Thiazole Containing Heterocycles with Antimalarial Activity

Expanding the Chemical Diversity of Grisechelins via Heterologous Expression

Thiazole scaffold-based small molecules exhibit a range of biological activities and play important roles in drug discovery. Based on bioinformatics analysis, a putative biosynthetic gene cluster (BGC) for thiazole-containing compounds was identified from Streptomyces sp. SCSIO 40020. Heterologous expression of this BGC led to the production of eight new thiazole-containing compounds, grisechelins E, F, and I-N (1, 2, 5-10), and two quinoline derivatives, grisechelins G and H (3 and 4). The structures of 1-10, including their absolute configurations, were elucidated by HRESIMS, NMR spectroscopic data, ECD calculations, and single-crystal X-ray diffraction analysis. Grisechelin F (2) is a unique derivative, distinguished by the presence of a salicylic acid moiety. The biosynthetic pathway for 2 was proposed based on bioinformatics analysis and in vivo gene knockout experiments. Grisechelin E (1) displayed moderate antimycobacterial activity against Mycobacterium tuberculosis H37Ra (MIC of 8 μg mL-1).

Latest developments in coumarin-based anticancer agents: mechanism of action and structure-activity relationship studies

Many researchers around the world are working on the development of novel anticancer drugs with different mechanisms of action. In this case, coumarin is a highly promising pharmacophore for the development of novel anticancer drugs. Besides, the hybridization of this moiety with other anticancer pharmacophores has emerged as a potent breakthrough in the treatment of cancer to decrease its side effects and increase its efficiency. This review aims to provide a comprehensive overview of the recent development of coumarin derivatives and their application as novel anticancer drugs. Herein, we highlight and describe the largest number of research works reported in this field from 2015 to August 2023, along with their mechanisms of action and structure-activity relationship studies, making this review different from the other review articles published on this topic to date.

Design, Synthesis, and Evaluation of New Hybrid Derivatives of 5,6-Dihydro-4H-pyrrolo[3,2,1-ij]quinolin-2(1H)-one as Potential Dual Inhibitors of Blood Coagulation Factors Xa and XIa

Cardiovascular diseases caused by blood coagulation system disorders are one of the leading causes of morbidity and mortality in the world. Research shows that blood clotting factors are involved in these thrombotic processes. Among them, factor Xa occupies a key position in the blood coagulation cascade. Another coagulation factor, XIa, is also a promising target because its inhibition can suppress thrombosis with a limited contribution to normal hemostasis. In this regard, the development of dual inhibitors as new generation anticoagulants is an urgent problem. Here we report the synthesis and evaluation of novel potential dual inhibitors of coagulation factors Xa and XIa. Based on the principles of molecular design, we selected a series of compounds that combine in their structure fragments of pyrrolo[3,2,1-ij]quinolin-2-one and thiazole, connected through a hydrazine linker. The production of new hybrid molecules was carried out using a two-stage method. The reaction of 5,6-dihydropyrrolo[3,2,1-ij]quinoline-1,2-diones with thiosemicarbazide gave the corresponding hydrazinocarbothioamides. The reaction of the latter with DMAD led to the target methyl 2-(4-oxo-2-(2-(2-oxo-5,6-dihydro-4H-pyrrolo[3,2,1-ij]quinolin-1(2H)-ylidene)hydrazineyl)thiazol-5(4H)-ylidene)acetates in high yields. In vitro testing of the synthesized molecules revealed that ten of them showed high inhibition values for both the coagulation factors Xa and XIa, and the IC50 value for some compounds was also assessed. The resulting structures were also tested for their ability to inhibit thrombin.

A Review on Synthetic Thiazole Derivatives as an Antimalarial Agent

BACKGROUND

Thiazole is a widely studied core structure in heterocyclic chemistry and has proven to be a valuable scaffold in medicinal chemistry. The presence of thiazole in both naturally occurring and synthetic pharmacologically active compounds demonstrates the adaptability of these derivatives.

METHODS

The current study attempted to review and compile the contributions of numerous researchers over the last 20 years to the medicinal importance of these scaffolds, with a primary focus on antimalarial activity. The review is based on an extensive search of PubMed, Google Scholar, Elsevier, and other renowned journal sites for a thorough literature survey involving various research and review articles.

RESULTS

A comprehensive review of the antimalarial activity of the thiazole scaffold revealed potential therapeutic targets in Plasmodium species. Furthermore, the correlation of structure-activity-relationship (SAR) studies from various articles suggests that the thiazole ring has therapeutic potential.

