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Abstract: Pyruvate kinase M2 (PKM2) has surfaced as a potential target for anti-cancer therapy. PKM2 is known to be overexpressed in the tumor cells and is a critical metabolic conduit in supplying the augmented bioenergetic demands of the recalcitrant cancer cells. The presence of PKM2 in structurally diverse tetrameric as well as dimeric forms has opened new avenues to design novel modulators. It is also a truism to state that drug discovery has advanced significantly from various computational techniques like molecular docking, virtual screening, molecular dynamics, and pharmacophore mapping. The present review focuses on the role of computational tools in exploring novel modulators of PKM2. The structural features of various isoforms of PKM2 have been discussed along with reported modulators. An extensive analysis of the structure-based and ligand-based in silico methods aimed at PKM2 modulation has been conducted with an in-depth review of the literature. The role of advanced tools like QSAR and quantum mechanics has been established with a brief discussion of future perspectives.

Tyrosine kinases are enzymes that can transfer a phosphate group from ATP to a specific protein tyrosine, serine or threonine residue within a cell, operating as a switch that can turn 'on' and 'off' causing different physiological alterations in the body. Mutated kinases have been shown to display an equilibrium shift toward the activated state. Types I-III have been studied intensively leading to drugs like imatinib (type II), cobimetinib (type III), among others. It is the same scenario for types V-VII; however, there is a lacuna in information regarding type IV inhibitors, although recently some advances have surfaced. This review aims to accumulate the knowledge gained so far about type IV inhibitors.

Introduction: The outburst of the novel coronavirus COVID-19, at the end of December 2019 has turned itself into a pandemic taking a heavy toll on human lives. The causal agent being SARS-CoV-2, a member of the long-known Coronaviridae family, is a positive sense single-stranded enveloped virus and quite closely related to SARS-CoV. It has become the need of the hour to understand the pathophysiology of this disease, so that drugs, vaccines, treatment regimens and plausible therapeutic agents can be produced. Methods: In this regard, recent studies uncovered the fact that the viral genome of SARS-CoV-2 encodes nonstructural proteins like RNA dependent RNA polymerase (RdRp) which is an important tool for its transcription and replication process. A large number of nucleic acid based anti-viral drugs are being repurposed for treating COVID-19 targeting RdRp. Few of them are in the advanced stage of clinical trials including Remdesivir. While performing close investigation of the large set of nucleic acid based drugs, we were surprised to find that the synthetic nucleic acid backbone is explored very little or rare. Results: We have designed scaffolds derived from peptide nucleic acid (PNA) and subjected them for in-silico screening systematically. These designed molecules have demonstrated excellent binding towards RdRp. Compound 12 was found to possess similar binding affinity as Remdesivir with comparable pharmacokinetics. However, the in-silico toxicity prediction indicates compound 12 may be a superior molecule which can be explored further due to its excellent safety-profile with LD50 (12,000mg/kg) as opposed to Remdesivir (LD50 =1000mg/kg). Conclusion: Compound 12 falls in the safe category of class 6. Synthetic feasibility, equipotent binding and very low toxicity of this peptide nucleic acid derived compounds can serve as a leading scaffold to design, synthesize and evaluate many of similar compounds for the treatment of COVID-19.

Magnetic hyperthermia (MH) has been studied for almost seventy-five years, but its efficacy in clinical applications is still fiercely contested. Despite this, few magnetic nanosystems are approved for clinical usage due to their strong affinity as drug carriers. The most important condition for hyperthermia applications for successful cancer therapy is magnetic nanoparticles with a controlled heating pattern (42-46 °C) for a prolonged timeframe. In the current study, cobalt-zinc nanoferrites (MNPs) having a Curie temperature of 46 ℃ with a tunable heating profile was loaded with Doxorubicin (DOX) through a surface conjugation technique (DOX-Cs-MNPs), and characterized by using multiple techniques. The magnetic hyterises (M-H) curves revealed the occurrence of superparamagnetism in the MNPs with extremely low coercivity; further, the DOX-loaded nanoparticles exhibited enhanced saturation magnetization. More importantly, the MNPs showed that they could maintain a therapeutic temperature for an indefinite amount of time. High drug loading affinity (86 %) was observed on MNPs with pH and temperature-controlled release. Under in vitro conditions, the biocompatible DOX-Cs-MNPs caused substantial apoptosis in MCF-7 cells (72 %) with overall cell death of 95 %. The distinctive MNPs thus have the potential to be used in clinical applications.

