Compounds 4k Research Articles

Synthesis and Biological Evaluation of Sclareolide-Indole Conjugates and Their Derivatives

Sclareolide is a sesquiterpene lactone isolated from various plant sources in tons every year and is commercially used as a flavor ingredient in the cosmetic and food industries. Antitumor and antiviral activities of sclareolide have been previously reported. However, biological studies of sclareolide synthetic analogous are few. In view of these, we developed a robust synthetic method that allows the assembly of 36 novel sclareolide-indole conjugates and their derivatives. The synthetic method was based on TiCl4-promoted nucleophilic substitution of sclareolide-derived hemiacetal 4, while electron-rich aryles including indoles, polyphenol ethers, and pyrazolo [1,5-a]pyridine were good substrates. The stereochemistry of the final products was confirmed by single-crystal X-ray diffraction analysis, while the antiproliferative activities of selected final products were tested in K562 and MV4-11 cancer cell lines. Cytometric flow analysis shows that lead compounds 8k- and 10-induced robust apoptosis in MV4-11 cancer cells, while they exhibited weak impact on cell cycle progression. Taken together, our study suggests that sclareolide could be a good template and substrate for the synthesis of novel antiproliferative compounds.

2-Phenylpyridine Derivatives: Synthesis and Insecticidal Activity against Mythimna separata, Aphis craccivora, and Tetranychus cinnabarinus

The increase in the insecticide resistance of pests, such as Mythimna separata, Aphis craccivora Koch, and Tetranychus cinnabarinus, necessitates the development of new heterocyclic compounds with high insecticidal activity. A series of novel 2-phenylpyridine derivatives containing N-phenylbenzamide moieties were designed and synthesised with Suzuki-Miyaura cross-coupling, nucleophilic substitution, and amidation reactions. The reaction conditions in each step are mild, and the product is easy to separate (yield is about 85%). The structures of the compounds were characterised using 1H and 13C NMR spectroscopy and HRMS. Moreover, the insecticidal activity of the compounds was analysed using the leaf dipping method. The compounds 5a, 5d, 5g, 5h, and 5k at 500 mg/L exhibited 100% inhibition against Mythimna separata. Therefore, the 2-phenylpyridine moieties have the potential to lead to the discovery of novel and effective insecticides.

Synthesis, anti-oomycete and fungal activities of resveratrol sulfonate derivatives containing three esters moieties

In order to explore novel natural product-based anti-oomycete and fungal agents, thirteen unreported resveratrol sulfonate derivatives containing three esters moieties were designed and prepared using the principle of activity superposition, and structurally confirmed by 1H NMR, 13C NMR, HRMS, and m.p. Furthermore, we evaluated the target compounds (3a–m) as anti-oomycete and fungal activities against two serious agricultural diseases of Phytophthora capsici and Fusarium graminearum, respectively. Among the thirteen resveratrol sulfonate derivatives tested, three compounds 3d, 3k, and 3l exhibited the most potent anti-oomycete activity against P. capsici with EC50 values of 27.31, 27.69, and 26.14 mg/L, respectively. Moreover, two compounds 3e and 3l exhibited the most potent anti-fungal activity against F. graminearum with EC50 values of 75.81, and 73.60 mg/L, respectively. Overall, the anti-oomycete activity against P. capsici of the target compound was significantly better than that of the anti-fungal activity against F. graminearum. In particular, anti-oomycete and fungal activities showed that the structural skeleton presentation activity was closely related to the different substituents of the sulfonyloxy groups, especially the anti-oomycete activity. This study will lay a solid foundation for further modifying resveratrol to develop potential new fungicides.

Synthesis, antitubercular evaluation, and molecular docking studies of hybrid pyridinium salts derived from isoniazid.

In the quest to develop potent inhibitors for Mycobacterium tuberculosis, novel isoniazid-based pyridinium salts were designed, synthesized, and tested for their antimycobacterial activities against the H37 Rv strain of Mycobacterium tuberculosis using rifampicin as a standard. The pyridinium salts 4k, 4l, and 7d showed exceptional antimycobacterial activities with MIC90 at 1 µg/mL. The in vitro cytotoxicity and pharmacokinetics profiles of these compounds were established for the identification of a lead molecule using in vivo efficacy proof-of-concept studies and found that the lead compound 4k possesses LC50 value at 25 µg/mL. The in vitro antimycobacterial activity results were further supported by in silico studies with good binding affinities ranging from -9.8to -11.6 kcal/mol for 4k, 4l, and 7d with the target oxidoreductase DprE1 enzyme. These results demonstrate that pyridinium salts derived from isoniazid can be a potentially promising pharmacophore for the development of novel antitubercular candidates.

