In silico ADMET study, docking, synthesis and antimalarial evaluation of thiazole-1,3,5-triazine derivatives as Pf-DHFR inhibitor

Design, synthesis and characterization of tetra substituted 2,3-dihydrothiazole derivatives as DNA and BSA targeting agents: advantages of the visible-light-induced multicomponent approach

This report describes the visible-light-induced one-pot multicomponent regioselective synthesis of a series of 5-aroyl-3-((arylidene)amino)-2-((arylidene)hydrazono)-4-methyl-2,3-dihydrothiazoles as DNA and BSA targeting agents. The multicomponent condensation of thiocarbohydrazide and aldehydes with α-bromo-1,3-diketones, generated in situ by the bromination of unsymmetrical 1,3-diketones with NBS using white LED light as an environmental friendly source in the presence of EtOAc solvent furnished the titled 2,3-dihydrothiazole derivatives in excellent yields. The exact regioisomeric structure was identified unambiguously by employing multinuclear 2D-NMR spectroscopy [1H-13C] HMBC; [1H-13C] HMQC and [1H-15N] HMBC. Furthermore, the binding characteristics of the synthesized 2,3-dihydrothiazole derivatives were assessed with double-stranded calf-thymus DNA duplex (ct-DNA) and bovine serum albumin (BSA). Initial screening of all the synthesized 2,3-dihydrothiazole derivatives using various in silico techniques including molecular reactivity analysis, Lipinski rule and molecular docking, concluded 5-(4'-chlorobenzoyl)-3-((4''-methoxybenzylidene)amino)-2-(4'''-methoxybenzylidene)hydrazono)-4-methyl-2,3-dihydrothiazole derivative 6a as the most suitable compound for studying binding interaction with DNA and BSA. Additionally, to illustrate the ex vivo binding mode of 6a with DNA and BSA, several spectroscopic techniques viz. UV-visible, circular dichroism (CD), steady-state fluorescence and competitive displacement assays were carried out.

Unlocking nitrogen compounds' promise against malaria: A comprehensive review

Plasmodium parasites are the primary cause of malaria, leading to high mortality rates, which require clinical attention. Many of the medications used in the treatment have resulted in resistance over time. Artemisinin combination therapy (ACT) has shown significant results for the treatment. However, mutations in the parasite have resulted in resistance, leading to decreased efficiency of the medications that are currently being used. Therefore, there is a critical need to find novel scaffolds that are safe, effective, and of economic advantage. Literature has reported several potent molecules with diverse scaffolds designed, synthesized, and evaluated against different strains of Plasmodium. With this growing list of compounds, it is essential to collect the data in one place to gain a concise overview of the emerging scaffolds in recent years. For this purpose, nitrogen-containing heterocycles such as β-carboline, imidazole, quinazoline, quinoline, thiazole, and thiophene have been highly explored due to their wide biological applications. Besides these, another scaffold, benzodiazepine, which is majorly used as a central nervous system depressant, is emerging as an anti-malarial agent. Hence, this review centers on the latest medication advancements designed to combat malaria, emphasizing special attention to 1,4-benzodiazepines as a novel scaffold for antimalarial drug discovery.

Design, in silico study, synthesis and evaluation of hybrid pyrazole substituted 1,3,5-triazine derivatives for antimalarial activity

OBJECTIVES

Malaria is a significant global health challenge, particularly in Africa, Asia, and Latin America, necessitating immediate investigation into innovative and efficacious treatments. This work involves the development of pyrazole substituted 1,3,5-triazine derivatives as antimalarial agent.

METHODS

In this study, ten compounds 7(a-j) were synthesized by using nucleophilic substitution reaction, screened for in silico study and their antimalarial activity were evaluated against 3D7 (chloroquine-sensitive) strain of P. falciparum.

