTD3 through SwissADME indicated that most of the predicted parameters including Lipinski rule were within acceptable limits. While these findings are promising, further research is necessary to elucidate the precise relationships between the chemical structures and their activity, as well as to understand the mechanisms underlying their pharmacological effects. This study lays the foundation for the development of novel anti-inflammatory therapeutics, potentially offering improved efficacy and safety profiles.

Molecular mechanisms underlying the regulation of tumour suppressor genes in lung cancer.

Tumour suppressor genes play a cardinal role in the development of a large array of human cancers, including lung cancer, which is one of the most frequently diagnosed cancers worldwide. Therefore, extensive studies have been committed to deciphering the underlying mechanisms of alterations of tumour suppressor genes in governing tumourigenesis, as well as resistance to cancer therapies. In spite of the encouraging clinical outcomes demonstrated by lung cancer patients on initial treatment, the subsequent unresponsiveness to first-line treatments manifested by virtually all the patients is inherently a contentious issue. In light of the aforementioned concerns, this review compiles the current knowledge on the molecular mechanisms of some of the tumour suppressor genes implicated in lung cancer that are either frequently mutated and/or are located on the chromosomal arms having high LOH rates (1p, 3p, 9p, 10q, 13q, and 17p). Our study identifies specific genomic loci prone to LOH, revealing a recurrent pattern in lung cancer cases. These loci, including 3p14.2 (FHIT), 9p21.3 (p16INK4a), 10q23 (PTEN), 17p13 (TP53), exhibit a higher susceptibility to LOH due to environmental factors such as exposure to DNA-damaging agents (carcinogens in cigarette smoke) and genetic factors such as chromosomal instability, genetic mutations, DNA replication errors, and genetic predisposition. Furthermore, this review summarizes the current treatment landscape and advancements for lung cancers, including the challenges and endeavours to overcome it. This review envisages inspired researchers to embark on a journey of discovery to add to the list of what was known in hopes of prompting the development of effective therapeutic strategies for lung cancer.

A Critical Review on Therapeutic Potential of Benzimidazole Derivatives: A Privileged Scaffold.

Benzimidazole nucleus is a predominant heterocycle displaying a wide spectrum of pharmacological activities. The privileged nature of the benzimidazole scaffold has been revealed by its presence in most small molecule drugs and in its ability to bind multiple receptors with high affinity. A literature review of the scaffold reveals several instances where structural modifications of the benzimidazole core have resulted in high-affinity lead compounds against a variety of biological targets. Hence, this structural moiety offers opportunities to discover novel, better, safe and highly potent biological agents. The goal of the present review is to compile the medicinal properties of benzimidazole derivatives with a focus on SAR (Structure-Activity Relationships).

2-Amino Thiazole Derivatives as Prospective Aurora Kinase Inhibitors against Breast Cancer: QSAR, ADMET Prediction, Molecular Docking, and Molecular Dynamic Simulation Studies.

The aurora kinase is a key enzyme that is implicated in tumor growth. Research revealed that small molecules that target aurora kinase have beneficial effects as anticancer agents. In the present study, in order to identify potential antibreast cancer agents with aurora kinase inhibitory activity, we employed QSARINS software to perform the quantitative structure-activity relationship (QSAR). The statistical values resulted from the study include R2 = 0.8902, CCCtr = 0.7580, Q2 LOO = 0.7875, Q2LMO = 0.7624, CCCcv = 0.7535, R2ext = 0.8735, and CCCext = 0.8783. Among the four generated models, the two best models encompass five important variables, including PSA, EstateVSA5, MoRSEP3, MATSp5, and RDFC24. The parameters including the atomic volume, atomic charges, and Sanderson's electronegativity played an important role in designing newer lead compounds. Based on the above data, we have designed six series of compounds including 1a-e, 2a-e, 3a-e, 4a-e, 5a-e, and 6a-e. All these compounds were subjected to molecular docking studies by using AutoDock v4.2.6 against the aurora kinase protein (1MQ4). Among the above 30 compounds, the 2-amino thiazole derivatives 1a, 2a, 3e, 4d, 5d, and 6d have excellent binding interactions with the active site of 1MQ4. Compound 1a had the highest docking score (-9.67) and hence was additionally subjected to molecular dynamic simulation investigations for 100 ns. The stable binding of compound 1a with 1MQ4 was verified by RMSD, RMSF, RoG, H-bond, molecular mechanics-generalized Born surface area (MM-GBSA), free binding energy calculations, and solvent-accessible surface area (SASA) analyses. Furthermore, newly designed compound 1a exhibited excellent ADMET properties. Based on the above findings, we propose that the designed compound 1a may be utilized as the best theoretical lead for future experimental research of selective inhibition of aurora kinase, therefore assisting in the creation of new antibreast cancer drugs.

