Efficient Synthesis and Docking Studies of Novel Benzothiazole-Based Pyrimidinesulfonamide Scaffolds as New Antiviral Agents and Hsp90α Inhibitors

In vitro inhibition of α-Synuclein aggregation and disaggregation of preformed fibers by polyphenol hybrids with 2-conjugated benzothiazole

The misfolding and aggregation of α-Syn play a pivotal role in connecting diverse pathological pathways in Parkinson's disease (PD). Preserving α-Syn proteostasis and functionality by inhibiting its aggregation or disaggregating existing aggregates using suitable inhibitors represents a promising strategy for PD prevention and treatment. In this study, a series of benzothiazole-polyphenol hybrids was designed and synthesized. Three identified compounds exhibited notable inhibitory activities against α-Syn aggregation in vitro, with IC50 values in the low micromolar range. These inhibitors demonstrated sustained inhibitory effects throughout the entire aggregation process, stabilizing α-Syn proteostasis conformation. Moreover, the compounds effectively disintegrated preformed α-Syn oligomers and fibers, potentially by binding to specific domains within the fibers, inducing fibril instability, collapse, and ultimately resulting in smaller-sized aggregates and monomers. These findings offer valuable insights into the therapeutic potential of polyphenol hybrids with 2-conjugated benzothiazole targeting α-Syn aggregation in the treatment of PD.

In the pursuit of novel therapeutic agents: synthesis, anticancer evaluation, and physicochemical insights of novel pyrimidine-based 2-aminobenzothiazole derivatives

Cancer remains a worldwide healthcare undertaking, demanding continual innovation in anticancer drug development due to frequent drug resistance and adverse effects associated with existing therapies. The benzothiazole compounds, particularly 2-aminobenzothiazole derivatives, have attracted interest for their versatility in generating novel anticancer agents. This study explores the synthesis, and anticancer evaluation of new pyrimidine-based 2-aminobenzothiazole derivatives. A range of synthetic methods have been developed based on the reaction of 2-benzothaizolyl guanidine with various reagents such as α,β-unsaturated carbonyl, 2-cyano-three-(dimethylamino)-N-acrylamide, β-diketones, β-keto esters, and S,S ketene dithioacetals. Human tumour cell lines such as HepG2, HCT116, and MCF7 were used in in vitro cytotoxicity studies, and the results showed that several of the synthesized compounds were more potent than the standard drug, 5-fluorouracil, in terms of cell viability% with low IC50. Furthermore, the computed drug likeness and ADMET properties of the most potent synthesized compounds suggest their potential as promising candidates for further development, with favorable bioavailability and pharmacokinetic profiles.

Current Development of Thiazole-Containing Compounds as Potential Antibacterials against Methicillin-Resistant Staphylococcus aureus

The emergence of multi-drug-resistant bacteria is threatening to human health and life around the world. In particular, methicillin-resistant Staphylococcus aureus (MRSA) causes fatal injuries to human beings and serious economic losses to animal husbandry due to its easy transmission and difficult treatment. Currently, the development of novel, highly effective, and low-toxicity antimicrobials is important to combat MRSA infections. Thiazole-containing compounds with good biological activity are widely used in clinical practice, and appropriate structural modifications make it possible to develop new antimicrobials. Here, we review thiazole-containing compounds and their antibacterial effects against MRSA reported in the past two decades and discuss their structure-activity relationships as well as the corresponding antimicrobial mechanisms. Some thiazole-containing compounds exhibit potent antibacterial efficacy in vitro and in vivo after appropriate structural modifications and could be used as antibacterial candidates. This Review provides insights into the development of thiazole-containing compounds as antimicrobials to combat MRSA infections.

Synthesis and Biological Evaluation of Benzothiazolyl-pyridine Hybrids as New Antiviral Agents against H5N1 Bird Flu and SARS-COV-2 Viruses