The dawn of targeted degradation using proteolysis-targeting chimeras (PROTACs) against recalcitrant proteins has prompted numerous efforts to develop complementary drugs. Although many of these are specifically directed against undruggable proteins, there is increasing interest in small molecule-based PROTACs that target intracellular pathways, and some have recently entered clinical trials. Concurrently, small molecule-based PROTACs that target protumorigenic pathways in cancer cells, the tumor microenvironment (TME), and angiogenesis have been found to have potent effects that synergize with the action of antibodies. This has led to the augmentation of PROTACs with variable substitution patterns. Several combinations with small molecules targeting undruggable proteins are now under clinical investigation. In this review, we discuss the recent milestones achieved as well as challenges encountered in this area of drug development, as well as our opinion on the best path forward.

Pyrazolopyrimidine ring present in various approved drugs is reported to target the tyrosine kinase receptor. A new pyrazolopyrimidine ferrocene derivative, which targets tumor pyruvate kinase M2 showed an impressive antiproliferative profile against human oral squamous cell carcinoma cell line CAL27 assessed using Alamar blue assay. In line with the lead optimization process, the molecule was studied for physicochemical properties where a bioanalytical method has been developed in plasma on liquid chromatography-mass spectrometry and validated following the USFDA bioanalytical method validation guideline. Plasma stability and plasma protein binding potential of the molecule have been evaluated. All the major metabolites of the compound have been identified through in vitro metabolite study employing rat liver microsome, human liver microsome, and human S9 fractions. The in silico toxicity profile of the metabolites was assessed using ProTox II software. Log P, Log D, and pKa of the molecule were found to be 4.5, 5, and 12, respectively. The molecule was found to be quite stable in plasma and have a moderate affinity towards plasma proteins (about 75 % binding). Four major metabolites have been identified and characterized by UHPLCQ-TOF-MS. The metabolites were found to have a moderate safety profile. The validated bioanalytical method and the metabolic pathway will be useful for future clinical studies and to assess the safety profile of the molecule. The finding of this study may also be useful in analyzing the desired drug-like properties through bioanalysis while designing new chemical entities based on metallocenes.

Outcomes of various clinical studies for the coronavirus disease 2019 (COVID-19) treatment indicated that the drug acts via inhibition of multiple pathways (targets) is likely to be more successful and promising. Keeping this hypothesis intact, the present study describes for the first-time, Grazoprevir, an FDA approved anti-viral drug primarily approved for Hepatitis C Virus (HCV), mediated multiple pathway control via synergistic inhibition of viral entry targeting host cell Angiotensin-Converting Enzyme 2 (ACE-2)/transmembrane serine protease 2 (TMPRSS2) and viral replication targeting RNA-dependent RNA polymerase (RdRP). Molecular modeling followed by in-depth structural analysis clearly demonstrated that Grazoprevir interacts with the key residues of these targets. Futher, Molecular Dynamics (MD) simulations showed stability and burial of key residues after the complex formation. Finally, Molecular Mechanics Poisson-Boltzmann Surface Area (MM-PBSA) analysis identified the governing force of drug-receptor interactions and stability. Thus, we believe that Grazoprevir could be an effective therapeutics for the treatment of the COVID-19 pandemic with a promise of unlikely drug resistance owing to multiple inhibitions of eukaryotic and viral proteins, thus warrants further clinical studies.

Thiazole has widespread importance in materials and medicines. Several reviews are reported which cover essential properties of thiazoles such as pharmacological activities, structure-activity relationship studies, and various synthetic routes. However, synthesis based on a greener approaches, particularly metal-free reactions, usage of mild, nontoxic, recyclable catalysts, eco-sustainable protocols, efficient solvents have not been exclusively reviewed. Current review emphasizes green synthetic approaches for substituted thiazoles that have been performed within the last decade.

[Image: see text] Alzheimer’s disease (AD) is a debilitating disorder characterized by age-related dementia, which has no effective treatment to date. β-Amyloid depositions and hyperphosphorylated tau proteins are the main pathological hallmarks, along with oxidative stress, N-methyl-d-aspartate (NMDA) receptor-mediated excitotoxicity, and low levels of acetylcholine. Current pharmacotherapy for AD only provides symptomatic relief and limited improvement in cognitive functions. Many molecules have been explored that show promising outcomes in AD therapy and can regulate cellular survival through different pathways. To have a vivid approach to strategize the treatment regimen, AD physiopathology should be better explained considering diverse etiological factors in conjunction with biochemical disturbances. This Review attempts to discuss different disease modification approaches and address the novel therapeutic targets of AD that might pave the way for new drug discovery using the well-defined targets for therapy of the disease.

