Synthesis, molecular docking and evaluation of novel sulfonyl hydrazones as anticancer agents and COX-2 inhibitors

Current scenario of pyrazole hybrids with anti-breast cancer therapeutic applications

Breast cancer stands as the leading cause of cancer-related deaths among women globally, but current therapy is restricted to the serious adverse effects and multidrug resistance, necessitating the exploration of novel, safe, and efficient anti-breast cancer chemotherapeutic agents. Pyrazoles exhibit excellent potential for utilization as effective anti-breast cancer agents due to their ability to act on various biological targets. Particularly, pyrazole hybrids demonstrated the advantage of targeting multiple pathways, and some of them, which are exemplified by larotrectinib (pyrazolo[1,5-a]pyrimidine hybrid), can be applied for breast cancer therapy. Thus, pyrazole hybrids hold great promise as useful therapeutic interventions for breast cancer. The aim of this review is to summarize the current scenario of pyrazole hybrids with in vitro and/or in vivo anti-breast cancer potential, along with the modes of action and structure-activity relationships, covering articles published from 2020 to the present, to streamline the development of rational, effective and safe anti-breast cancer candidates.

Ultrasonic-assisted synthesis and antitumor evaluation of novel variant heterocyclic compounds based on piperidine ring

Aim: This work explores the eco-friendly synthesis of various heterocycles from a piperidine-based compound (1) and explore their potential as antitumor agents.Materials & methods: Ultrasonic irradiation was used to synthesize heterocycles like pyridone, thiophene and coumarin, with computational tools analyzing stability and biological interactions.Results: Compounds 9 and 14 exhibit strong cytotoxic activity, surpassing doxorubicin. Compounds 2, 6, 10 and 13 exhibited intermediate activity, while compounds 3, 7 and 12 had minimal effects. Docking studies suggest potential ADORA1 receptor interaction. Computational tools analyze stability and interaction with biological systems, revealing potential antitumor mechanisms.Conclusion: Green synthesis of diverse heterocycles yielded potent antitumor agents (compounds 9 & 14). DFT and Docking studies suggest interaction with ADORA1 receptor, a potential mechanism.

Selective COX-2 inhibitors as anticancer agents: a patent review (2018-2023)

INTRODUCTION

COX-2 is a crucial enzyme in the manufacture of prostaglandins. The enzyme's metabolites might have an important function as regulators of the inflammatory response and other medical conditions such as cancer. Selective COX-2 inhibitors are believed to enhance or reverse the response of cancer chemotherapeutics.

AREAS COVERED

This study addresses the chemical structures as well as the antitumor activity of new COX-2 inhibitors produced in the recent five years, aiming to provide an insight into the mechanism of COX-2 induced PGE2 powerful signal in cancer development.

EXPERT OPINION

The significance of selective COX-2 inhibitors as an efficient superfamily of compounds with anti-inflammatory, anti-Alzheimer's, anti-Parkinson's disease, and anticancer properties has piqued the passion of academics in the field of drug development. Long-term usage of selective COX-2 inhibitors, such as celecoxib has been proven in clinical trials to lower the incidence of several human malignancies. Furthermore, celecoxib has the potential to greatly increase the effectiveness of chemotherapy. Our extensive understanding of selective COX-2 inhibitor SAR may aid in the development of safer and more effective selective COX-2 inhibitors as cancer chemopreventive agents. This review focuses on the different structural classes of selective COX-2 inhibitors, with a particular emphasis on their SAR.

In silico and pharmacokinetic assessment of echinocystic acid effectiveness in Alzheimer's disease like pathology

Aim: Alzheimer's disease causes dementia which impairs the cognitive domains. Methodology: The pharmacokinetic characteristics and biological activity of echinocystic acid are predicted in this work using in silico or computational approaches, including pkCSM, Swiss ADME, OSIRIS® property explorer, PASS online web resource and MOLINSPIRATION® software. Results & discussion: The compound has lipid metabolism regulating property as major role in decreasing the progression of Alzheimer's disease and it has no major side effects and ADR. The drug also has anti-inflammatory properties which can help in regulating the innate immunity that plays a major role in Alzheimer's disease. Conclusion: From the computational screening, we infer that, echinocystic acid can regulate memory loss, cognitive disability and also slow down the progression of Alzheimer's disease-like pathology.