A novel series of benzothiazolyl-pyridine hybrids 8a-h and 14a-e were produced from the reaction of enamine derivative 4 with each of the arylcyanoacetamides 5a-h and cyanoacetohydrazides 9a-e. The new products were characterized by spectral techniques (IR, 1H NMR, 13C NMR, and MS). Biological evaluation of 8a-h and 14a-e in vitro against H5N1 and SARS-COV-2 viruses showed that several compounds had significant activity. Compounds 8f-h, which contain fluorine atoms, have better activity against H5N1 and anti-SARS-CoV-2 viruses than the other compounds included in this study. Compound 8h has a trifluoromethyl group at position-3 of the phenyl ring and exhibits a high activity against H5N1 virus with 93 and 60% inhibition at concentrations of 0.5 and 0.25 μmol/μL, respectively, among the tested compounds, and it also showed anti-SARS-CoV-2 virus with a half-maximum inhibition rate of 3.669 μM, among the remaining compounds. The mechanism of action of 8f-h, which is expected to be repurposed against COVID-19, was investigated. The results showed that the compounds have virucidal effects at different stages of the three mechanisms of action. Furthermore, compounds 8f-h were found to possess CoV-3CL protease inhibitory activities with IC50 values of 544.6, 868.2, and 240.6 μg/mL, respectively, compared to IC50 = 129.8 μg/mL of the standard drug lopinavir. Interestingly, compounds 8f-h also showed high inhibitory activity against the H5N1 virus as well as the SARS-CoV-2 virus. Moreover, compounds 8f-h fit admirably into the active site of the SARS-CoV-2 main protease (PDB ID: 6LU7) using the molecular docking Moe software 2015.10.

Synthesis of Fe3O4@SiO2@Pr-NH2@DAP as a magnetic recyclable nano-catalyst for efficient synthesis of pyranothiazolopyrimidines and 4H-pyrans under solvent-free condition

In this research, we describe the synthesis of silica-coated nano-Fe3O4 particles, which were successfully modified by diaminopyrimidine, and their physicochemical properties were characterized using FT-IR, XRD, TEM, FE-SEM, EDX, EDX-mapping, and TGA. The catalytic activity of this novel nano-catalyst was evaluated by three-component reactions for the preparation of pyranothiazolopyrimidines and 4H-pyrans under solvent-free conditions. Recyclability of the catalyst up to six consecutive rounds, atom economy, high yield and purity of desired products, and easy work-up method are some of the exciting features of this system that make it more favorable from a green chemistry point of view.

Crystal structure of 2-{[5-(methyl-sulfan-yl)-4-phenyl-4H-1,2,4-triazol-3-yl]meth-yl}benzo[d]thia-zole

In the structure of the title compound, C17H14N4O2, the triazole ring exhibits inter-planar angles of 63.86 (2) and 76.96 (2)° with the phenyl and benzo-thia-zole planes, respectively. The C-C-C angle at the methyl-ene group is rather wide at 114.28 (4)°. The packing involves three borderline C-H⋯N contacts, two of which combine to form layers parallel to ac, and a pairing of the triazole rings across an inversion centre [inter-planar distance of 3.1852 (2) Å].

Novel Fluorescent Benzothiazolyl-Coumarin Hybrids as Anti-SARS-COVID-2 Agents Supported by Molecular Docking Studies: Design, Synthesis, X-ray Crystal Structures, DFT, and TD-DFT/PCM Calculations

This study revealed the design and preparation of new 3-(benzo[d]thiazol-2-yl)-2H-chromen-2-one derivatives 9a-h. The structures of the synthesized products were elucidated by their spectroscopic data and X-ray crystallography for compounds 9a and 9d. The prepared new compounds were measured for their fluorescence, and a good result indicated that the emission efficiency was decreased by increasing the electron-withdrawing groups from the unsubstituted compound 9a to the highly substituted derivative 9h (2 Br heavy atoms). On the other hand, the B3LYP/6-311G** theoretical level of theory was used to optimize the quantum mechanical calculations of the geometrical characteristics and energy of the novel compounds 9a-h under study. The electronic transition was investigated using the TD-DFT/PCM B3LYP approach, which uses time-dependent density functional calculations. Moreover, the compounds exhibited nonlinear optical properties (NLO) and a small HOMO-LUMO energy gap, which makes them easy to polarize. Furthermore, the acquired infrared spectra were compared with the expected harmonic vibrations of the substances 9a-h. On the other hand, binding energy analyses of compounds 9a-h with human corona virus nucleocapsid protein Nl63 (PDB ID: 5epw) were predicted using molecular docking and virtual screening tools. The results showed a promising binding and how these potent compounds were inhibiting the COVID-19 virus. Compound 9h was the most active anti-COVID-19 agent among all the synthesized benzothiazolyl-coumarin derivatives, as it forms five bonds. The presence of the two bromine atoms in its structure was responsible for the potent activity.

