Design, synthesis, and in-Silco ADME prediction of some novel bis(1,3,4-thiadiazoles) encapsulated lipid-chitosan nano capsule decorative with magnetic nanoparticles and their potential anti-helicobacter pylori activity

Helicobacter pylori (H. pylori) is an extremely prevalent human pathogen globally that leads to severe illnesses. Sadly, the worldwide issue of H. pylori's resistance to antimicrobial medications persists. In this context, creating an anti-H. pylori vaccine that can deliver a satisfactory eradication rate with fewer side effects would be highly beneficial. In this regard, a new series of bis(1,3,4-thiadiazoles) was synthesized and assessed for antimicrobial activity against H. pylori. Combining two bioactive 1,3,4-thiadiazole portions within a single molecule to create a new bis-heterocycle represents an efficient strategy to produce powerful compounds and address issues of resistance and effectiveness. Every synthesized compound showed outstanding inhibition results. Compounds 5c and 8 exhibited the lowest MIC values, recorded at 7.5 and 15.6 μg/mL, respectively. Theoretical predictions were employed to evaluate ADME, leading to outcomes of low solubility, stability, and bioavailability. The effective agents aimed at H. pylori were encapsulated in an appropriate newly developed nanocarrier to tackle challenges related to low bioavailability and stability. Further tests were carried out to evaluate the efficacy of antimicrobials against H. pylori, resulting in promising results. Additionally, the MIC values decreased by 4 and 2 times relative to their original synthetic versions. The activity of the enzyme urease was assessed before nanoencapsulation, showing an IC50 value of 8.99 μg/mL, which was reduced to 7.8 μg/mL after nanoencapsulation.

Novel 3,5‐Dimethylpyrazole‐Linked 1,2,4‐Triazole‐3‐thiols as Potent Antihyperglycemic Agents: Synthesis, Biological Evaluation, and In Silico Molecular Modelling Investigations

In this work, a series of pyrazole‐linked 1,2,4‐triazole‐3‐thiol derivatives (3a–i) were prepared and identified by 13C NMR, 1H NMR, and mass spectrometry (ESI‐MS) data. The newly synthesized molecules were also evaluated in vitro for their α‐amylase and α‐glucosidase inhibitory potential. All newly synthesized compounds exhibited potent α‐glucosidase inhibition activity with IC50 in the range of 1.016 ± 0.70 to 24.40 ± 0.02 µM and good α‐amylase inhibitory with IC50 in the range of 49.91 ± 0.32 to 500 µM, as compared to acarbose. The most potent compound among this series is derivative 3e, with IC50 value of 1.016 ± 0.70 µM, which is many folds more than that of acarbose. In addition, in docking studies, both compounds exhibited good interactions at the active region of target proteins. Therefore, this study may lead via structural modifications to the discovery of new potent α‐amylase and α‐glucosidase inhibitors useful in the diabetes treatment.

Copper-catalyzed aerobic annulation of hydrazones with dienones: an efficient route to pyrazole-linked hybrid molecules

A copper-catalyzed aerobic [3 + 2] annulation reaction to access various pyrazole-bound chalcones starting from readily available and cost-effective hydrazones and dienones is reported. These pyrazole-bound chalcones were further utilized effectively to prepare a series of pyrazole-linked hybrid molecules, such as pyrazole-pyrazoline, pyrazole-aziridine, and pyrazole-pyridine hybrids by efficient simple transformations. Synthetically challenging hybrid molecules were obtained in a simple, two-step process with high atom economy under aerobic copper catalysis.

Potential of covalently linked tamoxifen hybrids for cancer treatment: recent update

Cancer is a complex disease and the second leading cause of death globally, and breast cancer is still a leading cause of cancer death in women. Tamoxifen is the most commonly used drug for breast cancer (ER-positive) treatment and chemoprevention, saving the lives of millions of patients every year. In addition, the tamoxifen template has been explored extensively for the development of selective estrogen receptor modulators (SERMs) applicable in breast cancer, osteoporosis, and postmenopausal symptom treatment. Numerous anticancer drugs, including tamoxifen, are in use, but the complexity and heterogeneous nature of cancer complicate the effect of conventional targeted drugs, leading to adverse reactions and resistance. One of the significant approaches to overcome these shortcomings is drug hybrids, generated by covalently linking two or more active pharmacophores. These drug hybrids are remarkably effective in acting on multiple drug targets with higher selectivity and specificity. In recent years, several tamoxifen hybrids have been discovered as potential candidates for cancer treatment. The review highlights the recent progress in developing anticancer hybrids, including organometallic, fluorescent, photocaged, and novel ligand-based tamoxifen hybrids. It also demonstrates the significance of merging various pharmacophores with tamoxifen to produce more potent, precise, and effective anticancer agents. The study offers valuable knowledge to researchers working on cancer research with the hope of enhancing drug potency and reducing drug toxicity to improve cancer patients' lives.