CONCLUSION

This article intends to point researchers in the right direction for developing potential thiazole-based compounds as antimalarial agents in the future.

Recent advances in antifungal drug development targeting lanosterol 14α-demethylase (CYP51): A comprehensive review with structural and molecular insights

Fungal infections are posing serious threat to healthcare system due to emerging resistance among available antifungal agents. Among available antifungal agents in clinical practice, azoles (diazole, 1,2,4-triazole and tetrazole) remained most effective and widely prescribed antifungal agents. Now their associated side effects and emerging resistance pattern raised a need of new and potent antifungal agents. Lanosterol 14α-demethylase (CYP51) is responsible for the oxidative removal of 14α-methyl group of sterol precursors lanosterol and 24(28)-methylene-24,25-dihydrolanosterol in ergosterol biosynthesis hence an essential component of fungal life cycle and prominent target for antifungal drug development. This review will shed light on various azole- as well as non-azoles-based derivatives as potential antifungal agents that target fungal CYP51. Review will provide deep insight about structure activity relationship, pharmacological outcomes, and interactions of derivatives with CYP51 at molecular level. It will help medicinal chemists working on antifungal development in designing more rational, potent, and safer antifungal agents by targeting fungal CYP51 for tackling emerging antifungal drug resistance.

Oxygen- and Sulphur-Containing Heterocyclic Compounds as Potential Anticancer Agents

Oxygen- and sulphur-based heterocycles form the core structure of many biologically active molecules as well as U.S. FDA-approved drugs. Moreover, they possess broad range of biological activities, viz. anticancer, antiinflammatory, antioxidant, antitumour, antibacterial, antiviral, antidiabetic, anticonvulsant, anti-tubercular, analgesic, anti-leishmanial, antimalarial, antifungal, and anti-histaminic, Hence, O- and S-based heterocycles are gaining more attention in recent years on the road to the discovery of innovative anticancer drugs after the extensive investigation of nitrogen-based heterocycles as anticancer agents. Several attempts have been made to synthesize fused oxygen- and sulphur-based heterocyclic derivatives as joining one heterocyclic moiety with another may lead to improvement in the biological profile of a molecule. Humans have been cursed with cancer since long time. Despite the development of several heterocyclic anticancer medications such as 5-fluorouracil, doxorubicin, methotrexate, and daunorubicin, cure of cancer is difficult. Hence, researchers are trying to synthesize new fused/spiro heterocyclic molecules to discover novel anticancer drugs which may show promising anticancer effects with fewer side effects. Furthermore, fused heterocycles behave as DNA intercalating agents which have the ability to interact with DNA, leading to cell death thereby exerting anticancer effect. This review article highlights the synthesis and anticancer potentiality of oxygen- and sulphur-containing heterocyclic compounds covering the period from 2011 to 2021.

Synthesis of Functionalized N-(4-Bromophenyl)furan-2-carboxamides via Suzuki-Miyaura Cross-Coupling: Anti-Bacterial Activities against Clinically Isolated Drug Resistant A. baumannii, K. pneumoniae, E. cloacae and MRSA and Its Validation via a Computational Approach

N-(4-bromophenyl)furan-2-carboxamide (3) was synthesized by the reaction furan-2-carbonyl chloride (1) and 4-bromoaniline (2) in the presence of Et₃N in excellent yields of 94%. The carboxamide (3) was arylated by employing triphenylphosphine palladium as a catalyst and K₃PO₄ as a base to afford N-(4-bromophenyl)furan-2-carboxamide analogues (5a-i) in moderate to good yields (43–83%). Furthermore, we investigated the in vitro anti-bacterial activities of the respective compounds against clinically isolated drug-resistant bacteria A. baumannii, K. pneumoniae, E. cloacae and S. aureus. The molecule (3) was found to be the most effective activity against these bacteria, particularly NDM-positive bacteria A. baumannii as compared to various commercially available drugs. Docking studies and MD simulations further validated it, expressing the active site and molecular interaction stability.

