Synthesis of novel 2-pyrazoline analogues with potent anti-inflammatory effect mediated by inhibition of phospholipase A2: Crystallographic, in silico docking and QSAR analysis

A novel class of potent antiangiogenic and antioxidant pyrazoles: synthesis, bioactivity, docking and ADMET studies

Aim: Angiogenesis is the hallmark of cancer progression driven by VEGF/VEGFR-2 signalling pathway, inhibition of which could be a solution to tackle the progression of tumour cells and thus arresting their growth.Materials & methods: A novel class of pyrazoles was synthesized using arginine and dibromo ketones. Antiangiogenic activity was performed by in vivo yolk sac method. Antioxidant activity was evaluated by hydroxyl and superoxide radical scavenging assays. Docking studies were performed to determine the pyrazoles' binding potential with VEGFR-2 receptor and VEGF tyrosine kinase. ADMET properties were calculated using SwissADME and admetSAR for drug-likeness.Results: Compounds 5a-e showed significant antiangiogenic effects. Compound 5f exhibited effective hydroxyl and superoxide radical scavenging activities. Docking results confirmed the potential binding efficiency with VEGFR-2 receptor over VEGF tyrosine kinase, thus, functioning as competitive-inhibitors. ADMET studies revealed that the compounds possess favourable drug-like qualities.Conclusion: This study presents a novel class of pyrazoles as promising antioxidant and antiangiogenic agents with favourable drug-likeness properties.

Fragment merging approach for the design of thiazole/thiazolidine clubbed pyrazoline derivatives as anti-inflammatory agents: Synthesis, biopharmacological evaluation and molecular modeling studies

Fragment merging approach was applied for the design of thiazole/thiazolidinone clubbed pyrazoline derivatives 5a-e, 6a-c, 7 and 10a-d as dual COX-2 and 5-LOX inhibitors. Compounds 5a, 6a, and 6b were the most potent and COX-2 selective inhibitors (IC50= 0.03-0.06 μM, SI = 282.7-472.9) with high activity against 5-LOX (IC50 = 4.36-4.86 μM), while compounds 5b and 10a were active and selective 5-LOX inhibitors with IC50 = 2.43 and 1.58 μM, respectively. In vivo assay and histopathological examination for most active candidate 6a revealed significant decrease in inflammation with higher safety profile in comparison to standard drugs. Compound 6a exhibited the same orientation and binding interactions as the reference COX-2 and 5-LOX inhibitors (celecoxib and quercetin, respectively). Consequently, compound 6a has been identified as a potential lead for further optimization and the development of safe and effective anti-inflammatory drugs.

Antibacterial potential of chalcones and its derivatives against Staphylococcus aureus

Chalcones are natural substances found in the metabolism of several botanical families. Their structure consists of 1,3-diphenyl-2-propen-1-one and they are characterized by having in their chains an α, β-unsaturated carbonyl system, two phenol rings and a three-carbon chain that unites them. In plants, Chalcones are mainly involved in the biosynthesis of flavonoids and isoflavonoids through the phenylalanine derivation. This group of substances has been shown to be a viable alternative for the investigation of its antibacterial potential, considering the numerous biological activities reported and the increase of the microbial resistance that concern global health agencies. Staphylococcus aureus is a bacterium that has stood out for its ability to adapt and develop resistance to a wide variety of drugs. This literature review aimed to highlight recent advances in the use of Chalcones and derivatives as antibacterial agents against S. aureus, focusing on research articles available on the Science Direct, Pub Med and Scopus data platforms in the period 2015-2021. It was constructed informative tables that provided an overview of which types of Chalcones are being studied more (Natural or Synthetic); its chemical name and main Synthesis Methodology. From the analysis of the data, it was observed that the compounds based on Chalcones have great potential in medicinal chemistry as antibacterial agents and that the molecular skeletons of these compounds as well as their derivatives can be easily obtained through substitutions in the A and B rings of Chalcones, in order to obtain the desired bioactivity. It was verified that Chalcones and derivatives are promising agents for combating the multidrug resistance of S. aureus to drugs.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13205-022-03398-7.