Design and synthesis of pyrrolo[2,3-d]pyrimidine linked hybrids as α-amylase inhibitors: molecular docking, MD simulation, ADMET and antidiabetic screening

Novel pyrrolo[2,3-d]pyrimidine-based analogues were designed, synthesized, and evaluated for their ability to inhibit the α-amylase enzyme in order to treat diabetes. In vitro antidiabetic analysis demonstrated excellent antidiabetic action for compounds 5b, 6c, 7a, and 7b, with IC50 values in the 0.252-0.281 mM range. At a 200 μg/mL concentration, the exceptional percent inhibition values for compounds 5a, 5b, 5d, and 6a varied from 97.79 ± 2.86% to 85.56 ± 4.13% overperforming the standard (acarbose). Molecular docking of all compounds performed with Bacillus paralicheniformis α-amylase enzyme. The most active compounds via in vitro and non-toxic via in silico ADMET and molecular docking analysis, hybrids 6c, 7a, and 7b displayed binding affinity from - 8.2 and - 8.5 kcal/mol. Molecular dynamic simulations of most active compound 5b and 7a investigated into the active sites of the Bacillus paralicheniformis α-amylase enzyme for a 100-ns indicating the stability of hybrid-protein complex. Consistent RGyr values for the two complexes under study further suggest that the system's proteins are closely packed in the dynamic state. Synthesized analogs' in vitro biological assessments, ADMET, molecular docking, and MD modelling reveal that 5b, 6c, 7a, and 7b hybrid analogs may be employed in the development of future antidiabetic drugs.

Novel GSH-responsive prodrugs derived from indole-chalcone and camptothecin trigger apoptosis and autophagy in colon cancer

Antineoplastic agents that target tubulin have shown efficacy as chemotherapeutic drugs, yet they are often constrained by multidrug resistance (MDR) and unwanted side effects. A multi-targeted strategy demonstrates great potency in reducing toxicity and enhancing efficacy and provides an alternative way for attenuating MDR. In this study, a series of dual-targeted anti-cancer agents based on indole-chalcone derivatives and the camptothecin (CPT) scaffold were synthesized. Among them, 14-1 demonstrated superior anti-proliferative activity than its precursor 13-1, CPT or their physical mixtures against tested cancer cells, including multidrug-resistant variants, while exhibited moderate cytotoxicity toward human normal cells. Mechanistic studies revealed that 14-1 acted as a glutathione-responsive prodrug, inducing apoptosis by substantially enhancing intracellular uptake of CPT, inhibiting tubulin polymerization, increasing the accumulation of intracellular reactive oxygen species, and initiating a mitochondrion-dependent apoptotic pathway. Moreover, 14-1 notably induced autophagy and suppressed topoisomerase I activity to further promote apoptosis. Importantly, 14-1 displayed potent inhibitory effect on tumor growth in paclitaxel (PTX)-resistant colorectal cancer (HCT-116/PTX) xenograft models without inducing obvious toxicity compared with CPT- or combo-treated group. These results suggest that 14-1 holds promise as a novel candidate for anti-cancer therapy, particularly in PTX-resistant cancers.

Sulfonamide derivatives with benzothiazole scaffold: Synthesis and carbonic anhydrase I-II inhibition properties

The secondary sulfonamide derivatives containing benzothiazole scaffold (1-10) were synthesized to determine their inhibition properties on two physiologically essential human carbonic anhydrases isoforms (hCAs, EC, 4.2.1.1), hCA I, and hCA II. The inhibitory effects of the compounds on hCA I and hCA II isoenzymes were investigated by comparing their IC50 and Ki values. The Ki values of compounds (1-10) against hCA I and hCA II are in the range of 0.052 ± 0.022-0.971 ± 0.280 and 0.025 ± 0.010-0.682 ± 0.335, respectively. Some of these inhibited the enzyme more effectively than the standard drug, acetazolamide. In particular, compounds 5 and 4 were found to be most effective on hCA I and hCA II.

