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.

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.

Hybrid PABA-glutamic acid conjugated 1,3,5-triazine derivatives: Design, synthesis, and antimalarial activity screening targeting Plasmodium falciparum dihydro folate reductase enzyme.

Despite the successful reduction in the malaria health burden in recent years, it continues to remain a significant global health problem mainly because of the emerging resistance to first-line treatments. Also because of the disruption in malaria prevention services during the COVID-19 pandemic, there was an increase in malaria cases in 2021 compared to 2020. Hence, the present study outlined the in silico study, synthesis, and antimalarial evaluation of 1,3,5-triazine hybrids conjugated with PABA-glutamic acid. Docking study revealed higher binding energy compared to the originally bound ligand WR99210, predominant hydrogen bond interaction, and involvement of key amino acid residues, like Arg122, Ser120, and Arg59. Fourteen compounds were synthesized using traditional and microwave synthesis. The in vitro antimalarial evaluation against chloroquine-sensitive 3D7 and resistant Dd2 strain of Plasmodium falciparum showed a high to moderate activity range. Compounds C1 and B4 showed high efficacy against both strains and a further study revealed that compound C1 is non-cytotoxic against the HEK293 cell line with no acute oral toxicity. In vivo, study was performed for the most potent antimalarial compound C1 to optimize the research work and found to be effectively suppressing parasitemia of Plasmodium berghei strain in the Swiss albino mice model.

Discovery of imeglimin-inspired novel 1,3,5-triazine derivatives as antidiabetic agents in streptozotocin-induced diabetes in Wistar rats via inhibition of DPP-4.

Novel 1,3,5-triazine derivatives bearing oxazine have been synthesized and tested for their ability to inhibit a panel of dipeptidyl peptidase (DPP)-4, 8, and 9 enzymes. In a comparative inhibitory assay, the molecules showed potent inhibition of DPP-4 ranging from IC50 of 4.2 ± 0.30-260.5 ± 0.42 nM, with no activity against DPP-8 and DPP-9. Among the tested series, compound 8c demonstrated the strongest DPP-4 inhibitory activity with an IC50 of 4.2 ± 0.30 nM. It also showed the greatest binding affinity during docking studies with DPP-4 with a docking score of -8.956 and a glide energy of -78.546 kcal mol-1 and was found oriented in the S1 and S2 pockets of the DPP-4 active site, which is composed of the catalytic triad Ser 630, Asp 710, and His 740. The in vivo pharmacological assay revealed that compound 8c in a dose-dependent manner improved the insulin level, body weight, antioxidants, and HDL, and reduced the levels of blood glucose, LDL, and VLDL in streptozotocin-induced diabetes in Wistar rats. Our study demonstrated the discovery and development of novel 1,3,5-triazine derivatives bearing oxazine as a novel class of anti-diabetic agents via inhibition of DPP-4.

Discovery of novel 1,3,5-triazine derivatives as an antidiabetic agent in Wistar rats via inhibition of DPP-4.

Aim: To develop imeglimin-inspired novel 1,3,5-triazine derivatives as antidiabetic agents. Materials & methods: These derivatives were synthesized and tested against DPP enzymes. Compound 8c was tested for in vivo antidiabetic activity in streptozotocin-induced diabetes in Wistar rats by estimating various biochemical parameters. Docking experiments were also performed. Results: Compound 8c was identified as a selective and potent DPP-4 inhibitor. It was proficiently docked into the catalytic triad of Ser 630, Asp 710 and His740 in S1 and S2 pockets of DPP-4. In experimental animals, it also showed dose-dependent improvement in blood glucose, blood insulin, bodyweight, lipid profile and kidney and liver antioxidant profiles. Conclusion: This study demonstrated the discovery of imeglimin-inspired novel 1,3,5-triazines as a potent antidiabetic agent.

