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Epigenetic regulations play a crucial role in the expression of various genes that are important in the normal cell function. Any alteration in these epigenetic mechanisms can lead to the modification of histone and DNA, resulting in the silencing or enhanced expression of some genes causing various diseases. Acetylation, methylation, ribosylation, or phosphorylation of histone proteins modifies its interaction with the DNA, consequently changing the ratio of heterochromatin and euchromatin. Terminal lysine residues of histone proteins serve as potential targets of such epigenetic modifications. The current review focuses on the histone modifications, and their contributing factors; the role of these modifications on metabolism leads to cancer, and methylation of histone in cancer affects the DNA repair mechanisms.

Heterocycles are among the well-established classes of compounds, constituting a wide range of organic molecules. These structural motifs not only have a dominant presence in a wide variety of drugs but are also equally present as ubiquitous fragments of numerous vitamins, biologically active natural products, biomolecules, and synthetic drug candidates. Their key role in medicinal chemistry in the design of safe, effective, and efficacious drug molecules gives an impetus to the scientific community to access heterocyclic entities from robust chemical reactions. In this review, we summarize a diverse range of synthetic methods employing alkynoates as key starting materials to furnish useful bioactive heterocyclic frameworks (nitrogen, oxygen, sulfur, fused- and hetero-spirocycles), thus offering new opportunities and expanding the toolbox of synthetic chemistry reactions under transition-metal-free conditions. Several reaction parameters such as the use of easily available starting materials, commercially accessible reagents, and ease of synthesis (moderate temperatures, short reaction times, high yields, limited by-products) are included in the discussion alongside the reaction scope and limitations as well as mechanistic insights. The application of these methodologies in the synthesis of natural products and pharmaceuticals has also been discussed. We hope that the diverse utilities of alkynoates in the delivery of various heterocycles will fulfil the objectives of medicinal chemists in overcoming the formidable challenges associated with drug discovery and development.

Type 2 diabetes mellitus has been a major health issue with increasing morbidity and mortality due to macrovascular and microvascular complications. The urgent need for improved methods to control hyperglycemic complications reiterates the development of innovative preventive and therapeutic treatment strategies. In this perspective, xanthone compounds in the pericarp of the mangosteen fruit, especially α-mangostin (MGN), have been recognized to restore damaged pancreatic β-cells for optimal insulin release. Therefore, taking advantage of the robust use of nanotechnology for targeted drug delivery, we herein report the preparation of MGN loaded nanosponges for anti-diabetic therapeutic applications. The nanosponges were prepared by quasi-emulsion solvent evaporation method. Physico-chemical characterization of formulated nanosponges with satisfactory outcomes was performed with Fourier transform infra-red (FTIR) spectroscopy, differential scanning calorimetry (DSC), and scanning electron microscopy (SEM). Zeta potential, hydrodynamic diameter, entrapment efficiency, drug release properties, and stability studies at stress conditions were also tested. Molecular docking analysis revealed significant interactions of α-glucosidase and MGN in a protein-ligand complex. The maximum inhibition by nanosponges against α-glucosidase was observed to be 0.9352 ± 0.0856 µM, 3.11-fold higher than acarbose. In vivo studies were conducted on diabetic rats and plasma glucose levels were estimated by HPLC. Collectively, our findings suggest that MGN-loaded nanosponges may be beneficial in the treatment of diabetes since they prolong the antidiabetic response in plasma and improve patient compliance by slowly releasing MGN and requiring less frequent doses, respectively.

Alzheimer’s disease (AD) is a progressive neurodegenerative disorder and the leading cause of dementia worldwide. The limited pharmacological approaches based on cholinesterase inhibitors only provide symptomatic relief to AD patients. Moreover, the adverse side effects such as nausea, vomiting, loss of appetite, muscle cramps, and headaches associated with these drugs and numerous clinical trial failures present substantial limitations on the use of medications and call for a detailed insight of disease heterogeneity and development of preventive and multifactorial therapeutic strategies on urgent basis. In this context, we herein report a series of quinoline-thiosemicarbazone hybrid therapeutics as selective and potent inhibitors of cholinesterases. A facile multistep synthetic approach was utilized to generate target structures bearing multiple sites for chemical modifications and establishing drug-receptor interactions. The structures of all the synthesized compounds were fully established using readily available spectroscopic techniques (FTIR, 1H- and 13C-NMR). In vitro inhibitory results revealed compound 5b as a promising and lead inhibitor with an IC50 value of 0.12 ± 0.02 μM, a 5-fold higher potency than standard drug (galantamine, IC50 = 0.62 ± 0.01 μM). The synergistic effect of electron-rich (methoxy) group and ethylmorpholine moiety in quinoline-thiosemicarbazone conjugates contributes significantly in improving the inhibition level. Molecular docking analysis revealed various vital interactions of potent compounds with amino acid residues and reinforced the in vitro results. Kinetics experiments revealed the competitive mode of inhibition while ADME properties favored the translation of identified inhibitors into safe and promising drug candidates for pre-clinical testing. Collectively, inhibitory activity data and results from key physicochemical properties merit further research to ensure the design and development of safe and high-quality drug candidates for Alzheimer’s disease.

