A class of pyrrole derivatives endowed with analgesic/anti-inflammatory activity

Insights into the Biological Activities and Substituent Effects of Pyrrole Derivatives: The Chemistry-Biology Connection

Pyrrole, with its versatile heterocyclic ring structure, serves as a valuable template for generating a diverse range of lead compounds with various pharmacophores. Researchers and scientists globally are intrigued by pyrrole and its analogs for their broad pharmacological potential, prompting thorough investigations aimed at advancing human welfare. This comprehensive review delves into the diverse activities exhibited by pyrrole compounds, encompassing their synthesis, reactions, and pharmacological properties alongside their derivatives. In addition to detailing the characteristics of pyrrole and its derivatives within the context of green chemistry, the review also examines microwave-assisted reactions. It provides insights into their chemical structures, natural occurrences, and potential applications across various domains. Furthermore, the article investigates structural alterations of pyrrole compounds and their implications on their functionality, highlighting their versatility as foundational elements for both functional materials and bioactive compounds. The review emphasizes the need for ongoing research and development in the field of pyrrole compounds to discover new activities and benefits.

Pyrrole-thiazolidinone hybrids as a new structural class of broad-spectrum anti-infectives

A series of pyrrole-thiazolidinone hybrids was designed, synthesized and evaluated for activities against ESKAP bacteria panel and mycobacterial pathogens. From the series, compound 9d showed prominent activity against S. aureus (MIC = 0.5 μg/mL) and compound 9k showed the most promising activity against M. tuberculosis H37Rv (MIC = 0.5 μg/mL). Potent derivatives were found to be non-toxic when tested against Vero cells. Compound 9d upon evaluation in vitro against several MRSA and VRSA strains produced activity comparable or better than standard drugs. In the anti-biofilm assay, 9d reduced S. aureus biofilm by >11% at 10x MIC. The dual inhibitory effect exhibited by pyrrole-thiazolidinone hybrids confirms their potential as new class of promising anti-infective agents.

Preparation of chitosan derivatives containing aromatic five-membered heterocycles for efficient antimicrobial and antioxidant activities

In this study, nine chitosan derivatives containing aromatic five-membered heterocycles were prepared and the effects of different grafting methods on the biological activities of chitosan derivatives were investigated. The structures of all the compounds were characterized by Fourier Transform Infrared (FT-IR) spectroscopy and Nuclear Magnetic Resonance (NMR) spectroscopy, while the antioxidant, antifungal and antibacterial activities of the chitosan derivatives were tested. The experimental data suggested that the chitosan derivatives had outstanding inhibitory ability against Fusarium graminearum, Fusarium oxysporum f.sp.cucumbrum, Staphylococcus aureus and Escherichia coli. At the same time, some of the compounds showed strong scavenging ability against DPPH radical and superoxide radical. Cytotoxicity experiments have demonstrated that some chitosan derivatives are non-toxic to L929 cells. More importantly, compared to chitosan, these chitosan derivatives have good water solubility and can be used as potential polymers for antifungal and antibacterial biomaterials in agriculture.

Clauson-Kaas pyrrole synthesis using diverse catalysts: a transition from conventional to greener approach

Pyrrole is an important aromatic heterocyclic scaffold found in many natural products and predominantly used in pharmaceuticals. Continuous efforts are being made to design and synthesize various pyrrole derivatives using different synthetic procedures. Among them, the Clauson-Kaas reaction is a very old and well-known method for synthesizing a large number of N-substituted pyrroles. In recent years, due to global warming and environmental concern, research laboratories and pharmaceutical industries around the world are searching for more environmentally friendly reaction conditions for synthesizing compounds. As a result, this review describes the use of various eco-friendly greener protocols to synthesize N-substituted pyrroles. This synthesis involves the reaction of various aliphatic/aromatic primary amines, and sulfonyl primary amines with 2,5-dimethoxytetrahydrofuran in the presence of numerous acid catalysts and transition metal catalysts. The goal of this review is to summarize the synthesis of various N-substituted pyrrole derivatives using a modified Clauson-Kaas reaction under diverse conventional and greener reaction conditions.