Filamentous temperature sensitive mutant Z: a putative target to combat antibacterial resistance.

In the pre-antibiotic era, common bacterial infections accounted for high mortality and morbidity. Moreover, the discovery of penicillin in 1928 marked the beginning of an antibiotic revolution, and this antibiotic era witnessed the discovery of many novel antibiotics, a golden era. However, the misuse or overuse of these antibiotics, natural resistance that existed even before the antibiotics were discovered, genetic variations in bacteria, natural selection, and acquisition of resistance from one species to another consistently increased the resistance to the existing antibacterial targets. Antibacterial resistance (ABR) is now becoming an ever-increasing concern jeopardizing global health. Henceforth, there is an urgent unmet need to discover novel compounds to combat ABR, which act through untapped pathways/mechanisms. Filamentous Temperature Sensitive mutant Z (FtsZ) is one such unique target, a tubulin homolog involved in developing a cytoskeletal framework for the cytokinetic ring. Additionally, its pivotal role in bacterial cell division and the lack of homologous structural protein in mammals makes it a potential antibacterial target for developing novel molecules. Approximately 2176 X-crystal structures of FtsZ were available, which initiated the research efforts to develop novel antibacterial agents. The literature has reported several natural, semisynthetic, peptides, and synthetic molecules as FtsZ inhibitors. This review provides valuable insights into the basic crystal structure of FtsZ, its inhibitors, and their inhibitory activities. This review also describes the available in vitro detection and quantification methods of FtsZ-drug complexes and the various approaches for determining drugs targeting FtsZ polymerization.

Cyclohexane-1,3-dione Derivatives as Future Therapeutic Agents for NSCLC: QSAR Modeling, In Silico ADME-Tox Properties, and Structure-Based Drug Designing Approach.

The abnormal expression of the c-Met tyrosine kinase has been linked to the proliferation of several human cancer cell lines, including non-small-cell lung cancer (NSCLC). In this context, the identification of new c-Met inhibitors based on heterocyclic small molecules could pave the way for the development of a new cancer therapeutic pathway. Using multiple linear regression (MLR)-quantitative structure-activity relationship (QSAR) and artificial neural network (ANN)-QSAR modeling techniques, we look at the quantitative relationship between the biological inhibitory activity of 40 small molecules derived from cyclohexane-1,3-dione and their topological, physicochemical, and electronic properties against NSCLC cells. In this regard, screening methods based on QSAR modeling with density-functional theory (DFT) computations, in silico pharmacokinetic/pharmacodynamic (ADME-Tox) modeling, and molecular docking with molecular electrostatic potential (MEP) and molecular mechanics-generalized Born surface area (MM-GBSA) computations were used. Using physicochemical (stretch-bend, hydrogen bond acceptor, Connolly molecular area, polar surface area, total connectivity) and electronic (total energy, highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energy levels) molecular descriptors, compound 6d is identified as the optimal scaffold for drug design based on in silico screening tests. The computer-aided modeling developed in this study allowed us to design, optimize, and screen a new class of 36 small molecules based on cyclohexane-1,3-dione as potential c-Met inhibitors against NSCLC cell growth. The in silico rational drug design approach used in this study led to the identification of nine lead compounds for NSCLC therapy via c-Met protein targeting. Finally, the findings are validated using a 100 ns series of molecular dynamics simulations in an aqueous environment on c-Met free and complexed with samples of the proposed lead compounds and Foretinib drug.

Herbs as a Source for the Treatment of Polycystic Ovarian Syndrome: A Systematic Review.