Pomegranate (Punica granatum L.) extract has been reported to inhibit cholinesterase and the β-site amyloid precursor protein cleaving enzyme 1 (BACE1); however, most of its constituents' potential inhibition of these enzymes remains unknown. Thus, we investigated the anti-Alzheimer's disease (anti-AD) potential of 16 ellagitannin and gallotannin, and nine anthocyanin derivatives' inhibition of BACE1, AChE, and BChE, and gallagic acid inhibited both the best. Further, a kinetic study identified different modes of inhibition, and a molecular docking simulation revealed that active compounds inhibited these three enzymes with low binding energy through hydrophilic and hydrophobic interactions in the active site cavities. Gallagic acid and castalagin decreased Aβ peptides secretion from neuroblastoma cells that overexpressed human β-amyloid precursor protein significantly by 10 μM. Further, treatment with gallagic acid and castalagin reduced BACE1 and APPsβ expression levels significantly without affecting amyloid precursor protein (APP) levels in the amyloidogenic pathway. Co-incubation of Aβ42 with gallagic acid reduced Aβ42-induced intracellular reactive oxygen species (ROS) production significantly. Our results suggest that pomegranate constituents, specifically gallagic acid, may be useful in developing therapeutic treatment modalities for AD.

The discovery of life-changing medicines continues to be the driving force for the rapid exploration and expansion of chemical space, enabling access to innovative small molecules of medicinal importance. These small molecules remain the backbone for modern drug discovery. In this context, the treatment of ureolytic bacterial infections inspires the identification of potent and effective inhibitors of urease, a promising and highly needed target for H. pylori eradication. The present study explores the evaluation of sulfamate derivatives for the inhibition of urease enzyme. The tested compounds showed remarkable inhibitory effect and high level of potency. Compound 1q emerged as the lead inhibitor with an IC

Benzohydrazide derivatives 1–43 were synthesized via “one-pot” reaction and structural characterization of these synthetic derivatives was carried out by different spectroscopic techniques such as 1H NMR and EI-MS. The synthetic molecules were evaluated for their in vitro urease inhibitory activity. All synthetic derivatives showed good inhibitory activities in the range of (IC50 = 0.87 ± 0.31–19.0 ± 0.25 µM) as compared to the standard thiourea (IC50 = 21.25 ± 0.15 µM), except seven compounds 17, 18, 23, 24, 29, 30, and 41 which were found to be inactive. The most active compound of the series was compound 36 (IC50 = 0.87 ± 0.31 μM) having two chloro groups at meta positions of ring A and methoxy group at para position of ring B. The structure–activity relationship (SAR) of the active compounds was established on the basis of different substituents and their positions in the molecules. Kinetic studies of the active compounds revealed that compounds can inhibit enzyme via competitive and noncompetitive modes. In silico study was also performed to understand the binding interactions of the molecules (ligand) with the active site of enzyme.

COVID-19, an infectious disease caused by a newly discovered enveloped virus (SARS-CoV-2), was first reported in Wuhan, China, in December 2019 and affected the whole world. The infected individual may develop symptoms such as high fever, cough, myalgia, lymphopenia, respiratory distress syndrome etc., or remain completely asymptomatic after the incubation period of two to fourteen days. As the virus is transmitted by inhaling infectious respiratory droplets that are produced by sneezing or coughing, so early and rapid diagnosis of the disease can prevent infection and transmission. In the current pandemic situation, the medical industry is looking for new technologies to monitor and control the spread of COVID-19. In this context, the current review article highlights the Artificial Intelligence methods that are playing an effective role in rapid, accurate and early diagnosis of the disease via pattern recognition, machine learning, expert system and fuzzy logic by improving cognitive behavior and reducing human error. Auto-encoder deep learning method, α-satellite, ACEMod and heterogeneous graph auto- encoder are AI approaches that determine the transfer rate of virus and are helpful in shaping public health and planning. In addition, CT scan, X-ray, MRI, and RT-PCR are some of the techniques that are being employed in the identification of COVID-19. We hope using AI techniques; the world can emerge from COVID-19 pandemic while mitigating social and economic crisis.

Alkaline phosphatases (ALPs) are membrane bound metalloenzymes, distributed all over the body. Recent studies have revealed that by targeting ALPs can lead towards the treatment of many deadliest diseases including cardiac, cancerous and brain diseases. Thioureas and their derivatives are of considerable significance and are privileged scaffolds in medicinal chemistry. They show a wide range of pharmacological activities such as antibacterial, antiparasitic, anti-inflammatory and antioxidants etc. On the other hand, salicylic acid and its derivatives are known for its broad spectrum of activities. The work presented comprises of synthesis of N-acyl-N'-aryl substituted bisthioureas of pimelic acid (1-7) and 3,5-dimethyl pyrazole (11), 1-aroyl-3-aryl thiourea (12) and 1,3,4-oxadiazole (13) derivatives of 4-methyl salicylic acid. Structures of all the synthesized compounds were characterized by FT-IR and 1H NMR spectroscopic analysis. Synthesized compounds were evaluated for their alkaline phosphatases inhibition potential and exhibited high potency as well as selectivity towards h-TNAP and h-IAP. Compound 7 and 12 which were the bisthiourea derivative of pimmelic acid and thiourea derivative of 4-methyl salicylic acid, respectively, showed excellent selectivity against h-TNAP and h-IAP, respectively.