Type 2 diabetes mellitus is a complicated heterogeneous and polygenic metabolic disease. Therefore, in search of a potent antidiabetic drug, the authors have synthesized 13 novel 1,3,5-triazine-morpholino-pyrazole derivatives, compounds 8(a­m), and they were subsequently tested for in vitro inhibitory activity against a panel of DPP enzymes (DPP-4, DPP-8 and DPP-9) where they are found active toward DPP-4 while inactive toward DPP-8 and DPP-9. Compound 8c was observed to be the most potent DPP-4 inhibitor and showed excellent interaction with DPP-4 in docking analysis. Furthermore, in high-fat, low-dose streptozotocin-induced diabetes in rats, compound 8c significantly reduced blood glucose, cholesterol, triglyceride, low-density lipoprotein, very low-density lipoprotein and reactive species levels and increased high-density lipoprotein levels, possibly by the potent inhibition of DPP-4. It also showed intense antioxidant activity. The potent DPP-4 inhibition, antidiabetic and antioxidant activity render compound 8c a probable lead for antidiabetic drug discovery.

In silico screening, synthesis, and antimalarial evaluation of PABA substituted 1,3,5-triazine derivatives as Pf-DHFR inhibitors.

OBJECTIVES: Drug resistance in malaria parasites necessitates the development of new antimalarial drugs with unique mechanisms of action. In the present research work, the PABA conjugated 1,3,5-triazine derivatives were designed as an antimalarial agent. METHODS: In this present work, a library of two hundred-seven compounds was prepared in twelve different series such as [4A (1-23), 4B(1-22), 4C(1-21), 4D(1-20), 4E(1-19), 4F(1-18), 4G(1-17), 4H(1-16), 4I(1-15), 4J(1-13), 4K(1-12) and 4L(1-11) ] respectively using different primary and secondary aliphatic and aromatic amines. Ten compounds were ultimately selected through in silico screening. They were synthesized by conventional and microwave-assisted methods followed by in vitro antimalarial evaluations performed in chloroquine-sensitive (3D7) and resistant (DD2) strains of P. falciparum. RESULTS: The docking results showed that compound 4C(11) had good binding interaction with Phe116, Met55 (-464.70 kcal/mol) and Phe116, Ser111 (-432.60 kcal/mol) against wild (1J3I) and quadruple mutant (1J3K) type of Pf-DHFR. Furthermore, in vitro, antimalarial activity results indicated that compound 4C(11) showed potent antimalarial activity against chloroquine-sensitive (3D7) and chloroquine-resistant (Dd2) strain of P. falciparum along with IC50 (14.90 µg mL-1) and (8.30 µg mL-1). CONCLUSION: These PABA-substituted 1,3,5-triazine compounds could be exploited to develop a new class of Pf-DHFR inhibitors as a lead candidate.

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.

A Review Of Preclinical Tools To Validate Anti-Diarrheal Agents.

BACKGROUND: Since their inception, preclinical experimental models have played an important role in investigating and characterizing disease pathogenesis. These in vivo, ex vivo, and in vitro preclinical tests also aid in identifying targets, evaluating potential therapeutic drugs, and validating treatment protocols. INTRODUCTION: Diarrhea is a leading cause of mortality and morbidity, particularly among children in developing countries, and it represents a huge health-care challenge on a global scale. Due to its chronic manifestations, alternative anti-diarrheal medications must be tested and developed because of the undesirable side effects of currently existing anti-diarrheal drugs. METHODS: Several online databases, including Science Direct, PubMed, Web of Science, Google Scholar and Scopus, were used in the literature search. The datasets were searched for entries of studies up to May, 2022. RESULTS: The exhaustive literature study provides a large number of in vivo, in vitro and ex vivo models, which have been used for evaluating the mechanism of the anti-diarrheal effect of drugs in chemically-, pathogen-, disease-induced animal models of diarrhea. The advances and challenges of each model were also addressed in this review. CONCLUSION: This review encompasses diverse strategies for screening drugs with anti-diarrheal effects and covers a wide range of pathophysiological and molecular mechanisms linked to diarrhea, with a particular emphasis on the challenges of evaluating and predictively validating these experimental models in preclinical studies. This could also help researchers find a new medicine to treat diabetes more effectively and with fewer adverse effects.

Molecular docking and antimalarial evaluation of novel N-(4-aminobenzoyl)-l-glutamic acid conjugated 1,3,5-triazine derivatives as Pf-DHFR inhibitors.