Design, synthesis, and cytotoxic evaluation of quinazoline derivatives bearing triazole-acetamides

A novel series of quinazoline-based agents bearing triazole-acetamides 8a-l were designed and synthesized. All the obtained compounds were tested for in vitro cytotoxic activities against three human cancer cell lines named HCT-116, MCF-7, and HepG2, as well as a normal cell line WRL-68 after 48 and 72 h. The results implied that quinazoline-oxymethyltriazole compounds exhibited moderate to good anticancer potential. The most potent derivative against HCT-116 was 8a (X = 4-OCH3 and R = H) with IC50 values of 10.72 and 5.33 μM after 48 and 72 h compared with doxorubicin with IC50 values of 1.66 and 1.21 μM, respectively. The same trend was seen in the HepG2 cancerous cell line in which 8a recorded the best results with IC50 values of 17.48 and 7.94 after 48 and 72 h, respectively. The cytotoxic analysis against MCF-7 showed that 8f with IC50 = 21.29 μM (48 h) exhibited the best activity, while compounds 8k (IC50 = 11.32 μM) and 8a (IC50 = 12.96 μM), known as the most effective cytotoxic agents after 72 h. Doxorubicin as positive control exhibited IC50 values of 1.15 and 0.82 μM after 48 and 72 h, respectively. Noteworthy, all derivatives showed limited toxicity against the normal cell line. Moreover, docking studies were also presented to understand the interactions between these novel derivatives and possible targets.

Design, synthesis, and biological evaluation of indolin-2-one derivatives as novel cyclin-dependent protein kinase 8 (CDK8) inhibitors

Cyclin-dependent protein kinase 8 (CDK8) plays important roles in regulating fibrotic growth factors and inflammatory signaling pathways. Long-term chronic inflammation of the lungs can lead to idiopathic pulmonary fibrosis (IPF). Abnormal alveolar epithelial regeneration leads to the release of various fibrotic growth factors and the activation of inflammatory cells. CDK8 regulates profibrotic cytokines broadly implicated in the pathogenesis of fibrosis. Therefore, inhibition of CDK8 is considered a promising strategy for treating IPF. Here, CDK8 inhibitors were designed and optimized using a fragment-based drug design strategy. Testing results revealed that 71% of the synthesized compounds inhibited CDK8 activity better than the original compound E966–0530. Of these compounds, compound 4k exhibited the strongest CDK8 enzyme-inhibiting activity (IC50 =129 nM). Notably, it displayed a 13-fold increase in potency when compared to E966–0530. Experiments on toxicity and inhibition of epithelial-mesenchymal transition (EMT) protein expressions showed that compound 4k can inhibit EMT protein expressions, but with no significant cytotoxicity for alveolar epithelial cells. Compound 4k showed a potent inhibitory effect in cell migration assays. Furthermore, compound 4k significantly inhibited the phosphorylation of p-Smad3 and RNA Pol II, which are critical mediators in the fibrotic response signaling pathway. Compound 4k remarkably reduced TGF-β1-induced oxidative stress. The above results reveal optimized CDK8 inhibitors with potential use for IPF therapeutic treatment.

Synthesis and Biological Evaluation of Novel N-[3-fluoro-4-(morpholin-4-yl)phenyl]thiazol-2-amine Derivatives as Potent Antibacterial and Anticancer Agents and ADMET

In search of better antibacterial and anticancer agents, this report presents a series of novel N-[3-fluoro-4-(morpholin-4-yl)aryl]thiazol-2-amine derivatives (6a–6l) that were synthesized and evaluated for their antibacterial and anticancer activity in vitro. Antibacterial activity against three G+ bacterial strains and anticancer activity against MCF-7 and A-549 was evaluated. Among all the tested compounds, 6i and 6j exhibited potent antibacterial activity against Staphylococcus aureus and Staphylococcus epidermidis bacterial strains. Biofilm profiles for the potent compounds and it was observed from the results that the active derivatives 6i and 6j were not only potent antibacterial agents but also efficient inhibitors of S. aureus and S. epidermidis biofilm growth. Compared to the standard drug, erlotinib, the anticancer activity screening results of 6h and 6k demonstrated high cytotoxic activity against the A-549 cancer cell line. Later, the results of the inhibitory assay of potent compounds 6h and 6k against the tyrosine kinase EGFR revealed that compound 6k showed ≈1.5 fold potency of the reference drug erlotinib. Finally, compounds 6h, 6i, 6j, and 6k did not show AMES toxicity and followed the rules of Lipinski, Ghose, Veber, Egan, and Muegge rules without any deviation.