Glandular cancers have a significant share of the total cancer patients all over the world. In the case of adrenocortical carcinomas (ACCs), although the benign form is more frequent and common, the malignant form provides a very less percentage of patients with five or more than five years of survival rate. There are gene alterations that are involved as a crucial factor behind the occurrence of ACCs. Out of these, the most prominent genetic alterations (PRKAR-1A, CTNNB1, ZNRF3, TP53, CCNE1 and TERF2 genes) are linked with a glycolytic enzyme pyruvate kinase M2 (PKM2), which converts phosphoenolpyruvate (PEP) to pyruvate in the glycolytic pathway. The involvementof PKM2 renders a cumulative effect through different pathways that may result in the onset of ACCs. Thus, this review aims to establish a link between ACCs, alterations of specific genes and PKM2.

Metabolic reprogramming is a newly emerged hallmark of cancer attaining a recent consideration as an essential factor for the progression and endurance of cancer cells. A prime event of this altered metabolism is increased glucose uptake and discharge of lactate into the cells surrounding constructing a favorable tumor niche. Several oncogenic factors help in promoting this consequence including, pyruvate kinase M2 (PKM2) a rate-limiting enzyme of glycolysis in tumor metabolism via exhibiting its low pyruvate kinase activity and nuclear moon-lightening functions to increase the synthesis of lactate and macromolecules for tumor proliferation. Not only its role in cancer cells but also its role in the tumor microenvironment cells has to be understood for developing the small molecules against it which is lacking with the literature till date. Therefore, in this present review, the role of PKM2 with respect to various tumor niche cells will be clarified. Further, it highlights the updated list of therapeutics targeting PKM2 pre-clinically and clinically with their added limitations. This upgraded understanding of PKM2 may provide a pace for the reader in developing chemotherapeutic strategies for better clinical survival with limited resistance.

Gliomas are lethal and aggressive form of brain tumors with resistance to conventional radiation and cytotoxic chemotherapies; inviting continuous efforts for drug discovery and drug delivery. Interestingly, small molecule hybrids are one such pharmacophore that continues to capture interest owing to their pluripotent medicinal effects. Accordingly, we earlier reported synthesis of potent Styryl-cinnamate hybrids (analogues of Salvianolic acid F) along with its plausible mode of action (MOA). We explored iTRAQ-LC/MS-MS technique to deduce differentially expressed landscape of native & phospho-proteins in treated glioma cells. Based on this, Protein-Protein Interactome (PPI) was looked into by employing computational tools and further validated in vitro. We hereby report that the Styryl-cinnamate hybrid, an analogue of natural Salvianolic acid F, alters key regulatory proteins involved in translation, cytoskeleton development, bioenergetics, DNA repair, angiogenesis and ubiquitination. Cell cycle analysis dictates arrest at G0/G1 stage along with reduced levels of cyclin D; involved in G1 progression. We discovered that Styryl-cinnamate hybrid targets glioma by intrinsically triggering metabolite-mediated stress. Various oncological circuits alleviated by the potential drug candidate strongly supports the role of such pharmacophores as anticancer drugs. Although, further analysis of SC hybrid in treating xenografts or solid tumors is yet to be explored but their candidature has gained huge impetus through this study. This study equips us better in understanding the shift in proteomic landscape after treating glioma cells with SC hybrid. It also allows us to elicit molecular targets of this potential drug before progressing to preclinical studies.

IMID-2, a newly identified piperazine-based anticancer molecule, has been shown to be cytotoxic against various cancer cell lines. The primary aim of this research was to identify and characterize possible metabolites of the molecule formed during biotransformation. A metabolite identification study was first executed using an in silico tool to predict the possible metabolism sites of IMID-2. Thereafter, metabolites generated in vitro (rat liver microsomes, rat S9 fractions and human liver microsomes) and in vivo (rat plasma, urine and feces) were identified and characterized employing UPLC-QTOF-MS/MS. A total of eight metabolites, among which were six in phase I and two in phase II reactions, were recognized. The plausible structure of the metabolites and probable metabolic pathway have been established based on the mass fragmentation pattern, mass ppm error, ring double bond calculation and nitrogen rule. The majority of phase I metabolites were generated by N-oxidation, hydroxylation, oxidative deamination followed by reduction, oxidative dechlorination, N-dearylation, and N-dealkylation. Glucuronidation played a significant role in the formation of phase II metabolites of the molecule.

Pyruvate kinase M2 (PKM2) catalyzes the conversion of phosphoenolpyruvate (PEP) to pyruvate. It plays a central role in the metabolic reprogramming of cancer cells and is expressed in most human tumors. It is essential in indiscriminate proliferation, survival, and tackling apoptosis in cancer cells. This positions PKM2 as a hot target in cancer therapy. Despite its well-known structure and several reported modulators targeting PKM2 as activators or inhibitors, a comprehensive review focusing on such modulators is lacking. Herein we summarize modulators of PKM2, the assays used to detect their potential, the preferable tense (T) and relaxed (R) states in which the enzyme resides, lacunae in existing modulators, and several strategies that may lead to effective anticancer drug development targeting PKM2.