Antiviral activity of some benzo[g]quinazolines against coxsackievirus B4: biological screening and docking study

BACKGROUND

Serotype coxsackievirus B (CVB) infection has been linked to viral myocarditis, dilated cardiomyopathy, meningitis, and pancreatitis in children and young adults. As of yet, no antiviral drug has been authorized for the treatment of coxsackievirus infection. Therefore, there is perpetual demand for new therapeutic agents and the improvement of existing ones. Benzo[g]quinazolines, the subject of several well-known heterocyclic systems, have risen to prominence and played a significant role in the development of antiviral agents, particularly those for anti-coxsackievirus B4 infection.

METHODS

This study investigated the cytotoxicity of the target benzo[g]quinazolines (1-16) in the BGM cells line as well as their anti-coxsackievirus B4 activity. Determination of CVB4 titers using a plaque assay.

RESULTS

Most of the target benzoquinazolines exhibited antiviral activity, however, compounds 1-3 appeared to be the most effective (reduction percentages of 66.7, 70, and 83.3%, respectively). The binding mechanisms and interactions of the three most active 1-3 with the constitutive amino acids in the active site of the multi-target of coxsackievirus B4 (3Clpro and RdRp) targets were also investigated using molecular docking.

CONCLUSION

The anti coxsackievirus B4 activity has resulted, and the top three active benzoquinazolines (1-3) have bonded to and interacted with the constitutive amino acids in the active region of the multi-target coxsackievirus B4 (RdRp and 3Clpro). Further research is required in the lab. to determine the exact benzoquinazolines mechanism of action.

Crystal structure of 3-(benzo[d]thia-zol-2-yl)-6-methyl-2H-chromen-2-one

The mol-ecule of the title compound, C₁₇H₁₁NO₂S, is almost planar, with an inter-planar angle of 3.01 (3)° between the benzo-thia-zole and chromene ring systems. A short intra-molecular S⋯O=C contact of 2.727 (2) Å is observed. The crystal packing involves a layer structure parallel to (211), containing dimeric inversion-symmetric units connected by a 'weak' C-H⋯O=C hydrogen bond.

Crystal structure of N-[3-(benzo[d]thia-zol-2-yl)-6-bromo-2H-chromen-2-yl-idene]-4-methyl-benzenamine

The title compound, C₂₃H₁₅BrN₂OS, was the unexpected product in an attempted synthesis of the isomeric 3-(benzo[d]thia-zol-2-yl)-6-bromo-1-p-tolyl-quinolin-2(1H)-one. The C_chromene=N-C angle is wide [125.28 (8)°]. The benzo-thia-zole and chromene ring systems are almost coplanar, with their planes parallel to (10); the toluene ring system is rotated by ca 40° out of the chromene plane. The mol-ecular packing involves layers with π-stacking, borderline 'weak' hydrogen bonds and possible C-H⋯π contacts.

Sulfonamides with Heterocyclic Periphery as Antiviral Agents

Sulfonamides are the basic motifs for a whole generation of drugs from a large group of antibiotics. Currently, research in the field of the new sulfonamide synthesis has received a "second wind", due to the increase in the synthetic capabilities of organic chemistry and the study of their medical and biological properties of a wide spectrum of biological activity. New reagents and new reactions make it possible to significantly increase the number of compounds with a sulfonamide fragment in combination with other important pharmacophore groups, such as, for example, a wide class of N-containing heterocycles. The result of these synthetic possibilities is the extension of the activity spectrum-along with antibacterial activity, many of them exhibit other types of biological activity. Antiviral activity is also observed in a wide range of sulfonamide derivatives. This review provides examples of the synthesis of sulfonamide compounds with antiviral properties that can be used to develop drugs against coxsackievirus B, enteroviruses, encephalomyocarditis viruses, adenoviruses, human parainfluenza viruses, Ebola virus, Marburg virus, SARS-CoV-2, HIV and others. Since over the past three years, viral infections have become a special problem for public health throughout the world, the development of new broad-spectrum antiviral drugs is an extremely important task for synthetic organic and medicinal chemistry. Sulfonamides can be both sources of nitrogen for building a nitrogen-containing heterocyclic core and the side chain substituents of a biologically active substance. The formation of the sulfonamide group is often achieved by the reaction of the N-nucleophilic center in the substrate molecule with the corresponding sulfonylchloride. Another approach involves the use of sulfonamides as the reagents for building a nitrogen-containing framework.