BACKGROUND: Polycystic ovarian syndrome (PCOS) is a neuroendocrine metabolic disorder characterized by an irregular menstrual cycle. Treatment for PCOS using synthetic drugs is effective. However, PCOS patients are attracted towards natural remedies due to the effective therapeutic outcomes with natural drugs and the limitations of allopathic medicines. In view of the significance of herbal remedies, herein, we discuss the role of different herbs in PCOS. METHODS: By referring to the Scopus, PubMed, Google Scholar, Crossref and Hinari databases, a thorough literature search was conducted and data mining was performed pertaining to the effectiveness of herbal remedies against PCOS. RESULTS: In this review, we discuss the significance of herbal remedies in the treatment of PCOS, and the chemical composition, mechanism of action and therapeutic application of selected herbal drugs against PCOS. CONCLUSIONS: The present review will be an excellent resource for researchers working on understanding the role of herbal medicine in PCOS.

Synthetic Imidazopyridine-Based Derivatives as Potential Inhibitors against Multi-Drug Resistant Bacterial Infections: A Review.

Fused pyridines are reported to display various pharmacological activities, such as antipyretic, analgesic, antiprotozoal, antibacterial, antitumor, antifungal, anti-inflammatory, and antiapoptotic. They are widely used in the field of medicinal chemistry. Imidazopyridines (IZPs) are crucial classes of fused heterocycles that are expansively reported on in the literature. Evidence suggests that IZPs, as fused scaffolds, possess more diverse profiles than individual imidazole and pyridine moieties. Bacterial infections and antibacterial resistance are ever-growing risks in the 21st century. Only one IZP, i.e., rifaximin, is available on the market as an antibiotic. In this review, the authors highlight strategies for preparing other IZPs. A particular focus is on the antibacterial profile and structure-activity relationship (SAR) of various synthesized IZP derivatives. This research provides a foundation for the tuning of available compounds to create novel, potent antibacterial agents with fewer side effects.

Identification of hydantoin based Decaprenylphosphoryl-ß-D-Ribose Oxidase (DprE1) inhibitors as antimycobacterial agents using computational tools.

Tuberculosis (TB) is one of the emerging infectious diseases in the world. DprE1 (Decaprenylphosphoryl-ß-D-ribose 2'-epimerase), an enzyme accountable for mycobacterial cell wall synthesis was the first drug gable target based on discoveries of inhibitors via HTS (high throughput screening). Since then, many literature reports have been published so far enlightening varieties of chemical scaffolds acting as inhibitors of DprE1. Herein, in our present study, we have developed statistically robust GA-MLR (genetic algorithm multiple linear regression), atom-based as well as field based-3D-QSAR models. Both atom-based as well as field based-3D-QSAR models (internally as well as externally validated) were obtained with robust Training set, R2 > 0.69 and Test set, Q2 > 0.50. We have also developed top ranked 5 point hypothesis AAAHR_1 among 14 CPHs (common pharmacophore hypotheses). We found that our dataset molecule had more docking score (XP mode = - 9.068 kcal/mol) than the standards isoniazid and ethambutol; when docked into binding pockets of enzyme 4P8C with Glide module. We further queried our best docked dataset molecule 151 for ligand based virtual screening using "SwissSimilarity" platform. Among 9 identified hits, we found ZINC12196803 had best binding energies and docking score (docking score = - 9.437 kcal/mol, MMGBSA dgBind = - 70.508 kcal/mol). Finally, our molecular dynamics studies for 1.2-100 ns depicts that these complexes are stable. We have also carried out in-silico ADMET predictions, Cardiac toxicity, 'SwissTargetPredictions' and Molecular Mechanics/Generalized Born Surface Area (MM/GBSA) binding energy calculations for further explorations of dataset as well as hit molecules. Our current studies showed that the hit molecule ZINC12196803 may enlighten the path for future developments of DprE1 inhibitors.

Synthesis and biological evaluation of coumarin-thiazole hybrids as selective carbonic anhydrase IX and XII inhibitors.

A series of coumarin-linked thiazoles (6a-p) was synthesized and the synthesized compounds were evaluated against human carbonic anhydrases (hCAs) IX and XII, which have been implicated in cancer. All the compounds exhibited selective inhibition of both isoforms. The designed compounds inhibited hCA IX in a moderate nanomolar to submicromolar range. The hCA XII was inhibited in a low to moderate nanomolar range. Compound 6o exhibited the best inhibition of hCA XII with a Ki value of 91.1 nM. The hydrolyzed form of compound 6o also exhibited favorable interactions as well as good docking scores with both the isoforms. Hence, this compound can be taken as a template for the design of selective and potent hCA XII inhibitors.