Chronic inflammation (CI) is a primary contributing factor involved in multiple diseases like cancer, stroke, diabetes, Alzheimer's disease, allergy, asthma, autoimmune diseases, coeliac disease, glomerulonephritis, sepsis, hepatitis, inflammatory bowel disease, reperfusion injury, and transplant rejections. Despite several expansions in our understanding of inflammatory disorders and their mediators, it seems clear that numerous proteins participate in the onset of CI. One crucial protein pyruvate kinase M2 (PKM2) much studied in cancer is also found to be inextricably woven in the onset of several CI's. It has been found that PKM2 plays a significant role in several disorders using a network of proteins that interact in multiple ways. For instance, PKM2 forms a close association with epidermal growth factor receptors (EGFRs) for uncontrolled growth and proliferation of tumor cells. In neurodegeneration, PKM2 interacts with apurinic/apyrimidinic endodeoxyribonuclease 1 (APE1) to onset Alzheimer's disease pathogenesis. The cross-talk of protein tyrosine phosphatase 1B (PTP1B) and PKM2 acts as stepping stones for the commencement of diabetes. Perhaps PKM2 stores the potential to unlock the pathophysiology of several diseases. Here we provide an overview of the notoriously convoluted biology of CI's and PKM2. The cross-talk of PKM2 with several proteins involved in stroke, Alzheimer's, cancer, and other diseases has also been discussed. We believe that considering the importance of PKM2 in inflammation-related diseases, new options for treating various disorders with the development of more selective agents targeting PKM2 may appear.

PKM2is considered a desirable target as its enzymatic activation is expected to cause a diminution in tumorigenesis and prevent limitless replication in cancerous cells. However, considering the functional consequences of kinase inhibitors, the design of PKM2 activators has been an attractive strategy that has yielded potent anticancer molecules like DASA-58. Therefore, a new class of boronic acid derivate was developed to elucidate the possible mechanistic link between PKM2 activation and TPI1 activity, which has a significant role in the redox balance in cancer. The present in vitro study revealed that treatment with boronic acid-based compound 1 and DASA-58 was found to activate PKM2 with an AC

Potassium tertiary butoxide (KOtBu) mediated constructions of C–C, C–O, C–N, and C–S bonds are reviewed with special emphasis on their synthetic applications. KOtBu can be used to perform reactions already known to be carried out using transition metals, but it has advantages in terms of environmental congruence and economic cost. KOtBu is widely employed in organic synthesis to mediate the construction of C–C, C–O, C–N, C–S and miscellaneous bonds in good to excellent yields. Synthetic uses of KOtBu in coupling, alkylation, arylation, α-phenylation, cyclization, Heck-type, annulation, photo-arylation, aromatic-substitution, amidation, and silylation reactions are summarized and discussed. The mechanisms through which KOtBu carries out a specific reaction are also discussed. One of the goals of this review is to attract the attention of chemists as to the benefits of using KOtBu as an environmentally benign alternative to transition metals and its applications in the construction of chemical bonds with predominant importance in organic synthesis. This review completely covers the synthetic protocols that have been performed using KOtBu in the last two decades.

It is evident from the on-going clinical studies (trials) for coronavirus disease 2019 (COVID-19) that treatment with a single drug is not likely to be sufficient. This, in turn, suggests that the drug acts via inhibition of multiple pathways likely to be more successful and promising. Keeping this hypothesis intact, the present study describes for the first-time, Grazoprevir, an FDA approved anti-viral drug primarily approved for HCV, mediated multiple pathway control via synergistic inhibition of viral entry targeting host cell Angiotensin Converting Enzyme 2 (ACE- 2)/transmembrane serine protease 2 (TMPRSS2) and viral replication targeting RNA-dependent, RNA polymerase (RdRP). We believe that Grazoprevir either alone or given in combination could be effective therapeutics for treatment of COVID-19 pandemic with a promise of unlikely drug resistance owing to multiple inhibition of eukaryotic and viral proteins.