Alkaline phosphatases (APs) are a class of homodimeric enzymes which physiologically possess the dephosphorylation ability. APs catalyzes the hydrolysis of monoesters into phosphoric acid which in turn catalyze a transphosphorylation reaction. Thiazoles are nitrogen and sulfur containing aromatic heterocycles considered as effective APs inhibitors. In this context, the current research paper presents the successful synthesis, spectroscopic characterization and in vitro alkaline phosphatase inhibitory potential of new thiazole derivatives. The structure activity relationship and molecular docking studies were performed to find out the binding modes of the screened compounds with the target site of tissue non-specific alkaline phosphatase (h-TNAP) as well as intestinal alkaline phosphatase (h-IAP). Compound 5e was found to be potent inhibitor of h-TNAP with IC50 value of 0.17 ± 0.01 µM. Additionally, compounds 5a and 5i were found to be highly selective toward h-TNAP with IC50 values of 0.25 ± 0.01 µM and 0.21 ± 0.02 µM, respectively. In case of h-IAP compound 5f was the most potent inhibitor with IC50 value of 1.33 ± 0.10 µM. The most active compounds were resort to molecular docking studies on h-TNAP and h-IAP to explore the possible binding interactions of enzyme-ligand complexes. Molecular dynamic simulations were carried out to investigate the overall stability of protein in apo and holo state.

We developed a simple and robust method for synthesis of 1,3-oxathiol-2-ylidene benzamides (4a–m) a sporadic class of heterocycles, by reacting freshly prepared aroyl isothiocyanates, with ethyl 2-chloroacetoacetate in presence of N-methylimidazole in dry acetonitrile. The synthesized compounds were explored for their inhibition against alkaline phosphatases and HeLa cancer cell lines. The results suggest that almost all the compounds possess good % inhibition against both enzymes, with compound 4m showing dual inhibition while 4g and 4i as potent and selective inhibitors of TNAP and c-IAP respectively. Structure activity relationship for the active members of series has been carried out based on molecular docking studies. The result of SAR shows the involvement of active inhibitors in H-bonding at various sites with different amino acid residues in addition to secondary metal ion interactions with Zn ions inside the active pocket of the enzyme. The π-π interactions between the 1,3-oxathiole ring and imidazole ring of His321 and His 317 further defines the dual mode of inhibition by compound 4m. These compounds also possess inhibition potential against cervical cell lines in the range of 2.42–69.03% with the maximum inhibition shown by the unsubstituted member 4a compared to the reference drug cisplatin.

Alzheimer is a neurodegenerative disease and requires the development of new scaffold to treat it. In this regard, thiazoles derivative are playing their significant role. In the current research paper we have focused our attention for the development of tetrasubstituted thiazole (3a-h) derivatives using domino synthesis by mixing the thiourea as a precursor, with acetophenone in the presence of iodine and tosic acid in DMSO and refluxed for 12–22 h. The structures of the newly synthesized compounds were confirmed by FTIR, 1H NMR, 13C NMR and EIMS analysis. Thiazole derivatives were analyzed for their biological significances against acetyl and butylcholinesterase enzymes and compound 3b and 3d were found more active against these enzyme, respectively. The mode of inhibition was determined for the potent compounds against both the enzymes. Moreover, the molecular docking studies were carried out to explore the interactive behavior of the compounds within the active pocket of enzymes. Furthermore, the derivatives (3a-h) were evaluated for their anticancer potential against HeLa cancer cell lines. Most potent inhibition was observed by compound 3b.

An efficient and facile microwave-assisted solution phase parallel synthesis for a 38-member library of N-aroyl-N′-aryl thioureas was accomplished successfully. These analogues (1–38) were synthesized under identical set of conditions. It has been observed that the reaction time was drastically reduced from 8 to 12 h for conventional methods to only 10–15 mins. Products obtained were more than 98% pure, as characterized by elemental analysis along with FT-IR and 1H, 13C NMR. The solid-phase structural analysis was accomplished by single crystal XRD analysis. The urease inhibitory potential of synthetic compounds was tested and compounds were found to inhibit urease in moderate to significant manner. Compound 17 was the most potent inhibitor of urease having an IC50 value of 0.17 ± 0.1 μM. To check the cytotoxic profile of the derivatives, lungs cancer cell lines were used. Cytotoxicity analysis revealed remarkable toxicity of the compounds against tested lungs carcinoma and compounds showed variation in inhibition activity due to the substituents attached. The molecular docking studies were carried out to identify the possible binding modes of potent inhibitors in the active site of enzyme. The results suggested that the compounds can be further investigated and used against different cancers.