Vaccine for Diabetes-Where Do We Stand?

Diabetes is an endocrinological disorder with a rapidly increasing number of patients globally. Over the last few years, the alarming status of diabetes has become a pivotal factor pertaining to morbidity and mortality among the youth as well as middle-aged people. Current developments in our understanding related to autoimmune responses leading to diabetes have developed a cause for concern in the prospective usage of immunomodulatory agents to prevent diabetes. The mechanism of action of vaccines varies greatly, such as removing autoreactive T cells and inhibiting the interactions between immune cells. Currently, most developed diabetes vaccines have been tested in animal models, while only a few human trials have been completed with positive outcomes. In this review, we investigate the undergoing clinical trial studies for the development of a prototype diabetes vaccine.

Selectivity profile comparison for certain γ-butyrolactone and oxazolidinone-based ligands on a sigma 2 receptor over sigma 1: a molecular docking approach.

Sigma receptors (σ1 R and σ2 R) are pharmacologically characterized membrane-bound receptors that bind a wide range of chemical compounds. Alzheimer's disease, traumatic brain injury, schizophrenia, and neuropathic pain have all been associated with abnormal σ2 activity. The σ2 receptor has recently been identified as a potential therapeutic target for inhibiting the formation of amyloid plaques. Numerous laboratories are now investigating the potential of σ2 ligands. Small molecule discovery is the focus of current research, with the goal of using target-based action to treat a variety of illnesses and ailments. Functionalized γ-butyrolactone and oxazolidinone-based ligands, in particular, are pharmacologically important scaffolds in drug discovery research and have been thoroughly examined for σ2 receptor efficacy. The purpose of this study was to evaluate the pharmacophoric features of different σ2 receptor ligands using in silico techniques. This study used a library of 58 compounds having a γ-butyrolactone and oxazolidinone core. To investigate the binding characteristics of the ligands with the σ2 receptor, a 3D homology model was developed. To understand the binding pattern of the γ-butyrolactone and oxazolidinone based ligands, molecular docking studies were performed on both σ1 and σ2 receptors. Furthermore, MM/GBSA binding energy calculations were used to confirm the binding of ligands on the σ2 over σ1 receptor. These in silico findings will aid in the discovery of selective σ2 ligands with good pharmacophoric properties and potency in the future.

QSAR and Molecular Docking Studies of Pyrimidine-Coumarin-Triazole Conjugates as Prospective Anti-Breast Cancer Agents.

Cancer is a life-threatening disease and is the second leading cause of death worldwide. Although many drugs are available for the treatment of cancer, survival outcomes are very low. Hence, rapid development of newer anticancer agents is a prime focus of the medicinal chemistry community. Since the recent past, computational methods have been extensively employed for accelerating the drug discovery process. In view of this, in the present study we performed 2D-QSAR (Quantitative Structure-Activity Relationship) analysis of a series of compounds reported with potential anticancer activity against breast cancer cell line MCF7 using QSARINS software. The best four models exhibited a r2 value of 0.99. From the generated QSAR equations, a series of pyrimidine-coumarin-triazole conjugates were designed and their MCF7 cell inhibitory activities were predicted using the QSAR equations. Furthermore, molecular docking studies were carried out for the designed compounds using AutoDock Vina against dihydrofolate reductase (DHFR), colchicine and vinblastine binding sites of tubulin, the key enzyme targets in breast cancer. The most active compounds identified through these computational studies will be useful for synthesizing and testing them as prospective novel anti-breast cancer agents.

In Silico and In Vitro Studies for Benzimidazole Anthelmintics Repurposing as VEGFR-2 Antagonists: Novel Mebendazole-Loaded Mixed Micelles with Enhanced Dissolution and Anticancer Activity.