KEY FINDING

The present work involves the development of hybrid trimethoxy pyrazole 1,3,5-triazine derivatives 7 (a-j). Through in silico analysis, four compounds were identified with favorable binding energy and dock scores. The primary focus of the docking investigations was on the examination of hydrogen bonding and the associated interactions with certain amino acid residues, including Arg A122, Ser A108, Ser A111, Ile A164, Asp A54, and Cys A15. The IC50 values of the four compounds were measured in vitro to assess their antimalarial activity against the chloroquine sensitive 3D7 strain of P. falciparum. The IC50 values varied from 25.02 to 54.82 μg/mL.

CONCLUSION

Among the ten derivatives, compound 7J has considerable potential as an antimalarial agent, making it a viable contender for further refinement in the realm of pharmaceutical exploration, with the aim of mitigating the global malaria load.

Estragole Ameliorates CFA Induced Rheumatoid Arthritis Symptoms in Wistar Rats by Inhibiting JAK-2/STAT-3 Pathway

The present study was conducted to scrutinize the pharmacological effect of Estragole (ESG) against CFA-induced arthritis in rats. The rats underwent induction of arthritis using the administration of CFA and after that, the rats were randomly divided into five different groups, where three groups correspond to diverse dosages of ESG, and the other two were control and CFA-arthritic control. Results of the study suggested that ESG in a dose-dependent manner, improves body weight and arthritis score of rats as evidenced by reduction of hind-paw volume. ESG also improved the antioxidant status of rats by reducing MDA levels and enhancing the concentration of endogenous antioxidants SOD and GPx. The level of pro-inflammatory cytokines was also found to be reduced in the case of ESG treated group as compared to CFA-group. In a western blot analysis, ESH showed downregulation of p-JAK-2/STAT-3. The study provided concrete evidence for the protective effect of ESG against rheumatoid arthritis in rats.

Piperazin incorporated Schiff Base derivatives: Assessment of in vitro biological activities, metabolic enzyme inhibition properties, and molecular docking calculations

The cytotoxic activities of the compounds were determined by the 3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide (MTT) method in human breast cancer (MCF-7), human cervical cancer (HeLa), and mouse fibroblast (L929) cell lines. The compounds MAAS-5 and four modified the supercoiled tertiary structure of pBR322 plasmid DNA. MAAS-5 showed the highest cytotoxic activity in HeLa, MCF-7, and L929 cells with IC50 values of 16.76 ± 3.22, 28.83 ± 5.61, and 2.18 ± 1.22 µM, respectively. MAAS-3 was found to have almost the lowest cytotoxic activities with the IC50 values of 93.17 ± 9.28, 181.07 ± 11.54, and 16.86 ± 6.42 µM in HeLa, MCF-7, and L929 cells respectively at 24 h. Moreover, the antiepileptic potentials of these compounds were investigated in this study. To this end, the effect of newly synthesized Schiff base derivatives on the enzyme activities of carbonic anhydrase I and II isozymes (human carbonic anhydrase [hCA] I and hCA II) was evaluated spectrophotometrically. The target compounds demonstrated high inhibitory activities compared with standard inhibitors with Ki values in the range of 4.54 ± 0.86-15.46 ± 8.65 nM for hCA I (Ki value for standard inhibitor =  12.08 ± 2.00 nM), 1.09 ± 0.32-29.94 ± 0.82 nM for hCA II (Ki value for standard inhibitor = 18.22 ± 4.90  nM). Finally, the activities of the compounds were compared with the Gaussian programme in the B3lyp, HF, M062X base sets with 6-31++G (d,p) levels. In addition, the activities of five compounds against various breast cancer proteins and hCA I and II were compared with molecular docking calculations. Also, absorption, distribution, metabolism, excretion, and toxicity analysis was performed to investigate the possibility of using five compounds as drug candidates.