Investigating multifaceted action of ibuprofen derivatives towards cox isozymes and interleukin-6 (IL-6) site correlating with various target sites

The multifaceted action of new ibuprofen analogs has been investigated against inflammation, neurological and pro-inflammation factors. On the basis of ADMET (absorption, distribution, metabolism, excretion, and toxicity) analysis, molecular docking as well as molecular dynamics simulation, compound 3 was thought to have good anti-inflammatory activity. As the presence of structural interactions such as conventional hydrogen bonds and electrostatic interactions through the nitrogen atoms of the linker in compound 3 gave strong evidence of its potency. The major finding of the current work is that the presence of appropriate number of hetero atoms (NH, OH) in a compound makes it more efficient than the number of labile groups (i.e., hydroxyl groups). Additionally, the position of hetero atoms in a compound and orientation also play a vital role in its efficacy. It was also screened for in vitro anti-inflammatory activity by membrane stability method, where it has shown 90.8% protection of RBC hemolysis. Thus, compound 3 with effective structural features may have good anti-inflammatory activity.Communicated by Ramaswamy H. Sarma.

Design of potential anti-cancer agents as COX-2 inhibitors, using 3D-QSAR modeling, molecular docking, oral bioavailability proprieties, and molecular dynamics simulation

Modeling the structural properties of novel morpholine-bearing 1, 5-diaryl-diazole derivatives as potent COX-2 inhibitor, two proposed models based on CoMFA and CoMSIA were evaluated by external and internal validation methods. Partial least squares analysis produced statistically significant models with Q 2 values of 0.668 and 0.652 for CoMFA and CoMSIA, respectively, and also a significant non-validated correlation coefficient R² with values of 0.882 and 0.878 for CoMFA and CoMSIA, respectively. Both models met the requirements of Golbraikh and Tropsha, which means that both models are consistent with all validation techniques. Analysis of the CoMFA and CoMSIA contribution maps and molecular docking revealed that the R1 substituent has a very significant effect on their biological activity. The most active molecules were evaluated for their thermodynamic stability by performing MD simulations for 100 ns; it was revealed that the designed macromolecular ligand complex with 3LN1 protein exhibits a high degree of structural and conformational stability. Based on these results, we predicted newly designed compounds, which have acceptable oral bioavailability properties and would have high synthetic accessibility.

Design of Balanced Cyclooxygenase Inhibitors Based on Natural Anti-inflammatory Ascidian Metabolites and Celecoxib

The serious adverse effects caused by non-selective and selective cyclooxygenase-2 (COX-2) inhibitors remain significant concerns for current anti-inflammatory drugs. In this study, we present the design and synthesis of a novel series of celecoxib analogs incorporating a hydrazone linker, which were subjected to in silico analysis to compare their binding poses with those of clinically used nonsteroidal anti-inflammatory drugs (NSAIDs) against COX-1 and COX-2. The synthesized analogs were evaluated for their inhibitory activity against both COX enzymes, and compound 6 m, exhibiting potent balanced inhibition, was selected for subsequent in vitro anti-inflammatory assays. Treatment with 6 m effectively suppressed the NF-κB signaling pathway in lipopolysaccharide (LPS)-stimulated murine RAW264.7 macrophages, resulting in reduced expression of pro-inflammatory factors such as inducible nitric oxide synthase (iNOS), COX-2, tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), IL-1β, as well as decreased production of prostaglandin E2 (PGE2 ), nitric oxide (NO), and reactive oxygen species (ROS). However, 6 m has no effect on the MAPK signaling pathway. Therefore, due to its potent in vitro anti-inflammatory activity coupled with lack of cytotoxicity, 6 m represents a promising candidate for further development as a new lead compound targeting inflammation.

Therapeutic Study of Cinnamic Acid Derivative for Oxidative Stress Ablation: The Computational and Experimental Answers