The present study is designed to identify various bioactive flavonoid compounds from the methanolic fern extract (MFE) of Cheilanthes tenuifolia. Flavonoids derived from C. tenuifolia (fern) possess potent anti-cancerous, anti-bacterial, anti-oxidant activities that are responsible for their chemo-preventive potential against selected bacterial panel. A preparative column chromatography with a column Sephadex LH-20 was used to isolate and purify flavonoids from C. tenuifolia. Their structure and chemical bonds were identified by using Nuclear Magnetic Resonance (NMR) spectroscopy and Fourier Transform-Infra Red Spectroscopy (FTIR). Two flavonoids were identified as rutin (2.8 mg) and quercetin (3.34 mg) from 100 g of C. tenuifolia. The minimum inhibitory concentration (MIC) values of (2.25 and 0.45 µg/ml) were obtained in purified flavonoids against Staphylococcus aureus and Enterobacter sp., respectively. The two flavonoids (Rutin and quercetin) showed significant in vitro anti-oxidant activity; in this regard, the 2, 2-diphenyl-1-picrylhydrazyl (DPPH) scavenging potential of quercetin (86.1%) was higher than that of rutin (73.2%). However, for human hepatoma HepG2 and human carcinoma HeLa cells, quercetin exhibited high anti-cancer activity than rutin. The purified compounds (rutin and quercetin) with having great potential of free radical inactivator in HepG2 cells. The results suggest that MFE of C. tenuifolia could potentially be employed in traditional medicine as they are rich in compounds with anti-oxidant, anti-microbial and anti-cancer properties. Keywords: Cheilanthes tenuifolia, Column chromatography, Rutin, Quercetin, Fourier Transform-Infra Red Spectroscopy, Nuclear Magnetic Resonance

Kinesins are one of the neoteric and efficacious targets recently reported to play an important role in the initiation and progression of chronic pain. Kinesins are anterograde microtubule-based motor proteins that are involved in trafficking of receptors including nociceptors and progression of pain. The specific kinesin and regulatory proteins interplay is crucial for the delivery of nociceptors to the synapse. If this complex and less understood interplay is inhibited, it may result in a decrease in central sensitization, and thus attenuation of pain. This review is focused on the transportation process of receptors/cargos, the role of regulatory proteins influencing the respective kinesin, and their relationship with chronic pain. The review also features specific strategies adopted by researchers for targeting kinesin and chronic pain. Considering the recent preclinical success of kinesin inhibition in pain, it is expected that inhibitors for kinesin or enzymes responsible for kinesin activation could be developed or repurposed as alternative, safe, and potential therapies for the treatment of chronic pain.

A simple, economical and one-pot protocol is developed for construction of multiple carbon-carbon bonds having C(sp2)-C(sp2) and C(sp2)-C(sp) hybridization, as these intriguing molecular architectures embrace significant optoelectronic and medicinal properties. To this end, a sequencial reaction is devised that allows one-pot three-component reaction of hydroxy benzaldehydes (C6-C1 unit), halo-phenylacetic acid (C6-C2 unit) and arylacetylenes (C6-C3 unit) resulting in the formation of highly π-conjugated complex arylethenyl-arylethynyl-arenes (C6-C2-C6-C2-C6 unit) bearing hydroxy group via sequential Perkin condensation/ decarboxylation-Sonogashira coupling reaction in poly(ethylene glycol) under microwave irradiation. The process avoids protection-deprotection manipulations, generates CO2 and H2O as by-products and has been successfully extended for the efficient construction of a wide series of novel aliphatic/ alicyclic/(hetero)aromatic arylethenyl-arylethynyl-arene with pendant hydroxy functionality which could allow further chemical modification to achieve desired biological and physical properties.

Several studies have established that cancer cells explicitly over-express the less active isoform of pyruvate kinase M2 (PKM2) is critical for tumorigenesis. The activation of PKM2 towards tetramer formation may increase affinity towards phosphoenolpyruvate (PEP) and avoidance of the Warburg effect. Herein, we describe the design, synthesis, and development of boronic acid-based molecules as activators of PKM2. The designed molecules were inspired by existing anticancer scaffolds and several fragments were assembled in the derivatives. 6a-6d were synthesized using a multi-step synthetic strategy in 55–70% yields, starting from cheap and readily available materials. The compounds were selectively cytotoxic to kill the cancerous cells at 80 nM, while they were non-toxic to the normal cells. The kinetic studies established the compounds as novel activators of PKM2 and (E/Z)-(4-(3-(2-((4-chlorophenyl)amino)-4-(dimethylamino)thiazol-5-yl)-2-(ethoxycarbonyl)-3-oxoprop-1-en-1-yl) phenyl)boronic acid (6c) emerged as the most potent derivative. 6c was further evaluated using various in silico tools to understand the molecular mechanism of tetramer formation. Docking studies revealed that 6c binds to the PKM2 dimer at the dimeric interface. Further to ascertain the binding site and mechanism of action, rigorous MD (molecular dynamics) simulations were undertaken, which led to the conclusion that 6c stabilizes the center of the dimeric interface that possibly promotes tetramer formation. We further planned to make a tablet of the developed molecule for oral delivery, but it was seriously impeded owing to poor aqueous solubility of 6c. To improve aqueous solubility and retain 6c at the lower gastrointestinal tract, thiolated chitosan-based nanoparticles (TCNPs) were prepared and further developed as tablet dosage form to retain anticancer potency in the excised goat colon. Our findings may provide a valuable pharmacological mechanism for understanding metabolic underpinnings that may aid in the clinical development of new anticancer agents targeting PKM2.