Nitrogen-fused Heterocycles: Empowering Anticancer Drug Discovery

The worldwide impact of cancer is further compounded by the constraints of current anticancer medications, which frequently exhibit a lack of selectivity, raise safety apprehensions, result in significant adverse reactions, and encounter resistance mechanisms. The current situation highlights the pressing need to develop novel and more precise anticancer agents that prioritize safety and target specificity. Remarkably, more than 85% of drugs with physiological activity contain heterocyclic structures or at least one heteroatom. Nitrogen-containing heterocycles hold a significant position among these compounds, emerging as the most prevalent framework within the realm of heterocyclic chemistry. This article explores the medicinal chemistry behind these molecules, highlighting their potential as game-changing possibilities for anticancer medication development. The analysis highlights the inherent structural variety in nitrogen-containing heterocycles, revealing their potential to be customized for creating personalized anticancer medications. It also emphasizes the importance of computational techniques and studies on the relationships between structure and activity, providing a road map for rational medication design and optimization. Nitrogen- containing heterocycles are a promising new area of study in the fight against cancer, and this review summarises the state of the field so far. By utilizing their inherent characteristics and exploiting cooperative scientific investigations, these heterocyclic substances exhibit potential at the forefront of pioneering therapeutic approaches in combating the multifaceted obstacles posed by cancer.

Therapeutic significance of molecular hybrids for breast cancer research and treatment

Worldwide, breast cancer is still a leading cause of cancer death in women. Indeed, over the years, several anti-breast cancer drugs have been developed; however, the complex heterogeneous nature of breast cancer disease reduces the applicability of conventional targeted therapies with the upsurge in side effects and multi-drug resistance. Molecular hybrids generated by a combination of two or more active pharmacophores emerged as a promising approach in recent years for the design and synthesis of anti-breast cancer drugs. The hybrid anti-breast cancer molecules are well known for their several advantages compared to the parent moiety. These hybrid forms of anti-breast cancer molecules demonstrated remarkable effects in blocking different pathways contributing to the pathogenies of breast cancer and improved specificity. In addition, these hybrids are patient compliant with reduced side effects and multi-drug resistance. The literature revealed that molecular hybrids are applied to discover and develop novel hybrids for various complex diseases. This review article highlights the recent progress (∼2018-2022) in developing molecular hybrids, including linked, merged, and fused hybrids, as promising anti-breast cancer agents. Furthermore, their design principles, biological potential, and future perspective are discussed. The provided information will lead to the development of novel anti-breast cancer hybrids with excellent pharmacological profiles in the future.

Benzoxazole-appended piperidine derivatives as novel anticancer candidates against breast cancer

Novel series of benzoxazole-appended piperidine derivatives were planned, synthesized and screened against two breast cancer cell lines. Considerable antiproliferative activity was observed for screened compounds (IC₅₀ = 33.32 ± 0.2 µM to 7.31 ± 0.43 µM and 1.66 ± 0.08 µM to 12.10 ± 0.57 µM) against MCF-7 and MDA-MB-231 cell lines respectively being more potent than doxorubicin (IC₅₀ = 8.20 ± 0.39 µM and 13.34 ± 0.63 µM respectively). Active compounds were submitted for enzyme inhibition assays when 4d and 7h demonstrated potent EGFR inhibition (0.08 ± 0.002 µM and 0.09 ± 0.002 µM respectively) compared to erlotinib (0.11 ± 0.003 µM). However, no one compound displayed effective ARO inhibition activity as tested compounds were less active than letrozole. Apoptosis inducing ability results implied that apoptosis was provoked by significant stimulation of caspase-9 protein levels (4.25-7.04-fold) upon treatment of MCF-7 cells with 4a, 7h, 9, 12e and 12f. Alternatively, MDA-MB-231 cells treated with 4d, 7a, 12b and 12c considerably increased caspase-9 levels (2.32-4.06-fold). Cell cycle arrest and annexin-V/Propidium iodide assays further confirmed apoptosis when tested compounds arrested cell cycle at various phases and demonstrated high annexin V binding affinity. Docking outcomes proved valuable binding affinities for compounds 4d and 7h to EGFR enzyme while compounds 4a and 12e, upon docking into the active site of ARO, failed to interact with heme, suggesting their inabilities to act as AIs. Therefore, these benzoxazoles can act as promising candidates exhibiting EGFR inhibition and apoptosis-promoting properties.