Multicomponent synthesis of chromophores – The one-pot approach to functional π-systems

Multicomponent reactions, conducted in a domino, sequential or consecutive fashion, have not only considerably enhanced synthetic efficiency as one-pot methodology, but they have also become an enabling tool for interdisciplinary research. The highly diversity-oriented nature of the synthetic concept allows accessing huge structural and functional space. Already some decades ago this has been recognized for life sciences, in particular, lead finding and exploration in pharma and agricultural chemistry. The quest for novel functional materials has also opened the field for diversity-oriented syntheses of functional π-systems, i.e. dyes for photonic and electronic applications based on their electronic properties. This review summarizes recent developments in MCR syntheses of functional chromophores highlighting syntheses following either the framework forming scaffold approach by establishing connectivity between chromophores or the chromogenic chromophore approach by de novo formation of chromophore of interest. Both approaches warrant rapid access to molecular functional π-systems, i.e. chromophores, fluorophores, and electrophores for various applications.

Design, synthesis and evaluation of 1-(1,5-bis(4-substituted phenyl)-2-methyl-1H-pyrrol-3-yl)-N-methylmethanamines as SERT inhibitors with potential antidepressant action

BM212 is a potent anti-TB agent with pharmacophoric features similar to the antidepressant drug sertraline. The shape-based virtual screening of the DrugBank database on BM212 resulted in the identification of several CNS drugs with appreciable Tanimoto scores. The docking simulations also ascertained the selectivity of BM212 towards the serotonin reuptake transporter protein (SERT) with a docking score of -6.51 kcal mol-1. Based on the SAR data available for sertraline and other antidepressant drugs, we designed, synthesized and screened twelve 1-(1,5-bis(4-substituted phenyl)-2-methyl-1H-pyrrol-3-yl)-N-methylmethanamines (SA-1 to SA-12) for in vitro SERT inhibition and in vivo antidepressant activity. The compounds were screened for in vitro 5HT reuptake inhibition using the platelet model. Among the screened compounds, (1-(1,5-bis(4-chlorophenyl)-2-methyl-1H-pyrrol-3-yl)-N-methylmethanamine) showed the same serotonin uptake inhibition (absorbance 0.22) as that of the standard drug sertraline (absorbance 0.22). BM212 had an effect on 5-HT uptake, albeit a weaker one compared to the standard (absorbance 0.671). Further, SA-5 was screened for in vivo antidepressant activity using the unpredictable chronic mild stress (UCMS) protocol to induce depression in mice. The effect of BM212 and SA-5 on the behaviour of the animals was assessed and compared against the standard drug sertraline. SA-5 at 20 mg per kg body weight was found to have a statistically significant impact on the behaviour of depressed animals.

A Concise Synthesis of Pyrrole-Based Drug Candidates from α-Hydroxyketones, 3-Oxobutanenitrile, and Anilines

A simple and concise three-component synthesis of a key pyrrole framework was developed from the reaction between α-hydroxyketones, oxoacetonitriles, and anilines. The synthesis was used to obtain several pyrrole-based drug candidates, including COX-2 selective NSAID, antituberculosis lead candidates BM212, BM521, and BM533, as well as several analogues. This route has potential to obtain diverse libraries of these pyrrole candidates in a concise manner to develop optimum lead compounds.

Novel pyrrolopyrimidine derivatives: design, synthesis, molecular docking, molecular simulations and biological evaluations as antioxidant and anti-inflammatory agents

Current medical approaches to control the Covid-19 pandemic are either to directly target the SARS-CoV-2 via innovate a defined drug and a safe vaccine or indirectly target the medical complications of the virus. One of the indirect strategies for fighting this virus has been mainly dependent on using anti-inflammatory drugs to control cytokines storm responsible for severe health complications. We revealed the discovery of novel fused pyrrolopyrimidine derivatives as promising antioxidant and anti-inflammatory agents. The newly synthesised compounds were evaluated for their in vitro anti-inflammatory activity using RAW264.7 cells after stimulation with lipopolysaccharides (LPS). The results revealed that 3a, 4b, and 8e were the most potent analogues. Molecular docking and simulations of these compounds against COX-2, TLR-2 and TLR-4 respectively was performed. The former results were in line with the biological data and proved that 3a, 4b and 8e have potential antioxidant and anti-inflammatory effects.