In-vitro antiviral activity and in-silico targeted study of quinoline-3-carboxylate derivatives against SARS-Cov-2 isolate

In recent years, the viral outbreak named COVID-19 showed that infectious diseases have a huge impact on both global health and the financial and economic sectors. The lack of efficacious antiviral drugs worsened the health problem. Based on our previous experience, we investigated in vitro and in silico a series of quinoline-3-carboxylate derivatives against a SARS-CoV-2 isolate. In the present study, the in-vitro antiviral activity of a series of quinoline-3-carboxylate compounds and the in silico target-based molecular dynamics (MD) and metabolic studies are reported. The compounds' activity against SARS-CoV-2 was evaluated using plaque assay and RT-qPCR. Moreover, from the docking scores, it appears that the most active compounds (1j and 1o) exhibit stronger binding affinity to the primary viral protease (NSP5) and the exoribonuclease domain of non structural protein 14 (NSP14). Additionally, the in-silico metabolic analysis of 1j and 1o defines CYP2C9 and CYP3A4 as the major P450 enzymes involved in their metabolism.

Discovery of new pyridine heterocyclic hybrids; design, synthesis, dynamic simulations, and in vitro and in vivo breast cancer biological assays

Pyridine is a nitrogen bearing heterocyclic scaffold that shows a wide range of biological activities. The pyridine nucleus has become an interesting target for medicinal chemistry researchers worldwide. Several pyridine derivatives exhibited good anticancer effects against diverse cell lines. Therefore, to explore new anticancer pyridine entities, novel pyridine derivatives were designed and synthesized and evaluated for their anticancer abilities in vitro and in vivo. All of the target compounds were evaluated against three different human cancer cell lines (Huh-7, A549 and MCF-7) via MTT assay. Most of the compounds exhibited significant cytotoxic activities. Compounds 3a, 3b, 5a and 5b showed superior antiproliferative activities to Taxol. Where, compound 3b showed IC₅₀ values of 6.54, 15.54 and 6.13 μM compared to Taxol (6.68, 38.05, 12.32 μM) against Huh-7, A549 and MCF-7, respectively. Also, tubulin polymerization assay was carried out. The most potent compounds 3a, 3b, 5a and 5b could significantly inhibit tubulin polymerization with IC₅₀ values of 15.6, 4.03, 6.06 and 12.61 μM, respectively. Compound 3b exhibited the highest tubulin polymerization inhibitory effect with an IC₅₀ value of 4.03 μM compared to combretastatin (A-4) (1.64 μM). Molecular modeling studies of the designed compounds confirmed that most of the compounds made the essential binding interactions compared to the reference compound which assisted in the prediction of the structure requirements for the detected anticancer activity. Finally, in vivo studies showed that compound 3b could significantly inhibit breast cancer.

Molecular docking and antimalarial evaluation of hybrid para-aminobenzoic acid 1,3,5 triazine derivatives via inhibition of Pf-DHFR

In this study, a structurally guided pharmacophore hybridization strategy is used to combine the two key structural scaffolds, para-aminobenzoic acid (PABA), and 1,3,5 triazine in search of new series of antimalarial agents. A combinatorial library of 100 compounds was prepared in five different series as [4A (1-22), 4B (1-21), 4 C (1-20), 4D (1-19) and 4E (1-18)] using different primary and secondary amines, from where 10 compounds were finally screened out through molecular property filter analysis and molecular docking study as promising PABA substituted 1,3,5-triazine scaffold as an antimalarial agent. The docking results showed that compounds 4A12 and 4A20 exhibited good binding interaction with Phe58, IIe164, Ser111, Arg122, Asp54 (-424.19 to -360.34 kcal/mol) and Arg122, Phe116, Ser111, Phe58 (-506.29 to -431.75 kcal/mol) against wild (1J3I) and quadruple mutant (1J3K) type of Pf-DHFR. These compounds were synthesized by conventional as well as microwave-assisted synthesis and characterized by different spectroscopic methods. In-vitro antimalarial activity results indicated that two compounds 4A12 and 4A20 showed promising antimalarial activity against chloroquine-sensitive (3D7) and chloroquine-resistant (Dd2) strains of Plasmodium falciparum with IC50 (1.24-4.77 μg mL-1) and (2.11-3.60 μg mL-1). These hybrid PABA substituted 1,3,5-triazine derivatives might be used in the lead discovery towards a new class of Pf-DHFR inhibitors.Communicated by Ramaswamy H. Sarma.