Pyrazolyl-s-triazine with indole motif as a novel of epidermal growth factor receptor/cyclin-dependent kinase 2 dual inhibitors

A series of pyrazolyl-s-triazine compounds with an indole motif was designed, synthesized, and evaluated for anticancer activity targeting dual EGFR and CDK-2 inhibitors. The compounds were tested for cytotoxicity using the MTT assay. Compounds 3h, 3i, and 3j showed promising cytotoxic activity against two cancer cell lines, namely A549, MCF-7, and HDFs (non-cancerous human dermal fibroblasts). Compound 3j was the most active candidate against A549, with an IC₅₀ of 2.32 ± 0.21 μM. Compounds 3h and 3i were found to be the most active hybrids against MCF-7 and HDFs, with an IC₅₀ of 2.66 ± 0.26 μM and 3.78 ± 0.55 μM, respectively. Interestingly, 3i showed potent EGFR inhibition, with an IC₅₀ of 34.1 nM compared to Erlotinib (IC₅₀ = 67.3 nM). At 10 μM, this candidate caused 93.6% and 91.4% of EGFR and CDK-2 inhibition, respectively. Furthermore, 3i enhanced total lung cancer cell apoptosis 71.6-fold (43.7% compared to 0.61% for the control). Given the potent cytotoxicity exerted by 3i through apoptosis-mediated activity, this compound emerges as a promising target-oriented anticancer agent.

Novel imidazolium-thiohydantoin hybrids and their Mn(iii) complexes for antimicrobial and anti-liver cancer applications

We present the effective synthesis and structural characterization of three novel imidazolium-thiohydantoin ligands (IMTHs, 5a–c) and their Mn(iii) complexes (Mn(iii)IMTHs, 6a–c) in this study. The findings of elemental analyses, spectral analyses and magnetic measurements will be used to infer the stoichiometry, coordination styles, and geometrical aspects of Mn(iii)IMTHs. The new compounds were evaluated for their chemotherapeutic potential against ESKAPE pathogens and liver cancer (HepG2). According to the MIC and MBC values, the bactericidal and bacteriostatic activities of IMTHs have been significantly improved following coordination with the Mn(iii) ion. The MTT assay results showed that all Mn(iii)IMTHs had the potential to reduce the viability of liver carcinoma (HepG2) cells in a dose-dependent manner, with the BF₄-supported complex (6b) outperforming its counterparts (6a and 6c) as well as a clinical anticancer drug (VBL). Additionally, Mn-IMTH₂ (6b) showed the highest level of selectivity (SI = 32.05) for targeting malignant cells (HepG2) over healthy cells (HL7702).

We present the effective synthesis and structural characterization of three novel imidazolium-thiohydantoin ligands (IMTHs, 5a–c) and their Mn(iii) complexes (Mn(iii)IMTHs, 6a–c) in this study.

Anti-inflammatory effects of β-ionone-curcumin hybrid derivatives against ulcerative colitis

A series of β-ionone-curcumin hybrid derivatives were designed and chosen to merge the biological characteristics of two parent molecules and to obtain a leading compound with higher biological activity. Through the initial screening, the structure activity relationship of their hybrid derivatives as inhibitors of nitric oxide (NO) production showed that meta-substituted derivatives exhibited the best inhibitory activity, among which 1h was the best one. In lipopolysaccharide-induced Raw264.7 macrophage cells, 1h showed anti-inflammatory activity by inhibiting the productions of NO and reactive oxygen species, the expressions of Interleukin-1β and tumor necrosis factor-α, and the translocation of nuclear factor (NF)-κB from the cytosol to the nucleus. Furthermore, molecular docking simulation displayed that 1h could interact with cluster of differentiation 14 to inhibit the toll-like receptor 4/NF-κB signaling. In dextran sulfate sodium (DSS)-induced ulcerative colitis (UC) of mice, 100 mg/kg of 1h could significantly reduce the colon length shortening and protect against colon injury, liver injury and oxidative stress in DSS-induced UC of mice. Besides, 1h was safety in vivo. In conclusion, 1h was the potential anti-inflammatory agent, and further investigations were underway in our laboratory.

