Synthesis and evaluation of pyrazolines bearing benzothiazole as anti-inflammatory agents

Recent Advances in the Application of 2-Aminobenzothiazole to the Multicomponent Synthesis of Heterocycles

Heterocycles are a vital class of compounds in numerous fields, including drug discovery, agriculture, and materials science. Efficient methods for the synthesis of heterocycles remain critical for meeting the demands of these industries. Recent advances in multicomponent reactions (MCRs) utilizing 2-aminobenzothiazole (ABT) have shown promising results for the formation of heterocycles. The versatility of 2-aminobenzothiazole in this context has enabled the rapid and efficient construction of diverse heterocyclic structures. Various synthetic methodologies and reactions involving 2-aminobenzothiazole are discussed, highlighting its importance as a valuable building block in the synthesis of complex heterocycles. The potential applications of these heterocycles in drug discovery and material science are also explored. Overall, this review provides a comprehensive overview of the current state of research in the field and offers insights into the future directions of this promising area of study. We highlight the potential of ABT as a versatile and sustainable starting material in heterocyclic synthesis via MCRs, with significant implications for the chemical industry.

Synthesis, DFT, and in silico biological evaluation of chalcone bearing pyrazoline ring against Helicobacter pylori receptors

Peptic ulcer disease (PUD), often caused by Helicobacter pylori infection, is a prevalent gastrointestinal condition characterized by the erosion of the gastric or duodenal mucosal lining. H. pylori adheres to gastric epithelial cells, secreting toxins and disrupting the stomach's defenses. H. pylori relies on various receptors to establish infection, making these molecules attractive therapeutic targets. This study aimed to develop novel anti-ulcer compounds by combining benzothiazole, pyrazoline, and chalcone pharmacophores. A series of chalcone derivatives 4a-c were synthesized via Claisen-Schmidt condensation and characterized using spectroscopic techniques such as FT-IR, NMR and elemental analysis. The DFT calculations, using B3LYP method with 6-311G basis set, revealed the p-tolyl derivative 4b exhibited the highest thermal stability while the p-bromophenyl derivative 4c showed the lowest stability but highest chemical reactivity. The HOMO-LUMO energy gaps as well as the dipole moments decreased in the order: 4b > 4a > 4c, reflecting a similar reactivity trend. Molecular docking showed ligands 4a-c bound effectively to the H. pylori urease enzyme, with docking scores from -5.3862 to -5.7367 kcal/mol with superior affinity over lansoprazole. Key interactions involved hydrogen bonds and hydrophobic pi-hydrogen bonds with distances ranging 3.46-4.34 Å with active site residues ASN666, SER714 and ASN810. The combined anti-inflammatory, antimicrobial, and H. pylori anti-adhesion properties make these novel chalcones promising PUD therapeutic candidates.

New pyridine-based chalcones and pyrazolines with anticancer, antibacterial, and antiplasmodial activities

New pyridine-based chalcones 4a-h and pyrazolines 5a-h (N-acetyl), 6a-h (N-phenyl), and 7a-h (N-4-chlorophenyl) were synthesized and evaluated by the National Cancer Institute (NCI) against 60 different human cancer cell lines. Pyrazolines 6a, 6c-h, and 7a-h satisfied the pre-determined threshold inhibition criteria, obtaining that compounds 6c and 6f exhibited high antiproliferative activity, reaching submicromolar GI50 values from 0.38 to 0.45 μM, respectively. Moreover, compound 7g (4-CH3) exhibited the highest cytostatic activity of these series against different cancer cell lines from leukemia, nonsmall cell lung, colon, ovarian, renal, and prostate cancer, with LC50 values ranging from 5.41 to 8.35 μM, showing better cytotoxic activity than doxorubicin. Furthermore, the compounds were tested for antibacterial and antiplasmodial activities. Chalcone 4c was the most active with minimal inhibitory concentration (MIC) = 2 μg/mL against methicillin-resistant Staphylococcus aureus (MRSA), while the pyrazoline 6h showed a MIC = 8 μg/mL against Neisseria gonorrhoeae. For anti-Plasmodium falciparum activity, the chalcones display higher activity with EC50 values ranging from 10.26 to 10.94 μg/mL. Docking studies were conducted against relevant proteins from P. falciparum, exhibiting the minimum binding energy with plasmepsin II. In vivo toxicity assay in Galleria mellonella suggests that most compounds are low or nontoxic.