Novel hybrids of quinoline with pyrazolylchalcones as potential antimalarial agents: Synthesis, biological evaluation, molecular docking and ADME prediction

A novel series of pyrazolyl chalcones containing quinoline scaffold, 5 a-v has been synthesized by Claisen Schimdt condensation of aromatic acetophenone with 1-(4-methylquinolin-2-yl)-3-aryl-1H-pyrazole-4-carbaldehyde in quantitative yield. The compounds were characterized using IR, NMR, MS and elemental analysis. An E-configuration about CC ethylenic bond was determined using ¹H NMR spectroscopy. These compounds exhibited significant antimalarial potential against CQ-sensitive and CQ-resistant strain of Plasmodium falciparum. Structure activity relationship has also been established based on outcomes of in vitro schizont inhibition assay. Compound 5u, (Z)-3-(1-(4-methylquinolin-2-yl)-3-p-tolyl-1H-pyrazol-4-yl)-1-p-tolylprop-2-en-1-one, was found to be the most potent among the series of synthetic analogues. In vivo, it demonstrated significant parasitemia suppression of 78.01% at a dose of 200 mg/kg against P. berghei in infected mice without any mortality in 7 days. In silico molecular docking study revealed that this compound 5u bound to the active site of cysteine protease falcipain-2 enzyme. Furthermore, in silico ADME studies, were also performed and physicochemical qualifications of the title compounds were determined. The biological outcomes of newer heterocyclic compounds may pave the new paths for researchers in development of potential antimalarial agents.

Design and development of novel N ‐(4‐aminobenzoyl)‐ l ‐glutamic acid conjugated 1,3,5‐triazine derivatives as Pf ‐DHFR inhibitor: An in‐silico and in‐vitro study

In the present work, a library of 120 compounds was prepared using various aliphatic and aromatic amines. Finally, 10 compounds were selected through in silico screening carrying 4-aminobenzoyl-l-glutamic acid and 1,3,5-triazine moiety. The docking results of compounds 4d16 and 4d38 revealed higher binding interaction with amino acids Asp54 (-537.96 kcal/mol) and Asp54, Phe116 (-618.22 kcal/mol) against wild (1J3I) and quadruple mutant (1J3K) type of Pf-DHFR inhibitors and were comparable to standard WR99210. These compounds were developed by facile and microwave-assisted synthesis via nucleophilic substitution reaction and characterized by different spectroscopic methods. In vitro antimalarial assay results also suggested that these two compounds were having higher antimalarial activity against chloroquine-sensitive (3D7) and chloroquine-resistant (Dd2) strain out of the ten synthesized compounds with IC₅₀ 13.25 μM and 14.72 μM, respectively. These hybrid scaffolds might be useful in the lead discovery of a new class of Pf-DHFR inhibitors.

Synthesis and Molecular Docking Study of New Thiazole Derivatives as Potential Tubulin Polymerization Inhibitors

A new series of 2,4-disubstituted thiazole derivatives containing 4-(3,4,5-trimethoxyphenyl) moiety was synthesized and evaluated for their potential anticancer activity as tubulin polymerization inhibitors. All designed compounds were screened for cytotoxic activity against four human cancer cell lines, namely, HepG2, MCF-7, HCT116, and HeLa, using 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide assay, with combretastatin A-4 as a reference drug. Compounds 5c, 6d, 7c, 8, and 9a,b showed superior activity against the tested cell lines, with IC₅₀ values ranging from 3.35 ± 0.2 to 18.69 ± 0.9 μM. Further investigation for the most active cytotoxic agents as tubulin polymerization inhibitors was also performed in order to explore the mechanism of their antiproliferative activity. The obtained results suggested that compounds 5c, 7c, and 9a remarkably inhibit tubulin polymerization, with IC₅₀ values of 2.95 ± 0.18, 2.00 ± 0.12, and 2.38 ± 0.14 μM, respectively, which exceeded that of the reference drug combretastatin A-4 (IC₅₀ 2.96 ± 0.18 μM). Molecular docking studies were also conducted to investigate the possible binding interactions between the targeted compounds and the tubulin active site. The interpretation of the results showed clearly that compounds 7c and 9a were identified as the most potent tubulin polymerization inhibitors with promising cytotoxic activity and excellent binding mode in the docking study.