This study aimed to examine the therapeutic activity of the cinnamic acid derivative KAD-7 (N'-(2,4-dichlorobenzylidene)-3-(4-methoxyphenyl) acrylohydrazide) on Fe2+-induced oxidative hepatic injury via experimental and computational models. In addition, the role of ATPase and ectonucleoside triphosphate diphosphohydrolase (ENTPDase) in the coordination of cellular signals is speculated upon to proffer suitable therapeutics for metabolic stress disorder upon their inhibition. While we know little about therapeutics with flexible dual inhibitors for these protein targets, this study was designed to screen KAD-7's (N'-(2,4-dichlorobenzylidene)-3-(4-methoxyphenyl) acrylohydrazide) inhibitory potential for both protein targets. We induced oxidative hepatic damage via the incubation of hepatic tissue supernatant with 0.1 mM FeSO4 for 30 min at 37 °C. We achieved the treatment by incubating the hepatic tissues with KAD-7 under the same conditions. The catalase (CAT), glutathione (GSH), malondialdehyde (MDA), ATPase, and ENTPDase activity were all measured in the tissues. We predicted how the drug candidate would work against ATPase and ENTPDase targets using molecular methods. When hepatic injury was induced, there was a significant decrease in the levels of the GSH, CAT, and ENTPDase (p < 0.05) activities. In contrast, we found a noticeable rise in the MDA levels and ATPase activity. KAD-7 therapy resulted in lower levels of these activities overall (p < 0.05), as compared to the control levels. We found the compound to have a strong affinity for ATPase (-7.1 kcal/mol) and ENTPDase (-7.4 kcal/mol), and a better chemical reactivity than quercetin. It also met all drug-likeness parameters. Our study shows that KAD-7 can protect the liver from damage caused by FeSO4 by reducing oxidative stress and purinergic actions. Our studies indicate that KAD-7 could be developed as a therapeutic option since it can flexibly inhibit both ATPase and ENTPDase.

Synthesis of novel spirochromane incorporating Schiff's bases, potential antiproliferative activity, and dual EGFR/HER2 inhibition: Cell cycle analysis and in silico study

Spirochromanes incorporating Schiff's bases and semicarbazones 4a-e and 5a-j were synthesizedand analyzed for their potential antiproliferative activity using four human cancer cell lines (MCF-7, HCT-116, PC3, and A549). Compounds 5a, 5b and 5g possessed the highest antiproliferative activity among the tested compounds,with an IC50 range of 1.154-9.09 μM. Compound 5j selectively inhibited the PC3 cell proliferation (IC50 = 5.47 μM). Spirochromanes 5a, 5b and 5g exhibited high inhibitory activity against EGFR (IC50 = 0.116, 0.132, and 0.077 μM, respectively) and HER2 (IC50 = 0.055, 0.210 and 0.085 μM, respectively) compared with the references, erlotinib (IC50 = 0.090 and 0.038 μM, respectively) and gefitinib (IC50 = 0.052 and 0.072 μM, respectively). Cell cycle analysis and apoptosis results showed that compounds 5a, 5b and 5g arrested growth inthe S phase, and the programmed cell death induced by these compounds was an apoptotic mechanism rather than a necrotic pathway. Molecular docking studies of spirochromanes 5a, 5b and 5g to EGFR and HER2 binding sites were performed to explore the orientation mode and interaction.

Ultrasonic-induced synthesis of novel diverse arylidenes via Knoevenagel condensation reaction. Antitumor, QSAR, docking and DFT assessment

A series of arylidenes derivatives was synthesized under ultrasonic methodology via Knoevenagel condensation reaction of cyanoacetohydrazide derivative with the appropriate aldehydes and/or ketone. The anticancer properties of the newly synthesized compounds were tested against four different human cancer cell lines (HEPG-2, MCF-7, HCT-116, and PC-3); compounds 5d and 6 demonstrated the greatest anticancer activity against all cancer cell lines. The MLR technique was used to create the QSAR model using five molecular descriptors (AATS6p, AATS7p, AATS8p, AATS0i, and SpMax4_Bhv). The examination of the constructed QSAR model equations revealed that the selected descriptors influence the tested compound's anti-proliferative activity. The descriptors identified in this work by QSAR models can be utilized to predict the anticancer activity levels of novel arylidenes derivatives. This will allow for significant cost savings in the drug development process and synthesis at pharmaceutical chemistry laboratories. According to the physicochemical properties, the results revealed that all of these compounds comply with Lipinski's Rule of Five, indicating that they may have high permeability across biological membranes and reveal drug-relevant properties. The Swiss Target Prediction webtool was used to assess the probable cellular mechanism for the promising candidate compounds (5d and 6), and the results revealed that adenosine A1 receptor (ADORA1) was a common target for both compounds. ADORA1 is involved in the regulation of cell metabolism and gene transcription. ADORA1 overexpression has been linked to a variety of cancers, including colon cancer, breast cancer, leukemia, and melanoma. The docking study of tested compounds 5d and 6 revealed that their binding scores to ADORA1 are more favorable than those of its co-crystalized ligand (DU172, selective ADORA1 antagonist) and adenosine (ADORA1 endogenous agonist), implying that they may hold great promise as an anti-cancer therapy. Density functional theory (DFT) with a (B3LYP)/6-31G (d,p) basis set was used to calculate the physicochemical parameters of these compounds. The theoretical data from the DFT computation was found to be in good agreement with the experimental values.