Synthesis, Physicochemical Properties and Molecular Docking of New Benzothiazole Derivatives as Antimicrobial Agents Targeting DHPS Enzyme

The drug-resistance problem is widely spread and becoming more common in community-acquired and nosocomial strains of bacteria. Therefore, finding new antimicrobial agents remains an important drug target. From this perspective, new derivatives of benzothiazole were synthesized and evaluated for their antimicrobial activity and ability to inhibit the DHPS enzyme. The synthesis was carried out by the reaction of benzothiazole N-arylsulphonylhydrazone with N-aryl-2-cyano-3-(dimethylamino)acrylamide, N-aryl-3-(dimethylamino)prop-2-en-1-one, arylaldehydes or diazonium salt of arylamine derivatives, which led to the formation of N-arylsulfonylpyridones 6a-d (yield 60-70%) and 12a-c (yield 50-60%),N-(2-(benzo[d]thiazole-2-yl)-3-arylacryloyl-4-methylsulfonohydrazide 14a-c (yield 60-65%), 4-(benzo[d]thiazole-2-yl)-5-aryl-1H-pyrazol-3(2H)-one 16a-c (yield 65-75%), and N'-(2-(benzo[d]thiazol-2-yl)-2-(2-arylhydrazono)acetyl)-4-arylsulfonohydrazide 19a-e (yield 85-70%). The antimicrobial evaluations resulted into a variety of microbial activities against the tested strains. Most compounds showed antimicrobial activity against S. aureus with an MIC range of 0.025 to 2.609 mM. The most active compound, 16c, exhibited superior activity against the S. aureus strain with an of MIC 0.025 mM among all tested compounds, outperforming both standard drugs ampicillin and sulfadiazine. The physicochemical-pharmacokinetic properties of the synthesized compounds were studied, and it was discovered that some compounds do not violate rule of five and have good bioavailability and drug-likeness scores. The five antimicrobial potent compounds with good physicochemical-pharmacokinetic properties were then examined for their inhibition of DHPS enzyme. According to the finding, three compounds, 16a-c, had IC₅₀ values comparable to the standard drug and revealed that compound 16b was the most active compound with an IC₅₀ value of 7.85 μg/mL, which is comparable to that of sulfadiazine (standard drug) with an IC₅₀ value of 7.13 μg/mL. A docking study was performed to better understand the interaction of potent compounds with the binding sites of the DHPS enzyme, which revealed that compounds 16a-c are linked by two arene-H interactions with Lys220 within the PABA pocket.

Pyrimidine: An elite heterocyclic leitmotif in drug discovery-synthesis and biological activity

Heterocyclic compounds bearing the pyrimidine core are of tremendous interest as they constitute an important class of natural and synthetic compounds exhibiting diverse useful biological activities that hold attractive potential for clinical translation as therapeutic agents in alleviation of a myriad of diseases. Heterocycles possessing a pyrimidine scaffold have piqued tremendous interest of organic and medicinal chemists owing to their privileged bioactivities. Drugs having the pyrimidine motif have manifested to exhibit gratifying biological activity like anticancer, antiviral, anti-inflammatory, antibacterial, and antihypertensive activities. This heterocycle, being a significant endogenous component of the body, the pyrimidine derivatives can easily interact with enzymes, genetic materials, and bio components within the cell. The landscape of FDA approved drugs, presently marketed incorporating the pyrimidine scaffold continues to evolve in number and diversity. There is a tremendous surge in discovery of new targets across many diseases especially those involving emerging resistance to clinically used battery of drugs. Pyrimidine scaffolds will continue to be explored expanding their chemical space portfolio in an effort to find novel drugs impacting these targets. This review aims to provide an elaborate recapitulation of the recent trends adopted to synthesize propitious pyrimidine incorporated hits and also focuses on the clinical significance reported for functionalized pyrimidine analogues that would quintessentially aid medicinal chemists for new research explorations in this arena.

Novel Thiophene Thioglycosides Substituted with the Benzothiazole Moiety: Synthesis, Characterization, Antiviral and Anticancer Evaluations, and NS3/4A and USP7 Enzyme Inhibitions

Novel derivatives of benzothiazole-2-thiophene S-glycoside were synthesized and tested for their antiviral and anticancer potency and NS3/4A and USP7 enzyme inhibitions. The ring system was formed by first synthesizing new derivatives of 5-mercaptothiophene substituted with the benzothiazole moiety, followed by coupling with various halo sugar derivatives. New compounds were tested in vitro for the cytotoxic effect on five types of normal cell lines and for antiviral activity using a plaque reduction assay against CBV4, HSV-1, HCVcc genotype 4 viruses, HAV HM 175, and HAdV7. Notably, three compounds demonstrated substantial IC₅₀, CC₅₀, and SI values against HSV-1 with a viral reduction of 80% or more. Two substances have demonstrated a reduction of more than 50% in CBV4 and HCVcc viruses. The effectiveness of the compounds against HSV-1 and HCVcc was tested for their capability to inhibit NS3/4A protease and USP7 enzyme. Additionally, a panel of 60 human cancer cells was used to investigate the ability of the newly synthesized compounds to inhibit the in vitro tumor growth. The results revealed that two compounds, 6a and 6c, have an inhibitory effect on most cancer types, whereas 6d and 6f inhibited only three and two cell lines, respectively.