Molecular modeling and biological investigation of novel s-triazine linked benzothiazole and coumarin hybrids as antimicrobial and antimycobacterial agents

A novel series of s-triazine linked benzothiazole and coumarin hybrids (6a-6d, 7a-7d, and 8a-8d) were synthesized and characterized by IR, NMR, and mass spectrometry. The compound's in vitro antibacterial and antimycobacterial activities were also evaluated. Remarkable antibacterial activity with MIC in the range of 12.5-62.5 μM and antifungal activity of 100-200 μM were demonstrated by in vitro antimicrobial analysis. Compounds 6b, 6d, 7b, 7d, and 8a strongly inhibited all bacterial strains, while 6b, 6c, and 7d had good to moderate efficacy against M. tuberculosis H37Rv. Synthesized hybrids are observed in the active pocket of the S. aureus dihydropteroate synthetase enzyme, according to a molecular docking investigations. Among the docked compounds, 6d had a strong interaction and a greater binding affinity, and the dynamic stability of protein-ligand complexes was examined using molecular dynamic simulation with various settings at 100 ns. The proposed compounds successfully maintained their molecular interaction and structural integrity inside the S. aureus dihydropteroate synthase, according to the MD simulation analysis. These in silico analyses supported the in vitro antibacterial results of compound 6d, which demonstrated outstanding in vitro antibacterial efficacy against all bacterial strains. In the quest for new antibacterial drug-like molecules, compounds 6d, 7b, and 8a have been identified as promising lead compounds.Communicated by Ramaswamy H. Sarma.

Two Novel Regioisomeric Series of Bis-pyrazolines: Synthesis, In Silico Study, DFT Calculations, and Comparative Antibacterial Potency Profile against Drug-Resistant Bacteria; MSSA, MRSA, and VRSA

Aims: Design and synthesis of antimicrobial prototypes that are capable of eradicating bacterial biofilm formation that is responsible for many health challenges particularly with antibiotic-resistant bacterial species. Materials and Methods: The utility of 1,3-diarylenones, aka chalcones, 3a-i and 8a-j as building blocks to construct the corresponding bis-pyrazoline derivatives 5aa-bh and 9ad-bj. Screening the antibacterial behavior of the novel bis-pyrazoline derivatives against methicillin-sensitive Staphylococcus aureus (MSSA), methicillin-resistant S. aureus (MRSA), and vancomycin-resistant S. aureus (VRSA) bacterial strains was investigated. Results: Chalcones were used as building scaffolds to construct two series of di- and trisubstituted bis-pyrazoline derivatives. Numerous novel bis-compounds displayed decent bacterial biofilm suppression. Conclusions: Two regioisomeric series of bis-chalcones were designed and constructed, and their structural diversity was manipulated to access the intrinsically bioactive, pyrazoline ring. The newly synthesized bis-pyrazoline derivatives presented decent antibacterial behavior against multiple drug-resistant bacterial strands (MSSA, MRSA, and VRSA).

Novel promising benzoxazole/benzothiazole-derived immunomodulatory agents: Design, synthesis, anticancer evaluation, and in silico ADMET analysis

