Discovery of (S)-flurbiprofen-based novel azine derivatives as prostaglandin endoperoxide synthase-II inhibitors: Synthesis, in-vivo analgesic, anti-inflammatory activities, and their molecular docking

Synthesis, Urease Inhibitory Activity, Molecular Docking, Dynamics, MMGBSA and DFT Studies of Hydrazone-Schiff Bases Bearing Benzimidazole Scaffold

In this study, eleven hydrazone-Schiff bases bearing benzimidazole moiety were synthesized successfully via three step reactions and structures of these products were deduced by HR-ESI-MS, 1H-, and 13C-NMR spectroscopic techniques. Lastly, these derivatives were tested for their in vitro urease inhibitory potential. Six compounds among the series attributed excellent inhibition with IC50 values of 7.20±0.59 to 19.61±1.10 μM better than the reference drug thiourea (IC50=22.12±1.20 μM). Similarly, three derivatives showed significant while two compounds showed less inhibitory effects against the urease enzyme. The molecular docking analysis was carried out to reveal the binding modes and types of interaction taking place between protein (urease) and synthesized compounds. The Density Functional Theory (DFT) calculations were performed at B3LYP/6-311++G(d,p) to check the structure stability. For the account of intramolecular interaction, the DFT-D3 and Reduced Density Gradient (RDG) analysis were performed. Furthermore, the chemical nature of all compounds was explored by TD-DFT method using CAM-B3LYP functional with 6-311++G(d,p) basis set. The dynamic simulation as well as MMGBSA studies validated the binding affinity and stability of the ligand receptor complex, displaying main interactions contributing in the biological activity of the product derivatives.

Exploring the Versatility of Azine Derivatives: A Comprehensive Review on Synthesis and Biological Applications

Organic compounds containing azines, di-imines, or bis-Schiff-bases have two azomethine (-CH=N-) functional groups associated with a bridging component. These constituents have attracted attention from a diversity of disciplines, comprising coordination, medicinal, agriculture chemistry, and organic synthesis, because of their comprehensive chemical reactivity and nature. This study determines common synthetic approaches and various biological and pharmacological activities of several substituted bis-Schiff byproducts. The usefulness of bis-Schiff bases in synthetic chemistry and their potential as inhibitors of a number of enzymes have attracted research attention. We have examined different biological activities and common synthetic methods used to make bis- Schiff bases that have been published in the literature. A systematic search of the literature has been performed, and studies fitting the prearranged inclusion standards have been inspected. This review can open up new potentials for upcoming research in this area and advance our information on bis- Schiff bases.

Design, synthesis, in vitro and in vivo trypanosomaticidal efficacy of novel 5-nitroindolylazines

Leishmaniasis and trypanosomiasis rank among lethal vector-borne parasitic diseases that are endemic in tropical and sub-tropical countries. There are currently no preventive vaccines against them, and once diagnosed, a handful of less effective drugs clinically accessible are the only therapeutic options offered to treat these ailments. And although curable, the eradication and elimination of these diseases are hampered by the emergence of multidrug-resistant strains of the causal pathogens. Hence, there is accrued necessity for the development of new, effective, and affordable drugs. In recent decades, several molecular scaffolds, including nitroaromatics, endoperoxides, etc., have been attempted as building blocks to generate new effective clinical antitrypanosomatid agents with low toxicity so far to no avail. In this regard, a series of nitroindolylazine derivatives was synthesised in a three-step process involving nucleophilic substitution (SN), hydrazination and Schiff base condensation reactions, and was evaluated against various Leishmania and Trypanosoma species and strains. Several promising hits portraying leishmanicidal and trypanocidal with in vitro submicromolar activities, and devoid of toxicity on mammalian cells were uncovered. Among these, nitrofurylazine 11 (Tc IC50: 0.08 ± 0.03 μM) and nitrothienylazine 13 (Tc IC50: 0.09 ± 0.01 μM) were evaluated in vivo against Trypanosoma congolense, the causative agent of nagana, which is livestock most virulent trypanosome species in mice-infected preliminary study. However, only partial efficacy was observed as all mice succumbed due to high parasitemia within 13 days post-infection during the treatment. The translational potential of antileishmanial and antichagasic hits, as well as further identification of their molecular targets, will be assessed in future research.

Biologically active franchetine-type diterpenoid alkaloids: Isolation, synthesis, anti-inflammatory, agalgesic activities, and molecular docking

In this study, four franchetine-type diterpenoid alkaloids (1-4) were isolated from Aconitum sinoaxillare, and fourteen diverse franchetine analogs (5-18) were synthesized. Compounds 1, 2, 7 and 16 exhibited stronger inhibitory effects on NO production when compared to celecoxib. Among them, compound 1 had the best inhibitory effect on iNOS and COX-2 inflammatory proteins. The in vitro studies displayed that the anti-inflammatory effect of the most active compound 1 was ascribed to the inhibition of the TLR4-MyD88/NF-κB/MAPKs signalling pathway. Consequently, this led to a inhibition in the expression of inflammatory factors or mediators including NO, ROS, TNF-α, IL-6, IL-1β, iNOS, and COX-2. Additionally, compound 1 had low toxicity (LD50 > 20 mg/kg) in mice, and it had notable analgesic effects on acetic acid-induced visceral pain (ED50 = 2.15 ± 0.07 mg/kg). Moreover, compound 1 exhibited a distinct reduction in the NaV1.7 and NaV1.8 channel currents during both resting and half-inactivated states at 50 μM. The present study enriches the pharmacological activities of franchetine derivatives and provides valuable insights for the development of novel anti-inflammatory and analgesic agents.