Diabetes mellitus (DM), a chronic multifarious metabolic disorder resulting from impaired glucose homeostasis has become one of the most challenging diseases with severe life threat to public health. The inhibition of α-glucosidase, a key carbohydrate hydrolyzing enzyme, could serve as one of the effective methodology in both preventing and treating diabetes through controlling the postprandial glucose levels and suppressing postprandial hyperglycemia. In this context, three series of diamine-bridged bis-coumarinyl oxadiazole conjugates were designed and synthesized by one-pot multi-component methodology. The synthesized conjugates (4a–j, 5a–j, 6a–j) were evaluated as potential inhibitors of glucosidases. Compound 6f containing 4,4′-oxydianiline linker was identified as the lead and selective inhibitor of α-glucosidase enzyme with an IC50 value of 0.07 ± 0.001 μM (acarbose: IC50 = 38.2 ± 0.12 μM). This inhibition efficacy was ∼545-fold higher compared to the standard drug. Compound 6f was also emerged as the lead molecule against intestinal maltase-glucoamylase with good inhibition strength (IC50 = 0.04 ± 0.02 μM) compared to acarbose (IC50 = 0.06 ± 0.01 μM). Against β-glucosidase enzyme, compound 6 g was noted as the lead inhibitor with IC50 value of 0.08 ± 0.002 μM. Michaelis–Menten kinetic experiments were performed to explore the mechanism of inhibition. Molecular docking studies of the synthesized library of hybrid structures against glucosidase enzyme were performed to describe ligand-protein interactions at molecular level that provided an insight into the biological properties of the analyzed compounds. The results suggested that the inhibitors could be stabilized in the active site through the formation of multiple interactions with catalytic residues in a cooperative fashion. In addition, strong binding interactions of the compounds with the amino acid residues were effective for the successful identification of α-glucosidase inhibitors.

In the present study, we have designed and synthesized a Schiff base derivative 3 and characterized by FT-IR, 1H and 13C NMR spectroscopy. Single crystal X-ray diffraction and NMR studies were also performed. The synthetic compound was screened for its inhibitory potential against carbonic anhydrase II. The experimental results were validated by molecular docking and dynamic simulations of compound 3 in the active pocket of enzyme. Important binding interactions with the key residues in the active site of the carbonic anhydrase enzyme were revealed. Moreover, supramolecular assembly of the title compound was analyzed by density functional theory (DFT) calculations. These studies rendered a more clear understanding for the demonstration of novel molecular mechanism involved in CA II inhibition by the synthesized compound.

Due to the immense importance of aryl indole nucleus, herein we report the palladium-catalyzed arylation of N-substituted 2-aryl indole utilizing Suzuki-Miyaura cross coupling methodology. The biological screening for cholinesterase inhibition of the resulted biaryl indole moieties was carried out to evaluate their pharmacological potential, expecting to involve the development of new therapeutics for various inflammatory, cardiovascular, gastrointestinal and neurological diseases. This research work also involved the use of utilization of microwave-assisted organic synthesis (MAOS) for the synthesis of Bischler-Möhlau indole which is further biarylated via palladium-catalyzed cross coupling reaction. All the synthetic compounds (3a-n) were tested for cholinesterase inhibition and exhibited high level of AChE inhibitory activities. Interestingly, compounds 3m and 3n were found to be dual inhibitors, however, remaining compound exhibited no inhibitory activity against BChE. The biological potential of the resulted compounds was explained on the basis of molecular docking studies, performed against AChE and BChE, exploring the probable binding modes of most potent inhibitors.

Fifteen N 4-benzyl-substituted isatin-3-thiosemicarbazones 5a–o were synthesized and evaluated for their urease and glycation inhibitory potential. Lemna aequinocitalis growth and Artemia salina assays were also done to determine their phytotoxic and toxic effects. All compounds are potent inhibitors of the urease enzyme, displaying inhibition [half maximal inhibitory concentration (IC50)=1.08±0.12–11.23±0.19 μm] superior to that of the reference inhibitor thiourea (IC50=22.3±1.12 μm). Compounds 5c, 5d, 5h, 5j,k are potent antiglycating agents, showing glycation inhibitory activity better than that of the reference inhibitor rutin (IC50 values 209.87±0.37–231.70±6.71 vs. 294.5±1.5 μm). In the phytotoxicity assay, 11 thiosemicarbazones 5a–d, 5g, 5h, 5j–l, 5n,o are active, demonstrating 5–100% growth inhibition of L. aequinocitalis at the highest tested concentrations (1000 or 500 μg/mL). In the brine shrimp (A. salina) lethality bioassay, three derivatives 5b, 5j and 5o are active with median lethal dose (LD50) values of 3.63×10−5, 2.90×10−5 and 2.31×10−4 m, respectively.

A new and efficient domino reaction of 3-chlorochromones with electron-rich aminoheterocycles was developed which allows for a convenient synthesis of a variety of pyrazolo[3,4-b]pyridines, pyrrolo[2,3-b]pyridines, pyrido[2,3-d]pyrimidines and benzofuro[3,2-b]pyridines. The products exhibit strong fluorescence. In addition, they exhibit significant ecto-5'-nucleotidase inhibition properties and cytotoxic behavior.