Microwave synthesis and antimalarial screening of novel 4-amino benzoic acid (PABA)-substituted pyrimidine derivatives as Plasmodium falciparum dihydrofolate reductase inhibitors

Antimalarial drug resistance is a major threat due to the emerging resistance to all the available drugs in the market. In an approach to develop alternative drugs, a novel class of Pf-DHFR inhibitors was developed using pyrimidine as the core nucleus and substituting the 4- and 6- positions with amines and 4-amino benzoic acid (PABA) to avoid the problem of drug resistance. The resultant compounds 3(a-j) after primary in silico screening and filtering were synthesized using microwave efficiently in high yield and reduced time period compared to conventional synthesis. The antimalarial assay was performed in vitro, against chloroquine-sensitive (3D7) and chloroquine-resistant (Dd2) strains of Plasmodium falciparum using chloroquine as a reference standard. The IC₅₀ values were in the range of 5.26-106.76 µg/ml for 3D7 and in Dd2 the value ranges from 4.71 to 112.98 µg/ml. Compounds 3d, 3e, 3f and 3h showed significant antimalarial activity against both the strains of P. falciparum with no cytotoxicity against fibroblast cell line and 3f was found to be the most potent among them. The hemolysis assay of all the compounds in fresh erythrocytes showed insignificant hemolysis below 5% at a higher dose level. Hence, the present study suggests the possible utility of PABA-substituted pyrimidine scaffold for further development of new Pf-DHFR inhibitors.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13205-022-03236-w.

Dihydrofolate reductase, thymidylate synthase, and serine hydroxy methyltransferase: successful targets against some infectious diseases

Parasitic diseases have a serious impact on the world in terms of health and economics and are responsible for worldwide mortality and morbidity. The present review features the hybrid targeting involving three main enzymes for the treatment of different parasitic diseases. The enzymes Dihydrofolate reductase, thymidylate synthase, and Serine hydroxy methyltransferase play an essential role in the folate pathway. The present review focuses on these enzymes, which can be targeted against several diseases. It shed light on the past, present, and future of these targets, and it can be assessed that these targets can play a significant role against several infectious diseases. For combating viral and protozoal infectious diseases, these targets in combination should be addressed.

Thiazole: A Versatile Standalone Moiety Contributing to the Development of Various Drugs and Biologically Active Agents

For many decades, the thiazole moiety has been an important heterocycle in the world of chemistry. The thiazole ring consists of sulfur and nitrogen in such a fashion that the pi (π) electrons are free to move from one bond to other bonds rendering aromatic ring properties. On account of its aromaticity, the ring has many reactive positions where donor–acceptor, nucleophilic, oxidation reactions, etc., may take place. Molecules containing a thiazole ring, when entering physiological systems, behave unpredictably and reset the system differently. These molecules may activate/stop the biochemical pathways and enzymes or stimulate/block the receptors in the biological systems. Therefore, medicinal chemists have been focusing their efforts on thiazole-bearing compounds in order to develop novel therapeutic agents for a variety of pathological conditions. This review attempts to inform the readers on three major classes of thiazole-bearing molecules: Thiazoles as treatment drugs, thiazoles in clinical trials, and thiazoles in preclinical and developmental stages. A compilation of preclinical and developmental thiazole-bearing molecules is presented, focusing on their brief synthetic description and preclinical studies relating to structure-based activity analysis. The authors expect that the current review may succeed in drawing the attention of medicinal chemists to finding new leads, which may later be translated into new drugs.