Cancer is a leading cause of death worldwide and its incidence is unfortunately anticipated to rise in the next years. On the other hand, vascular endothelial growth factor receptor 2 (VEGFR-2) is highly expressed in tumor-associated endothelial cells, where it affects tumor-promoting angiogenesis. Therefore, VEGFR-2 is considered one of the most promising therapeutic targets for cancer treatment. Furthermore, some FDA-approved benzimidazole anthelmintics have already shown potential anticancer activities. Therefore, repurposing them against VEGFR-2 can provide a rapid and effective alternative that can be implicated safely for cancer treatment. Hence, 13 benzimidazole anthelmintic drugs were subjected to molecular docking against the VEGFR-2 receptor. Among the tested compounds, fenbendazole (FBZ, 1), mebendazole (MBZ, 2), and albendazole (ABZ, 3) were proposed as potential VEGFR-2 antagonists. Furthermore, molecular dynamics simulations were carried out at 200 ns, giving more information on their thermodynamic and dynamic properties. Besides, the anticancer activity of the aforementioned drugs was tested in vitro against three different cancer cell lines, including liver cancer (HUH7), lung cancer (A549), and breast cancer (MCF7) cell lines. The results depicted potential cytotoxic activity especially against both HUH7 and A549 cell lines. Furthermore, to improve the aqueous solubility of MBZ, it was formulated in the form of mixed micelles (MMs) which showed an enhanced drug release with better promising cytotoxicity results compared to the crude MBZ. Finally, an in vitro quantification for VEGFR-2 concentration in treated HUH7 cells has been conducted based on the enzyme-linked immunosorbent assay. The results disclosed that FBZ, MBZ, and ABZ significantly (p < 0.001) reduced the concentration of VEGFR-2, while the lowest inhibition was achieved in MBZ-loaded MMs, which was even much better than the reference drug sorafenib. Collectively, the investigated benzimidazole anthelmintics could be encountered as lead compounds for further structural modifications and thus better anticancer activity, and that was accomplished through studying their structure-activity relationships.

Ureidosulfocoumarin Derivatives As Selective and Potent Carbonic Anhydrase IX and XII Inhibitors.

Owing to severe allergic reactions (anaphylaxis) and resistance exhibited by sulfonamide-based carbonic anhydrase (CA) inhibitors, non-classical or non-sulfonamide CA inhibitors are gaining increased attention by medicinal chemists. In this context, we report the design and synthesis of 30 new non-sulfonamide sulfocoumarin derivatives as CA inhibitors. They were investigated against hCA I and II (cytosolic isozymes) as well as hCA IX and XII (transmembrane, tumor-associated enzymes). All compounds showed prominent selectivity for the tumor-associated isoenzymes hCA IX and XII over the cytosolic isoenzymes hCA I and II. Among all synthesized compounds, 1-(2,2-dioxidobenzo[e][1,2]oxathiin-6-yl)-3-(o-tolyl)urea(5 j)and1-(3-fluorophenyl)-3-(8-methoxy-2,2-dioxidobenzo[e][1,2]oxathiin-6-yl)urea(5 q)were found to be more potent and to have better inhibition constant values against hCA IX than the standard acetazolamide (AAZ), with Ki values of 23.6 and 23.3 nM, respectively. All other compounds were found to be active under Ki =920 nM against hCA IX and XII.This study provides a new perspective for the future development of non-sulfonamide derivatives as selective CA inhibitors.

Thiazole-Chalcone Hybrids as Prospective Antitubercular and Antiproliferative Agents: Design, Synthesis, Biological, Molecular Docking Studies and In Silico ADME Evaluation.

Compounds bearing thiazole and chalcone pharmacophores have been reported to possess excellent antitubercular and anticancer activities. In view of this, we designed, synthesized and characterized a novel series of thiazole-chalcone hybrids (1-20) and further evaluated them for antitubercular and antiproliferative activities by employing standard protocols. Among the twenty compounds, chalcones 12 and 7, containing 2,4-difluorophenyl and 2,4-dichlorophenyl groups, showed potential antitubercular activity higher than the standard pyrazinamide (MIC = 25.34 µM) with MICs of 2.43 and 4.41 µM, respectively. Chalcone 20 containing heteroaryl 2-thiazolyl moiety exhibited promising antiproliferative activity against the prostate cancer cell line (DU-145), higher than the standard methotrexate (IC50 = 11 ± 1 µM) with an IC50 value of 6.86 ± 1 µM. Furthermore, cytotoxicity studies of these compounds against normal human liver cell lines (L02) revealed that the target molecules were comparatively less selective against L02. Additional computational studies using AutoDock predicted the key binding interactions responsible for the activity and the SwissADME tool computed the in silico drug likeliness properties. The lead compounds generated through this study, create a way for the optimization and development of novel drugs against tuberculosis infections and prostate cancer.