Synthesis of Flurbiprofen Based Amide Derivatives as Potential Leads for Diabetic Management: In Vitro α‐glucosidase Inhibition, Molecular Docking and DFT Simulation Approach

This research is based on the synthesis, characterization and in vitro α‐glucosidase inhibitory activity of fourteen amides (2 a–2 n) of flurbiprofen drug. Seven compounds in the series displayed potent inhibitory activity having IC50 values (IC50=5.67±0.89 μM) to (IC50=17.87±2.39 μM) in comparison with acarbose standard (IC50=875.75±1.24 μM). The FMO of 2 a–2 n molecules was quantified by the DFT assay. The promising value for energygap explained the higher poteny agannist α‐glucosidase. MEP provides the insights into the distribution of electrostatic potential on the molecular surface of 2 a–2 n, showing that C=O group has the highest negative potential. The AIM investigation revealed minimal hydrogen bond energy and non‐covalent interactions. This suggests that these molecules may have limited hydrogen bonding and non‐covalent interactions, which could be relevant to their chemical behavior. Molecular docking and (MEP) showed the C=O group, with its high negative potential, is a key in recognizing the catalytic non‐polar regions of enzymes, such as TYR72, GLU277, and ARG442. Similarly, the hydrophobic regions of investigated compounds play a significant role in identifying essential amino acids like ASP352 and ARG442, which are vital for the ligand's proper orientation and subsequent biological activity.

Tailored quinoline hybrids as promising COX-2/15-LOX dual inhibitors endowed with diverse safety profile: Design, synthesis, SAR, and histopathological study

Complications of the worldwide use of non-steroidal anti-inflammatory drugs (NSAIDs) sparked scientists to design novel harmless alternatives as an urgent need. So, a unique hybridization tactic of quinoline/pyrazole/thioamide (4a-c) has been rationalized and synthesized as potential COX-2/15-LOX dual inhibitors, utilizing relevant reported studies on these pharmacophores. Moreover, we extended these preceding hybrids into more varied functionality, bearing crucial thiazole scaffolds(5a-l). All the synthesized hybrids were evaluatedin vitroas COX-2/15-LOX dual inhibitors. Initially, series4a-cexhibited significant potency towards 15-LOX inhibition (IC50 = 5.454-4.509 μM) compared to meclofenamate sodium (IC50 = 3.837 μM). Moreover, they revealed reasonable inhibitory activities against the COX-2 enzyme in comparison to celecoxib.Otherwise, conjugates 5a-ldisclosed marked inhibitory activity against 15-LOX and strong inhibitory to COX-2. In particular, hybrids5d(IC50 = 0.239 μM, SI = 8.95), 5h(IC50 = 0.234 μM, SI = 20.35) and 5l (IC50 = 0.201 μM, SI = 14.42) revealed more potency and selectivity outperforming celecoxib (IC50 = 0.512 μM, SI = 4.28). In addition, the most potentcompounds, 4a, 5d, 5h, and 5l have been elected for further in vivoevaluation and displayed potent inhibition of edema in the carrageenan-induced rat paw edema test that surpassed indomethacin. Further, compounds5d, 5h, and 5l decreased serum inflammatory markers including oxidative biomarkersiNO, and pro-inflammatory mediators cytokines like TNF-α, IL-6, and PGE. Ulcerogenic liability for tested compounds demonstrated obvious gastric mucosal safety. Furthermore, a histopathological study for compound 5l suggested a confirmatory comprehensive safety profile for stomach, kidney, and heart tissues. Docking and drug-likeness studies offered a good convention with the obtained biological investigation.

Synthesis, biochemical and computational evaluations of novel bis-acylhydrazones of 2,2'-(1,1'-biphenyl)-4,4'-diylbis(oxy))di(acetohydrazide) as dual cholinesterase inhibitors