Eleven novel benzoxazole/benzothiazole-based thalidomide analogs were designed and synthesized to obtain new effective antitumor immunomodulatory agents. The synthesized compounds were evaluated for their cytotoxic activities against HepG-2, HCT-116, PC3, and MCF-7 cells. Generally, the open analogs with semicarbazide and thiosemicarbazide moieties (10, 13a-c, 14, and 17a,b) exhibited higher cytotoxic activities than derivatives with closed glutarimide moiety (8a-d). In particular, compound 13a (IC50  = 6.14, 5.79, 10.26, and 4.71 µM against HepG-2, HCT-116, PC3, and MCF-7, respectively) and 14 (IC50  = 7.93, 8.23, 12.37, and 5.43 µM, respectively) exhibited the highest anticancer activities against the four tested cell lines. The most active compounds 13a and 14 were further evaluated for their in vitro immunomodulatory activities on tumor necrosis factor-alpha (TNF-α), caspase-8 (CASP8), vascular endothelial growth factor (VEGF), and nuclear factor kappa-B p65 (NF-κB p65) in HCT-116 cells. Compounds 13a and 14 showed a remarkable and significant reduction in TNF-α. Furthermore, they showed significant elevation in CASP8 levels. Also, they significantly inhibited VEGF. In addition, compound 13a showed significant decreases in the level of NF-κB p65 while compound 14 demonstrated an insignificant decrease with respect to thalidomide. Moreover, our derivatives exhibited good in silico absorption, distribution, metabolism, elimination, toxicity (ADMET) profiles.

Synthetic Approaches, Biological Activities, and Structure-Activity Relationship of Pyrazolines and Related Derivatives

It has been established that pyrazolines and their analogs are pharmacologically active scaffolds. The pyrazoline moiety is present in several marketed molecules with a wide range of uses, which has established its importance in pharmaceutical and agricultural sectors, as well as in industry. Due to its broad-spectrum utility, scientists are continuously captivated by pyrazolines and their derivatives to study their chemistry. Pyrazolines or their analogs can be prepared by several synthesis strategies, and the focus will always be on new greener and more economical ways for their synthesis. Among these methods, chalcones, hydrazines, diazo compounds, and hydrazones are most commonly applied under different reaction conditions for the synthesis of pyrazoline and its analogs. However, there is scope for other molecules such as Huisgen zwitterions, different metal catalysts, and nitrile imine to be used as starting reagents. The present article consists of recently reported synthetic protocols, pharmacological activities, and the structure-activity relationship of pyrazoline and its derivatives, which will be very useful to researchers.

Pyrazole and pyrazoline derivatives as antimalarial agents: A key review

Malaria poses a severe public health risk and a significant economic burden in disease-endemic countries. One of the most severe issues in malaria control is the development of drug resistance in malaria parasites. The standard treatment for malaria is artemisinin-combination therapy (ACT). Nevertheless, the Plasmodium parasite's extensive resistance to prior drugs and reduced ACT efficiency necessitates novel drug discovery. The progress in discovering novel, affordable, and effective antimalarial agents is significant in combating drug resistance, and the hybrid drug concept can be used to covalently link two or more active pharmacophores that may act on multiple targets. Pyrazole and pyrazoline derivatives are considered pharmacologically necessary active heterocyclic scaffolds that possess almost all types of pharmacological activities. This review summarized recent progress in antimalarial activities of synthesized pyrazole and pyrazoline derivatives. The studies published since 2000 are included in this systematic review. This review is anticipated to be beneficial for future study and new ideas in searching for rational development strategies for more effective pyrazole and pyrazoline derivatives as antimalarial drugs.

Peripherally, non-peripherally and axially pyrazoline-fused phthalocyanines: synthesis, aggregation behaviour, fluorescence, singlet oxygen generation, and photodegradation studies

Pyrazoline-fused peripheral zinc phthalocyanine (HY-ZnPcP) showed the highest singlet oxygen generation in DMSO, and it is thought to be a photosensitizer candidate for photodynamic therapy.

Synthesis, Anticancer and Antitubercular Properties of New Chalcones and Their Nitrogen-Containing Five-Membered Heterocyclic Hybrids Bearing Sulfonamide Moiety