Identification of lactoferrin-derived peptides as potential inhibitors against the main protease of SARS-CoV-2

COVID-19 is a global health emergency that causes serious concerns. A global effort is underway to identify drugs for the treatment of COVID-19. One possible solution to the present problem is to develop drugs that can inhibit SARS-CoV-2 main protease (M^pro), a coronavirus protein that been considered as one among many drug targets. In this work, lactoferrin from Bos taurus L. was in silico hydrolyzed. The bioactivity, water solubility, and ADMET properties of the generated peptides were predicted using various online tools. The molecular interactions between M^pro and the peptides were studied using molecular docking and molecular dynamic simulation. The results demonstrated that peptide GSRY was predicted to have better physicochemical properties, and the value of '-C DOCKER interaction energy' between peptide GSRY and M^pro was 80.8505 kcal/mol. The interaction between the peptide GSRY and the native ligand N3 co-crystallized with M^pro had overlapped amino acids, i.e., HIS163, GlY143, GLU166, GLN189 and MET165. Molecular dynamic simulation revealed that M^pro/GSRY complexes were stable. Collectively, the peptide GSRY may be a potential candidate drug against M^pro of SARS-CoV-2.

Discovery of Traditional Chinese Medicine Derived Compounds as Wild Type and Mutant Plasmodium falciparum Dihydrofolate Reductase Inhibitors: Induced Fit Docking and ADME Studies

BACKGROUND

In a bid to come up with effective compounds as inhibitors for antimalarial treatment, we built a library of 2,000 traditional Chinese medicine(TCM)-derived compounds retrieved from TCM Database@Taiwan.

METHODS

The active sites of both the wild type and mutant Plasmodium falciparum dihydrofolatereductase (pfDHFR) were explored using computational tools. pfDHFR, one of the prime drug targets in the prevention of malaria infection induced by the female anopheles mosquito has continued to offer resistance to drugs (antifolates) due to mutation in some of the key amino acid residues crucial for its inhibition.

RESULTS

We utilized virtual throughput screening and glide XP docking to screen the compounds, and 8 compounds were found to have promising docking scores with both the wild type and mutant pfDHFR. They were further subjected to Induce Fit Docking (IFD) to affirm their inhibitory potency. The ADME properties and biological activity spectrum of the compounds were also considered. The inhibition profile of the compounds revealed that a number of compounds formed intermolecular interactions with ASP54, ILE14, LEU164, SER108/ASN108, ARG122 and ASP58. Most of the compounds can be considered as drug candidates due to their antiprotozoal activities and accordance with the Lipinski's Rule of Five (ROF).

CONCLUSION

The outcome of the present study should further be investigated to attest the efficacy of these compounds as better drug candidates than the antifolates.

Design and development of novel thiazole-sulfonamide derivatives as a protective agent against diabetic cataract in Wistar rats via inhibition of aldose reductase

In recent years, ALR2 (aldose reductase) inhibitors have attracted attention for their effective ability to reduce the progression of diabetes-associated cataracts. Therefore, in the present article, we intended to develop novel thiazole-sulfonamide hybrids as a potent inhibitor of ALR2. These molecules significantly inhibited the ALR2 level in the rat lenses homogenate, where the most potent compound 7b showed activity comparable to sorbinil as standard. In Wistar rats, compound 7b improved the insulin level and body weight of the experimental animal together with a reduction in the glucose output. Compound 7b showed a significant reduction in the expression of ALR2 in rat lenses in western blot analysis.

Thiazole Ring-A Biologically Active Scaffold

BACKGROUND

Thiazole is a good pharmacophore nucleus due to its various pharmaceutical applications. Its derivatives have a wide range of biological activities such as antioxidant, analgesic, and antimicrobial including antibacterial, antifungal, antimalarial, anticancer, antiallergic, antihypertensive, anti-inflammatory, and antipsychotic. Indeed, the thiazole scaffold is contained in more than 18 FDA-approved drugs as well as in numerous experimental drugs.

