Synthesis, Biological Evaluation, and Molecular Modeling Studies of 1-Aryl-1H-pyrazole-Fused Curcumin Analogues as Anticancer Agents

Antibacterial and antifungal pyrazoles based on different construction strategies

The growing prevalence of microbial infections, and antimicrobial resistance (AMR) stemming from the overuse and misuse of antibiotics, call for novel therapeutic agents, particularly ones targeting resistant microbial strains. Scientists are striving to develop innovative agents to tackle the rising microbial infections and abate the risk of AMR. Pyrazole, a five-membered heterocyclic compound belonging to the azole family, is a versatile scaffold and serves as a core structure in many drugs with antimicrobial and other therapeutic effects. In this review, we have updated pyrazole-based antibacterial and antifungal agents mainly developed between 2016 and 2024, by combining with diverse pharmacophores such as coumarin, thiazole, oxadiazole, isoxazole, indole, etc. Meanwhile, the various strategies (molecular hybridization, bioisosterism, scaffold hopping, multicomponent reactions, and catalyst-free synthesis) for integrating different functional groups with the pyrazole ring are discussed. Additionally, structure-activity relationships of these pyrazole derivatives, i.e., how structural modifications impact their selectivity and therapeutic potential against bacterial and fungal strains, are highlighted. This review provides insights into designing next-generation antimicrobials to combat AMR, and offers valuable perspectives to the scientists working on heterocyclic compounds with diverse bioactivities.

Development of the Curcumin Analog CA7 Liposome and Its Evaluation for Efficacy Against Cervical Cancer in vitro and in vivo

Objective

The objective of this study was to develop liposomes (LP) containing a curcumin (CU) analog CA7 to enhance its pharmacokinetic profile and anti-cervical cancer (CC) effects.

Methods

Single-factor and Box-Behnken experiments were conducted to optimize the formulation of CA7-loaded liposomes (CA7-LP). The in vitro release, stability, biocompatibility, and pharmacokinetic of CA7-LP were evaluated. The biological effects of CA7-LP on Hela cells were assessed using MTT assays, colony formation assays, wound healing assays, and flow cytometry. Additionally, the anti-CC efficacy of CA7-LP was tested in mouse models of transplanted tumors.

Results

The optimal formulation of CA7-LP exhibited a particle size of 92.43 ± 1.52 nm, a polydispersity index of 0.27 ± 0.01, an encapsulation efficiency of 97.79 ± 1.49%, a drug loading of 3.23 ± 0.20%, and a zeta potential of -6.69 ± 0.77 mV. Transmission electron microscopy confirmed that a spherical morphology was exhibited by CA7-LP. The cumulative in vitro release of CA7-LP was found to be 2.84 times greater than that of CA7, and stability at room temperature was maintained for at least 90 d. Furthermore, a significantly higher uptake of CA7-LP by Hela cells was observed compared to curcumin and CA7, leading to enhanced inhibition of cell proliferation, migration and cell cycle, as well as increased apoptosis (p < 0.05). In vivo studies revealed that CA7-LP exhibited superior pharmacokinetic properties compared to CA7 (AUC: 3.58-fold, Cmax: 5.65-fold, t1/2z: 1.2-fold). The anti-CC effects of CA7-LP were found to be comparable to those of Cisplatin injection, with a better safety profile.

Conclusion

The newly developed CA7-LP is considered a promising candidate for the treatment of CC, demonstrating high potential for clinical application.

Recent highlights in the synthesis and biological significance of pyrazole derivatives

Aza-heterocyclic scaffolds are privileged cores in the composition of their potential therapeutic profiles and versatile synthetic intermediates. Pyrazole is one of the frequently studied compounds of "azole" family and consists of nitrogen in a 1,2 linking sequence. These motifs possess a wide-spectrum of applications in the field of pharmaceuticals, agrochemicals, polymer chemistry, cosmetics, food industries and more. In addition, functionalized pyrazole derivatives are frequently used as ligands in coordination chemistry and metal-catalysed reactions. As exemplified by numerous recent reports, pyrazoles are highly promising pharmacophores with excellent therapeutic applications. Owing to their aromaticity, the ring structures have many reactive positions, where electrophilic, nucleophilic, alkylation and oxidative reactions might occur. The structural adroitness and diversity of pyrazole cores further emanated numerous fused bicyclic skeletons with various biological applications. In this review, we highlight the recent synthetic methods developed for the preparation of functionalized pyrazole derivatives (From 2017 to present). In addition, we have also covered the notable biological activities (anti-cancer, anti-inflammatory, anti-bacterial and anti-viral) of this ubiquitous core. Herein, we emphasised the synthesis of pyrazoles from variety of precursors such as, alkynes, α,β-unsaturated carbonyl compounds, diazo reagents, nitrile imines, diazonium salts, 1,3-dicarbonyl compounds and etc. Moreover, the recent synthetic methodologies focusing on the preparation of pyrazolines and pyrazolones and variously fused-pyrazoles are also included. Authors expect this review could significantly help the researchers in finding elegant novel tools to synthesize pyrazole skeletons and expand their biological evaluation.