The multifactorial nature of Parkinson's disease necessitates the development of new chemical entities with inherent ability to address key pathogenic processes. To this end, two series of new symmetrical 1,2- and 1,4-bis(2-aroyl/alkoylimino-5-(2-methoxy-2-oxoethylidene)-4-oxo-thiazolidin-3-yl)benzene derivatives (3a-g and 5a-e) were synthesized in good yields by the cyclization of 1,2- and 1,4-bis(N'-substituted thioureido)benzene intermediates with dimethyl acetylenedicarboxylate (DMAD) in methanol at ambient temperature. The bis-iminothiazolidinone compounds were investigated in vitro for their inhibition of monoamine oxidase (MAO-A & MAO-B) enzymes with the aim to identify new and distinct pharmacophores for the treatment of neurodegenerative disorders like Parkinson's disease. Most of the designed compounds exhibited good inhibitory efficacy against monoamine oxidases. Compound 5a was identified as the most potent inhibitor of MAO-A depicting an IC50 value of 0.001μM, a 4-fold stronger inhibitory strength compared to standard inhibitor (clorgyline: IC50=0.0045μM). Molecular docking studies provided insights into enzyme-inhibitor interactions and a rationale for the observed inhibition towards monoamine oxidases.

A series of fifteen N4-benzyl substituted 5-nitroisatin-3-thiosemicarbazones 5a–o was synthesized and evaluated for urease inhibitory, phytotoxic and cytotoxic influences. All the compounds proved to be highly potent inhibitors of the enzyme, showing inhibitory activity (IC50 = 0.87 ± 0.25–8.09 ± 0.23 μM) much better than the reference inhibitor, thiourea (IC50 = 22.3 ± 1.12 μM) and may thus act as persuasive leads for further studies. In phytotoxicity assay, twelve out of fifteen thiosemicarbazones tested i.e. 5a–e, 5g, 5i and 5k–o appeared to be active, exhibiting weak or non-significant (5–35%) growth inhibition at the highest tested concentrations (1000 or 500 μg/mL). In contrast, only one compound i.e. 5i was active in the brine shrimp (Artemia salina) lethality bioassay, demonstrating cytotoxic activity with LD50 value 2.55 × 10−5 M. Molecular docking studies of compounds 5a–o were also performed to identify their probable binding modes in the active site of the enzyme.

Two new series of pyrazolobenzothiazine-based carbothioamides (3a-o and 4a-o) were synthesized using saccharin as the starting material. The synthesized derivatives were investigated for their ability to inhibit monoamine oxidases (MAO). Compound 3b was found to be a very potent MAO-A inhibitor with an IC50 value of 0.003 ± 0.0007 μM, while compound 4d was the most effective inhibitor of MAO-B having an IC50 value of 0.02 ± 0.001 μM. Molecular docking studies were performed to identify the probable binding modes in the active site of the monoamine oxidase enzymes. The synthetic and computational investigations in the current work suggested that these newly identified inhibitors may serve as a powerful starting point for the exploration and optimization of potential therapeutic agents targeting Parkinson's disease.

Type 2 diabetes mellitus (T2DM) is one of the most widely prevalent metabolic disorders with no cure to date thus remains the most challenging task in the current drug discovery. Therefore, the only strategy to control diabetes prevalence is to develop novel efficacious therapeutics. Dipeptidyl Peptidase 4 (DPP-4) inhibitors are currently used as anti-diabetic drugs for the inhibition of incretins. This study aims to construct the chemical feature based on pharmacophore models for dipeptidyl peptidase IV. The structure-based pharmacophore modeling has been employed to evaluate new inhibitors of DPP-4. A four-featured pharmacophore model was developed from crystal structure of DPP-4 enzyme with 4-(2-aminoethyl) benzenesulfonyl fluoride in its active site via pharmacophore constructing tool of Molecular Operating Environment (MOE) consisting F1 Hyd (hydrophobic region), F2 Hyd|Cat|Don (hydrophobic cationic and donor region), F3 Acc (acceptor region) and F4 Hyd (hydrophobic region). The generated pharmacophore model was used for virtual screening of in-house compound library (the available compounds which were used for initial screening to get the few compounds for the current studies). The resultant selected compounds, after virtual screening were further validated using in vitro assay. Furthermore, structure-activity relationship was carried out for the compounds possessing significant inhibition potential after docking studies. The binding free energy of analogs was evaluated via molecular mechanics generalized Born surface area (MM-GBSA) and Poisson-Boltzmann surface area (MM-PBSA) methods using AMBER 16 as a molecular dynamics (MD) simulation package. Based on potential findings, we report that selected candidates are more likely to be used as DPP-4 inhibitors or as starting leads for the development of novel and potent DPP-4 inhibitors.