A new series of sulfonamides, 8a-b, 10, 12, and 14a-b, were synthesized by N-sulfonation reaction with sulfonyl chlorides 6a-b. Five new series of chalcone-sulfonamide hybrids (16-20)a-f were prepared via Claisen–Schmidt condensation of the newly obtained sulfonamides with aromatic aldehydes 15a-f in basic medium. Chalcones substituted with chlorine at position 4 of each series were used as precursors for the generation of their five-membered heterocyclic pyrazoline (22-23)a-d, (24-25)a-b and carbothioamide 27a-f derivatives. The synthesized compounds were evaluated for their anticancer and antituberculosis activities. To determine their anticancer activity, compounds were screened against sixty human cancer cell lines at a single dose (10 μM). Compounds 17a-c were highly active against LOX IMVI (melanoma), with IC₅₀ values of 0.34, 0.73 and 0.54 μM, respectively. Chalcone 18e showed remarkable results against the entire panel of leukemia cell lines with IC₅₀ values between 0.99–2.52 μM. Moreover, compounds 20e and 20f displayed growth inhibition of Mycobacterium tuberculosis H37Rv at concentrations below 10 μM. Although they showed low selectivity in cytotoxicity tests against the Vero cell line, further optimization could advance the potential biological activity of the selected compounds.

Current Perspective of Synthesis of Medicinally Relevant Benzothiazole Based Molecules: Potential for Antimicrobial and Anti-Inflammatory Activities

The therapeutic potential of the majority of the marketed drugs is due to the presence of a heterocyclic nucleus, which constitutes a huge role in the field of medicinal chemistry. These heterocyclic scaffolds could act as a template in order to design potential therapeutic agents against several diseases. Benzothiazole scaffold is one of the influential heteroaromatic rings in the field of medicinal chemistry owing to its extensive pharmacological features. Herein, we have focused on the synthesis of benzothiazole based medicinal molecules, which possess antimicrobial and anti-inflammatory activities. This review covers a systematic description of synthetic routes for biologically relevant benzothiazole derivatives in the last five years. The main aim of this study is to show the diversification of benzothiazole based molecules into their pharmacologically more active derivatives. This review's synthetic protocols include metal-free, metal-catalyzed, and metal precursor azo dyes strategies for the development of benzothiazole derived bioactive compounds. The discussion under the various headings covers synthetic schemes and biological activities of the most potent molecules in the form of minimum inhibitory concentration.

Recent advances in the synthesis of benzothiazole and its derivatives

Abstract:

Benzothiazoles have recognized pharmacophores in the field of research, predominantly in synthetic and medicinal chemistry, on account of their significant pharmaceutical properties. This important class of derivatives endows an extensive range of biological activities like anti-inflammatory, antidiabetic, anticancer, anticonvulsant, antibacterial, antiviral, antioxidant, antituberculosis, enzyme inhibitors, etc. Hence, various methodologies have been accomplished to synthesize benzothiazole compounds considering the purity, yield, and selectivity of the products. This review provides different reaction methods that are involved in the synthesis of a variety of benzothiazole derivatives.

A review on synthetic chalcone derivatives as tubulin polymerisation inhibitors

Microtubules play an important role in the process of cell mitosis and can form a spindle in the mitotic prophase of the cell, which can pull chromosomes to the ends of the cell and then divide into two daughter cells to complete the process of mitosis. Tubulin inhibitors suppress cell proliferation by inhibiting microtubule dynamics and disrupting microtubule homeostasis. Thereby inducing a cell cycle arrest at the G2/M phase and interfering with the mitotic process. It has been found that a variety of chalcone derivatives can bind to microtubule proteins and disrupt the dynamic balance of microtubules, inhibit the proliferation of tumour cells, and exert anti-tumour effects. Consequently, a great number of studies have been conducted on chalcone derivatives targeting microtubule proteins. In this review, synthetic or natural chalcone microtubule inhibitors in recent years are described, along with their structure-activity relationship (SAR) for anticancer activity.

Novel quinolinone-pyrazoline hybrids: synthesis and evaluation of antioxidant and lipoxygenase inhibitory activity

The present project deals with the investigation of structure-activity relationship of several quinolinone-chalcone and quinolinone-pyrazoline hybrids, in an effort to discover promising antioxidant and anti-inflammatory agents. In order to accomplish this goal, four bioactive hybrid quinolinone-chalcone compounds (8a-8d) were synthesized via an aldol condensation reaction, which were then chemically modified, forming fifteen new pyrazoline analogues (9a-9o). All the synthesized analogues were in vitro evaluated in terms of their antioxidant and soybean lipoxygenase (LOX) inhibitory activity. Among all the pyrazoline derivatives, compounds 9b and 9m were found to possess the best combined activity, whereas 9b analogue exhibited the most potent LOX inhibitory activity, with IC50 value 10 μM. The in silico docking results revealed that the synthetic pyrazoline analogue 9b showed high AutoDock Vina score (- 10.3 kcal/mol), while all the tested derivatives presented allosteric interactions with the enzyme.