Malaria has been a source of concern for humans for millennia; therefore in the present study we have utilized in-silico approach to generate diverse anti-malarial hit. Towards this, Molinspiration cheminformatics and Biovia Discovery Studio (DS) 2020 were used to conduct molecular modelling studies on 120 designed compounds. Furthermore, the TOPKAT module was used to evaluate the toxicity of the screened compounds. The CDOCKER docking technology was used to investigate protein-ligand docking against the Pf-DHFR-TS protein (PDB ID: 1J3I and 1J3K). These compounds were synthesized using a conventional and microwave-assisted nucleophilic substitution reaction, and they were characterized using a variety of physicochemical and spectroscopic methods. Among the ten compounds tested, Df3 had the highest antimalarial activity against the chloroquine-resistant (Dd2) strain, with an IC50 value of 9.54 µg mL-1 and further demonstrate, molecular dynamics (MD) simulation studies and estimation of MM-PBSA-based free binding energies of docked complexes with 1J3I and 1J3K were carried out. The discovery of a novel class of Pf-DHFR inhibitors can be accomplished using this hybrid scaffold. Supplementary Information: The online version contains supplementary material available at 10.1007/s13205-022-03400-2.

Molecular insights into a mechanism of resveratrol action using hybrid computational docking/CoMFA and machine learning approach.

A phytoalexin, Resveratrol remains a legendary anticancer drug candidate in the archives of scientific literature. Although earlier wet-lab experiments rendering its multiple biological targets, for example, epidermal growth factors, Pro-apoptotic protein p53, sirtuins, and first apoptosis signal (Fas) receptor, Mouse double minute 2 (MDM2) ubiquitin-protein ligase, Estrogen receptor, Quinone reductase, etc. However, notwithstanding some notable successes, identification of an appropriate Resveratrol target(s) has remained a major challenge using physical methods, and hereby limiting its translation into an effective therapeutic(s). Thus, computational insights are much needed to establish proof-of-concept towards potential Resveratrol target(s) with minimum error rate, narrow down the search space, and to assess a more accurate Resveratrol signaling pathway/mechanism at the starting point. Herein, a brute-force technique combining computational receptor-, ligand-based virtual screening, and classification-based machine learning, reveals the precise mechanism of Resveratrol action. Overall, MDM2 ubiquitin-protein ligase (4OGN.pdb) and co-crystallized quinone reductases 2 (4QOH.pdb) were found two suitable drug targets in the case of Resveratrol derivatives. Indeed, carotenoid cleaving oxygenase together with later twos gave gigantic momentum in guiding the rational drug design of Resveratrol derivatives. These molecular modeling insights would be useful for Resveratrol lead optimization into a more precise science.Communicated by Ramaswamy H. Sarma.

Pharmacoinformatics-based identification of transmembrane protease serine-2 inhibitors from Morus Alba as SARS-CoV-2 cell entry inhibitors.

Transmembrane protease serine-2 (TMPRSS2) is a cell-surface protein expressed by epithelial cells of specific tissues including those in the aerodigestive tract. It helps the entry of novel coronavirus (n-CoV) or Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) in the host cell. Successful inhibition of the TMPRSS2 can be one of the crucial strategies to stop the SARS-CoV-2 infection. In the present study, a set of bioactive molecules from Morus alba Linn. were screened against the TMPRSS2 through two widely used molecular docking engines such as Autodock vina and Glide. Molecules having a higher binding affinity toward the TMPRSS2 compared to Camostat and Ambroxol were considered for in-silico pharmacokinetic analyses. Based on acceptable pharmacokinetic parameters and drug-likeness, finally, five molecules were found to be important for the TMPRSS2 inhibition. A number of bonding interactions in terms of hydrogen bond and hydrophobic interactions were observed between the proposed molecules and ligand-interacting amino acids of the TMPRSS2. The dynamic behavior and stability of best-docked complex between TRMPRSS2 and proposed molecules were assessed through molecular dynamics (MD) simulation. Several parameters from MD simulation have suggested the stability between the protein and ligands. Binding free energy of each molecule calculated through MM-GBSA approach from the MD simulation trajectory suggested strong affection toward the TMPRSS2. Hence, proposed molecules might be crucial chemical components for the TMPRSS2 inhibition.

Facile synthesis, antimicrobial and antiviral evaluation of novel substituted phenyl 1,3-thiazolidin-4-one sulfonyl derivatives.