Ferrocene-based nitroheterocyclic sulfonylhydrazones: design, synthesis, characterization and trypanocidal properties

A series of new ferrocenyl nitroheterocyclic sulfonylhydrazones (1a-4a and 1b-2b) were prepared by the reaction between formyl (R = H) or acetyl (R = CH3) nitroheterocyclic precursors [4/5-NO2(C5H2XCOR), where X = O, S)] and ferrocenyl tosyl hydrazine [(η5-C5H5)Fe(η5-C5H4SO2-NH-NH2)]. All compounds were characterized by conventional spectroscopic techniques. In the solid state, the molecular structures of compounds 1a, 2b, and 3a were determined by single-crystal X-ray diffraction. The compounds showed an E-configuration around the C=N moiety. Evaluation of trypanocidal activity, measured in vitro against the Trypanosoma cruzi and Trypanosoma brucei strains, indicated that all organometallic tosyl hydrazones displayed activity against both parasite species with a higher level of potency toward T. brucei than T. cruzi. Moreover, the biological evaluation showed that the 5-nitroheterocyclic derivatives were more efficient trypanocidal agents than their 4-nitroheterocyclic counterparts.

Design and Development of COX-II Inhibitors: Current Scenario and Future Perspective

Innate inflammation beyond a threshold is a significant problem involved in cardiovascular diseases, cancer, and many other chronic conditions. Cyclooxygenase (COX) enzymes are key inflammatory markers as they catalyze prostaglandins production and are crucial for inflammation processes. While COX-I is constitutively expressed and is generally involved in "housekeeping" roles, the expression of the COX-II isoform is induced by the stimulation of different inflammatory cytokines and also promotes the further generation of pro-inflammatory cytokines and chemokines, which affect the prognosis of various diseases. Hence, COX-II is considered an important therapeutic target for drug development against inflammation-related illnesses. Several selective COX-II inhibitors with safe gastric safety profiles features that do not cause gastrointestinal complications associated with classic anti-inflammatory drugs have been developed. Nevertheless, there is mounting evidence of cardiovascular side effects from COX-II inhibitors that resulted in the withdrawal of market-approved anti-COX-II drugs. This necessitates the development of COX-II inhibitors that not only exhibit inhibit potency but also are free of side effects. Probing the scaffold diversity of known inhibitors is vital to achieving this goal. A systematic review and discussion on the scaffold diversity of COX inhibitors are still limited. To address this gap, herein we present an overview of chemical structures and inhibitory activity of different scaffolds of known COX-II inhibitors. The insights from this article could be helpful in seeding the development of next-generation COX-II inhibitors.

Switching of newly synthesized linker-based derivatives of non-steroidal anti-inflammatory drugs toward anti-inflammatory and anticancer activity

A new series of linker-based derivatives of non-steroidal anti-inflammatory drugs were designed and synthesized. All the compounds were well characterized with the help of various spectroscopic techniques such as FT-IR, ¹H NMR, ¹³C NMR, and HRMS. The main emphasis of this paper is to understand the switching of the most promising compounds 8 and 10 towards anti-inflammatory and anticancer activity in terms of in-silico and in-vitro studies in detail. During the molecular docking study, compounds 8 and 10 demonstrated the importance of hetero atoms as well as the perfect alignment of a compound in the binding pocket of a target site, which may affect their bioactivity. Here, the presence of 1,3‑dicarbonyl interactions with ASN 351 in compound 8 (not found in compound 10) may be responsible for its better inhibitory activity against the COX-2 target site. On the other hand, a slight increase in the potency of compound 10 towards anticancer activity may be due to the instantaneous participation of the OH group and carbonyl group to give conventional hydrogen bonds towards THR 149 amino acid residue, which was missing in compound 8. Molecular dynamics simulation was also performed for compounds 10 and 8 toward COX-2 and HER-2 protein sites. Further, compounds 8 and 10 were subjected to in-vitro COX-2 inhibition and cytotoxicity assay and the results obtained were in accordance with the in-silico study. Thus, compound 8 become more potent towards COX-2 inhibition with IC₅₀ value of 48.51 µg/ml and compound 10 showed good bioactivity toward cytotoxic activity with IC₅₀ value of 93.03 µg/ml.