Synthesis, Antimicrobial - Cytotoxic Evaluation, and Molecular Docking Studies of Quinolin-2-one Hydrazones Containing Nitrophenyl or Isonicotinoyl/Nicotinoyl Moiety

By applying the hybrid molecular strategy, in this study, we reported the synthesis of fifteen quinolin-2-one hydrazones containing nitrophenyl or nicotinonyl/isonicotinoyl moiety, followed by in vitro and in silico evaluations of their potential antimicrobial and anticancer activities. In vitro antimicrobial evaluation of the target compounds on seven pathogenic strains, applying the broth microdilution method, revealed that compound 4a demonstrated the most potential antifungal activity against C. albicans (MIC 512 μg mL-1) and C. krusei (MIC 128 μg mL-1). In vitro cytotoxic evaluation of the target compounds on three human cancer cell lines, employing the MTT method, suggested that compound 5c exhibited the most potential cytotoxicities against HepG2 (IC50 10.19 μM), A549 (IC50 20.43 μM), and MDA-MB-231 (IC50 16.82 μM) cells. Additionally, molecular docking studies were performed to investigate the binding characteristics of compounds 4a and 5c with fungal lanosterol 14α-demethylase and human topoisomerase I-II, respectively, thereby contributing to the elucidation of their in vitro antifungal and cytotoxic properties. Furthermore, compounds 4a and 5c, via SwissADME prediction, could exhibit favorable physicochemical and pharmacokinetic properties. In conclusion, this study provides valuable insights into the potential of quinolin-2-one hydrazones as promising candidates for the development of novel antimicrobial and anticancer agents in the future.

Anticancer perspectives of monocarbonyl analogs of curcumin: A decade (2014-2024) review

Monocarbonyl analogs of curcumin (MACs) represent structurally modified versions of curcumin. The existing literature indicates that MACs exhibit enhanced anticancer properties compared with curcumin. Numerous research articles in recent years have emphasized the significance of MACs as effective anticancer agents. This review focuses on the latest advances in the anticancer potential of MACs, from 2014 to 2024, including discussions on their mechanism of action, structure-activity relationship (SAR), and in silico molecular docking studies.

The untold story of starch as a catalyst for organic reactions

Starch is one of the members of the polysaccharide family. This biopolymer has shown many potential applications in different fields such as catalytic reactions, water treatment, packaging, and food industries. In recent years, using starch as a catalyst has attracted much attention. From a catalytic point of view, starch can be used in organic chemistry reactions as a catalyst or catalyst support. Reports show that as a catalyst, simple starch can promote many heterocyclic compound reactions. On the other hand, functionalized starch is not only capable of advancing the synthesis of heterocycles but also is a good candidate catalyst for other reactions including oxidation and coupling reactions. This review tries to provide a fair survey of published organic reactions which include using starch as a catalyst or a part of the main catalyst. Therefore, the other types of starch applications are not the subject of this review.

Advances in β-Diketocyclisation of Curcumin Derivatives and their Antitumor Activity

Curcumin, derived from the popular spice turmeric, is a pharmacologically active polyphenol. Curcumin's therapeutic activity has been extensively studied in recent decades, with reports implicating curcumin in many biological activities, particularly, its significant anticancer activity. However, its potential as an oral administration product is hampered by poor bioavailability, which is associated with a variety of factors, including low water solubility, poor intestinal permeability, instability, and degradation at alkaline pH. To improve its bioavailability, modifying β-diketone curcumin with heterocycles, such as pyrazole, isoxazole and triazole is a powerful strategy. Derivatives are synthesized while maintaining the basic skeleton of curcumin. The β-diketone cyclized curcumin derivatives are regulators of multiple molecular targets, which play vital roles in a variety of cellular pathways. In some literatures, structurally modified curcumin derivatives have been compared with curcumin, and the former has enhanced biological activity, improved water solubility and stability. Therefore, the scope of this review is to report the most recently synthesized heterocyclic derivatives and to classify them according to their chemical structures. Several of the most important and effective compounds are reviewed by introducing different active groups into the β-diketone position to achieve better therapeutic efficacy and bioavailability.