Design, Synthesis and Cytotoxicity of Thiazole-Based Stilbene Analogs as Novel DNA Topoisomerase IB Inhibitors

A series of new thiazole-based stilbene analogs were designed, synthesized and evaluated for DNA topoisomerase IB (Top1) inhibitory activity. Top1-mediated relaxation assays showed that the synthesized compounds possessed variable Top1 inhibitory activity. Among them, (E)-2-(3-methylstyryl)-4-(4-fluorophenyl)thiazole (8) acted as a potent Top1 inhibitor with high Top1 inhibition of ++++ which is comparable to that of CPT. A possible binding mode of compound 8 with Top1–DNA complex was further provided by molecular docking. An MTT assay against human breast cancer (MCF-7) and human colon cancer (HCT116) cell lines revealed that the majority of these compounds showed high cytotoxicity, with IC₅₀ values at micromolar concentrations. Compounds 8 and (E)-2-(4-tert-butylstyryl)-4-(4-fluorophenyl)thiazole (11) exhibited the most potent cytotoxicity with IC₅₀ values of 0.78 and 0.62 μM against MCF-7 and HCT116, respectively. Moreover, the preliminary structure–activity relationships of thiazole-based stilbene analogs was also discussed.

Comprehensive Overview of Carboxamide Derivatives as Succinate Dehydrogenase Inhibitors

Up to now, a total of 24 succinate dehydrogenase inhibitors (SDHIs) fungicides have been commercialized, and SDHIs fungicides were also one of the most active fungicides developed in recent years. Carboxamide derivatives represented an important class of SDHIs with broad spectrum of antifungal activities. In this review, the development of carboxamide derivatives as SDHIs with great significances were summarized. In addition, the structure-activity relationships (SARs) of antifungal activities of carboxamide derivatives as SDHIs was also summarized based on the analysis of the structures of the commercial SDHIs and lead compounds. Moreover, the cause of resistance of SDHIs and some solutions were also introduced. Finally, the development trend of SDHIs fungicides was prospected. We hope this review will give a guide for the development of novel SDHIs fungicides in the future.

Urease inhibitory kinetics, molecular docking, SAR and ADME studies of imine analogues

A series of synthesized imine derivatives (3a–m), including thio-semicarbazone, semicarbazone, thiazole and oxazole functional moieties, were examined for in vitro urease inhibition activity.

4-(Indol-3-yl)thiazole-2-amines and 4-ιndol-3-yl)thiazole Acylamines as Νovel Antimicrobial Agents: Synthesis, In Silico and In Vitro Evaluation

This manuscript deals with the synthesis and computational and experimental evaluation of the antimicrobial activity of twenty-nine 4-(indol-3-yl)thiazole-2-amines and 4-ιndol-3-yl)thiazole acylamines. An evaluation of antibacterial activity against Gram (+) and Gram (-) bacteria revealed that the MIC of indole derivatives is in the range of 0.06-1.88 mg/mL, while among fourteen methylindole derivatives, only six were active, with an MIC in the range of of 0.47-1.88 mg/mL. S. aureus appeared to be the most resistant strain, while S. Typhimurium was the most sensitive. Compound 5x was the most promising, with an MIC in the range of 0.06-0.12 mg/mL, followed by 5d and 5m. An evaluation of these three compounds against resistant strains, namely MRSA P. aeruginosa and E. coli, revealed that they were more potent against MRSA than ampicillin. Furthermore, compounds 5m and 5x were superior inhibitors of biofilm formation, compared to ampicillin and streptomycin, in terms Compounds 5d, 5m, and 5x interact with streptomycin in additive manner. The antifungal activity of some compounds exceeded or was equipotent to those of the reference antifungal agents bifonazole and ketoconazole. The most potent antifungal agent was found to be compound 5g. Drug likeness scores of compounds was in a range of -0.63 to 0.29, which is moderate to good. According to docking studies, E. coli MurB inhibition is probably responsible for the antibacterial activity of compounds, whereas CYP51 inhibition was implicated in antifungal activity. Compounds appeared to be non-toxic, according to the cytotoxicity assessment in MRC-5 cells.

Valosin-Containing Protein (VCP)/p97: A Prognostic Biomarker and Therapeutic Target in Cancer

Valosin-containing protein (VCP)/p97, a member of the AAA+ ATPase family, is a molecular chaperone recruited to the endoplasmic reticulum (ER) membrane by binding to membrane adapters (nuclear protein localization protein 4 (NPL4), p47 and ubiquitin regulatory X (UBX) domain-containing protein 1 (UBXD1)), where it is involved in ER-associated protein degradation (ERAD). However, VCP/p97 interacts with many cofactors to participate in different cellular processes that are critical for cancer cell survival and aggressiveness. Indeed, VCP/p97 is reported to be overexpressed in many cancer types and is considered a potential cancer biomarker and therapeutic target. This review summarizes the role of VCP/p97 in different cancers and the advances in the discovery of small-molecule inhibitors with therapeutic potential, focusing on the challenges associated with cancer-related VCP mutations in the mechanisms of resistance to inhibitors.