Protecting-group-free synthesis of hydroxylated styryl–cinnamate hybrids (C6–C2–C6–C3 unit), inspired by the natural product salvianolic acid F, was achieved by a step-economical route involving sequential double C–C bond formation in one pot. The method involved multiple reactions (Perkin condensation/decarboxylation–Heck cross-coupling reactions) by using simple precursors (i.e., hydroxylated benzaldehyde, arylacetic acid, and acrylic acid derivatives) in one pot and yielded the desired unnatural small hybrid molecules in varying yields of 35–65 % with E selectivity under microwave irradiation, whereas the reported conventional route for the synthesis of salvianolic acid F itself requires six steps with an overall yield of 10.0 % in addition to tedious separation of E/Z isomers that arise from a Wittig reaction. Apart from an economical synthesis and product diversity, we herein report the potential of some hybrid molecules with the catechol core to selectively inhibit glioma cells. The intrinsic mode of action of our lead molecule, involving caspase 6 and the quinonemethide pathway, is also reported on the basis of 1H NMR spectroscopy guided metabolomic profiling. We emphatically demonstrate the role of our hybrid molecules, analogues of salvianolic acid F, in forcing glioma cells towards apoptosis by specifically perturbing the concentration of glutathione along with that of caspase 6.

(E/Z)-(4-(3-(2-((4-chlorophenyl)amino)-4-(dimethylamino)thiazol-5-yl)-2-(ethoxy carbonyl)-3-oxoprop-1-en-1-yl)phenyl) boronic acid, a newly developed molecule having anticancer activity serves as a potential candidate for the further drug development process. In this study, to ascertain the anticancer potential of the molecule, we screened it against different cell lines and compared the activity against the standard drug doxorubicin. The molecule showed promising activity at a low concentration against almost all cell lines used in the study. Apart from that, the molecule was characterized for its pKa and a precise reverse phase high-performance liquid chromatography bioanalytical method has been developed. The method was validated according to the United States of Food and Drug Administration bioanalytical guideline and was found to produce linear response over the calibration range of 0.8–25 μg/mL. Inter- and intra-day accuracy were found to be in the range of 93.44–99.74%, whereas precision [% coefficient of variation (CV)] for inter- and intra-day was ranged between 1.63 and 5.79%, and 0.87 and 6.96%, respectively. The bioanalytical stability testing was carried out in different conditions including 8 h benchtop, 12 h autosampler and three freeze–thaw cycles. The analyte was stable in all the tested stability conditions. Finally, an in vitro metabolite identification study was conducted using quadrupole-time of flight-mass spectrometer, and two metabolites have been identified.

Background Abolition of cancer warrants effective treatment modalities directed towards specific pathways dysregulated in tumor proliferation and survival. The antiapoptotic Bcl-2 proteins are significantly altered in several tumor types which position them as striking targets for therapeutic intervention. Here we designed, computationally evaluated, synthesized, and biologically tested structurally optimized thiazole-based small molecules as anticancer agents. Methods The virtually designed 200 molecules were subjected to rigorous docking and in silico ADME-Toxicity studies. Out of this, 23 skeletally diverse thiazole-based molecules which passed pan assay interference compounds (PAINS) filter and were synthetically feasible were synthesized in 3 steps using cheap and readily available reagents. The molecules were in vitro evaluated against Bcl-2-Jurkat, A-431 cancerous cell lines and ARPE-19 cell lines. Molecular Dynamics (MD) simulation studies were performed to analyse conformational changes induced by ligand 32 in Bcl-2. Flow cytometry analysis of compound 32 treated Bcl-2 cells was done to check apoptosis. Results The molecules exhibited appreciable interactions with Bcl-2 and were having acceptable drug like properties as tested in silico. The multi step synthesis yielded 23 skeletally diverse thiazole-based molecules in up to 80% yield. The molecules simultaneously inhibited Bcl-2 Jurkat cells in vitro without causing detectable toxicity to normal cells (ARPE-19 cells). Among them molecules 32, 50, 53, 57 and 59 showed considerable activities against Bcl-2 Jurkat and A-431cell lines at concentrations ranging from 32–46 μM and 34–52 μM, respectively. The standard doxorubicin exhibited IC50 in Bcl-2 Jurkat and A-431cell lines at 45.87 μM and 42.37 μM, respectively. The molecule 32, almost equipotent in both the cell lines was subjected to molecular dynamics (MD) simulation with Bcl-2 protein (4IEH). It was shown that 32 interacted with protein majorly via hydrophobic interactions and few H-bonding interactions. Fluorescence-activated cell sorting (FACS) analysis established that molecule is dragging cancerous cells towards apoptosis. Discussion and conclusion The chemical intuition was checked by computation coupled with biological results confirmed that thiazole-based hits have the potential to be developed downstream into potent and safer leads against antiapoptotic Bcl-2 cells.