Purine analogs: synthesis, evaluation and molecular dynamics of pyrazolopyrimidines based benzothiazole as anticancer and antimicrobial CDK inhibitors

Cyclin dependent kinases (CDKs) enzymes regulate cell proliferation and transcriptional processes and can be considered as important targets for the development of anticancer and antimicrobial drugs. In this work, novel benzothiazolyl pyrazolopyrimidine carboxamide and benzothiazolyl pyrazolopyrimidine carbonitrile derivatives were synthesized and characterized. The synthetic process was carried out via the reaction of ylidine benzothiazole derivatives with pyrazolocarboxamide and pyrazolocarbonitrile through a Michael addition pathway. Docking studies were done against CDK2 and CDK9 enzymes and revealed that compound 8a showed high free energy of binding against CDK2 (-8.10 kcal/mol) while compound 15a showed the highest free energy of binding against CDK2 (-8.16 kcal/mol) and CDK9 (-7.87 kcal/mol). Molecular dynamics simulations were conducted to compare the stability of binding of the most active compound 15a and the potent reference drugs roscovitine and dinaciclib. A CDK enzyme assay was done against CDK2 and CDK9 for the previously mentioned top-ranked compounds, 8a and 15a. It was found that compound 15a was the most potent inhibitor for both enzymes with IC₅₀ of 127 ± 1.01 nM and 65 ± 0.50 nM. The anticancer activity of the synthesized compounds was also determined by NCI against 60 cell lines. Compound 8a showed the highest cytotoxic activity against a large number of the tested cell lines. The antimicrobial activity of the synthesized compounds was determined against various gram positive and gram-negative bacteria as well as fungi. The results showed that compound 15a had the strongest antibacterial activity.

Highly diastereoselective synthesis of benzothiazolo[3,2-a]pyridines via [4 + 2] annulation reaction of 2-vinylbenzothiazoles and azlactones

An efficient AgOTf-catalyzed [4 + 2] annulation reaction of 2-vinylbenzothiazoles and azlactones was successfully performed under mild reaction conditions. With this approach, a series of novel benzothiazolo[3,2-a]pyridine derivatives was readily obtained in good to excellent yields (68-96%), with high diastereoselectivities and tolerating quite a broad scope of substituents. By using chiral phosphoric acid catalyst, the desired products were obtained in high enantioselectivities, up to -94%. This methodology provides a rapid and useful method for constructing fused benzothiazole derivatives.

4-Amino-5-(4-bromobenzoyl)-3-(benzo[d]thiazol-2-yl)-2-[(2′,3′,4′,6′-tetra-O-acetyl-β-D-galactopyranosyl)sulfanyl]thiophene

In the title compound, C32H29BrN2O10S3, the benzothiazole and thiophene ring systems subtend an interplanar angle of 7.43 (12)°. The NH2 group forms intramolecular hydrogen bonds to Nthiazole and Ocarbonyl. The Sgalactose—Cthiophene bond is short [1.759 (2) Å]. The molecules are connected to form ribbons parallel to the b axis by two `weak' hydrogen bonds and a short Namino...Sgalactose contact.

Purine analogues as potential CDK9 inhibitors: New pyrazolopyrimidines as anti-avian influenza virus