Medicinal chemical optimization of fluorescent pyrrole-based COX-2 probes

Recent studies have demonstrated the ability of human prostaglandin-endoperoxide synthase 2 (COX-2) to guide the formation of fluorescent pyrroles through the Paal-Knorr reaction resulting in the discovery of a central motif. This initial discovery prompted further exploration of this motif for the design of COX-2 inhibitors through the modifications of the substituents on the pyrrole core. This effort led to the discovery of a set of pyrroles whose activity was comparable to Celecoxib, an orally prescribed nonsteroidal anti-inflammatory COX-2 inhibitor. Furthermore, structure-activity relationship (SAR) data, important for the discovery of COX-2 inhibitors, has been obtained.

Design, synthesis, in silico and biological evaluations of novel polysubstituted pyrroles as selective acetylcholinesterase inhibitors against Alzheimer's disease

The objective of this study was to design new polysubstituted pyrrole derivatives as selective acetylcholinesterase (AChE) inhibitors to target Alzheimer's disease. In this context, a highly efficient, one-pot, sequential, multi-component synthesis of a diverse range of polysubstituted pyrroles was developed through a sequential domino strategy by the condensation of amines with 1,1-bis(methylthio)-2-nitroethene (BMTNE), Knovenagle reaction of arylglyoxals with malono derivatives and subsequent Michael addition and intramolecular cyclization reaction in EtOH at reflux. Thirty-nine synthesized compounds were evaluated as AChE and butyrylcholinesterase (BChE) inhibitors. Among the synthesized compounds, compound 4ad (IC₅₀ = 2.95 ± 1.31 µM) was the most potent and selective AChE inhibitor with no significant inhibition against butyrylcholinesterase BChE. A kinetic study of 4ad revealed that this compound inhibited AChE in an uncompetitive mode. Based on a molecular modeling study, compound 4ad due to its small size properly fitted into the active site of AChE compared to BChE and stabilized by H-bond and hydrophobic interactions with the critical residues of the AChE binding pocket. Consequently, it was proposed that the 4ad derivative can be an ideal lead candidate against AD with a simple and practical operation of synthetic procedures.

Selective One-Pot Cascade Synthesis of N-Substituted Highly Functionalized Pyrroles from Unprotected Sugars, Primary Amines, and Oxoacetonitriles

A one-pot, three-component cascade reaction between unprotected sugars, primary amines, and 3-oxoacetonitriles gave N-substituted 2,3,5-functionalized pyrroles or N-substituted 2,3,4-functionalized pyrroles in excellent yields and selectivities. The selectivity of the reaction was achieved by simple control of the sequence of substrate addition. The reaction showed a wide substrate scope, and various types of sugars, primary amines, and oxoacetonitriles reacted smoothly. The work demonstrates a highly desired simple reaction for embedding nitrogen into sugars to produce valuable N-heterocyclic compounds that are amenable to further modifications to natural products and drug intermediates.

Selective One-Pot Multicomponent Synthesis of N-Substituted 2,3,5-Functionalized 3-Cyanopyrroles via the Reaction between α-Hydroxyketones, Oxoacetonitriles, and Primary Amines

A one-step, three-component reaction between α-hydroxyketones, oxoacetonitriles, and primary amines gives N-substituted 2,3,5-functionalized 3-cyanopyrroles with complete selectivity in up to 90% isolated yields. The reaction worked on a wide substrate scope under mild reaction conditions (AcOH as a catalyst, EtOH, 70 °C, 3 h). The reaction proceeded with very high atom efficiency as water is the only molecule lost during the reaction. The practicality of the reaction was demonstrated on a large gram scale. The structures of the 3-cyanopyrroles were confirmed by single-crystal X-ray diffraction and NMR; this work provides a general and practical entry to pyrrole scaffolds suitably decorated for the synthesis of various bioactive pyrroles in a concise manner.