Concept of Hybrid Drugs and Recent Advancements in Anticancer Hybrids

Cancer is a complex disease, and its treatment is a big challenge, with variable efficacy of conventional anticancer drugs. A two-drug cocktail hybrid approach is a potential strategy in recent drug discovery that involves the combination of two drug pharmacophores into a single molecule. The hybrid molecule acts through distinct modes of action on several targets at a given time with more efficacy and less susceptibility to resistance. Thus, there is a huge scope for using hybrid compounds to tackle the present difficulties in cancer medicine. Recent work has applied this technique to uncover some interesting molecules with substantial anticancer properties. In this study, we report data on numerous promising hybrid anti-proliferative/anti-tumor agents developed over the previous 10 years (2011–2021). It includes quinazoline, indole, carbazole, pyrimidine, quinoline, quinone, imidazole, selenium, platinum, hydroxamic acid, ferrocene, curcumin, triazole, benzimidazole, isatin, pyrrolo benzodiazepine (PBD), chalcone, coumarin, nitrogen mustard, pyrazole, and pyridine-based anticancer hybrids produced via molecular hybridization techniques. Overall, this review offers a clear indication of the potential benefits of merging pharmacophoric subunits from multiple different known chemical prototypes to produce more potent and precise hybrid compounds. This provides valuable knowledge for researchers working on complex diseases such as cancer.

<p class="CB-Manuscripttitle"><span lang="EN-US">Synthesis, Biological Activity and Molecular Docking Studies of Heterocyclic Chalcones<o:p></o:p></span></p>

Nineteen heterocyclic chalcones were synthesized from 4-acetyl-5-methylquinolylpyrazole and heteroaryl (imidazole, pyrazole, thiophene, indole and triazole) aldehydes and screened in vitro using four tumor cell lines for their anticancer capability and for antimicrobial activity. The chalcone 5b exhibited the highest activity with IC 50 values 2.14 μM against colon (HCT-116) and 5.0 μM, against prostate (PC-3) cancer cell lines and also displayed good activity against fungal strain ( A. Niger) with MIC value 9.1 μM . The chalcones 5q and 5p displayed good activity against Gram-positive bacterial strains ( S. aureus ) with MIC value 2.6 µM and fungal strain ( C. Albicans ) with MIC value 5.4 µM, respectively. Molecular docking studies revealed that the synthesized heterocyclic chalcones exhibited hydrogen bond, electrostatic and hydrophobic interactions with their respective biochemical targets.

Hybrid Molecules Containing Naphthoquinone and Quinolinedione Scaffolds as Antineoplastic Agents

In recent decades, molecular hybridization has proven to be an efficient tool for obtaining new synthetic molecules to treat different diseases. Based on the core idea of covalently combining at least two pharmacophore fragments present in different drugs and/or bioactive molecules, the new hybrids have shown advantages when compared with the compounds of origin. Hybridization could be successfully applied to anticancer drug discovery, where efforts are underway to develop novel therapeutics which are safer and more effective than those currently in use. Molecules presenting naphthoquinone moieties are involved in redox processes and in other molecular mechanisms affecting cancer cells. Naphthoquinones have been shown to inhibit cancer cell growth and are considered privileged structures and useful templates in the design of hybrids. The present work aims at summarizing the current knowledge on antitumor hybrids built using 1,4- and 1,2-naphthoquinone (present in natural compounds as lawsone, napabucasin, plumbagin, lapachol, α-lapachone, and β -lapachone), and the related quinolone- and isoquinolinedione scaffolds reported in the literature up to 2021. In detail, the design and synthetic approaches adopted to produce the reported compounds are highlighted, the structural fragments considered in hybridization and their biological activities are described, and the structure–activity relationships and the computational analyses applied are underlined.

New benzimidazole based hybrids: Synthesis, molecular modeling study and anticancer evaluation as TopoII inhibitors

Three series of new benzimidazole hybrids were designed and synthesized as promising human TopoII inhibitors. They were characterized by different spectroscopic techniques (¹H, ¹³C NMR, ESI-MS and IR). All hybrids (6-23) were screened for their in vitro antiproliferative activity against five human cancer cell lines namely; HepG-2, MCF-7, PC-3, HCT-116 and Hela. Compound 21 showed the most potent anticancer activity against all cancer cell lines, with IC₅₀ range of 2.82 to 12.59 µM, while proving safe towards normal cells WI-38 (IC₅₀ = 31.89 µM) compared to the reference drug doxorubicin (IC₅₀ = 6.72 µM). The most active candidates 13, 20, 21, 22 and 23 were further assessed for their human TopoII inhibition. The best of which, compounds 13 and 20 showed IC₅₀ of 6.72 and 8.18 µM respectively compared to staurosporine (IC₅₀ = 4.64 µM). Further mechanistic studies for compound 13 showed cell cycle arrest at S-phase by 51.29 % and a significant increase in the total apoptosis by 62.5 folds. Furthermore, apoptosis study proved that it induced apoptosis by decreasing both IAP and Bcl-2, activating caspases 3, 8 and 9, and increasing accumulation of ROS in HepG-2 cells. Besides, it decreased transcription factors' binding activity to DNA. Comparative molecular docking study was performed between the most potent TopoII inhibitors 13 and 20, and the least potent one 23 to relate the binding pattern with TopoII catalytic active site to the biological activity, where all results came in agreement with the biological results. Additional molecular modeling studies including surface mapping and contact preferences were performed to emphasize the importance of hydrophobicity. Physicochemical calculations were assessed where compounds 13 and 20 represented very promising orally active drug candidates.