Cyclin dependent kinases (CDKs) are a group of enzymes involved in different phases of the cell cycle. In addition, it has been reported that CDK9 could be used as a crucial target for the development of antiviral drugs such as purine analogues; roscovitine and dinaciclib. A new series of benzothiazolyl pyrazolopyrimidine carboxamide derivatives were synthesized and evaluated for their antiviral activity against avian influenza "bird flu" (H5N1). The novel compounds were synthesized via the reaction of pyrazolo carboxamide derivatives with different derivatives of ylidine benzothiazole. The reaction proceeded via a Michael addition pathway. Antiviral activity was determined using a plaque reduction assay against the H5N1 virus. Five compounds showed the highest inhibitory activity in the range of 61.6 to 71.6% at 0.1 μmol/mL. Based on a molecular docking study, an enzyme assay was carried out against CDK9 for the previously mentioned top-ranked compounds. It was found that compound 11f was the most potent inhibitor of CDK9 with an IC₅₀ of 0.062 μmol/mL. A QSAR model was built to determine the hidden feature responsible for the biological activity of the novel compounds. It was found that two sets of descriptors, 3 D Potential energy descriptors and 2 D Atom Counts and Bond Counts descriptors, were correlated to a linear model with RMSE and r2 coefficient values of 0.75 and 0.80, respectively. A molecular dynamic simulations study of 11f over 10 ns against dinaciclib showed that both 11f and dinaciclib achieved equilibrium at 2 Å.Supplemental data for this article is available online at https://doi.org/10.1080/15257770.2022.2059674 .

Crystal structure of 2-(2,5-dimethoxyphenyl)benzo[d]thiazole

The title compound was synthesized efficiently in the solid state by exploiting pepsin catalysis. The ring systems are nearly coplanar. A short intra­molecular S⋯O=C contact is observed.

The title compound, C₁₅H₁₃NO₂S, was synthesized efficiently in the solid state by exploiting pepsin catalysis. The ring systems are nearly coplanar [inter­planar angle of 5.38 (2)°] with an associated intra­molecular S⋯O=C short contact of 2.7082 (4) Å. The packing involves C—H⋯O, C—H⋯π and π–π contacts.

3-(Benzo[d]thiazol-2-yl)-2H-chromen-2-one

The inter­planar angle is 6.47 (6)°, with an associated intra­molecular S⋯O= C contact. The packing involves various secondary inter­actions.

In the title compound, C₁₆H₉NO₂S, the inter­planar angle is 6.47 (6)°. An intra­molecular S⋯O=C contact of 2.727 (2) Å is observed. The packing is determined by several types of weak inter­action (‘weak’ hydrogen bonds, S⋯S contacts and π–π stacking).

Crystal structure of 2-(benzo[d]thiazol-2-yl)-3,3-bis(ethylsulfanyl)acrylonitrile

In the title compound, C14H14N2S3, the double-bond system of the acrylonitrile moiety is significantly non-planar, with absolute cis torsion angles of 13.9 (2) and 15.1 (2)°. The ring system and the double bond system subtend an interplanar angle of 11.16 (4)°. The wide angle C—C(CN)=C of 129.40 (12)° may be associated with a balance between planarity and avoidance of a very short S...S contact.

Developing a scaffold for urease inhibition based on benzothiazoles: Synthesis, docking analysis, and therapeutic potential

The synthesis, in silico molecular docking, and in vitro urease inhibition studies of a novel series of benzothiazole derivatives are reported. The title compounds in the two series, namely, 2-({5-[(benzothiazol-2-ylthio)methyl]-1,3,4-oxadiazol-2-yl}thio)-1-(4-substituted-phenyl)ethan-1-one and 2-(benzothiazol-2-ylthio)-1-(4-substituted-phenyl)ethan-1-one oxime, were synthesized by the reaction of benzo[d]thiazole-2-thiol with different kinds of intermediates in several steps using both conventional and microwave techniques. All compounds were found to have an excellent degree of urease-inhibitory potential ranging between 16.16 ± 0.54 and 105.32 ± 2.10 µM when compared with the standard inhibitor acetohydroxamic acid with IC₅₀  = 320.70 ± 4.24 µM. The structure-activity relationship was established in detail. The binding interactions of the compounds with the enzyme were confirmed through molecular docking. Further, 100 -ns molecular dynamics simulations were performed to investigate the stability and structural perturbations experienced by the most potent compound over the urease active site.

Crystal structure of N'-[2-(benzo[d]thia-zol-2-yl)acet-yl]benzohydrazide, an achiral compound crystallizing in space group P1 with Z = 1

In the mol-ecule of the title compound, C16H13N3O2S, one hydrazinic nitro-gen atom is essentially planar, but the other is slightly pyramidalized. The torsion angle about the hydrazinic bond is 66.44 (15)°. Both hydrazinic hydrogen atoms lie anti-periplanar to the oxygen of the adjacent carbonyl group. The mol-ecular packing is a layer structure determined by two classical hydrogen bonds, N-H⋯O=C and N-H⋯Nthia-zole. The space group is P1 with Z = 1, which is unusual for an achiral organic compound.