Photocatalytic three-component radical cascade: a general route to heterocyclic-substituted alkyl sulfones

A photoredox-catalyzed three-component radical cascade reaction of β,γ-unsaturated oximes/hydrazones, the sulfur dioxide surrogate of DABCO·(SO2)2 and alkenes under mild conditions is developed.

Recent advancements in the development of bioactive pyrazoline derivatives

Pyrazolines remain privileged heterocycles in drug discovery. 2-Pyrazoline scaffold has been proven as a ubiquitous motif which is present in a number of pharmacologically important drug molecules such as antipyrine, ramifenazone, ibipinabant, axitinib etc. They have been widely explored by the scientific community and are reported to possess wide spectrum of biological activities. For combating unprecedented diseases and worldwide increasing drug resistance, 2-pyrazoline has been tackled as a fascinating pharmacophore to generate new molecules with improved potency and lesser toxicity along with desired pharmacokinetic profile. This review aims to summarizes various recent advancements in the medicinal chemistry of pyrazoline based compounds with the following objectives: (1) To represent inclusive data on pyrazoline based marketed drugs as well as therapeutic candidates undergoing preclinical and clinical developments; (2) To discuss recent advances in the medicinal chemistry of pyrazoline derivatives with their numerous biological significances for the eradication of various diseases; (3) Summarizes structure-activity relationships (SAR) including in silico and mechanistic studies to afford ideas for the design and development of novel compounds with desired therapeutic implications.

Antimicrobial, Antioxidant, and Anticancer Activities of Some Novel Isoxazole Ring Containing Chalcone and Dihydropyrazole Derivatives

Our previous work identified isoxazole-based chalcones and their dihydropyrazole derivatives as two important five-membered heterocycles having antitubercular activity. Hence, in the present study, we biologically evaluated 30 compounds, including 15 isoxazole ring-containing chalcones (17-31) and 15 dihydropyrazoles (32-46) derived from these chalcones for their antimicrobial, antioxidant, and anticancer activities. Chalcones exhibited superior antibacterial and antioxidant activities compared to dihydropyrazoles. Among the chalcones, compound 28 showed potent antibacterial (MIC = 1 µg/mL) and antioxidant activities (IC₅₀ = 5 ± 1 µg/mL). Dihydropyrazoles, on the contrary, demonstrated remarkable antifungal and anticancer activities. Compound 46 (IC₅₀ = 2 ± 1 µg/mL) showed excellent antifungal activity whereas two other dihydropyrazoles 45 (IC₅₀ = 2 ± 1 µg/mL) and 39 (IC₅₀ = 4 ± 1 µg/mL) exhibited potential anticancer activity. The compounds were also tested for their toxicity on normal human cell lines (LO2) and were found to be nontoxic. The active compounds that have emerged out of this study are potential lead molecules for the development of novel drugs against infectious diseases, oxidative stress, and cancer.

A Mild Synthesis of 2-Substituted Benzothiazoles via Nickel-Catalyzed Intramolecular Oxidative C-H Functionalization

A highly efficient synthetic method for the preparation of 2-aminobenzothiazoles starting from arylthioureas has been reported. By using a nickel catalyst, arylthioureas undergo intramolecular oxidative C-H bond functionalization, giving the desired 2-aminobenzothiazoles in good to excellent yields. This protocol features an inexpensive catalyst, low catalyst loading, mild reaction conditions, a short reaction time, and good to excellent yields, and it can be scaled up easily to a gram scale with almost no yields decreasing.