Novel thiosemicarbazone and thiazolidin‐4‐one derivatives containing vanillin core: Synthesis, characterization, and anticancer activity studies

AbstractCancer is one of the most common and lethal disease in the world, therefore, patients need new and potent anticancer agents for treatment. In this study, starting from vanillin, 24 new compounds, which are 12 thiosemicarbazone (4a‐h, 5i‐j, 6k) and 12 thiazolidin‐4‐one (7a‐h, 8i‐j and 9k) derivatives, were synthesized and characterized by Nuclear Magnetic Resonance (NMR), High‐Resolution Mass Spectroscopy (HRMS), and Fourier‐transform Infrared (FTIR) techniques. In vitro cytotoxic effects were investigated on CCD‐1079Sk human healthy fibroblast and MDA‐MB‐231 human breast cancer cell lines. For MDA‐MB‐231, molecules showed IC50 in ranging of 88.08 ± 0.027–16.54 ± 0.031 μM (Doxorubicin: 61.70 ± 0.021 μM) and for CCD‐1079Sk, molecules showed IC50 in ranging of 192.36 ± 0.018–13.58 ± 0.035 μM (Doxorubicin:52.01 ± 0.028 μM). Compounds 6k and 7f were found most selective and potent anticancer agents compared to Doxorubicin used as a standard drug.

Design, synthesis, molecular docking, and biological evaluation of coumarin-thymidine analogs as potent anti-TB agents.

With the intent to discover new antituberculosis (TB) compounds, coumarin-thymidine analogs were synthesized using second-order nucleophilic substitution reactions of bromomethyl coumarin with thymidine. The newly synthesized coumarin-thymidine conjugates (1a-l) were characterized using IR, NMR, GC-MS, and CHN elemental analysis. The novel conjugates were found to exhibit potent anti-TB activity against the Mycobacterium tuberculosis H37 Rv strain, with minimum inhibitory concentrations (MIC) of the active compounds ranging between 0.012 and 0.482 µM. Compound 1k was established as the most active candidate with a MIC of 0.012 µM. The toxicity study on HEK cells confirmed the nontoxic nature of compounds 1e, 1h, 1i, 1j, and 1k. Also, the most active compounds (1k, 1j, and 1e) were stable in the pH range from 2.5 to 10, indicating compatibility with the biophysical environment. Based on the pKa studies, compounds 1k, 1j, and 1e are capable of crossing lipid-membrane barriers and acting on target cells. Molecular docking studies on the M. tuberculosis β-oxidation trifunctional enzyme (PDB ID: 7O4V) were conducted to investigate the mechanisms of anti-TB activity. All compounds showed excellent hydrogen binding interactions and exceptional docking scores against M. tuberculosis, which was in accordance with the results. Compounds 1a-l possessed excellent affinity to proteins, with binding energies ranging from -7.4 to -8.7 kcal/mol.

Design, Synthesis and Molecular Docking Studies of (S)-1-(2-(substituted benzylamino)-3- methylbutanoyl)pyrrolidin-2-one analogues as GABA Mediated Anticonvulsant agents

Abstract: Background: Epilepsy is a deep rooted, partially curable brain illness that affects all individuals irrespective of ages and genders. Despite the discovery of various innovative antiepileptic drugs (AEDs), selectivity and toxicity issues remain. Materials and Methods: A series of (S)-1-(2-(substituted benzylamino)-3-methylbutanoyl)pyrrolidin-2-one analogues (5a-r) were synthesized and evaluated for their anticonvulsant activity. The analogues were screened by two gold standard methods, i.e., electroshock (MES) and chemoshock (scPTZ) seizure tests. In addition, the rotarod method was used to test motor impairment in all synthetic analogues for acute neurotoxicity. The paper also reports ADME prediction of all the 18 synthesized compounds, with each parameter discussed in detail. Furthermore, the GABA-A target protein was used in molecular docking experiments. Results: In the MES model, compounds 5e, 5h, 5k, 5l, 5o, and 5r were identified to be the most effective, while compounds 5j, 5k, 5l, 5o, and 5r were the most active against the scPTZ model. The majority of the synthesized analogues passed the neurotoxicity test, according to the findings. ADME prediction of the compounds exhibited good agreement with the in vivo outcomes. The results of molecular docking showed important interactions with TYR 62, ASN 85, ARG 114, ARG 129, and MET 115 at the active site of GABA-A and the results showed good agreement with in vivo results. Conclusion: The findings of the study indicated some of the compounds possessed excellent anticonvulsant activity without noticeable neurotoxicity. These compounds can be investigated further for the formation of newer/novel anticonvulsant agents. Keywords: Pyrrolidine, Anticonvulsant activity, Molecular Docking, GABA-A, Toxicity, ADME prediction.