Discovery of Anticancer Agents from 2-Pyrazoline-Based Compounds

As nitrogen-containing five-membered heterocyclic structural units, the substituted pyrazole derivatives have a broad spectrum of pharmacological activities, especially 4,5-dihydro-1H-pyrazoles that also commonly known as 2-pyrazolines. Since 2010, considerable studies have been found that the 2-pyrazoline derivatives possess potent anticancer activities. In the present review, it covers the pyrazoline derivatives reported by literature from 2010 till date (2010-2019). This review aims to establish the relationship between the anticancer activities variation and different substituents introduced into a 2-pyrazoline core, which could provide important pharmacophore clues for the discovery of new anticancer agents containing 2-pyrazoline scaffold.

Screening of chalcone analogs with anti-depressant, anti-inflammatory, analgesic, and COX-2-inhibiting effects

A group of 2-methyl-4-phenylquinoline-chalcone analogs (2a-2x) was synthesized and investigated for anti-depressant, anti-inflammatory, and analgesic effects as cyclooxygenase-2 inhibitors. Pharmacological experiments identified 24 analogs that exhibited anti-depressant, anti-inflammatory, and analgesic activities. In particular, compounds 2c, 2k, and 2w markedly shortened immobility times and exhibited the most anti-depressant activity. In addition, the mechanisms of action of the analogs 2c, 2k, and 2w were likely related to increased serotonin levels in the central nervous system. Compounds 2c, 2k, and 2w displayed reasonable cyclooxygenase-2 inhibitory effects (IC₅₀ values from 0.21 to 0.29 µmol/L) similar to celecoxib (IC₅₀: 0.19 µmol/L) in vitro. A molecular docking study of compound 2k also was conducted.

A QSAR Study for Analgesic and Anti-inflammatory Activities of 5-/6-Acyl-3-alkyl-2-Benzoxazolinone Derivatives

In this publication, QSAR models were developed to predict analgesic and anti-inflammatory activities of some 2-benzoxazolinone derivatives using multiple linear regression method. The models were validated internally and externally according to the OECD principles. With the help of these models, pronounced molecular properties of these compounds related to activities were also explored. The developed models demonstrated that hydrophobicity, the number of halogens, and the shape of the molecular structure of these candidate drugs are prominent to represent analgesic and anti-inflammatory activities. Based on the previously tested compounds and the developed models, 77 new compounds were designed as potential analgesic and anti-inflammatory drugs. Majority of the newly designed compounds demonstrated promising analgesic and anti-inflammatory activity.

Deciphering Block Copolymers as Carriers of a Pyrazoline Derivative through Its Solvatochromic Behavior: A Spectroscopic and Theoretical Exploration

Many biologically active water-insoluble drug molecules have limited clinical application because of strong hydrophobicity. Recently triblock copolymers have attracted enormous interest as potential drug carriers. For the purpose of delivering the 5-(1-(bromohexa-1,3,5-triyn-1-yl)-3a,4,5,6,7,7a-hexahydro-1H-4,7-methanoindazol-3-yl)-3-methyl-1-phenyl-1H-pyrazole-4-carbonitrile (PYZ) molecule, triblock copolymers are used. In order to understand the delivery of this water-insoluble probe through triblock copolymers (TBP), the solvent-dependent fluorescence properties of this compound have been examined in different homogeneous solvents. Besides the experimental work, theoretical studies have also been conducted to explain actual orientation of atoms in PYZ through optimized structures to support the experimental findings. Moreover, the three TBP polymers P-123 (PEO₁₉ PPO₆₉ PEO₁₉ ), F-127 (PEO₁₀₀ PPO65PEO₁₀₀ ) and L-64 (PEO₁₃ PPO₃₀ PEO₁₃ ) have been treated here as potential carriers that encapsulate a pyrazoline derivative. The consequence of spatial captivity on the emission properties was systematically visualized by means of steady-state and time-resolved fluorescence spectroscopy. From DLS measurements the size variation with the polydispersity index of TBP in the presence and absence of PYZ in different triblock copolymers was also monitored. Furthermore these measurements have been supported by TEM imaging also.