OBJECTIVE

To summarize recent literature on the biological activities of thiazole ring-containing compounds Methods: A literature survey regarding the topics from the year 2015 up to now was carried out. Older publications were not included, since they were previously analyzed in available peer reviews.

RESULTS

Nearly 124 research articles were found, critically analyzed, and arranged regarding the synthesis and biological activities of thiazoles derivatives in the last 5 years.

Thiazole-Based Thiosemicarbazones: Synthesis, Cytotoxicity Evaluation and Molecular Docking Study

Introduction

Hybrid drug design has developed as a prime method for the development of novel anticancer therapies that can theoretically solve much of the pharmacokinetic disadvantages of traditional anticancer drugs. Thus a number of studies have indicated that thiazole-thiophene hybrids and their bis derivatives have important anticancer activity. Mammalian Rab7b protein is a member of the Rab GTPase protein family that controls the trafficking from endosomes to the TGN. Alteration in the Rab7b expression is implicated in differentiation of malignant cells, causing cancer.

Methods

1-(4-Methyl-2-(2-(1-(thiophen-2-yl) ethylidene) hydrazinyl) thiazol-5-yl) ethanone was used as building block for synthesis of novel series of 5-(1-(2-(thiazol-2-yl) hydrazono) ethyl) thiazole derivatives. The bioactivities of the synthesized compounds were evaluated with respect to their antitumor activities against MCF-7 tumor cells using MTT assay. Computer-aided docking protocol was performed to study the possible molecular interactions between the newly synthetic thiazole compounds and the active binding site of the target protein Rab7b. Moreover, the in silico prediction of adsorption, distribution, metabolism, excretion (ADME) and toxicity (T) properties of synthesized compounds were carried out using admetSAR tool.

Results

The results obtained showed that derivatives 9 and 11b have promising activity (IC₅₀ = 14.6 ± 0.8 and 28.3 ± 1.5 µM, respectively) compared to Cisplatin (IC₅₀ = 13.6 ± 0.9 µM). The molecular docking analysis reveals that the synthesized compounds are predicted to be fit into the binding site of the target Rab7b. In summary, the synthetic thiazole compounds 1–17 could be used as potent inhibitors as anticancer drugs.

Conclusion

Promising anticancer activity of compounds 9 and 11 compared with cisplatin reference drug suggests that these ligands may contribute as lead compounds in search of new anticancer agents to combat chemo-resistance.

An Overview of the Synthesis and Antimicrobial, Antiprotozoal, and Antitumor Activity of Thiazole and Bisthiazole Derivatives

Thiazole, a five-membered heteroaromatic ring, is an important scaffold of a large number of synthetic compounds. Its diverse pharmacological activity is reflected in many clinically approved thiazole-containing molecules, with an extensive range of biological activities, such as antibacterial, antifungal, antiviral, antihelmintic, antitumor, and anti-inflammatory effects. Due to its significance in the field of medicinal chemistry, numerous biologically active thiazole and bisthiazole derivatives have been reported in the scientific literature. The current review provides an overview of different methods for the synthesis of thiazole and bisthiazole derivatives and describes various compounds bearing a thiazole and bisthiazole moiety possessing antibacterial, antifungal, antiprotozoal, and antitumor activity, encouraging further research on the discovery of thiazole-containing drugs.

Discovery of novel pyrazole derivatives as a potent anti-inflammatory agent in RAW264.7 cells via inhibition of NF-ĸB for possible benefit against SARS-CoV-2

Due to unavailability of a specific drug/vaccine to attenuate severe acute respiratory syndrome coronavirus 2, the current strategy to combat the infection has been largely dependent upon the use of anti-inflammatory drugs to control cytokines storm responsible for respiratory depression. Thus, in this study, we discovered novel pyrazole analogs as a potent nuclear factor kappa B (NF-ĸB) inhibitor. The compounds were assessed for NF-ĸB transcriptional inhibitory activity in RAW264.7 cells after stimulation with lipopolysaccharides (LPS), revealing Compound 6c as the most potent analog among the tested series. The effect of Compound 6c was further investigated on the levels of interleukin-1β, tumor necrosis factor-α, and interleukin-6 in LPS-stimulated RAW267.4 cells by enzyme immunoassay, where it causes a significant reduction in the level of these cytokines. In Western blot analysis, Compound 6c also causes the inhibition of inhibitor kappa B-α and NF-κB. It was found to be snugly fitted into the inner grove of the active site of NF-ĸB by forming H-bonds and a nonbonded interaction with Asn28 in a docking analysis.