Identification of New N-methyl-piperazine Chalcones as Dual MAO-B/AChE Inhibitors

Monoamine oxidase-B (MAO-B), acetylcholinesterase (AChE), and butyrylcholinesterase (BChE) have been considered target enzymes of depression and neurodegenerative diseases, including Alzheimer's disease (AD). In this study, seventeen N-methyl-piperazine chalcones were synthesized, and their inhibitory activities were evaluated against the target enzymes. Compound 2k (3-trifluoromethyl-4-fluorinated derivative) showed the highest selective inhibition against MAO-B with an IC50 of 0.71 μM and selectivity index (SI) of 56.34, followed by 2n (2-fluoro-5-bromophenyl derivative) (IC50 = 1.11 μM, SI = 16.04). Compounds 2k and 2n were reversible competitive MAO-B inhibitors with Ki values of 0.21 and 0.28 μM, respectively. Moreover, 2k and 2n effectively inhibited AChE with IC50 of 8.10 and 4.32 μM, which underscored their multi-target inhibitory modes. Interestingly, compound 2o elicited remarkable inhibitions over MAO-B, AChE, and BChE with IC50 of 1.19-3.87 μM. A cell-based assay of compounds 2k and 2n against Vero normal cells pointed out their low cytotoxicity. In a docking simulation, 2k showed the lowest energy for MAO-B (-11.6 kcal/mol) with four hydrogen bonds and two π-π interactions. Furthermore, in silico studies were conducted, and disclosed that 2k and 2n are expected to possess favorable pharmacokinetic properties, such as the ability to penetrate the blood-brain barrier (BBB). In view of these findings, compounds 2k and 2n could serve as promising potential candidates for the treatment of neurodegenerative diseases.

New imidazole derivatives as aromatase inhibitor: Design, synthesis, biological activity, molecular docking, and computational ADME-Tox studies

In this study, a series of imidazole derivatives was designed, synthesized, and evaluated for in vitro biological activity on the human breast cancer cell line MCF7 by MTT assay. To determine the selectivity of the compounds, their cytotoxic effects on the L929 (healthy mouse fibroblast) cell line were also investigated. Compounds 1a, 1b, and 1d were found to be more effective than the reference drug cisplatin against the MCF7 cell line. It is seen that the cytotoxic effects of the compounds on the L929 cell line are quite low, and the compounds are found to be highly selective. The inhibition potentials of the compounds 1a, 1b, 1d, and 1k which were effective on the MCF7 cell line, and on the aromatase enzyme were evaluated and it was found that the compounds had similar effects to the reference drug letrozole. Further, the interactions between the best active compounds and the human aromatase cytochrome P450 (CYP) enzyme were analyzed through a molecular docking study. The findings suggest that these compounds could be a promising candidate for the creation of a new family of non-steroidal aromatase inhibitors. Finally, computational ADME-Tox studies of compounds 1a, 1b, 1d, and 1k were performed and found to have the appropriate profile.

Synthesis of oxamide-hydrazone hybrid derivatives as potential anticancer agents.

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). 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. 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). 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.

Synthesis and Phytotoxic Evaluation of 3-Indolylglycine Derivatives as New Natural-Like Herbicides

A novel class of potential herbicides, 3-indolylglycines were synthesized using an effective, green and rapid approach via multicomponent reaction (aza-Friedel-Crafts) between indoles, aldehydes and anilines in a water/sodium dodecyl sulfate system. The main advantages of this methodology are ease of handling, scalable to gram scale and a metal-free approach. The reaction is compatible with a variety of functional groups, obtaining the desired products in moderate to excellent yields. The biological activity of the 3-indolylglycines was evaluated, and it was found that these compounds interfere with the germination and radicle growth of Lactuca sativa, mainly the compound 4k.