A series of novel substituted phenyl 1, 3-thiazolidin-4-one sulfonyl derivatives 5 (a-t) were synthesized and screened for their in-vitro anti-microbial and anti-viral activity. The result of the anti-microbial assay demonstrated compounds 5d, 5f, 5g, 5h, 5i, 5j showed prominent inhibitory activity against all the tested Gram-positive and Gram-negative bacterial strains, while compounds 5g, 5j, 5o, 5p, 5q showed significant activity against the entire set of fungal strains as compared to standard drug Ampicillin and Clotrimazole, respectively. The antimicrobial study revealed that compounds having electron-withdrawing groups showed significant antimicrobial potency. The most active antibacterial compound 5j showed potent inhibition of S. aureus DNA Gyrase enzyme as a possible mechanism of action for antimicrobial activity. Moreover, the antiviral testing of selected compounds showed considerable activity against Herpes simplex virus-1(KOS), Herpes simplex virus-2 (G), Herpes simplex virus-1(TK- KOS ACVr), Vaccinia virus, Human Coronavirus (229E), Reovirus-1, Sindbis virus, Coxsackie virus B4, Yellow Fever virus and Influenza A, B virus. Compounds 5h exhibited low anti-viral activity against HIV-1(strain IIIB) and HIV-2 (strain ROD). The study clearly outlined that synthesized compounds endowed with good antimicrobial property together with considerable antiviral activity.

Synthesis and biological evaluation of substituted phenyl azetidine-2-one sulphonyl derivatives as potential antimicrobial and antiviral agents.

In the present study, we intend to synthesize a series of novel substituted phenyl azetidine-2-one sulphonyl derivatives. The entire set of derivatives 5 (a-t) were screened for in-vitro antibacterial, and antifungal activity, and among them eleven compounds were further screened for the antiviral activity to predict their efficacy against pathogenic viruses. Interestingly, compound 5d, 5e, 5f, 5h, 5i, and 5j showed similar or better antibacterial activity as compared to ampicillin (standard). Moreover, compounds 5h, 5i, 5j, and 5q showed good inhibitory activity against fungal strains whereas other derivatives had mild or diminished activity in comparison with standard drug clotrimazole. The antimicrobial study indicated that compounds having electron-withdrawing groups showed the highest activity. Interestingly, these tested compounds showed weak antiviral activity against Vaccinia virus, Human Coronavirus (229E), Reovirus-1, Herpes simplex virus, Sindbis virus, Coxsackievirus B4, Yellow Fever virus, and Influenza B virus in HEL cell, Vero cell, and MDCK cell cultures. The findings of the present study might open new avenues to target human disease-causing deadly microbes and viruses.

Acute and sub-chronic toxicity studies of Benincasa hispida (Thunb.) cogniaux fruit extract in rodents.

The objective of the present study was to evaluate the safety of standardized 70% ethanolic extract of Benincasa hispida fruit pulp (HABH) in rodents. Chemical characterization of HABH has been done by GC-MS and dimethylsulfoxonium formyl methylide, l-(+)-ascorbic acid and 2,6-dihexadecanoate were identified as major compounds in the extract. Acute oral toxicity study of HABH was done according to the Organization for Economic Cooperation and Development (OECD) guideline, by 'up and down' method, using the limit test at 2000 mg/kg, body weight in mice and were observed up to 14 days. In sub-chronic oral toxicity study, HABH was administered to Wistar rats at doses of 1000, 200 and 40 mg/kg b. w. per day for 90 days. In acute toxicity study, there was no mortality and no behavioural signs of toxicity at the limit test dose level (2000 mg/kg b. w.). In sub-chronic oral toxicity study, there was no significant difference observed in the consumption of food and water, body weight and relative organ weights. Haematological, serum biochemical and urine analysis revealed the non-adverse effects of prolonged oral consumption of HABH. The histopathologic examination did not show any differences in vital organs. Based on our findings, HABH, at dosage levels up to 1000 mg/kg b. w., is non-toxic and safe for long term oral consumption.

Design and development of 1,3,5-triazine-thiadiazole hybrids as potent adenosine A2A receptor (A2AR) antagonist for benefit in Parkinson's disease.