Synthesis, in silico modelling, and in vitro biological evaluation of substituted pyrazole derivatives as potential anti-skin cancer, anti-tyrosinase, and antioxidant agents

Twenty-five azole compounds (P1-P25) were synthesised using regioselective base-metal catalysed and microwave-assisted approaches, fully characterised by high-resolution mass spectrometry (HRMS), nuclear magnetic resonance (NMR), and infrared spectra (IR) analyses, and evaluated for anticancer, anti-tyrosinase, and anti-oxidant activities in silico and in vitro. P25 exhibited potent anticancer activity against cells of four skin cancer (SC) lines, with selectivity for melanoma (A375, SK-Mel-28) or non-melanoma (A431, SCC-12) SC cells over non-cancerous HaCaT-keratinocytes. Clonogenic, scratch-wound, and immunoblotting assay data were consistent with anti-proliferative results, expression profiling therewith implicating intrinsic and extrinsic apoptosis activation. In a mushroom tyrosinase inhibition assay, P14 was most potent among the compounds (half-maximal inhibitory concentration where 50% of cells are dead, IC50 15.9 μM), with activity greater than arbutin and kojic acid. Also, P6 exhibited noteworthy free radical-scavenging activity. Furthermore, in silico docking and absorption, distribution, metabolism, excretion, and toxicity (ADMET) simulations predicted prominent-phenotypic actives to engage diverse cancer/hyperpigmentation-related targets with relatively high affinities. Altogether, promising early-stage hits were identified - some with multiple activities - warranting further hit-to-lead optimisation chemistry with further biological evaluations, towards identifying new skin-cancer and skin-pigmentation renormalising agents.

Recent Advances in the Development of Pyrazole Derivatives as Anticancer Agents

Pyrazole derivatives, as a class of heterocyclic compounds, possess unique chemical structures that confer them with a broad spectrum of pharmacological activities. They have been extensively explored for designing potent and selective anticancer agents. In recent years, numerous pyrazole derivatives have been synthesized and evaluated for their anticancer potential against various cancer cell lines. Structure-activity relationship studies have shown that appropriate substitution on different positions of the pyrazole ring can significantly enhance anticancer efficacy and tumor selectivity. It is noteworthy that many pyrazole derivatives have demonstrated multiple mechanisms of anticancer action by interacting with various targets including tubulin, EGFR, CDK, BTK, and DNA. Therefore, this review summarizes the current understanding on the structural features of pyrazole derivatives and their structure-activity relationships with different targets, aiming to facilitate the development of potential pyrazole-based anticancer drugs. We focus on the latest research advances in anticancer activities of pyrazole compounds reported from 2018 to present.

Design, synthesis, in vitro and in silico evaluation of anti-colorectal cancer activity of curcumin analogues containing 1,3-diphenyl-1H-pyrazole targeting EGFR tyrosine kinase

Recent studies have shown that monocarbonyl analogues of curcumin (MACs) and 1H-pyrazole heterocycle both demonstrated promising anticancer activities, in which several compounds containing these scaffolds could target EGFR. In this research, 24 curcumin analogues containing 1H-pyrazole (a1-f4) were synthesized and characterized by using modern spectroscopic techniques. Firstly, synthetic MACs were screened for cytotoxicity against human cancer cell lines such as SW480, MDA-MB-231 and A549, from which the 10 most potential cytotoxic compounds were identified and selected. Subsequently, the selected MACs were further screened for their inhibition against tyrosine kinases, which showed that a4 demonstrated the most significant inhibitory effects on EGFR^WT and EGFR^L858R. Based on the results, a4 further demonstrated its ability to cause morphological changes, to increase the percentage of apoptotic cells, and to increase caspase-3 activity, suggesting its apoptosis-inducing activity on SW480 cells. In addition, the effect of a4 on the SW480 cell cycle revealed its ability to arrest SW480 cells at G₂/M phase. In subsequent computer-based assessments, a4 was predicted to possess several promising physicochemical, pharmacokinetic, and toxicological properties. Via molecular docking and molecular dynamics simulation, a reversible binding mode between a4 and EGFR^WT, EGFR^L858R, or EGFR^G719S, remained stable within the 100-ns simulation due to effective interactions especially the hydrogen bonding with M793. Finally, free binding energy calculations suggested that a4 could inhibit the activity of EGFR^G719S more effectively than other EGFR forms. In conclusion, our work would provide the basis for the future design of promising synthetic compounds as anticancer agents targeting EGFR tyrosine kinase.

Modified Curcumins as Potential Drug Candidates for Breast Cancer: An Overview

Breast cancer (BC), the most common malignancy in women, results from significant alterations in genetic and epigenetic mechanisms that alter multiple signaling pathways in growth and malignant progression, leading to limited long-term survival. Current studies with numerous drug therapies have shown that BC is a complex disease with tumor heterogeneity, rapidity, and dynamics of the tumor microenvironment that result in resistance to existing therapy. Targeting a single cell-signaling pathway is unlikely to treat or prevent BC. Curcumin (a natural yellow pigment), the principal ingredient in the spice turmeric, is well-documented for its diverse pharmacological properties including anti-cancer activity. However, its clinical application has been limited because of its low solubility, stability, and bioavailability. To overcome the limitation of curcumin, several modified curcumin conjugates and curcumin mimics were developed and studied for their anti-cancer properties. In this review, we have focused on the application of curcumin mimics and their conjugates for breast cancer.