The first systematic evaluation of the antiplasmodial activity of the hydroxystilbene family of natural products and di/tristyrylbenzenes is described. A library of 27 diversely substituted hydroxy stilbenoids was rapidly synthesized using modified Knoevenagel–Perkin-decarboxylation–Heck sequences from readily available starting materials (i.e. hydroxybenzaldehyde–phenylacetic acid–arylhalide). These compounds were evaluated for in vitro antiplasmodial activity against three different strains of Plasmodium falciparum. Notably, 4,4′4′′-((1E,1′E,1′′E)-benzene-1,3,5-triyltris(ethene-2,1-diyl))tris(2,6-dimethoxyphenol) (27), an octupolar stilbenoid, showed IC50 (μM) values of 0.6, 0.5 and 1.36 while a distyrylbenzene (11) showed IC50 values of 0.9, 2.0 and 2.7 against 3D7 (chloroquine sensitive), Dd2 and Indo (chloroquine resistant) strains of Plasmodium falciparum respectively. Moreover, 27 and 11, which exhibited selectivity indices of 40 and >111 were also found to be nontoxic to the HeLa cell line. Microscopic studies revealed that the rings and trophozoites obtained from the 27 and 11 (an octupolar tristyrylbenzene and distyrylbenzene respectively) treated cultures were growth inhibited and morphologically deformed. These cultures also showed DNA fragmentation and loss of mitochondrial membrane potential (ΔΨm), suggestive of apoptotic death of the parasite. Together, these studies introduce di/tristyrylbenzenes as a new class of antimalarial agents.

Ethyl 3-(2-(4-fluorophenyl)amino)-4-phenylthiazo)-5-yl)-3-oxopropanoate is a novel molecule with potent acetylcholinesterase inhibition property. In this research, we have developed a rapid and selective RP-HPLC bioanalytical method for quantitative measurement of the molecule. The method has been validated following the USFDA bioanalytical method validation guideline. In addition, as a part of drug development, in vitro metabolite identification has also been performed. A Kromasil C18 column was used in eluting the molecule chromatographically. The optimized mobile phase was composed of a mixture of acetonitrile and 10 mM ammonium formate buffer (pH 4.6) in 70:30 ratio (v/v). The response of the molecule was found to be linear over a calibration range of 0.2 μg/mL to 12 μg/mL. The inter-day and intra-day accuracy of the method ranged from 89.95% to 101.90% and 99.84% to 104.08%, respectively. On the other hand, the precision (%CV) value for inter-day was in between 3.50% to 6.91% and for intra-day, it was 2.11% to 8.03%. The mean recovery of the molecule at three different quality control levels was more than 85%. The analyte was stable under different stability conditions including 12 h autosampler, 8 h bench top, 15 days long term at −20 °C and three freeze-thaw cycles. The method was applied to determine stability of the molecule in human plasma. The molecule was found to be stable with more than 90% remaining even after 120 min of incubation in plasma. Two metabolites each in rat liver microsome and human liver microsome has been identified.

Hit, Lead & Candidate Discovery The thiazole ring system represents a significant building block that exists in many biologically active natural products and clinically successful anticancer drugs. Modifications of the thiazole core have been a proven and highly effective method in improving anticancer potency. We designed a novel thiazole-based molecule, 4-(dimethylamino)-2-(p-tolylamino) thiazole-5-carbonitrile, which showed potent in vitro anticancer effect against targeted Bcl-2 Jurkat cell-line quantified using 3-(4, 5-dimethythiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. Physicochemical parameters (pKa, LogP, LogD) of the molecule have also been evaluated as a part of the drug development process. Moreover, a rapid Reverse phase-high performance liquid chromatography (RP-HPLC) bioanalytical method has been developed to quantitate the molecule in human plasma. The method has been validated following the United States Food and Drug Administration bioanalytical method validation guideline. The stability studies showed no significant instability of the analyte in respective stability conditions (6 hr autosampler, 8 hr bench top, 30 days long-term, and 3 freeze-thaw cycles). The molecule was found to be stable for 3 hr in human plasma. The molecule was shown to have high plasma protein binding affinity. It showed favorable pKa (11), Log P (3.01), Log D (2.96), and plasma protein binding (90%) values toward its further exploitation as a lead anticancer candidate molecule. The developed bioanalytical method can be used for quantifying the molecule in different pharmacokinetic, toxicokinetic, or other clinical trial samples involving human plasma during development process or in routine bioavailability and bioequivalence study after its regulatory approval.