Various studies showed adenosine A2A receptors (A2ARs) antagonists have profound therapeutic efficacy in Parkinsons Disease (PD) by improving dopamine transmission, thus being active in reversing motor deficits and extrapyramidal symptoms related to the disease. Therefore, in the presents study, we have showed the development of novel 1,3,5-triazine-thiadiazole derivative as potent A2ARs antagonist. In the radioligand binding assay, these molecules showed excellent binding affinity with A2AR compared to A1R, with significant selectivity. Results suggest, compound 7e as most potent antagonist of A2AR among the tested series. In docking analysis with A2AR protein model, compound 7e found to be deeply buried into the cavity of receptor lined via making numerous interatomic contacts with His264, Tyr271, His278, Glu169, Ala63, Val84, Ile274, Met270, Phe169. Collectively, our study demonstrated 1,3,5-triazine-thiadiazole hybrid as a highly effective scaffold for the design of new A2A antagonists.

Potent antibacterial activity of dihydydropyrimidine-1,3,5-triazines via inhibition of DNA gyrase and antifungal activity with favourable metabolic profile.

The compounds were tested against panel of three Gram-positive, viz. Staphylococcus aureus, Bacillus subtilis, Bacillus cereus and three Gram-negative bacterial strains viz. Pseudomonas aeruginosa, Escherichia coli, and Proteus vulgaris where they showed significant to moderate antibacterial activity. The compound also showed considerable antibiofilm activity against S. aureus and B. subtilis. The most potent compounds 7l and 7m found bacteriostatic in time-kill assay via inhibition of DNA gyrase enzyme and interacting with Glu58, Val130, Ile175 and Ile186 via numerous H-bonds as revealed by docking. In S. aureus-induced murine infection model, compound 7m showed dose-dependent reduction of viability of bacteria with maximum activity in 25 mg/kg treated group. The antifungal activity against human fungal pathogens was also estimated, where these compounds showed considerable inhibitory activity as compared to standard. The metabolic liability of compound 7m was determined using RS-Predictor and MetaPrint 2D React. The molecules were proved as effective antibacterial agent via inhibition of DNA gyrase as a mechanism together with significant antifungal activity.

A Comprehensive Review on Preclinical Diabetic Models.

BACKGROUND: Preclinical experimental models historically play a critical role in the exploration and characterization of disease pathophysiology. Further, these in-vivo and in-vitro preclinical experiments help in target identification, evaluation of novel therapeutic agents and validation of treatments. INTRODUCTION: Diabetes mellitus (DM) is a multifaceted metabolic disorder of multidimensional aetiologies with the cardinal feature of chronic hyperglycemia. To avoid or minimize late complications of diabetes and related costs, primary prevention and early treatment are therefore necessary. Due to its chronic manifestations, new treatment strategies need to be developed, because of the limited effectiveness of the current therapies. METHODS: The study included electronic databases such as Pubmed, Web of Science and Scopus. The datasets were searched for entries of studies up to June, 2018. RESULTS: A large number of in-vivo and in-vitro models have been presented for evaluating the mechanism of anti-hyperglycaemic effect of drugs in hormone-, chemically-, pathogen-induced animal models of diabetes mellitus. The advantages and limitations of each model have also been addressed in this review. CONCLUSION: This review encompasses the wide pathophysiological and molecular mechanisms associated with diabetes, particularly focusing on the challenges associated with the evaluation and predictive validation of these models as ideal animal models for preclinical assessments and discovering new drugs and therapeutic agents for translational application in humans. This review may further contribute to discover a novel drug to treat diabetes more efficaciously with minimum or no side effects. Furthermore, it also highlights ongoing research and considers the future perspectives in the field of diabetes.