A series of twenty-seven bis(acylhydrazones) were successfully synthesized with high yields through a multistep process, which entailed the esterification of hydroxyl groups, hydrazination with an excess of hydrazine hydrate, and subsequent reactions with various carbonyl moieties (aldehydes). In the final stage of synthesis, different chemical species including aromatic, heterocyclic, and aliphatic compounds were integrated into the framework. The resulting compounds were characterized using several spectroscopic techniques (1H NMR, 13C NMR, and mass spectrometry). Their anticholinesterase activities were assessed in vitro by examining their interactions with two cholinesterase enzymes: acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). Among the synthesized hits, compounds 3, 5, 6, 9-12, and 14 exhibited good to moderate inhibition of AChE. Specifically, 10 (IC50 = 26.3 ± 0.4 μM) and 11 (IC50 = 28.4 ± 0.5 μM) showed good inhibitory activity against AChE, while 9, 12, 3, and 6 exhibited significant inhibition potential against AChE with IC50 values ranging from 35.2 ± 1.1 μM to 64.4 ± 0.3 μM. On the other hand, 5 (IC50 = 22.0 ± 1.1 μM) and 27 (IC50 = 31.3 ± 1.3 μM) displayed significant, and 19 (IC50 = 92.6 ± 0.4 μM) showed moderate inhibitory potential for BChE. Notably, 5 and 27 exhibited dual inhibition of AChE and BChE, with greater potency than the standard drug galantamine. The binding patterns of these molecules within the binding cavities of AChE and BChE were anticipated by molecular docking which showed good correlation with our in vitro findings. Further structural optimization of these molecules may yield more potent AChE and BChE inhibitors.

Synthesis, molecular docking and DFT analysis of novel bis-Schiff base derivatives with thiobarbituric acid for α-glucosidase inhibition assessment

A library of novel bis-Schiff base derivatives based on thiobarbituric acid has been effectively synthesized by multi-step reactions as part of our ongoing pursuit of novel anti-diabetic agents. All these derivatives were subjected to in vitro α-glucosidase inhibitory potential testing after structural confirmation by modern spectroscopic techniques. Among them, compound 8 (IC50 = 0.10 ± 0.05 µM), and 9 (IC50 = 0.13 ± 0.03 µM) exhibited promising inhibitory activity better than the standard drug acarbose (IC50 = 0.27 ± 0.04 µM). Similarly, derivatives (5, 6, 7, 10 and 4) showed significant to good inhibitory activity in the range of IC50 values from 0.32 ± 0.03 to 0.52 ± 0.02 µM. These derivatives were docked with the target protein to elucidate their binding affinities and key interactions, providing additional insights into their inhibitory mechanisms. The chemical nature of these compounds were reveal by performing the density functional theory (DFT) calculation using hybrid B3LYP functional with 6-311++G(d,p) basis set. The presence of intramolecular H-bonding was explored by DFT-d3 and reduced density gradient (RGD) analysis. Furthermore, various reactivity parameters were explored by performing TD-DFT at CAM-B3LYP/6-311++G(d,p) method.

Efficient microwave synthesis of flurbiprofen derivatives and their enhancement of efficacy in chronic inflammatory pain models and gastro-protective potential in post-operative model

Present research was designed to synthesize and characterize the flurbiprofen derivatives and to evaluate their analgesic, anti-inflammatory and gastro-protective activities in post-operative and chronic inflammatory pain models. Flurbiprofen derivatives were produced by using three-step processes involving esterification, hydrazide production, and schiff base, each of which modified a different carboxyl group. All the newly synthesized flurbiprofen derivatives (NS5-NS8) were characterized by 1H NMR,13C NMR,19F NMR and HR-ESI-MS, and the post-operative, inflammatory pain and ulcerogenic activities were determined in well-established in-vivo animal models. To evaluate post-operative and inflammatory pain, various doses of compounds [1, 3, 10, and 30 mg/kg (bwt)] were used, while their ulcerogenic potential was assessed at doses of 100 and 150 mg/kg (bwt). The incisional damage linked pain was significantly (p < 0.001) reduced by derivatives at different doses in both the acute and repeated tests with decreased response of phologistic agent-induced inflammation. The stomach histology and biochemical features demonstrate that the synthesized derivatives have no potential to cause ulcerogenicity as compared to aspirin and flurbiprofen. Furthermore, docking shows that the hydrazide moiety of these compounds is crucial in interacting within COX-2 binding site. Therefore, the synthesized compounds exhibit strong analgesic and anti-inflammatory effects and a low risk of causing ulcers. These attributes render them potentially valuable therapeutic agents for the treatment of pathological disorders associated with inflammation and pain.Communicated by Ramaswamy H. Sarma.

Small Schiff Base Molecules-A Possible Strategy to Combat Biofilm-Related Infections

Microorganisms participating in the development of biofilms exhibit heightened resistance to antibiotic treatment, therefore infections involving biofilms have become a problem in recent years as they are more difficult to treat. Consequently, research efforts are directed towards identifying novel molecules that not only possess antimicrobial properties but also demonstrate efficacy against biofilms. While numerous investigations have focused on antimicrobial capabilities of Schiff bases, their potential as antibiofilm agents remains largely unexplored. Thus, the objective of this article is to present a comprehensive overview of the existing scientific literature pertaining to small molecules categorized as Schiff bases with antibiofilm properties. The survey involved querying four databases (Web of Science, ScienceDirect, Scopus and Reaxys). Relevant articles published in the last 10 years were selected and categorized based on the molecular structure into two groups: classical Schiff bases and oximes and hydrazones. Despite the majority of studies indicating a moderate antibiofilm potential of Schiff bases, certain compounds exhibited a noteworthy effect, underscoring the significance of considering this type of molecular modeling when seeking to develop new molecules with antibiofilm effects.