1,2,3-Triazolyl-tetrahydropyrimidine Conjugates as Potential Sterol Carrier Protein-2 Inhibitors: Larvicidal Activity against the Malaria Vector Anopheles arabiensis and In Silico Molecular Docking Study

Alteration of insect growth regulators by the action of inhibitors is becoming an attractive strategy to combat disease-transmitting insects. In the present study, we investigated the larvicidal effect of 1,2,3-triazolyl-pyrimidinone derivatives against the larvae of the mosquito Anopheles arabiensis, a vector of malaria. All compounds demonstrated insecticidal activity against mosquito larvae in a dose-dependent fashion. A preliminary study of the structure-activity relationship indicated that the electron-withdrawing substituent in the para position of the 4-phenyl-pyrimidinone moiety enhanced the molecules' potency. A docking study of these derivatives revealed favorable binding affinity for the sterol carrier protein-2 receptor, a protein present in the intestine of the mosquito larvae. Being effective insecticides against the malaria-transmitting Anopheles arabiensis, 1,2,3-triazole-based pyrimidinones represent a starting point to develop novel inhibitors of insect growth regulators.

Quinazolinone-based hybrids with diverse biological activities: A mini-review

Quinazolinone and quinazoline have been shown different pharmacological activities, namely anticancer, anti-inflammatory, anti-hyperlipidemia, analgesic, antihypertensive, and antibacterial. On the other hand, molecular hybridization is a structural modification technique in the design of new ligands which consist of two or more pharmacologically active molecules in one structure. Therefore, due to the importance of the biological activities of quinazolinones for the development of new therapeutic agents, this review emphasizes current findings on various quinazolinone-based hybrids in medicinal chemistry. Moreover, it highlights the biological activities and structure-activity relationship of these hybrids.

Synthetic and Naturally Occurring Heterocyclic Anticancer Compounds with Multiple Biological Targets

Cancer is a complex group of diseases initiated by abnormal cell division with the potential of spreading to other parts of the body. The advancement in the discoveries of omics and bio- and cheminformatics has led to the identification of drugs inhibiting putative targets including vascular endothelial growth factor (VEGF) family receptors, fibroblast growth factors (FGF), platelet derived growth factors (PDGF), epidermal growth factor (EGF), thymidine phosphorylase (TP), and neuropeptide Y4 (NY4), amongst others. Drug resistance, systemic toxicity, and drug ineffectiveness for various cancer chemo-treatments are widespread. Due to this, efficient therapeutic agents targeting two or more of the putative targets in different cancer cells are proposed as cutting edge treatments. Heterocyclic compounds, both synthetic and natural products, have, however, contributed immensely to chemotherapeutics for treatments of various diseases, but little is known about such compounds and their multimodal anticancer properties. A compendium of heterocyclic synthetic and natural product multitarget anticancer compounds, their IC50, and biological targets of inhibition are therefore presented in this review.

Design, Synthesis, Biological Evaluation, 2D-QSAR Modeling, and Molecular Docking Studies of Novel 1H-3-Indolyl Derivatives as Significant Antioxidants