Novel Arylsulfonylhydrazones as Breast Anticancer Agents Discovered by Quantitative Structure-Activity Relationships

Breast cancer (BC) is the second leading cause of cancer death in women, with more than 600,000 deaths annually. Despite the progress that has been made in early diagnosis and treatment of this disease, there is still a significant need for more effective drugs with fewer side effects. In the present study, we derive QSAR models with good predictive ability based on data from the literature and reveal the relationships between the chemical structures of a set of arylsulfonylhydrazones and their anticancer activity on human ER+ breast adenocarcinoma and triple-negative breast (TNBC) adenocarcinoma. Applying the derived knowledge, we design nine novel arylsulfonylhydrazones and screen them in silico for drug likeness. All nine molecules show suitable drug and lead properties. They are synthesized and tested in vitro for anticancer activity on MCF-7 and MDA-MB-231 cell lines. Most of the compounds are more active than predicted and show stronger activity on MCF-7 than on MDA-MB-231. Four of the compounds (1a, 1b, 1c, and 1e) show IC50 values below 1 μM on MCF-7 and one (1e) on MDA-MB-231. The presence of an indole ring bearing 5-Cl, 5-OCH3, or 1-COCH3 has the most pronounced positive effect on the cytotoxic activity of the arylsulfonylhydrazones designed in the present study.

Synthesis of oxamide-hydrazone hybrid derivatives as potential anticancer agents

Background and purpose

Considering various studies implying anticancer activity of the hydrazone and oxamide derivatives through different mechanisms such as kinases and calpain inhibition, herein, we report the synthesis, characterization, and evaluation of the antiproliferative effect of a series of hydrazones bearing oxamide moiety compounds (7a-7n) against a panel of cancer cell lines to explore a novel and promising anticancer agent (7k).

Experimental approach

Chemical structures of the synthesized compounds were confirmed by FTIR, ¹H-NMR, ¹³C-NMR, and mass spectra. The antiproliferative activity and cell cycle progression of the target compound were investigated using the MTT assay and flow cytometry.

Findings/Results

Compound 7k with 2-hydroxybenzylidene structure was found to have a significant in vitro anti-proliferative influence on MDA-MB-231 (human adenocarcinoma breast cancer) and 4T1 (mouse mammary tumor) cells as the model of triple-negative breast cancer, with the IC50-72h values of 7.73 ± 1.05 and 1.82 ± 1.14 μM, respectively. Following 72-h incubation with compound 7k, it caused MDA-MB-231 cell death through G1/S cell cycle arrest at high concentrations (12 and 16 μM).

Conclusion and implications

Conclusively, this study for the first time reports the anti-proliferative efficacy of compound 7k possessing 2-hydroxyphenyl moiety, which may serve as a potent candidate in triple-negative breast cancer treatment.

Cyclooxygenase-2 (COX-2) as a Target of Anticancer Agents: A Review of Novel Synthesized Scaffolds Having Anticancer and COX-2 Inhibitory Potentialities

Cancer is a serious threat to human beings and is the second-largest cause of death all over the globe. Chemotherapy is one of the most common treatments for cancer; however, drug resistance and severe adverse effects are major problems associated with anticancer therapy. New compounds with multi-target inhibitory properties are targeted to surmount these challenges. Cyclooxygenase-2 (COX-2) is overexpressed in cancers of the pancreas, breast, colorectal, stomach, and lung carcinoma. Therefore, COX-2 is considered a significant target for the synthesis of new anticancer agents. This review discusses the biological activity of recently prepared dual anticancer and COX-2 inhibitory agents. The most important intermolecular interactions with the COX-2 enzyme have also been presented. Analysis of these agents in the active area of the COX-2 enzyme could guide the introduction of new lead compounds with extreme selectivity and minor side effects.