In the current work, we report the discovery of new sulfonate and sulfamate derivatives of benzofuran- and benzothiophene as potent inhibitors of human carbonic anhydrases (hCAs) II, IX and XII. A set of derivatives, 1a–t, having different substituents on the fused benzofuran and benzothiophene rings (R = alkyl, cyclohexyl, aryl, NH2, NHMe, or NMe2) was designed and synthesized. Most of the derivatives exhibited higher potency than acetazolamide as inhibitors of the purified hCAII, IX and XII isoforms. The most potent inhibitors for hCAII, hCAIX and hCAXII were 1g, 1b and 1d with an IC50 ± SEM values of 0.14 ± 0.03, 0.13 ± 0.03 and 0.17 ± 0.06 µM, respectively. In addition, compounds 1d and 1n exerted preferential inhibitory effect against hCAXII isozyme with good potencies. Some selected compounds were docked within the active pocket of these isozymes and binding of the molecules revealed that sulfonate and sulfamate rings were located towards the active cavity and compounds coordinated to zinc ions.

A new series of sulfonate derivatives 1a–zk were synthesized and evaluated as inhibitors of nucleotide pyrophosphatases. Most of the compounds exhibited good to moderate inhibition towards NPP1, NPP2, and NPP3 isozymes. Compound 1m was a potent and selective inhibitor of NPP1 with an IC50 value of 0.387 ± 0.007 µM. However, the most potent inhibitor of NPP3 was found as 1x with an IC50 value of 0.214 ± 0.012 µM. In addition, compound 1e was the most active inhibitor of NPP2 with an IC50 value of 0.659 ± 0.007 µM. Docking studies of the most potent compounds were carried out, and the computational results supported the in vitro results.

Design, synthesis and characterization of new trinary Benzocoumarin-Thiazoles-Azomethine derivatives having three bioactive scaffolds in a single structural unit were carried out. The newly synthesized molecules were investigated for the inhibitory activity on human tissue nonspecific alkaline phosphatase (h-TNAP) and human intestinal alkaline phosphatase (h-IAP) isozymes. All the tested compounds exhibited the potent inhibition profile on both isozymes of alkaline phosphatase i.e., h-TNAP and h-IAP. Molecular docking studies were performed to explore the putative binding mode of interactions of selective inhibitors. Moreover, the synthesized derivatives were evaluated against cervical cancer cell line, HeLa and a few compounds exhibited significant inhibition in the range of 21.0–69.7%. The derivatives can be potential and selective alkaline phosphatase inhibitors for future studies.

Owing to the desperate need of new drugs development to treat Alzheimer's ailment the synthesis of 1-aroyl-3-(5-(4-chlorophenyl)-1,2,4-triazole-3-thioneaminylthioureas (2–6) starting from (4-amino-5-(4-chlorophenyl)-4H-1,2,4-triazole-3-thiol) (1) and synthesis of 1-(3-(4-aminophenyl)-5-phenyl-4,5-dihydro-1H-pyrazol-1-yl)-2-(4-isobutylphenyl)propan-1-one (7–9) starting from 2-(4-isobutylphenyl)propanehydrazide (a) with the cyclization with substituted chalcones (c-e) was carried out. To check the biological potential of the synthesized compounds, all were subjected to acetylcholinesterase (AChE) and butrylcholinesterase (BChE) inhibition assays. The most potent and selective inhibitor for the acetylcholinesterase was compound 7 having an inhibitory concentration of 123 ± 51 nM, whereas, compound 6 was found as selective inhibitor of butyrylcholinesterase (BChE) with an IC50 value of 201 ± 80 nM. However, the compounds 1 and 2 were found as dual inhibitors i.e. active against both acetylcholinesterase as well as butyrylcholinesterase.

Alzheimer&rsquo, s disease (AD), a progressive neurodegenerative disorder, characterized by central cognitive dysfunction, memory loss, and intellectual decline poses a major public health problem affecting millions of people around the globe. Despite several clinically approved drugs and development of anti-Alzheimer&rsquo, s heterocyclic structural leads, the treatment of AD requires safer hybrid therapeutics with characteristic structural and biochemical properties. In this endeavor, we herein report a microwave-assisted synthesis of a library of quinoline thiosemicarbazones endowed with a piperidine moiety, achieved via the condensation of 6/8-methyl-2-(piperidin-1-yl)quinoline-3-carbaldehydes and (un)substituted thiosemicarbazides. The target N-heterocyclic products were isolated in excellent yields. The structures of all the synthesized compounds were fully established using readily available spectroscopic techniques (FTIR, 1H- and 13C-NMR). Anti-Alzheimer potential of the synthesized heterocyclic compounds was evaluated using acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes. The in vitro biochemical assay results revealed several compounds as potent inhibitors of both enzymes. Among them, five compounds exhibited IC50 values less than 20 &mu, M. N-(3-chlorophenyl)-2-((8-methyl-2-(piperidin-1-yl)quinolin-3-yl)methylene)hydrazine carbothioamide emerged as the most potent dual inhibitor of AChE and BChE with IC50 values of 9.68 and 11.59 &mu, M, respectively. Various informative structure&ndash, activity relationship (SAR) analyses were also concluded indicating the critical role of substitution pattern on the inhibitory efficacy of the tested derivatives. In vitro results were further validated through molecular docking analysis where interactive behavior of the potent inhibitors within the active pocket of enzymes was established. Quinoline thiosemicarbazones were also tested for their cytotoxicity using MTT assay against HepG2 cells. Among the 26 novel compounds, there were five cytotoxical and 18 showed proliferative properties.