Design and Amberlyst-15 mediated synthesis of novel thienyl-pyrazole carboxamides that potently inhibit Phospholipase A2 by binding to an allosteric site on the enzyme

Inflammation-mediated disorders are on the rise and hence, there is an urgent need for the design and synthesis of new anti-inflammatory drugs with higher affinity and specificity for their potential targets. The current study presents an effective and new protocol for the synthesis of thienyl-pyrazoles through 3 + 2 annulations using a recyclable heterogeneous catalyst Amberlyst-15. Chalcones 3(a-g) prepared from 3-methylthiophene-2-carbaldehyde and acetophenones by Claisen-Schmidt approach reacted with semicarbazide hydrochloride 4 in the presence of Amberlyst-15 in acetonitrile at room temperature producing thienyl-pyrazole carboxamides 5(a-h) in good yields. Alternatively, the compounds 5(a-h) were prepared by conventional method using acetic acid (30%) medium. Structures of synthesized new pyrazoles were confirmed by spectral and crystallographic studies. All the new compounds were evaluated for their in vitro inhibition of Phospholipase A2 from Vipera russelli and preliminary studies revealed that, amongst the designed series, compounds 5b, 5c and 5h showed promising inhibition. Further, the compounds exhibited linear mixed-type inhibition behavior for the sPLA2 enzyme indicating that they bind to an allosteric site distinct from either the calcium or substrate binding site on the enzyme. These kinetic conclusions were further validated by macromolecular rigid-body docking whereby compounds 5c and 5h showed binding to distinct pockets on the protein. These findings present a promising series of lead molecules that can serve as prototypes for the treatment of inflammatory related disorders.

Crystal structure and Hirshfeld surface analysis of (E)-3-(2-chloro-4-fluoro-phen-yl)-1-(2,5-di-chloro-thio-phen-3-yl)prop-2-en-1-one

In the title chalcone-thio-phene derivative, C13H6Cl3FOS, the aromatic rings are inclined to one another by 12.9 (2)°, and the thio-phene ring is affected by π-conjugation. In the crystal, mol-ecules are linked by C-H⋯F hydrogen bonds, forming an R22(8) ring motif. A Hirshfeld surface analysis was conducted to verify the contribution of the different inter-molecular inter-actions. The shape-index surface clearly shows that the two sides of the mol-ecules are involved in the same contacts with neighbouring mol-ecules and the curvedness plots show flat surface patches characteristic of planar stacking.

Synthesis and biological evaluation of novel pyrazoline-based aromatic sulfamates with potent carbonic anhydrase isoforms II, IV and IX inhibitory efficacy

Herein we report the synthesis of a new series of aromatic sulfamates designed considering the sulfonamide COX-2 selective inhibitors celecoxib and valdecoxib as lead compounds. These latter were shown to possess important human carbonic anhydrase (CA, EC 4.2.1.1) inhibitory properties, with the inhibition of the tumor-associated isoform hCA IX likely being co-responsible of the celecoxib anti-tumor effects. Bioisosteric substitution of the pyrazole or isoxazole rings from these drugs with the pyrazoline one was considered owing to the multiple biological activities ascribed to this latter heterocycle and paired with the replacement of the sulfonamide of celecoxib and valdecoxib with its equally potent bioisoster sulfamate. The synthesized derivatives were screened for the inhibition of four human carbonic anhydrase isoforms, namely hCA I, II, IV, and IX. All screened sulfamates exhibited great potency enhancement in inhibiting isoform II and IV, widely involved in glaucoma (K_Is in the range of 0.4-12.4 nM and 17.7 and 43.3 nM, respectively), compared to the lead compounds, whereas they affected the tumor-associated hCA IX as potently as celecoxib.