Semicarbazones, thiosemicarbazone, thiazole and oxazole analogues as monoamine oxidase inhibitors: Synthesis, characterization, biological evaluation, molecular docking, and kinetic studies

A series of semicarbazone, thiosemicarbazone, thiazole, and oxazole derivatives were designed, synthesized, and examined for monoamine oxidase inhibition using two isoforms, i.e., MAO-A and MAO-B. Among all the analogues, 3c and 3j possessed substantial activity against MAO-A with IC₅₀ values of 5.619 ± 1.04 µM and 0.5781 ± 0.1674 µM, respectively. Whereas 3d and 3j were active against monoamine oxidase B with the IC₅₀ values of 9.952 ± 1.831 µM and 3.5 ± 0.7 µM, respectively. Other derivatives active against MAO-B were 3c and 3g with the IC₅₀ values of 17.67 ± 5.6 µM and 37.18 ± 2.485 µM. Moreover, molecular docking studies were achieved for the most potent compound (3j) contrary to human MAO-A and MAO-B. Kinetic studies were also performed for the most potent analogue to evaluate its mode of interaction with MAO-A and MAO-B.

Organic Antifungal Drugs and Targets of Their Action

In recent decades, there has been a significant increase in the number of fungal diseases. This is due to a wide spectrum of action, immunosuppressants and other group drugs. In terms of frequency, rapid spread and globality, fungal infections are approaching acute respiratory infections. Antimycotics are medicinal substances endorsed with fungicidal or fungistatic properties. For the treatment of fungal diseases, several groups of compounds are used that differ in their origin (natural or synthetic), molecular targets and mechanism of action, antifungal effect (fungicidal or fungistatic), indications for use (local or systemic infections), and methods of administration (parenteral, oral, outdoor). Several efforts have been made by various medicinal chemists around the world for the development of antifungal drugs with high efficacy with the least toxicity and maximum selectivity in the area of antifungal chemotherapy. The pharmacokinetic properties of the new antimycotics are also important: the ability to penetrate biological barriers, be absorbed and distributed in tissues and organs, get accumulated in tissues affected by micromycetes, undergo drug metabolism in the intestinal microflora and human organs, and in the kinetics of excretion from the body. There are several ways to search for new effective antimycotics: - Obtaining new derivatives of the already used classes of antimycotics with improved activity properties. - Screening of new chemical classes of synthetic antimycotic compounds. - Screening of natural compounds. - Identification of new unique molecular targets in the fungal cell. - Development of new compositions and dosage forms with effective delivery vehicles. The methods of informatics, bioinformatics, genomics and proteomics were extensively investigated for the development of new antimycotics. These techniques were employed in finding and identification of new molecular proteins in a fungal cell; in the determination of the selectivity of drugprotein interactions, evaluation of drug-drug interactions and synergism of drugs; determination of the structure-activity relationship (SAR) studies; determination of the molecular design of the most active, selective and safer drugs for the humans, animals and plants. In medical applications, the methods of information analysis and pharmacogenomics allow taking into account the individual phenotype of the patient, the level of expression of the targets of antifungal drugs when choosing antifungal agents and their dosage. This review article incorporates some of the most significant studies covering the basic structures and approaches for the synthesis of antifungal drugs and the directions for their further development.

Antimicrobial activity screening of rhizosphere soil bacteria from tomato and genome-based analysis of their antimicrobial biosynthetic potential

Background

Tomato plant growth is frequently hampered by a high susceptibility to pests and diseases. Traditional chemical control causes a serious impact on both the environment and human health. Therefore, seeking environment-friendly and cost-effective green methods in agricultural production becomes crucial nowadays. Plant Growth Promoting Rhizobacteria (PGPR) can promote plant growth through biological activity. Their use is considered to be a promising sustainable approach for crop growth. Moreover, a vast number of biosynthetic gene clusters (BGCs) for secondary metabolite production are being revealed in PGPR, which helps to find potential anti-microbial activities for tomato disease control.

Results

We isolated 181 Bacillus-like strains from healthy tomato, rhizosphere soil, and tomato tissues. In vitro antagonistic assays revealed that 34 Bacillus strains have antimicrobial activity against Erwinia carotovora, Pseudomonas syringae; Rhizoctonia solani; Botrytis cinerea; Verticillium dahliae and Phytophthora infestans. The genomes of 10 Bacillus and Paenibacillus strains with good antagonistic activity were sequenced. Via genome mining approaches, we identified 120 BGCs encoding NRPs, PKs-NRPs, PKs, terpenes and bacteriocins, including known compounds such as fengycin, surfactin, bacillibactin, subtilin, etc. In addition, several novel BGCs were identified. We discovered that the NRPs and PKs-NRPs BGCs in Bacillus species are encoding highly conserved known compounds as well as various novel variants.