New Pyrrole Derivatives as Promising Biological Agents: Design, Synthesis, Characterization, In Silico, and Cytotoxicity Evaluation

The current study describes the synthesis, physicochemical characterization and cytotoxicity evaluation of a new series of pyrrole derivatives in order to identify new bioactive molecules. The new pyrroles were obtained by reaction of benzimidazolium bromide derivatives with asymmetrical acetylenes in 1,2-epoxybutane under reflux through the Huisgen [3 + 2] cycloaddition of several ylide intermediates to the corresponding dipolarophiles. The intermediates salts were obtained from corresponding benzimidazole with bromoacetonitrile. The structures of the newly synthesized compounds were confirmed by elemental analysis, spectral techniques (i.e., IR, 1H-NMR and 13C-NMR) and single-crystal X-ray analysis. The cytotoxicity of the synthesized compounds was evaluated on plant cells (i.e., Triticum aestivum L.) and animal cells using aquatic crustaceans (i.e., Artemia franciscana Kellogg and Daphnia magna Straus). The potential antitumor activity of several of the pyrrole derivatives was studied by performing in vitro cytotoxicity assays on human adenocarcinoma-derived cell lines (i.e., LoVo (colon), MCF-7 (breast), and SK-OV-3 (ovary)) and normal human umbilical vein endothelial cells (HUVECs). The obtained results of the cytotoxicity assessment indicated that the tested compounds had nontoxic activity on Triticum aestivum L., while on Artemia franciscana Kellogg nauplii, only compounds 2c and 4c had moderate toxicity. On Daphnia magna, 4b and 4c showed high toxicity; 2a, 2b, and 2c moderate to high toxicity; only 4a and 4d were nontoxic. The compound-mediated cytotoxicity assays showed that several pyrrole compounds demonstrated dose- and time-dependent cytotoxic activity against all tested tumor cell lines, the highest antitumor properties being achieved by 4a and its homologue 4d, especially against LoVo colon cells.

Employing of Fe3O4/CuO/ZnO@MWCNT MNCs in the solvent-free synthesis of new cyanopyrroloazepine derivatives and investigation of biological activity

In this research, we synthesized the Fe₃O₄/CuO/ZnO@MWCNT magnetic nanocomposites using water extract of Petasites hybridus rhizome, and the high performance of synthesized catalyst was confirmed by using in the solvent-free multicomponent reactions of isatoic anhydride, N-methylimidazole, alkyl bromides, activated acetylenic compounds and 2-aminoacetonitrile at ambient temperature for the production of new cyanopyrroloazepine derivatives in high yields. This catalyst could be used several times in these reactions and have main role in the yield of product. The synthesized cyanopyrroloazepines have NH groups in their structure and for this reason have good antioxidant activity. Also, employing Gram-positive and Gram-negative bacteria in the disk diffusion procedure confirmed some cyanopyrroloazepines antimicrobial effect. The results showed that synthesized cyanopyrroloazepine prevented the bacterial growth. This used process for preparation of new cyanopyrroloazepine has some improvements such as low reaction time, product with high yields, simple separation of catalyst and products.

A Novel Class of Dual-Acting DCH-CORMs Counteracts Oxidative Stress-Induced Inflammation in Human Primary Tenocytes