A key review on oxadiazole analogs as potential methicillin-resistant Staphylococcus aureus (MRSA) activity: Structure-activity relationship studies.

Methicillin-resistant Staphylococcus aureus (MRSA) is becoming dangerous to human beings due to easy transmission mode and leading to the difficult-to-treat situation. The rapid resistance development of MRSA to many approved antibiotics is of major concern. There is a lot of scope to develop novel, efficient, specific, and nontoxic drug candidates to fight against MRSA isolates. The interesting molecular structure and adaptable feature of oxadiazole moiety which are bioisosteres of esters and amides, and these functional groups show improved resistance to esterases mediated hydrolytic cleavage, attracting researchers to develop required novel antibiotics based on oxadiazole core. This review summarizes the developments of oxadiazole-containing derivatives as potent antibacterial agents against multidrug-resistant MRSA strains and discussing the structure-activity relationship (SAR) in various directions. The current survey is the highlight of the present scenario of oxadiazole hybrids on MRSA studies, covering articles published from 2011 to 2020. This collective information may become a good platform to plan and develop new oxadiazole-based small molecule growth inhibitors of MRSA with minimal side effects.

Design, Synthesis, and Antibacterial and Antifungal Activities of Novel Trifluoromethyl and Trifluoromethoxy Substituted Chalcone Derivatives.

Despite the availability of many drugs to treat infectious diseases, the problems like narrow antimicrobial spectrum, drug resistance, hypersensitivities and systemic toxicities are hampering their clinical utility. Based on the above facts, in the present study, we designed, synthesized and evaluated the antibacterial and antifungal activity of novel fluorinated compounds comprising of chalcones bearing trifluoromethyl (A1-A10) and trifluoromethoxy (B1-B10) substituents. The compounds were characterized by spectroscopic techniques and evaluated for their antimicrobial activity against four pathogenic Gram-positive (Staphylococcus aureus and Bacillus subtilis) and Gram-negative (Escherichia coli and Bacillus subtilis) bacterial and fungal (Candida albicans and Aspergillus niger) strains. In this study, the compounds with trifluoromethoxy group were more effective than those with trifluoromethyl group. Among the 20 fluorinated chalcones, compound A3/B3 bearing an indole ring attached to the olefinic carbon have been proved to possess the most antimicrobial activity compared to the standard drugs without showing cytotoxicity on human normal liver cell line (L02). Further, the minimum inhibitory concentration (MIC) for A3/B3 was determined by serial tube dilution method and showed potential activity. These results would provide promising access to future study about the development of novel agents against bacterial and fungal infections.

Design, Facile Synthesis and Characterization of Dichloro Substituted Chalcones and Dihydropyrazole Derivatives for Their Antifungal, Antitubercular and Antiproliferative Activities.

Infectious diseases caused by fungi and mycobacteria pose an important problem for humankind. Similarly, cancer is one of the leading causes of death globally. Therefore, there is an urgent need for the development of novel agents to combat the deadly problems of cancer, tuberculosis, and also fungal infections. Hence, in the present study, we designed, synthesized, and characterized 30 compounds including 15 chalcones (2-16) and 15 dihydropyrazoles (17-31) containing dichlorophenyl moiety and also screened these compounds for their antifungal, antitubercular, and antiproliferative activities. Among these compounds, the dihydropyrazoles showed excellent antifungal and antitubercular activities whereas the chalcones exhibited promising antiproliferative activity. Among the dihydropyrazoles, compound 31 containing 2-thienyl moiety showed promising antifungal activity (MIC 5.35 µM), whereas compounds 22 and 24 containing 2,4-difluorophenyl and 4-trifluoromethyl scaffolds revealed significant antitubercular activity with the MICs of 3.96 and 3.67 µM, respectively. Compound 16 containing 2-thienyl moiety in the chalcone series showed the highest anti-proliferative activity with an IC50 value of 17 ± 1 µM. The most active compounds identified through this study could be considered as starting points in the development of drugs with potential antifungal, antitubercular, and antiproliferative activities.