Conclusions

This study highlights the great number of varieties of BGCs in Bacillus strains. These findings pave the road for future usage of Bacillus strains as biocontrol agents for tomato disease control and are a resource arsenal for novel antimicrobial discovery.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12864-020-07346-8.

Anticancer activity, DNA binding and docking study of M(ii)-complexes (M = Zn, Cu and Ni) derived from a new pyrazine–thiazole ligand: synthesis, structure and DFT

A series of structurally related Zn(ii), Cu(ii) and Ni(ii) complexes of 4-(2-(2-(1-(pyrazin-2-yl)ethylidene)hydrazinyl)-thiazol-4-yl)-benzonitrile (PyztbH) have been synthesized and characterized by spectroscopy, single crystal X-ray crystallography and density functional theory (DFT).

Cu(I)-Catalyzed Three-Component Cyclization for the Construction of Functionalized Thiazoles

A novel and straightforward strategy for the synthesis of functionalized thiazoles from thioamides, ynals, and alcohols via a copper(I)-catalyzed three-component reaction has been described. Through the formation of new C-S, C-N, and C-O bonds in one pot, it is easy to produce various valuable thiazoles fixed with aryl or heteroaryl groups. In addition, the reaction also exhibits other unique advantages, such as high step economics, good functional group tolerance, and good regioselectivity.

Natural Bioactive Thiazole-Based Peptides from Marine Resources: Structural and Pharmacological Aspects

Peptides are distinctive biomacromolecules that demonstrate potential cytotoxicity and diversified bioactivities against a variety of microorganisms including bacteria, mycobacteria, and fungi via their unique mechanisms of action. Among broad-ranging pharmacologically active peptides, natural marine-originated thiazole-based oligopeptides possess peculiar structural features along with a wide spectrum of exceptional and potent bioproperties. Because of their complex nature and size divergence, thiazole-based peptides (TBPs) bestow a pivotal chemical platform in drug discovery processes to generate competent scaffolds for regulating allosteric binding sites and peptide–peptide interactions. The present study dissertates on the natural reservoirs and exclusive structural components of marine-originated TBPs, with a special focus on their most pertinent pharmacological profiles, which may impart vital resources for the development of novel peptide-based therapeutic agents.

Coumarin-containing hybrids and their anticancer activities

Cancer is the second leading cause of death worldwide, and it results in around 9 million deaths annually. The anticancer agents play an intriguing role in the treatment of cancers, while the severe anticancer scenario and the emergence of drug-resistant especially multidrug-resistant cancers create a huge demand for novel anticancer drugs with different mechanisms of action. The coumarin scaffold is ubiquitous in nature and is a highly privileged motif for the development of novel drugs due to its biodiversity and versatility. Coumarin derivatives can exert diverse antiproliferative mechanisms, and some of them such as Irosustat are under clinical trials for the treatment of various cancers, revealing their potential as putative anticancer drugs. Hybridization of coumarin moiety with other anticancer pharmacophores is a promising strategy to reduce side effects, overcome the drug resistance, and may provide valuable therapeutic intervention for the treatment of cancers. Thus, coumarin-containing hybrids occupy an important position in the development of novel anticancer agents. This review aims to summarize the recent advances made towards the development of coumarin-containing hybrids as potential anticancer agents, covering articles published between 2015 and 2019, and the structure-activity relationship together with mechanisms of action are also discussed.

Polyethylene glycol (PEG-400) promoted one-pot, five-component synthesis of (E)-ethyl2-(2-((E)-2-(1-(4-methyl-2-(phenylamino)thiazol-5yl)ethylidene)hydrazinyl)-4-oxothiazol-5(4H)-ylidene)acetates

A facile, inexpensive and eco-friendly synthesis of functionalised (E)-ethyl2-(2-((E)-2-(1-(4-methyl-2-(phenylamino)thiazol-5yl)ethylidene)hydrazinyl)14-oxothiazol-5(4H)-ylidene)acetates has been developed via one-pot five-component approach. The title compounds were synthesized by the reaction of anilines, 3-chloropentane-2,4-dione, ammoniumthiocyanate, thiosemicarbazide and dialkylacetylene dicarboxylate using polyethylene glycol as green and recyclable solvent. The domino reaction proceeded smoothly in good-to-excellent yields.