Carbon monoxide (CO) can prevent cell and tissue damage by restoring redox homeostasis and counteracting inflammation. CO-releasing molecules (CORMs) can release a controlled amount of CO to cells and are emerging as a safer therapeutic alternative to delivery of CO in vivo. Sustained oxidative stress and inflammation can cause chronic pain and disability in tendon-related diseases, whose therapeutic management is still a challenge. In this light, we developed three small subsets of 1,5-diarylpyrrole and pyrazole dicobalt(0)hexacarbonyl (DCH)-CORMs to assess their potential use in musculoskeletal diseases. A myoglobin-based spectrophotometric assay showed that these CORMs act as slow and efficient CO-releasers. Five selected compounds were then tested on human primary-derived tenocytes before and after hydrogen peroxide stimulation to assess their efficacy in restoring cell redox homeostasis and counteracting inflammation in terms of PGE₂ secretion. The obtained results showed an improvement in tendon homeostasis and a cytoprotective effect, reflecting their activity as CO-releasers, and a reduction of PGE₂ secretion. As these compounds contain structural fragments of COX-2 selective inhibitors, we hypothesized that such a composite mechanism of action results from the combination of CO-release and COX-2 inhibition and that these compounds might have a potential role as dual-acting therapeutic agents in tendon-derived diseases.

A Practical Synthesis of Densely Functionalized Pyrroles via a Three-Component Cascade Reaction between Carbohydrates, Oxoacetonitriles, and Ammonium Acetate

A practical three-component reaction between unactivated carbohydrates, oxoacetonitriles, and ammonium acetate gave densely functionalized pyrroles in 75-96% yields. Disaccharides afforded novel pyrrolo-glycosides. This metal-free, Et₃N-catalyzed cascade reaction proceeded with exclusive chemo-, regio-, and stereoselectivities and showed a wide substrate scope with high atom economy. It also proceeded successfully at a 2 g scale, demonstrating potential for large-scale synthesis. The functional groups on the pyrroles permit easy transformation to other handles for the construction of more complex structures. The reaction proceeded through a cascade mechanism involving several intermediates identified by mass spectrometric analysis. This work has great potential for the sustainable production of densely functionalized pyrroles from cheap and widely available carbohydrates and represents a key advancement in the sustainable synthesis of these ubiquitous heterocycles.

Dithiane-Induced [3+2] Cycloaddition Tactic for the Convergent Synthesis of Dihydropyrrole and Pyrrole Derivatives

An efficient transition-metal-free tactic for the convergent synthesis of substituted dihydropyrroles and pyrroles by β-chloro-vinyl dithiane cyclization with a broad range of imines was developed. [3+2] Cyclization and aromatization occur under these reaction conditions providing biologically relevant dihydropyrroles and pyrroles in good yields.

Microwave assisted synthesis of five membered nitrogen heterocycles

Our continuously changing environment demands sensible and sustainable chemistry. Consequently, organic synthesis started to follow green chemistry principles in recent years. It is observed that microwave (MW) radiation has been widely used as a source of energy in organic synthesis in the past decade. The MW heating approach has evolved into a new green method in organic synthesis since it provides short reaction time, high yields, and high product purities along with a decrease in the rate of by-product formation. Solvent-free reaction protocols worked well under MW irradiation. All these features make MW assisted organic synthesis an environment-friendly approach. In organic synthesis, heterocycles are vital targets especially nitrogen-containing ones because of their prominent presence in natural products and widespread applications in pharmaceutical industries. Five membered nitrogen heterocycles include pyrroles, oxazoles, pyrrolidones, etc. among which pyrroles are the most important ones due to their potent biological properties. Even though there are a variety of reaction protocols for the synthesis of pyrroles, a significant development materialized in MW assisted synthesis of pyrroles in the past few years. In this review, we focus on the developments in MW assisted synthesis of pyrroles and other five-membered nitrogen heterocycles.

Catalytic Applications of Saccharin and its Derivatives in Organic Synthesis

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Saccharin (1,2-benzisothiazol-3(2H)-one-1,1-dioxide) is a very mild, cheap, commercially available, water soluble, environmentally benign and edible Brønsted acidic substance. Recently, with other utilities, saccharin and its derivatives were employed as catalysts for various organic transformations. In this review, catalytic applicability of saccharin and its derivatives under various reaction conditions is summarized.