Novel candidates of 3-(4-(thiophen-2-yl)-pyridin/pyran/pyrimidin/pyrazol-2-yl)-1H-indole derivatives (2–12) were designed by pairing the pyridine/pyrane/pyrimidine/pyrazole heterocycles with indole and thiophene to investigate their potential activities as (2,2′-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) inhibitors. The purpose of these derivatives’ modification is to create high-efficiency antioxidants, especially against ABTS, as a result of the efficiency of this set of key heterocycles in the inhibition of ROS. Herein, 2D QSAR modeling was performed to recommend the most promising members for further in vitro investigations. Furthermore, the pharmacological assay for antioxidant activity evaluation of the yielded indole-based heterocycles was tested against ABTS (2,2′-azinobis (3-ethylbenzothiazoline-6-sulfonic acid); by utilizing ascorbic acid as the standard. Candidate 10 showed higher antioxidant activity (IC₅₀ = 28.23 μg/mL) than ascorbic acid itself which achieved (IC₅₀ = 30.03 μg/mL). Moreover, molecular docking studies were performed for the newly designed and synthesized drug candidates to propose their mechanism of action as promising cytochrome c peroxidase inhibitors compared to ascorbic acid as a reference standard. Our findings could be promising in the medicinal chemistry scope for further optimization of the newly designed and synthesized compounds regarding the introduced structure-activity relationship study (SAR) in order to get a superior antioxidant lead compound in the near future.

Design, Synthesis and Anticancer Evaluation of Substituted Cinnamic Acid Bearing 2-Quinolone Hybrid Derivatives

A new series of hybrid molecules containing cinnamic acid and 2-quinolinone derivatives were designed and synthesized. Their structures were confirmed by 1H-NMR, 13C-NMR and mass analyses. All the synthesized hybrid molecules were assessed for their in vitro antiproliferative activity against more than one cancer cell lines. Compound 3-(3,5-dibromo-7,8-dihydroxy-4-methyl-2-oxoquinolin-1(2H)-ylamino)-3-phenylacrylic acid (5a) with IC50 = 1.89 μM against HCT-116 was proved to the most potent compound in this study, as compared to standard drug staurosporin. DNA flow cytometry assay of compound 5a revealed G2/M phase arrest and pre-G1 apoptosis. Annexin V-FITC showed that the percentage of early and late apoptosis was increased. The results of topoisomerase enzyme inhibition activity showed that the hybrid molecule 5a displays potent inhibitory activity compared with control.

New 3-(1H-benzo[d]imidazol-2-yl)quinolin-2(1H)-one-based triazole derivatives: Design, synthesis, and biological evaluation as antiproliferative and apoptosis-inducing agents

A series of 1,2,3-triazole derivatives based on the quinoline-benzimidazole hybrid scaffold was designed, synthesized, and screened against a panel of NCI-60 humanoid cancer cell lines for in vitro cytotoxicity evaluation, which revealed that compound Q6 was the most potent cytotoxic agent with excellent GI₅₀ , TGI, and LC₅₀ values on multiple cancer cell lines. Q6 was tested further on the BT-474 breast cancer line to evaluate the mechanism of action. Preliminary screening studies based on the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay revealed that compound Q6 had an excellent antiproliferative effect against human breast cancer cells, BT-474, with IC₅₀ values of 0.59 ± 0.01 μM. The detailed study based on the acridine orange/ethidium bromide staining (AO/EB) and the 4',6-diamidino-2-phenylindole (DAPI) assay suggested that the antiproliferative activity shown was due to the induction of apoptosis on exposure to Q6. Further, DCFDA staining showed the generation of reactive oxygen species, altering the mitochondrial potential and leading to the initiation of apoptosis. This was further supported by JC-1 staining, indicating that this scaffold can contribute to the development of more potent derivatives.

New Hybrid Scaffolds Based on Carbazole-Chalcones as Potent Anticancer Agents

BACKGROUND AND OBJECTIVES

Despite various technological advances for the treatment of cancer, the identification of new chemical entities with potent anticancer effects remain an indispensable requirement of the time due to multi-drug resistance exhibited by previously developed anticancer drugs. Particularly, the hybrid drugs incorporating two individual bioactive pharmacophores present medicinally important structural leads, thus improving the pharmacodynamic profile of the drug molecules. The antiproliferative and pro-apoptotic activity of the carbazole-chalcone hybrids on human breast and cervical cancer cells will be examined.

MATERIALS AND METHODS

To overcome such complications, in the current study, we evaluated the cytotoxic effects of carbazole-chalcone hybrids on human breast adenocarcinoma (MCF-7), cervical adenocarcinoma (HeLa) cells and normal cells, i.e., Baby Hamster Kidney cells (BHK-21) using MTT (dimethyl-2-thiazolyl-2,5- diphenyl-2H-tetrazolium bromide) assay. The mechanistic studies were performed on potent compound 4g by fluorescent microscopic studies, release of Lactate Dehydrogenase (LDH) and mitochondrial membrane potential, activation of caspase-9 and -3 and flow cytometric analysis.