Methyl Effect on the Metabolism, Chemical Stability, and Permeability Profile of Bioactive N-Sulfonylhydrazones

Sulfonylhydrazones are privileged structures with multifaceted pharmacological activity. Exploring the hypoglycemic properties of these organic compounds, we previously revealed a new series of N-sulfonylhydrazones (NSH) as antidiabetic drug candidates. Here, we evaluated the microsomal metabolism, chemical stability, and permeability profile of these NSH prototypes, focusing on the pharmacokinetic differences in N-methylated and non-N-methylated analogs. Our results demonstrated that the N-methylated analogs (LASSBio-1772 and LASSBio-1774) were metabolized by CYP, forming three and one metabolites, respectively. These prototypes exhibited chemical stability at pH 2.0 and 7.4 and brain penetration ability. On the other hand, non-N-methylated analogs (LASSBio-1771 and LASSBio-1773) were hydrolyzed in acid pH and could not cross the artificial blood-brain barrier. The cyano group in LASSBio-1771 was postulated as a possible site of interaction with the heme group, potentially inhibiting CYP enzymes. Moreover, prototypes with the methyl ester group were metabolized by carboxylesterase, and non-N-methylated analogs did not show oxidative metabolism. The prototypes (except LASSBio-1774) showed excellent gastrointestinal absorption. Altogether, our data support the idea that the methyl effect on NSH strongly alters their pharmacokinetic profile, enhances the recognition by CYP enzymes, promotes brain penetration, and plays a protective effect upon acid hydrolysis.

Design, Synthesis and Biological Evaluation of New N-Acyl Hydrazones with a Methyl Sulfonyl Moiety as Selective COX-2 Inhibitors

The mechanism of action of nonsteroidal anti-inflammatory drugs (NSAIDs) is inhibition of specific prostaglandin (PG) synthesis by inhibition of cyclooxygenase (COX) enzymes. The two COX isoenzymes show 60 % similarity. It is known that the nonspecific side effects of conventional NSAIDs are physiologically caused by inhibition of the COX-1 enzyme. Therefore, the use of COX-2 selective inhibitors is seen to be a more beneficial approach in reducing these negative effects. However, some of the existing COX-2 selective inhibitors show cardiovascular side effects. Therefore, studies on the development of new selective COX-2 inhibitors remain necessary. It is important to develop new COX-2 inhibitors in the field of medicinal chemistry. Accordingly, novel N-acyl hydrazone derivatives were synthesized as new COX-2 inhibitors in this study. The hydrazone structure, also known for its COX activity, is important in terms of many biological activities and was preferred as the main structure in the design of these compounds. A methyl sulfonyl pharmacophore was added to the structure in order to increase the affinity for the polar side pocket present in the COX-2 enzyme. It is known that methyl sulfonyl groups are suitable for polar side pockets. The synthesis of the compounds (3a-3j) was characterized by spectroscopic methods. Evaluation of in vitro COX-1/COX-2 enzyme inhibition was performed by fluorometric method. According to the enzyme inhibition results, the obtained compounds displayed the predicted selectivity for COX-2 enzyme inhibition. Compound 3j showed important COX-2 inhibition with a value of IC₅₀ =0.143 uM. Interaction modes between the COX-2 enzyme and compound 3j were investigated by docking studies.

Synthesis, potential antitumor activity, cell cycle analysis, and multitarget mechanisms of novel hydrazones incorporating a 4-methylsulfonylbenzene scaffold: a molecular docking study

Hydrazone is a bioactive pharmacophore that can be used to design antitumor agents. We synthesised a series of hydrazones (compounds 4–24) incorporating a 4-methylsulfonylbenzene scaffold and analysed their potential antitumor activity. Compounds 6, 9, 16, and 20 had the most antitumor activity with a positive cytotoxic effect (PCE) of 52/59, 27/59, 59/59, and 59/59, respectively, while compounds 5, 10, 14, 15, 18, and 19 had a moderate antitumor activity with a PCE of 11/59–14/59. Compound 20 was the most active and had a mean 50% cell growth inhibition (GI₅₀) of 0.26 µM. Compounds 9 and 20 showed the highest inhibitory activity against COX-2, with a half-maximal inhibitory concentration (IC₅₀) of 2.97 and 6.94 μM, respectively. Compounds 16 and 20 significantly inhibited EGFR (IC₅₀ = 0.2 and 0.19 μM, respectively) and HER2 (IC₅₀ = 0.13 and 0.07 μM, respectively). Molecular docking studies of derivatives 9, 16, and 20 into the binding sites of COX-2, EGFR, and HER2 were carried out to explore the interaction mode and the structural requirements for antitumor activity.