Inhibition of nitric oxide and prostaglandin E2 production by pyrrolylated-chalcones: Synthesis, biological activity, crystal structure analysis, and molecular docking studies

In search of potent anti-inflammatory agents, twenty-four chalcone derivatives including seven new compounds (13 - 17, 21 and 23) containing pyrrole moiety were designed, synthesized, and assessed for their nitric oxide (NO) and prostaglandin E₂ (PGE₂) suppression ability on IFN-γ/LPS-induced RAW 264.7 macrophage cells. Results showed that none of the synthesized compounds were PAINS-associated molecules, with 3-(2,5-dimethoxyphenyl)-1-(1H-pyrrol-2-yl)-prop-2-en-1-one (compound 16) exhibiting remarkable inhibition activity towards PGE₂ and NO production with IC₅₀ values of 0.5 ± 1.5 µM and 12.1 ± 1.5 µM, respectively. Physicochemical and ADMET studies showed that majority of the compounds obey to Lipinski's rule of five (RO5) having high blood brain barrier (BBB) penetration, human intestinal absorption (HIA), P- glycoprotein (PgP) inhibition and plasma binding protein (PPB) inhibition. The obtained atomic coordinates for the single-crystal XRD of 16 were then applied in a molecular docking simulation, and compound 16 was found to participate in a number of important binding interactions in the binding sites of ERK and mPGES-1. Based on these results, we have observed the potential of compound 16 as a new hit anti-inflammatory agent, and these findings could serve as a basis for further studies on its mechanism of action.

A green method for the synthesis of pyrrole derivatives using arylglyoxals, 1,3-diketones and enaminoketones in water or water-ethanol mixture as solvent

Three-component reaction between arylglyoxals, 1,3-dicetones and enaminoketones leads to new polyfunctionalized tetraone derivatives which may be easily converted to polyfunctionalized pyrroles. Reactions were conducted in water or water-ethanol mixture as green solvents, and all products were isolated by simple washing of the resulting solids with diethyl ether.

Antinociceptive activity of methanol extract of Chlorophytum alismifolium tubers in murine model of pain: Possible involvement of α2-adrenergic receptor and KATP channels

The tubers of Chlorophytum alismifolium are used in Nigerian Herbal Medicine for the management of diabetes mellitus, painful and inflammatory conditions. The antinociceptive activity has been validated but the mechanism of this activity is yet to be explored. This study therefore, aimed to investigate the probable mechanism(s) of the antinociceptive activity of C. alismifolium tubers using experimental animal model of pain. HPLC and GC-MS analyses were carried out on the extract. Antinociceptive activity was investigated using acetic acid-induced writhing response test in mice. Three groups of mice were orally administered distilled water (10 ml/kg), C. alismifolium (400 mg/kg) and morphine (10 mg/kg) 60 min before administration of acetic acid and the resulting writhing were counted for 10 min. To establish the probable mechanism(s) of action of C. alismifolium, separate groups of animals were pretreated intraperitoneally with naloxone (2 mg/kg), prazosin (1 mg/kg), yohimbine (1 mg/kg), propranolol (20 mg/kg) and glibenclamide (5 mg/kg) 15 min before C. alismifolium administration. HPLC chromatogram of the extract revealed seventeen characteristic peaks with retention times ranging between 2.1 and 7.4 min. Administration of C. alismifolium significantly (p < 0.01) reduced the mean number of writhes compared to control group. Pretreatment with yohimbine and glibenclamide significantly (p < 0.05 and p < 0.01 respectively) reduced the antinociceptive activity of extract-alone treated group. However, pretreatment with prazosin, naloxone and propranolol showed no effect on its analgesic activity. The findings from this research revealed the possible involvement of α₂-adrenergic receptor and K_ATP channels in the antinociceptive activity of Chlorophytum alismifolium tuber extract.

Pyrrole: An insight into recent pharmacological advances with structure activity relationship

Pyrrole is a heterocyclic ring template with multiple pharmacophores that provides a way for the generation of library of enormous lead molecules. Owing to its vast pharmacological profile, pyrrole and its analogues have drawn much attention of the researchers/chemists round the globe to be explored exhaustively for the benefit of mankind. This review focusses on recent advancements; pertaining to pyrrole scaffold, discussing various aspects of structure activity relationship and its bioactivities.