Multicomponent reactions are compelling strategies for generating a chemically diverse set of multifunctionalized heterocyclic motifs with high atom economy, rendering the transformations green. These strategies can further become more prolific if catalyst recyclability, compatibility and exploration of precise mechanistic pathways are considered. To this end, an inexpensive and recyclable glycine nitrate (GlyNO3) ionic liquid has been efficiently employed to obtain diversely substituted symmetrical and unsymmetrical 1,4-dihydropyridines with up to 93% yields via three and four components, respectively. The catalyst recyclability and compatibility to obtain both symmetrical and unsymmetrical 1,4 DHPs under identical reaction conditions are added benefits to its practical utility. Furthermore, progress of the reaction was monitored by Q-TOF, direct infusion electrospray ionization mass spectrometry (ESI-MS), and key cationic intermediates involved in the reaction have been further identified by a tandem MS experiment (Q-TOF, ESI-MS/MS), which served as the proof of concept to the mechanistic model. This is the first report which revealed that the Hantzsch reaction predominantly follows the diketone pathway among four competing reaction pathways.

A green methodology utilizing a natural supplement such as L-arginine in conjunction with water and oxygen led to oxidative coupling of thiols into disulfides (S–S bond) whereas thiol–yne coupling to access vinyl sulfides (C–S bond) was facilitated in a nitrogen atmosphere. The tunable protocol offers several advantages such as low catalyst loading, high yields, clean reaction, no over-oxidation of the S–S bond besides being metal/base/waste-free. The synthesis of ubiquitous cystine and glutathione disulfide in the same catalytic system is an added advantage and the catalytic system has been recycled up to seven times.

The selective oxidative coupling of thiols has been studied in several imidazolium-based ionic liquids in the absence of any base/metal catalysts. Disulfides were obtained from the corresponding thiols in good to excellent yields in 1-hexyl-3-methylimidazolium bromide ([hmim]Br). Furthermore, a 1H NMR-based mechanistic study of the S–S bond formation demonstrated the cooperative role of halide anion and imidazolium cation of [hmim]Br as an “ambiphile” – a character found to be imperative for the efficient syntheses of disulfides. The developed methodology is simple, selective and green that utilises molecular oxygen as an oxidant and produces water as the only by-product.

All in one: a tandem strategy has been developed wherein secondary aryl alcohols are directly coupled with aryl halides to provide stilbenoids through a dehydrative Heck sequence in the ionic liquid [hmim]Br, and with water as a by-product under microwave irradiation. Classical methods do not permit this sequence to proceed in one pot, and some methods require multiple steps. hmim=1-n-hexyl-3-methylimidazolium.

Novel stilbene-chalcone (S-C) hybrids were synthesized via a sequential Claisen-Schmidt-Knoevenagel-Heck approach and evaluated for antiplasmodial activity in in vitro red cell culture using SYBR Green I assay. The most potent hybrid (11) showed IC(50) of 2.2, 1.4, and 6.4 μM against 3D7 (chloroquine sensitive), Indo, and Dd2 (chloroquine resistant) strains of Plasmodium falciparum, respectively. Interestingly, the respective individual stilbene (IC(50)100 μM), chalcone (IC(50) = 11.5 μM), or an equimolar mixture of stilbene and chalcone (IC(50) = 32.5 μM) were less potent than 11. Studies done using specific stage enriched cultures and parasite in continuous culture indicate that 11 and 18 spare the schizont but block the progression of the parasite life cycle at the ring or the trophozoite stages. Further, 11 and 18 caused chromatin condensation, DNA fragmentation, and loss of mitochondrial membrane potential in Plasmodium falciparum, thereby suggesting their ability to cause apoptosis in malaria parasite.

A series of chalcones (A–CH=CH–CO–B) were synthesized under microwave irradiation, and for the first time their pesticidal activity against diamondback moth (Plutella xylostella) was evaluated to identify the promising lead structures. The structure–activity relationship (SAR) analysis revealed that electron-withdrawing substituents on ring A of chalcone provided good pesticidal agents, whereas, ring B can bear either electron-withdrawing or electron-releasing substituents. Moreover, compound 22 having para-Cl substitution on ring A as well on ring B showed maximum activity with LC50 value of 170.24 μg mL−1.