Copper fluorapatite assisted synthesis of new 1,2,3-triazoles bearing a benzothiazolyl moiety and their antibacterial and anticancer activities

New 1,2,3-triazoles with a benzothiazolyl scaffold have been synthesized for the first time using copper fluorapatite as a catalyst and their antibacterial and anticancer activities are reported.

Therapeutic advancement of benzothiazole derivatives in the last decennial period

Benzothiazole, a fused heterocyclic moiety, has attracted synthetic and medicinal chemists for good reasons. It is a valuable scaffold that possesses diverse biological activities, such as anticancer, anti-inflammatory, antimicrobial, antiviral, antimalarial, and anticonvulsant effects. This review mainly focusses on the recent research work on the different biological activities of benzothiazole-based compounds.

Solvent-Free Synthesis of 2-Alkylbenzothiazoles and Bile Acid Derivatives Containing Benzothiazole Ring by Using Active Carbon/Silica Gel and Microwave

A highly efficient and simple method for the synthesis of 2-alkylbenzothiazoles through the condensation of 2-aminothiophenol and aliphatic aldehydes in the presence of active carbon/silica gel is described. The reaction proceeded under solvent-free and microwave irradiation to afford 2-alkylbenzothiazoles in high yields. This method was extended to the synthesis of bile acid derivatives containing a benzothiazole ring and obtained the desired products in high yields. The anti-inflammatory activity and cytotoxicity of the newly synthesized benzothiazole derivatives of bile acid were tested; the results showed that anti-inflammatory activities of all tested compounds tested were higher than that of standard drugs, such as indomethacin.

Synthesis, p38α MAP kinase inhibition, anti-inflammatory activity, and molecular docking studies of 1,2,4-triazole-based benzothiazole-2-amines

Recent studies have demonstrated that inhibition of p38α MAP kinase could effectively inhibit pro-inflammatory cytokines including TNF-α and interleukins. Thus, inhibition of this enzyme can prove greatly beneficial in the therapy of chronic inflammatory diseases. A new series of N-[3-(substituted-4H-1,2,4-triazol-4-yl)]-benzo[d]thiazol-2-amines (4a-n) were synthesized and subjected to in vitro evaluation for anti-inflammatory activity (BSA anti-denaturation assay) and p38α MAPK inhibition. Among the compounds selected for in vivo screening of anti-inflammatory activity (4b, 4c, 4f, 4g, 4j, 4m, and 4n), compound 4f was found to be the most active with an in vivo anti-inflammatory efficacy of 85.31% when compared to diclofenac sodium (83.68%). It was also found to have a low ulcerogenic risk and a protective effect on lipid peroxidation. The p38α MAP kinase inhibition of this compound (IC₅₀  = 0.036 ± 0.12 μM) was also found to be superior to the standard SB203580 (IC₅₀  = 0.043 ± 0.27 μM). Furthermore, the in silico binding mode of the compound on docking against p38α MAP kinase exemplified stronger interactions than those of SB203580.

Docking assisted design of novel 4-adamantanyl-2-thiazolylimino-5-arylidene-4-thiazolidinones as potent NSAIDs

Docking analysis was used to predict the effectiveness of adamantanyl insertion in improving cycloxygenase/lipoxygenase (COX/LOX) inhibitory action of previously tested 2-thiazolylimino-5-arylidene-4-thiazolidinones. The crystal structure data of human 5-LOX (3O8Y), ovine COX-1 (1EQH) and mouse COX-2 (3ln1) were used for docking analysis. All docking calculations were carried out using AutoDock 4.2 software. Following prediction results, 11 adamantanyl derivatives were synthesized and evaluated for biological action. Prediction evaluations correlated well with experimental biological results. Comparison of the novel adamantanyl derivatives with the 2-thiazolylimino-5-arylidene-4-thiazolidinones previously tested showed that insertion of the adamantanyl group led to the production of more potent COX-1 inhibitors, as well as LOX inhibitors (increased activity from 200% to 560%). Five compounds out of the 11 exhibited better activity than naproxen; while nine out of 11 showed better activity than NDGA and seven compounds possessed better anti-inflammatory activity than indomethacin.