Design, synthesis and X-ray crystallography of selenides bearing benzenesulfonamide moiety with neuropathic pain modulating effects

A series of selenides bearing benzensulfonamide were investigated as inhibitors of the metalloenzyme carbonic anhydrase (CA, EC 4.2.1.1). Potent inhibitory action, in the low nanomolar range, was detected against isoforms hCA II and VII, which are known to be involved in neuropathic pain modulation. These selenides showed on the other hand moderate inhibition against the cytosolic isoforms hCA I and transmembrane hCA IX. X-ray crystallographic data of two derivatives bound to hCA II allowed us to rationalize the excellent inhibitory data. In a mice model of neuropathic pain induced by oxaliplatin, some of the strong CA II/VII inhibitors induced a long lasting pain relieving effect.

Effects of a novel microtubule-depolymerizer on pro-inflammatory signaling in RAW264.7 macrophages

The Nuclear Factor-kappa B (NF-κB) pathway is vital for immune system regulation and pro-inflammatory signaling. Many inflammatory disorders and diseases, including cancer, are linked to dysregulation of NF-κB signaling. When macrophages recognize the presence of a pathogen, the signaling pathway is activated, resulting in the nuclear translocation of the transcription factor, NF-κB, to turn on pro-inflammatory genes. Here, we demonstrate the effects of a novel microtubule depolymerizer, NT-07-16, a polysubstituted pyrrole compound, on this process. Treatment with NT-07-16 decreased the production of pro-inflammatory cytokines in RAW264.7 mouse macrophages. It appears that the reduction in pro-inflammatory mediators produced by the macrophages after exposure to NT-07-16 may be due to activities upstream of the translocation of NF-κB into the nucleus. NF-κB translocation occurs after its inhibitory protein, IκB-α is phosphorylated which signals for its degradation releasing NF-κB so it is free to move into the nucleus. Previous studies from other laboratories indicate that these processes are associated with the microtubule network. Our results show that exposure to the microtubule-depolymerizer, NT-07-16 reduces the phosphorylation of IκB-α and also decreases the association of NF-κB with tubulin which may affect the ability of NF-κB to translocate into the nucleus. Therefore, the anti-inflammatory activity of NT-07-16 may be explained, at least in part, by alterations in these steps in the NF-κB signaling pathway leading to less NF-κB entering the nucleus and reducing the production of pro-inflammatory mediators by the activated macrophages.

Fluorinated pyrrole incorporated 2-thiazolyl hydrazone motifs: a new class of antimicrobial and anti tuberculosis agents

In aim of obtaining novel bio-active compounds, a new series of fluorinated 1-(4-(aryl)thiazol-2-yl)-2-((1-(aryl)-2,5-dimethyl-1H-pyrrol-3-yl)methylene)hydrazines (5a-t) and 1-(4-(4-aryl)thiazol-2-yl)-2-((3-(2,4-dichlorophenyl)-1-phenyl-1H-pyrazol-4-yl)methylene)hydrazines (8a-d) were synthesized and screened for their antibacterial and antifungal activities. The potent compounds were further screened in vitro for anti-tuberculosis activity against Mycobacterium tuberculosis H37Rv strain. Compounds 5a, 5c-5h and 5m were found to be good inhibitors of B. subtilis with MIC ranging from 0.2 to 0.8 µg mL-1, which are nearly three to ten times more potent than the standard drug Ciprofloxacin. Compounds 5a, 5h-5k and 5o exhibited potent antifungal activity against C. albicans strain with MIC ranging from 0.4 to 1.6 µg mL-1. Compounds 8a-8c were found to be excellent inhibitors of A. niger. Compounds 5a and 5k showed significant anti tubercular activity with MIC 3.12 and 6.25 µg mL-1 respectively. Furthermore, highly active compounds were tested for their preliminary toxicity profile by hemolytic assay and were found to be non hemolytic at higher concentration with good selectivity index. Cytotoxicity of the potent compounds 5a, 5d, 5g, 5i and 5k was checked by MTT assay using normal embryonic kidney cell line HEK 293 and found to be non-toxic up to 50-200 times the MIC for antibacterial activity.