Several isatin-3-thiosemicarbazones (a class of Schiff bases) from our earlier studies have been validated as promising cytotoxic agents and urease inhibitors. Also, a number of isatin-derived imines (Schiff bases) and their Cu(II) complexes have been reported in the literature to exhibit potential cytotoxic activity towards different cells. In view of this, a series of seven new 5-(un)-substituted isatin-derived bis-Schiff bases/ligands 3a–g and their Cu(II) complexes 5a–g were synthesized and evaluated for their cytotoxic and urease inhibitory activities. All the Schiff base ligands 3a–g proved to be active in sulforhodamine B (SRB) bioassay, displaying promising cytotoxic activity against lung carcinoma (H157) cells. Compound 3b was found to be the most potent inhibitor of H157 cells, exhibiting an IC50 value of 2.32 ± 0.11 μM. Similarly, all the metal complexes 5a–g proved to be active in this assay, demonstrating enhanced cytotoxic activity in each case, occurring as a result of coordination of the Schiff base ligands to the metal ion. Compound 5d proved to be the most potent inhibitor of H157 cells, showing cytotoxic activity comparable to that of the standard drug, vincristine (VCN) (IC50 = 1.29 ± 0.06 vs. 1.03 ± 0.04 μM). In the urease inhibition assay, all the synthesized Schiff base ligands except 3f proved to be highly potent enzyme inhibitors, displaying inhibitory activity even better than that of the reference inhibitor, thiourea (IC50 = 0.04 ± 0.004–5.86 ± 0.09 vs. 22.3 ± 1.12 μM), and thus may act as promising lead molecules for further studies. Molecular docking studies were also carried out for bis-Schiff bases 3a–g to elucidate their relationship with the binding pockets of the enzyme.

Fused diaza-heterocycles constitute the core structure of numerous bioactive natural products and effective therapeutic drugs. Among them, phthalazines have been recognized as remarkable structural leads in medicinal chemistry due to their wide application in pharmaceutical and agrochemical industries. Accessing such challenging pharmaceutical agents/drug candidates with high chemical complexity through synthetically efficient approaches remains an attractive goal in the contemporary medicinal chemistry and drug discovery arena. In this review, we focus on the recent developments in the synthetic routes towards the generation of phthalazine-based active pharmaceutical ingredients and their biological potential against various targets. The general reaction scope of these innovative and easily accessible strategies was emphasized focusing on the functional group tolerance, substrate and coupling partner compatibility/limitation, the choice of catalyst, and product diversification. These processes were also accompanied by the mechanistic insights where deemed appropriate to demonstrate meaningful information. Moreover, the rapid examination of the structure-activity relationship analyses around the phthalazine core enabled by the pharmacophore replacement/integration revealed the generation of robust, efficient, and more selective compounds with pronounced biological effects. A large variety of in silico methods and ADME profiling tools were also employed to provide a global appraisal of the pharmacokinetics profile of diaza-heterocycles. Thus, the discovery of new structural leads offers the promise of improving treatments for various tropical diseases such as tuberculosis, leishmaniasis, malaria, Chagas disease, among many others including various cancers, atherosclerosis, HIV, inflammatory, and cardiovascular diseases. We hope this review would serve as an informative collection of structurally diverse molecules enabling the generation of mature, high-quality, and innovative routes to support the drug discovery endeavors.

Ectonucleotidases are a broad family of ectoenzymes that play a crucial role in purinergic cell signaling. Ecto-nucleotide pyrophosphatases/phosphodiesterases (NPPs) belong to this group and are important drug targets. In particular, NPP1 and NPP3 are known to be druggable targets for treatment of impaired calcification disorders (including pathological aortic calcification) and cancer, respectively. In this study, we investigated a series of sulfonate and sulfamate derivatives of benzofuran and benzothiophene as potent and selective inhibitors of NPP1 and NPP3. Compounds 1c, 1g, 1n, and 1s are the most active NPP1 inhibitors (IC50 values in the range 0.12–0.95 µM). Moreover, compounds 1e, 1f, 1j, and 1l are the most potent inhibitors of NPP3 (IC50 ranges from 0.12 to 0.95 µM). Compound 1d, 1f and 1t are highly selective inhibitors of NPP1 over NPP3, whereas compounds 1m and 1s are found to be highly selective towards NPP3 over NPP1. Structure-activity relationship (SAR) study has been discussed in detailed. With the aid of molecular docking studies, a common binding mode of these compounds and suramin (the standard inhibitor) was revealed, where the sulfonate group acts as a cation-binding moiety that comes in close contact with the zinc ion of the active site. Moreover, cytotoxic evaluation against MCF-7 and HT-29 cancer cell lines revealed that compound 1r is the most cytotoxic towards MCF-7 cell line with IC50 value of 0.19 µM. Compound 1r is more potent and selective against cancer cells than normal cells (WI-38) as compared to doxorubicin.