Synthesis, molecular modelling studies and ADME prediction of benzothiazole clubbed oxadiazole-Mannich bases, and evaluation of their anti-diabetic activity through in vivo model

A small library of new benzothiazole clubbed oxadiazole-Mannich bases (M-1 to M-22) were synthesized and characterized by IR, NMR, Mass and Elemental analysis results. Molecular docking studies were done to assess the binding mode and interactions of synthesized hits at binding site of receptor Peroxisome proliferator-activated receptor, PPAR-γ or PPARG (PDB 1FM9). Among the synthesized compounds, nine compounds were selected on the basis of docking score and evaluated for their in vivo anti-diabetic activity using Oral Glucose Tolerance Test (OGTT) in normal rats followed by Streptozotocin (STZ) - induced diabetes. Results indicated that compound M-14 (161.39 ± 4.38) showed the highest reduction of blood glucose level comparable to that of the standard drug glibenclamide (140.29 ± 1.24) in STZ model. Other compounds exhibited moderate to good anti hyperglycaemic activity. ADME studies was done using Molinspiration online software, revealed that all compounds (except M-11) are likely to be orally active as they obeyed Lipinski's rule of five.

Facile synthesis of some pyrazoline-based compounds with promising anti-inflammatory activity

Aim: Search for new anti-inflammatory agents with higher efficacy and lower toxicity is an urgent demand in drug discovery era. Methodology: Different pyrazoline derivatives 4a,b, 5a,b, 6a–h and 7a–f were prepared from the condensation reactions of 1,5-bis(5-methylfuran/thiophen-2-yl)penta-1,4-dien-3-ones 3a,b with different hydrazine derivatives. All compounds were screened for their anti-inflammatory activity using the carrageenan-induced paw edema method in rats and TNF-α inhibition assay. Results: Many compounds revealed promising anti-inflammatory activity relative to indomethacin especially compounds 4a, 5a, 5b, 6b, 6d, 6f and 7b. They were safe to the gastric mucosa and did not cause toxicity up to tenfolds the anti-inflammatory dose, in addition, all compounds inhibited TNF-α with IC50 values of 1.7–100 nM.

Green synthesis, biological and spectroscopic study on the interaction of multi-component Mannich bases of imidazo[2,1-b]benzothiazoles with human serum albumin

A series of Mannich bases of imidazo[2, l-b]benzothiazoles were prepared through one-pot multi-component reaction in the presence of water as an eco-friendly solvent. All the synthesized compounds were confirmed from IR, ¹HNMR, ¹³CNMR, and Mass spectroscopy. Evaluation of in vitro anti-inflammatory and anti-microbial activities of all the synthesized derivatives was further accomplished. These results clearly displayed that compound 6d exhibited outstanding anti-inflammatory activity with a percentage inhibition of 70.23% by membrane stabilization method whereas 67.54% at 100μgmL^-1 by the albumin denaturation method, which is comparable to the standard Diclofenac. Further screening against five fungal species (C. albicans ATCC 76615, C. mycoderma, C. utilis, A. flavus, and B. yeast) along with four gram positive (Methicillin-resistant S. aureus N315 (MRSA), Staphylococcus aureus ATCC 6538, Bacillus subtilis ATCC 21216, and Micrococcus luteus ATCC 4698), and six Gram-negative bacterial strains (Escherichia coli DH52, Escherichia coli JM109, Salmonella dysenteriae, Pseudomonas aeruginosa ATCC 27853, Bacillus proteus ATCC13315 and Bacillus typhi) was carried out. These findings manifested that compound 7c displayed excellent antifungal efficacy while compound 7b revealed significant anti-microbial activity. In addition binding behaviour of compound 7b was investigated by binding study between calf thymus DNA and compound 7b by UV-Vis absorption spectroscopy and further research about HSA interactions was carried out.