Gonçalves Vianez JL, Santana da Costa K, de Molfetta FA, Nahum Alves C. Analysis of Kojic Acid Derivatives as Competitive Inhibitors of Tyrosinase: A Molecular Modeling Approach

Tyrosinases belong to the functional copper-containing proteins family, and their structure contains two copper atoms, in the active site, which are coordinated by three histidine residues. The biosynthesis of melanin in melanocytes has two stages depending on the actions of the natural substrates L-DOPA and L-tyrosine. The dysregulation of tyrosinase is involved in skin cancer initiation. In the present study, using molecular modeling tools, we analyzed the inhibition activity of tyrosinase activity using kojic acid (KA) derivatives designed from aromatic aldehydes and malononitrile. All derivatives showed conformational affinity to the enzyme active site, and a favorable distance to chelate the copper ion, which is essential for enzyme function. Molecular dynamics simulations revealed that the derivatives formed promising complexes, presenting stable conformations with deviations between 0.2 and 0.35 Å. In addition, the investigated KA derivatives showed favorable binding free energies. The most stable KA derivatives showed the following binding free energies: -17.65 kcal mol-1 (D6), -18.07 kcal mol-1 (D2), -18.13 (D5) kcal mol-1, and -10.31 kcal mol-1 (D4). Our results suggest that these derivatives could be potent competitive inhibitors of the natural substrates of L-DOPA (-12.84 kcal mol-1) and L-tyrosine (-9.04 kcal mol-1) in melanogenesis.

Nitrofurazone repurposing towards design and synthesis of novel apoptotic-dependent anticancer and antimicrobial agents: Biological evaluation, kinetic studies and molecular modeling

Drug repurposing has gained much attention as a cost-effective strategy that plays an exquisite role in identifying undescribed biological activities in clinical drugs. In the present work, we report the repurposing of the antibacterial drug nitrofurazone (NFZ) as a potential anticancer agent against CaCo-2, MDA-MB 231 and HepG-2 cancer cell lines. Novel series of nitrofurazone analogs were then designed considering the important pharmacologic features present in NFZ. Synthesis and biological evaluation of the target compounds revealed their promising anticancer activities endowed with antimicrobial potential and possessing better lipophilicity than NFZ. Compound 7, exclusively, inhibited the growth of all tested cancer cells more potently than NFZ with the least cytotoxicity against normal cells, displaying anti Gram-positive bacterial activities and antifungal potential. Analysis of the stereo-electronic properties of compound 7 via investigating the energies of HOMO, LUMO, HOMO-LUMO energy gap and MEP maps demonstrated its high reactivity and the expected molecular mechanism of action through reduction of the 5-nitrofuryl moiety. Data of the bioactivity studies indicated that the potent anticancer activity of 7 is mainly through increasing intracellular ROS levels and induction of apoptosis via significantly down-regulating the expression of Bcl-2 while up-regulating BAX, p53 and caspase 3 expression levels. Compound 7 potently inhibited the cellular expression levels of antioxidant enzymes GPx1 and GR compared to NFZ. Antioxidant enzymes kinetic studies and blind molecular docking simulations disclosed the mechanistic and structural aspects of the interaction between 7 and both GR and GPx1. Thus, the successful discovery of 7 as a potential dual anticancer-antimicrobial nitrofurazone analog might validate the applicability of drug repurposing strategy in unravelling the unrecognized bioactivity of the present conventional drugs, besides furnishing the way towards more optimization and development studies.

Antiplasmodial activity of sulfonylhydrazones: in vitro and in silico approaches

Malaria is still a life-threatening public health issue, and the upsurge of resistant strains requires continuous generation of active molecules. In this work, 35 sulfonylhydrazone derivatives were synthesized and evaluated against Plasmodium falciparum chloroquine-sensitive (3D7) and resistant (W2) strains. The most promising compound, 5b, had an IC₅₀ of 0.22 μM against W2 and was less cytotoxic and 26-fold more selective than chloroquine. The structure-activity relationship model, statistical analysis and molecular modeling studies suggested that antiplasmodial activity was related to hydrogen bond acceptor count, molecular weight and partition coefficient of octanol/water and displacement of frontier orbitals to the heteroaromatic ring beside the imine bond. This study demonstrates that the synthesized molecules with a simple scaffold allow the hit-to-lead process for new antimalarials to commence.