Poncirin, a natural flavanone glycoside present abundantly in many citrus fruits, contains an extensive range of biological activities. However, the antidiabetic mechanism of poncirin is unexplored yet. In this study, we examined the anti-diabetic prospective of poncirin by evaluating its ability to inhibit protein tyrosine phosphatase 1B (PTP1B), α-glucosidase, human recombinant AR (HRAR), rat lens aldose reductase (RLAR), and advanced glycation end-product (AGE) formation (IC50 = 7.76 ± 0.21, 21.31 ± 1.26, 3.56 ± 0.33, 11.91 ± 0.21, and 3.23 ± 0.09 µM, respectively). Kinetics data and docking studies showed the lowest binding energy and highest affinity for the mixed and competitive type of inhibitors of poncirin. Moreover, the molecular mechanisms underlying the antidiabetic outcomes of poncirin in insulin resistant C2C12 skeletal muscle cells were explored, which significantly increased glucose uptake and decreased the expression of PTP1B in C2C12 cells. Consequently, poncirin increased GLUT-4 expression level by activating the IRS-1/PI3K/Akt/GSK-3 signaling pathway. Moreover, poncirin (0.5–50 µM) remarkably inhibited the formation of fluorescent AGE, nonfluorescent CML, fructosamine, and β-cross amyloid structures in glucose-fructose-induced BSA glycation during 4 weeks of study. Poncirin also notably prevented protein oxidation demonstrated with decreasing the protein carbonyl and the consumption of protein thiol in the dose-dependent manner. The results clearly expressed the promising activity of poncirin for the therapy of diabetes and its related complications.

A series of oxadiazole-sulfonamide hybrids was synthesized through multistep reaction and for the formation of targeted thioethers 6(a-l), a much facile route was adopted through which S-alkylation was successfully carried out at room temperature. These novel thioethers 6(a-l) were later screened against aldehyde reductase (ALR1) and aldose reductase (ALR2). Beside the enzyme inhibition studies, the compounds were also tested against cervical cancer cell lines (HeLa). The results suggested the significant inhibition pattern towards ALR2, while few compounds were active against ALR1. The synthesized derivatives have shown weak to moderate cytotoxicity. The most potent inhibitors (6b, 6e, 6f and 6l) were selected for molecular docking studies and the binding interactions were reported.

A series of six compounds (1a-f) possessing pyridine-pyrazole-benzenethiourea or pyridine-pyrazole-benzenesulfonamide scaffold were synthesized. The target compounds were screened to evaluate their inhibitory effect on human nucleotide pyrophosphatase/phosphodiesterase 1 and −3 (ENPP1 and ENPP3) isoenzymes. Compounds 1c-e were the most potent inhibitors of ENPP1 with sub-micromolar IC50 values (0.69, 0.18, and 0.40 µM, respectively. Moreover, compound 1b was the most potent inhibitor of ENPP3 (IC50 = 0.21 µM). They were much more potent than the reference standard inhibitor, suramin (IC50 values against ENPP1 and −3 were 7.77 and 0.89 µM, respectively). Furthermore, all the six compounds were investigated for cytotoxic effect against cancerous cell lines (HeLa, MCF-7, and 1321N1) and normal cell line (BHK-21). Compound 1e was active against all the three cancer cell lines, however, showed preferential cytotoxicity against MCF-7 (IC50 = 16.05 µM), which is comparable to the potency of cisplatin. All the tested compounds exhibited low or negligible cytotoxic effect against the normal cells. They have the merit of superior selectivity towards cancer cells than normal cells compared to cisplatin. The relative selectivity and potency of the inhibitors was justified by molecular docking studies. All the docked structures showed considerable binding interactions with amino acids residues of active sites of ENPP isoenzymes.

With the aim to discover novel, efficient and selective inhibitors of human alkaline phosphatase and nucleotide pyrophosphatase enzymes, two new series of pyrazolyl pyrimidinetriones (PPTs) (6a–g) and thioxopyrimidinediones (PTPs) (6h–n) were synthesized in good chemical yields using Knoevenagel condensation reaction between pyrazole carbaldehydes (4a–g) and pharmacologically active N-alkylated pyrimidinetrione (5a) and thioxopyrimidinedione (5b). The inhibition potential of the synthesized hybrid compounds was evaluated against human alkaline phosphatase (h-TNAP and h-IAP) and ectonucleotidase (h-NPP1 and h-NPP3) enzymes. Most of the tested analogs were highly potent with a variable degree of inhibition depending on the functionalized hybrid structure. The detailed structure-activity relationship (SAR) of PPT and PTP derivatives suggested that the compound with unsubstituted phenyl ring from PPT series led to selective and potent inhibition (6a; IC50 = 0.33 ± 0.02 µM) of h-TNAP, whereas compound 6c selectively inhibited h-IAP isozyme with IC50 value of 0.86 ± 0.04 µM. Similarly, compounds 6b and 6h were identified as the lead scaffolds against h-NPP1 and h-NPP3, respectively. The probable binding modes for the most potent inhibitors were elucidated through molecular docking analysis. Structure-activity relationships, mechanism of action, cytotoxic effects and druglikeness properties are also discussed.