Synthesis and Evaluation of Some Uracil Nucleosides as Promising Anti-Herpes Simplex Virus 1 Agents

Since herpes simplex virus type 1 (HSV-1) infection is so widespread, several antiviral drugs have been developed to treat it, among which are uracil nucleosides. However, there are major problems with the current medications such as severe side-effects and drug resistance. Here we present some newly synthesized cyclic and acyclic uracil nucleosides that showed very promising activity against HSV-1 compared to acyclovir.

Discovery of potent Covid-19 main protease inhibitors using integrated drug-repurposing strategy

The emergence and rapid spreading of novel SARS-CoV-2 across the globe represent an imminent threat to public health. Novel antiviral therapies are urgently needed to overcome this pandemic. Given the significant role of the main protease of Covid-19 for virus replication, we performed a drug-repurposing study using the recently deposited main protease structure, 6LU7. For instance, pharmacophore- and e-pharmacophore-based hypotheses such as AARRH and AARR, respectively, were developed using available small molecule inhibitors and utilized in the screening of the DrugBank repository. Further, a hierarchical docking protocol was implemented with the support of the Glide algorithm. The resultant compounds were then examined for their binding free energy against the main protease of Covid-19 by means of the Prime-MM/GBSA algorithm. Most importantly, the machine learning-based AutoQSAR algorithm was used to predict the antiviral activities of resultant compounds. The hit molecules were also examined for their drug-likeness and toxicity parameters through the QikProp algorithm. Finally, the hit compounds activity against the main protease was validated using molecular dynamics simulation studies. Overall, the present analysis yielded two potential inhibitors (DB02986 and DB08573) that are predicted to bind with the main protease of Covid-19 better than currently used drug molecules such as N3 (cocrystallized native ligand), lopinavir, and ritonavir.

2-Aryl-3-(6-trifluoromethoxy)benzo[d]thiazole-based thiazolidinone hybrids as potential anti-infective agents: Synthesis, biological evaluation and molecular docking studies

The search for new antimicrobial agents is greater than ever due to the perpetual threat of multidrug resistance in known pathogens and the relentless emergence of new infections. In this manuscript, ten thiazole-based thiazolidinone hybrids bearing a 6-trifluoromethoxy substituent on the benzothiazole core were synthesized and evaluated against a panel of four bacterial strains Salmonella typhimurium, Staphylococcus aureus, Escherichia coli and Listeria monocytogenes and three resistant strains Pseudomonas aeruginosa, E. coli and MRSA. The evaluation of minimum bactericidal and minimum inhibitory concentrations was accomplished by microdilution assay. As reference compounds ampicillin and streptomycin were employed. All compounds displayed antibacterial efficiencies with MBCs/MICs at 0.25-1 mg/mL and 0.12-1 mg/mL respectively while ampicillin displayed MBCs/MICs at 0.15-0.3 mg/mL and at 0.1-0.2 mg/mL respectively. MICs/MBC of streptomycin varied from 0.05 to 0.15 mg/mL and from 0.1 to 0.3 mg/mL respectively. The best overall effect was observed for compound h4, while compound h1 exhibited the highest effective action against E. coli (MIC/MBC 0.12/0.25 mg/ml) among all tested compounds.

Novel Synthesis and Antiviral Evaluation of New Benzothiazole-Bearing N-Sulfonamide 2-Pyridone Derivatives as USP7 Enzyme Inhibitors

In this article, a series of benzothiazole-bearing N-sulfonamide 2-pyridone derivatives were synthesized via the reaction of benzothiazole sulfonylhydrazide with sodium salts of both (hydroxymethylene) cycloalkanones and unsaturated ketones, as well as ethoxymethylene derivatives. The structures of the resultant compounds were confirmed using IR, ¹H NMR, ¹³C NMR, ¹H-¹H correlation spectroscopy (COSY), ¹H-¹³C heteronuclear multiple bond coherence (HMBC), and ¹H-¹³C heteronuclear multiple quantum coherence (HSQC) spectral analysis and elemental analysis. The newly synthesized compounds were evaluated in vitro for their antiviral activities against the HSV-1, HAV HM175, HCVcc genotype 4, CBV4, and HAdV7 viruses. Additionally, the compounds were examined for their cytotoxic effect on five normal cell lines. It was observed that five compounds were found to possess viral reduction of 50% or more against CBV4 with significant IC₅₀, CC₅₀, and SI values. In the case of HSV-1 and HAV HM175 viruses, three compounds have shown more than 50% reduction, while in the case of HCVcc genotype 4 and HAdV7 viruses, only two compounds demonstrated more than 50% reduction. Furthermore, the physicochemical properties of the most active compounds were evaluated. The two most potent compounds against HSV-1 virus, 7e and 13a, were evaluated for their inhibitory activity against USP7. Docking studies using Molecular Operating Environment (MOE) were used to identify the interactions between 7e and 13a compounds and the active site of the USP7 enzyme.