Synthesis, In Vitro α-Glucosidase Inhibitory Activity and Molecular Docking Studies of Novel Benzothiazole-Triazole Derivatives

Benzothiazole-triazole derivatives 6a–6s have been synthesized and characterized by ¹H-NMR and ¹³C-NMR. All synthetic compounds were screened for their in vitro α-glucosidase inhibitory activity by using Baker’s yeast α-glucosidase enzyme. The majority of compounds exhibited a varying degree of α-glucosidase inhibitory activity with IC₅₀ values between 20.7 and 61.1 μM when compared with standard acarbose (IC₅₀ = 817.38 μM). Among the series, compound 6s (IC₅₀ = 20.7 μM) bearing a chlorine group at the 5-position of the benzothiazole ring and a tert-butyl group at the para position of the phenyl ring, was found to be the most active compound. Preliminary structure-activity relationships were established. Molecular docking studies were performed to predict the binding interaction of the compounds in the binding pocket of the enzyme.

Synthesis and Antidepressant Activity Profile of Some Novel Benzothiazole Derivatives

Within the scope of our new antidepressant drug development efforts, in this study, we synthesized eight novel benzothiazole derivatives 3a–3h. The chemical structures of the synthesized compounds were elucidated by spectroscopic methods. Test compounds were administered orally at a dose of 40 mg/kg to mice 24, 5 and 1 h before performing tail suspension, modified forced swimming, and activity cage tests. The obtained results showed that compounds 3c, 3d, 3f–3h reduced the immobility time of mice as assessed in the tail suspension test. Moreover, in the modified forced swimming tests, the same compounds significantly decreased the immobility, but increased the swimming frequencies of mice, without any alteration in the climbing frequencies. These results, similar to the results induced by the reference drug fluoxetine (20 mg/kg, po), indicated the antidepressant-like activities of the compounds 3c, 3d, 3f–3h. Owing to the fact that test compounds did not induce any significant alteration in the total number of spontaneous locomotor activities, the antidepressant-like effects of these derivatives seemed to be specific. In order to predict ADME parameters of the synthesized compounds 3a–3h, some physicochemical parameters were calculated. The ADME prediction study revealed that all synthesized compounds may possess good pharmacokinetic profiles.

3-(2-Hydroxy-4-methoxyphenyl)-N-(2-methoxyphenyl)-5-(naphthalen-1-yl)-4,5-dihydro-1H-pyrazole-1-carbothioamide

In the title molecule, C28H25N3O3S, the dihedral angles formed by the naphthalene ring system and the benzene rings are 73.03 (13) and 74.04 (11)°. The benzene rings attached to the central pyrazoline ring are almost coplanar, as indicated by the dihedral angle of 2.22 (10)° between them. The C atom of the methoxy group of the phenol ring is essentially coplanar with the ring [C—C—O—C = −0.3 (3)°], whereas the C atom of the methoxy group of the thioamide benzene ring is slightly twisted [C—C—O—C = 5.4 (3)°]. An intramolecular O—H...N hydrogen bond generates anS(6) ring motif. In the crystal, pairs of very weak C—H...S interactions form inversion dimers with anR22(18) motif.

Synthesis of new pyrazolo[3,4-d]pyrimidine derivatives and evaluation of their anti-inflammatory and anticancer activities

This study reports the synthesis of two series of new purine bioisosteres comprising a pyrazolo[3,4-d]pyrimidine scaffold linked to piperazine moiety through different amide linkages. The newly synthesized compounds were evaluated for anticancer activity against four cell lines (MDA-MB-231, MCF-7, SF-268, B16F-10) and cyclooxygenase (COX-2) protein expression inhibition in lipopolysaccharide (LPS)-activated rat monocytes. The results revealed that most of the synthesized compounds showed moderate-to-high cytotoxic activity against at least one cell line, with compound 10b being the most active against all used cell lines (IC₅₀ values 5.5-11 μg/ml) comparable to cisplatin. In addition, six of these compounds (7b, 10a-d, and 12c) demonstrated inhibition of LPS-induced COX-2 protein expression at low concentration (25 μg/ml) as compared to the control non-stimulated cells and showed a COX-2 selectivity index range comparable to diclofenac sodium. The overall results indicate that many of these pyrazolopyrimidine derivatives possess in vitro anti-inflammatory and anticancer activities at varying doses, and the most active compounds will be subjected to in vivo pharmacological evaluation.