Synthesis, characterization and biological evaluation of pyrazole-based benzene sulfonamides as inhibitors of human carbonic anhydrase II, IX and XII.

The aberrant level of the carbonic anhydrase isozymes is linked with various disorders which include glaucoma, epilepsy, altitude sickness and obesity. In the present study, a series of the pyrazole-based benzene sulfonamides derivatives (4a-4l) were designed, synthesized and evaluated as the inhibitors of the three isoforms of human carbonic anhydrases (hCAII, hCAIX and hCAXII). A number of the derivatives were found more active inhibitors than acetazolamide used as a standard against the human hCAII, hCAIX and hCAXII. Among the series, the compound 4k inhibited the hCAII to a submicromolar level presenting the IC50 ± SEM concentration of 0.24 ± 0.18 μM, the inhibitor 4j reduced the activity of the hCAIX to the IC50 ± SEM equals 0.15 ± 0.07 μM, whereas, the molecule 4g blocked the catalytic potential of the isozyme hCAXII with as low as IC50 concentration of 0.12 ± 0.07 μM. In addition, compounds 4e and 4k were screened as the preferential inhibitors of the isoform hCAXII as compared to the hCAIX and hCAXII with half of the maximal concentrations of 0.75 ± 0.13 μM, and 0.24 ± 0.18 μM, respectively. Moreover, the compounds 4k, 4j and 4g were docked inside the active pocket of the crystallographic structure of the isoforms hCAXII, hCAIX and hCAXII, respectively. The docked inhibitors showed the binding interactions with the important amino acid residues such as Leu1198, Thr1199, His1094, and Phe1131 in hCAXII isozyme; residues Val121, Thr200, Pro203, and Gln71 in hCAIX; the amino acids Val119, Leu197, Gln89, and Asn64 in the case of hCAXII. In addition, structural geometries, reactivity descriptors, optimization energy and electronic parameters were calculated to predict the activity of the synthesized compounds.

Design, synthesis, in silico, and in vitro evaluation of benzylbenzimidazolone derivatives as potential drugs on α-glucosidase and glucokinase as pharmacological targets.

Benzimidazolones have shown biological activities, including antihyperglycemic and hypoglycemic, by inhibiting or activating of α-glu and GK. The aim of this study is the rational design of compounds using in silico assays to delimitate the selection of structures to synthesize and the in vitro evaluation of benzimidazolone derivatives in blood glucose control. A docking of 23 benzimidazolone derivatives was performed; selecting the compounds with better in silico profiles to synthesize by microwave-irradiation/conventional heat and evaluate in enzymatic in vitro evaluation. Compounds 2k, 2m, 2r, and 2s presented the best in silico profiles, showing good affinity energy (-10.9 to -8.6 kcal mol-1) and binding with catalytic-amino acids. They were synthesized at 70 °C and 24 h using DMF as the solvent and potassium carbonate (yield: 22-38%). The results with α-glu showed moderate inhibition of 2k (14 ± 1.23-29 ± 0.45), 2m (12 ± 2.21-36 ± 0.30), 2r (7 ± 2.21-13 ± 1.34), and 2s (11 ± 0.74-35 ± 2.95) at evaluated concentrations (0.1 to 100 μg mL-1). The GK activation assay showed an enzymatic activity increase; compound 2k increased 1.31 and 2.83 more than normal activity, 2m (2.13-fold), 2s (2.86 and 3.74-fold) at 100 and 200 μg mL-1 respectively. The present study showed that the 2s derivative presents moderate potential as an α-glu inhibitor and a good activator potential of GK, suggesting that this compound is a good candidate for blood glucose control through antihyperglycemic and hypoglycemic mechanisms.

Antioxidant activity of novel 4H- chromene tethered 1,2,3-Triazole Analogues: Synthesis and molecular docking studies

Novel 4H chromene coupled triazole hybrids 8a-l were synthesized through a hassle free multicomponent one pot synthesis and click chemistry protocols. The structures of novel compounds were established by interpretation of 1H NMR, 13C NMR, IR and Mass spectral data. The novel hybrids were screened for their invitro antioxidant activity by employing DPPH and Hydrogen peroxide radical scavenging assays, using Ascorbic acid as standard reference. Novel compounds 8h and 8i exhibited superior radical quenching percentage with IC50 value of 1.29 ± 0.35 and 1.23 ± 0.34 µM respectively, compared to the IC50 value of (1.46 ± 0.52 µM)Ascorbic acid. Compounds 8f, 8j and 8k also demonstrated best IC50 value of 3.02 ± 0.62, 2.45 ± 0.53 and 3.18 ± 0.25 µM in comparison to reference. The molecular docking studies of target compounds against the crystal structure of NADPH oxidase endorsed best docking scores and binding interactions, and are in agreement to experimental data.