An insight into the recent development of the clinical candidates for the treatment of malaria and their target proteins

Malaria is an endemic disease, prevalent in tropical and subtropical regions which cost half of million deaths annually. The eradication of malaria is one of the global health priority nevertheless, current therapeutic efforts seem to be insufficient due to the emergence of drug resistance towards most of the available drugs, even first-line treatment ACT, unavailability of the vaccine, and lack of drugs with a new mechanism of action. Intensification of antimalarial research in recent years has resulted into the development of single dose multistage therapeutic agents which has advantage of overcoming the antimalarial drug resistance. The present review explored the current progress in the development of new promising antimalarials against prominent target proteins that have the potential to be a clinical candidate. Here, we also reviewed different aspects of drug resistance and highlighted new drug candidates that are currently in a clinical trial or clinical development, along with a few other molecules with excellent antimalarial activity overs ACTs. The summarized scientific value of previous approaches and structural features of antimalarials related to the activity are highlighted that will be helpful for the development of next-generation antimalarials.

Novel Quinazolin-2,4-Dione Hybrid Molecules as Possible Inhibitors Against Malaria: Synthesis and in silico Molecular Docking Studies

The research explores the synthesis of a series of novel hybrid quinazolin-2,4-dione analogs bearing acetyl/amide bridged-nitrogen heterocyclic moieties such as azetidinone, pyrrole, oxazole, oxadiazole, thiazole, pyrazole, and thiazolidine scaffolds 2-16. The newly synthesized compounds were structurally confirmed by means of IR, ¹H-NMR, ¹³C-NMR, MS and elemental analysis. In addition, an in silico molecular docking analysis of new compounds and standard drug (Chloroquine) has been performed to analyze the binding modes of interaction to the putative active site of Plasmodium falciparum Dihydroorotate dehydrogenase (pfDHODH). Aiming to search for potentially better antimalarials, a modern approach has been undertaken to identify new quinazolin-2,4-dione derivatives targeting pfDHODH. The identification of antimalarial activity of the newly synthesized compounds by using experimental techniques is expensive and requires extensive pains and labor. The compound 11 showed the highest binding affinity against pfDHODH. Moreover, the electrostatic potential (ESP) of the docked molecules was also calculated. Further, the pharmacokinetic properties (ADMET) of the prepared compounds were predicted through in silico technique.

Discovery of potential 1,3,5-Triazine compounds against strains of Plasmodium falciparum using supervised machine learning models

The Malaria burden was an escalating global encumbrance and need to be addressed with critical care. Anti-malarial drug discovery was integrated with supervised machine learning (ML) models to identify potent thiazolyl-traizine derivatives. This assimilated approach of Direct Kernel-based Partial Least Squares regression (DKPLS) with molprint 2D fingerprints in Quantitative Structure Activity Relationship models was utilized to map the knowledge of known actives and to design novel molecules. This QSAR study had revealed the structural features required for better antimalarial activity. Two of the molecules which were designed based on the results of this QSAR study, had shown good percentage of parasitemia against both chloroquine sensitive (3D7) and chloroquine resistant (Dd2) strains of Plasmodium falciparum respectively. The IC₅₀ of 201D and 204D was 3.02 and 2.17 µM against chloroquine resistant Dd2 strain of Plasmodium falciparum. This result had proved the efficiency of a multidisciplinary approach of medicinal chemistry and machine learning for the design of novel potent anti-malarial compounds.