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

BACKGROUND: Plasmodium falciparum dihydrofolate reductase (Pf-DHFR) is an essential enzyme in the folate pathway and is an important target for antimalarial drug discovery. In this study a modern approach has been undertaken to identify new hits of thiazole-1,3,5-triazine derivatives as antimalarials targeting Pf-DHFR. METHODS: The library of 378 thiazole-1,3,5-triazines were designed and subjected to ADME analysis. The compounds having optimal ADME score, was then evaluated by docking against wild and mutant Pf-DHFR complex. The resultant compound after screening from above these two methods were synthesized, and assayed for in vitro antimalarial against chloroquine-sensitive (3D-7) and chloroquine resistant (Dd-2) strains of P. falciparum. RESULTS: Twenty compounds were identified from the dataset based on considerable AlogP98 vs. PSA_2D confidence ellipse, ADME filter and TOPKAT toxicity analysis. Majority of compounds showed interaction with Asp54, Arg59, Arg122 and Ile 164 in docking analysis. Entire set of tested derivatives exhibited considerable activity at the tested dose against sensitive strain with IC50 values varying from 10.03 to 54.58 µg/ml. Furthermore, against chloroquine resistant strain, eight compounds showed IC50 from 11.29 to 40.92 µg/ml. Compound A5 and H16 were found to be the most potent against both the strains of P. Falciparum. CONCLUSION: Results of the study suggested the possible utility of thiazole-1,3,5-triazines as new lead for identifying new class of Pf-DHFR inhibitor.

Review on Synthetic Chemistry and Antibacterial Importance of Thiazole Derivatives.

BACKGROUND: Thiazole is one of the leading heterocyclic five-member ring compounds that contain nitrogen and sulphur atom. Many natural and/or synthetic compounds contain thiazole as an essential moiety and possess diverse therapeutic activities. The thiazole ring was modified at different positions to generate new molecules with potent antibacterial activities. Thus, the present review enumerates the antibacterial importance of thiazole and its derivatives. METHOD: The mining of literature has been performed using different database which includes only peer-reviewed journals. The quality of retrieved papers was appraised using standard tools. Moreover, the significant papers were described in detail to focus on thiazole derivatives showing considerable antibacterial activity. RESULT: The present review describes the chemistry, SAR (Structure Activity Relationship) studies and antibacterial importance of thiazole with different synthetic procedures. CONCLUSION: This particular study certainly benefits the researchers interested in exploiting the antibacterial activity of thiazoles in search of novel agents.

Update on Nitazoxanide: A Multifunctional Chemotherapeutic Agent.

BACKGROUND: The thiazolide nitazoxanide (NTZ) is a broad-spectrum antiinfective drug that adversely affects viability, growth, and proliferation of a range of extracellular and intracellular protozoan, helminths, anaerobic and microaerophilic bacteria, and viruses. METHOD: Current review compiled the potential chemotherapeutic efficacy of NTZ against a variety of such disease-causing macro and/or micro-organisms as well as neoplastic cells, using various search engines viz. Web of Science, Scopus and Pub- Med up to February 2017. RESULT: The most accepted anti-infective mechanism of NTZ involves impairment of the energy metabolism in anaerobic pathogens by inhibition of the pyruvate: ferredoxin/ flavodoxin oxidoreductase (PFOR). In parasitic-protozoan NTZ also induces lesions/voids in the cell membrane and depolarises the mitochondrial membrane along with the inhibition of quinone oxidoreductase NQO1, nitroreductase-1 and protein disulphide isomerase. NTZ also inhibits the glutathione-S-transferase (a major detoxifying enzyme) and modulates a gene (avr-14 gene) encoding for the alphatype subunit of glutamate-gated chloride ion channel present in the nematodes. Apart from well recognized non-competitive inhibition of the PFOR in anaerobic bacteria, NTZ also showed a variety of other antibacterial mechanisms viz. inhibits pyruvate dehydrogenase in the Escherichia coli, disrupts the membrane potential and pH homeostasis in the Mycobacterium tuberculosis, suppresses the chaperone/usher (CU) pathway of the gram-negative bacteria and stimulates host macrophage autophagy in the tubercular patients. NTZ also suppresses the viral replication by inhibiting maturation of the viral hemagglutinin and the viral transcription factor immediate early 2 (IE2) as well as by activating the eukaryotic translation initiation factor 2α (an antiviral intracellular protein). Additionally, NTZ expresses inhibitory effect on the tumour cell progression by modulating drug detoxification (glutathione-S-transferase P1), unfolded protein response, autophagy, anti-cytokines activities and c-Myc inhibition. CONCLUSION: These potentially versatile molecular interactions of NTZ within invading pathogen(s) and immunomodulatory efficacy over the hosts, justify the multifunctional chemotherapeutic significance of this chemical agent.