An efficient, catalyst-free and aqueous ethanol-mediated synthesis of 5-((2-aminothiazol-5-yl)(phenyl)methyl)-6-hydroxypyrimidine-2,4(1H,3H)-dione derivatives and their antioxidant activity.

In this study, we effectively developed a catalyst-free multicomponent synthesis of 5-((2-aminothiazol-5-yl)(phenyl)methyl)-6-hydroxypyrimidine-2,4(1H,3H)-dione derivatives employing 2-aminothiazole, N',N'-dimethyl barbituric acid/barbituric acid and different aldehydes at 80 °C in an aqueous ethanol medium (1 : 1) using group-assisted purification (GAP) chemistry. The essential characteristics of this methodology include superior green credential parameters, metal-free multicomponent synthesis, faster reaction times, greater product yields, simple product purification without column chromatography and higher product yields. All of the synthesized compounds were analyzed against the HepG2 cell line. Compounds 4j and 4k shows good anti-proliferative effects on HepG2 cells. Furthermore, the ABTS and DPPH scavenging assays were used to determine the antioxidant activity of all compounds (4a-r). In both ABTS and DPPH radical scavenging assays, compounds 4e, 4i, 4j, 4o and 4r exhibit excellent potency compared to the standard ascorbic acid.

Synthesis and biological evaluation of capsaicin analogues as antioxidant and neuroprotective agents.

Capsaicin and its analogues 3a-3q were designed and synthesized as potential new antioxidant and neuroprotective agents. Many analogues exhibited good antioxidant effects, and some showed more potent free radical scavenging activities than the positive drug quercetin (IC50 = 8.70 ± 1.75 μM for DPPH assay and 13.85 ± 2.87 μM for ABTS assay, respectively). The phenolic hydroxyl of capsaicin analogues was critical in determining antioxidant activity. Among these compounds, 3k displayed the most potent antioxidant activity. Cell vitality tests revealed that the representative compound 3k was good at protecting cells from H2O2-induced oxidative damage at low concentrations (cell viability increased to 90.0 ± 5.5% at 10 μM). In addition, the study demonstrated that 3k could reduce intracellular ROS accumulation and increase GSH levels to prevent H2O2-induced oxidative stress in SY5Y cells. In the mitochondrial membrane potential assay, 3k significantly increased the MMP level of SY5Y cells treated with H2O2 and played an anti-neuronal cell death role. These results provide a promising strategy to develop novel capsaicin analogues as potential antioxidant and neuroprotective agents.

Novel Specific Pyruvate Kinase M2 Inhibitor, Compound 3h, Induces Apoptosis and Autophagy through Suppressing Akt/mTOR Signaling Pathway in LNCaP Cells

Pyruvate kinase M2 (PKM2) is a key enzyme involved in the regulation of glycolysis. Although PKM2 is overexpressed in various tumor tissues, its functional role in cancer chemotherapy remains unexplored. In this study, we investigated the anticancer activity of a new PKM2 inhibitor, compound 3h, through the cell metabolism and associated signaling pathways in prostate cancer cells. To evaluate the molecular basis of specific PKM2 inhibitors, the interactions of compounds 3h and 3K with the PKM2 protein were assessed via molecular docking. We found that, compared to compound 3K, compound 3h exhibited a higher binding affinity for PKM2. Moreover, compound 3h significantly inhibited the pyruvate kinase activity and PKM2 expression. Cytotoxicity and colony formation assays revealed the potent anticancer activity of compound 3h against LNCaP cells. Compound 3h significantly increased the apoptotic and autophagic cell death in LNCaP cells. In addition, compound 3h induced AMPK activation along with the inhibition of the mTOR/p70S6K pathway. Furthermore, compound 3h significantly inhibited glycolysis and mitochondrial respiration, as determined by analyzing the extracellular acidification rate (ECAR) and oxygen consumption rate (OCR) production. Our results revealed that compound 3h caused apoptotic and autophagic cell death in LNCaP cells by inhibiting cancer cell metabolism. Therefore, blocking glycolytic pathways using specific PKM2 inhibitors can target cancer cell metabolism in PKM2-overexpressed prostate cancer cells.