Design and Synthesis of a New Class of Pyridine-Based N-Sulfonamides Exhibiting Antiviral, Antimicrobial, and Enzyme Inhibition Characteristics

A new strategy for designing and assembling a novel class of functionalized pyridine-based benzothiazole and benzimidazole incorporating sulfonamide moieties was developed. The synthesis was carried out by reacting N-cyanoacetoarylsulfonylhydrazide with various electrophiles such as 2-(benzo[d]thiazol-2-yl)-3,3-bis(alkylthio)acrylonitriles and 2-(benzo[d]imidazol-2-yl)-3,3-bis(methylthio)-acrylonitriles, as well as 2-ethoxyl acrylonitrile derivatives. The synthesized compounds were tested for their antiviral and antimicrobial potency. Two of the synthesized compounds, 15c and 15d, showed more than 50% viral reduction against HSV-1 and CBV4, with significant IC₅₀ and CC₅₀ values. The two potent compounds 15c and 15d have also shown inhibitory activity against Hsp90α protein with IC₅₀ values of 10.24 and 4.48 μg/mL, respectively. A combination of 15c and 15d with acyclovir has led to IC₅₀ values that are lower than that of acyclovir alone. Molecular modeling studies were used to identify the interactions between the 15c and 15d compounds and the active site of Hsp90α enzyme. The antimicrobial investigation of the new compounds has also shown that 8b and 15d exhibited a higher inhibition zone (IZ) than sulfadiazine and gentamicin against Klebsiella pneumonia, whereas 9a showed higher IZ than ampicillin against Staphylococcus aureus. According to the enzyme assay study on dihydrofolate reductase, 9a was shown to be the most potent compound among all examined compounds.

Design and synthesis of a new class of indeno[1,2-b]pyridine thioglycosides

This research reports a novel method for synthesizing a new class of indeno[1,2-b]pyridine thioglycosides. This series of indenopyridine thioglycosides was designed by the reaction of (E)-2-cyano-3-(furan/or thiophene-2-yl)prop-2-enethioamide 1a or 1b with 1-indanone 2 to give the corresponding 2-thiooxo-1H-indeno[1,2-b]pyridine-3-carbonitriles 3a,b. The latter compounds were treated with peracetylated sugar bromides 5 in KOH-acetone to give the corresponding indenopyridine thioglycosides 6a-h. Ammonolysis of the protected indenopyridine thioglycosides 6a-h gave the corresponding free indenopyridine thioglycosides 7a-h. The compounds have been characterized by ¹³C NMR, ¹H NMR and IR spectra.

Design, Synthesis, and Antimicrobial Evaluation of a New Series of N-Sulfonamide 2-Pyridones as Dual Inhibitors of DHPS and DHFR Enzymes

Sulfonamides and trimethoprim (TMP) drugs are normally used to inhibit the action of dihydropteroate synthase (DHPS) and dihydrofolate reductase (DHFR) enzymes, respectively. In this work, a new series of N-sulfonamide 2-pyridone derivatives that combine the inhibitory activities of DHPS and DHFR into one molecule were synthesized and evaluated for its in vitro antimicrobial activity and the ability to inhibit the action of both enzymes simultaneously. The synthesis was carried out via the reaction of novel benzothiazol sulfonylhydrazide with ketene dithioacetal derivatives, and the structures of the resultant compounds were confirmed using spectral and elemental techniques. Among the synthesized compounds, five compounds 3b, 5a, 5b, 11a, and 11b were found to possess significant antimicrobial activities against tested bacterial and fungi strains. The compounds were also examined for their cytotoxicity on HFB4 human dermal fibroblast cell line using MTT assay. The in vitro enzyme assay study of these compounds against DHPS and DHFR enzymes showed that compound 11a was the most potent inhibitor against both enzymes with IC₅₀ values of 2.76 and 0.20 μg/mL, respectively. Docking studies showed that this compound has occupied both the p-aminobenzoic acid and pterin binding pockets of DHPS as well as the pterin binding pocket of DHFR. The results of these investigations confirmed that compound 11a is the most potent dual DHPS/DHFR inhibitor.