RESULTS

As revealed by MTT assay, compound 4g was identified as the most potent derivative among the tested series with IC₅₀ values of 5.64 and 29.15μM against HeLa and MCF-7 cells, respectively. The results were compared with cisplatin. Fluorescent microscopic studies using 4',6-diamidino-2-phenylindole (DAPI) and Propidium Iodide (PI) staining confirmed the occurrence of apoptosis in HeLa cells treated with the most active compound 4g. Moreover, compound 4g also triggered the release of Lactate Dehydrogenase (LDH) in treated HeLa and MCF-7 cells while a fluorescence assay displayed a remarkable increase in the activity of caspase-9 and -3. Moreover, flow cytometric results revealed that compound 4g caused G₀/G₁ arrest in the treated HeLa cells.

CONCLUSION

Our results demonstrated that the compound 4g possesses chemotherapeutic properties against breast cancer and cervical adenocarcinoma cells, thus warranting further research to test the anticancer potential of this compound at preclinical and clinical level.

Synthesis and Biological Screening of New Cyano-Substituted Pyrrole Fused (Iso)Quinoline Derivatives

Several new cyano-substituted derivatives with pyrrolo[1,2-a]quinoline and pyrrolo[2,1-a]isoquinoline scaffolds were synthesized by the [3 + 2] cycloaddition of (iso)quinolinium ylides to fumaronitrile. The cycloimmonium ylides reacted in situ as 1,3-dipoles with fumaronitrile to selectively form distinct final compounds, depending on the structure of the (iso)quinolinium salt. Eleven compounds were evaluated for their anticancer activity against a panel of 60 human cancer cell lines. The most potent compound 9a showed a broad spectrum of antiproliferative activity against cancer cell lines representing leukemia, melanoma and cancer of lung, colon, central nervous system, ovary, kidney, breast and prostate cancer. In vitro assays and molecular docking revealed tubulin interaction properties of compound 9a.

Synthesis and Anticancer Activity of Thiadiazole Containing Thiourea, Benzothiazole and Imidazo[2,1-b][1,3,4]thiadiazole Scaffolds

BACKGROUND

A great array of nitrogen-containing heterocyclic rings were being extensively explored for their functional versatility in the field of medicine, especially in anticancer research. 1,3,4- thiadiazole is one of such heterocyclic rings with promising anticancer activity against several cancer cell lines, inhibiting diverse biological targets.

INTRODUCTION

The 1,3,4-thiadiazole, when equipped with other heterocyclic scaffolds, has displayed enhanced anticancer properties. The thiourea, benzothiazole, imidazo[2,1,b][1,3,4]-thiadiazoles are such potential scaffolds with promising anticancer activity.

METHODS

A new series of 5-substituted-1,3,4-thiadiazoles linked with phenyl thiourea, benzothiazole and 2,6-disubstituted imidazo[2,1-b][1,3,4]thiadiazole derivatives were synthesized and tested for invitro anticancer activity on various cancer cell lines.

RESULTS

The National Cancer Institute's preliminary anticancer screening results showed compounds 4b and 5b having potent antileukemic activity. Compound 4b selectively showed 32 percent lethality on Human Leukemia-60 cell line. The docking studies of the derivatives on aromatase enzyme (Protein Data Bank: 3S7S) have shown reversible interactions at the active site with good docking scores comparable to Letrozole and Exemestane. Furthermore, the selected derivatives were tested for anticancer activity on HeLa cell line based on the molecular docking studies.

CONCLUSION

Compounds 4b and 5b showed effective inhibition equivalent to Letrozole. These preliminary biological screening studies have given positive anticancer activity for these new classes of derivatives. An additional research study like the mechanism of action of the anticancer activity of this new class of compounds is necessary. These groundwork studies illuminate a future pathway for research of this class of compounds enabling the discovery of potent antitumor agents.

A silver-catalyzed stereoselective domino cycloisomerization-vinylogous aldol reaction of ortho-alkynylbenzaldehydes with 3-alkylidene oxindoles: an entry to functionalized isochromenes

A silver tetrafluoroborate catalyzed domino cycloisomerization-vinylogous aldol addition sequence on a multifunctional substrate such as ortho-alkynylbenzaldehydes yielding functionalized 1H-isochromenes in a single step with high yield and excellent diastereoselectivity (>19 : 1) is described. The reaction was well tolerated by alkyl, aryl, and unsubstituted alkynylbenzaldehydes, and furnished selective 6-endo-dig adducts exclusively without loss in the regio- as well as diastereoselectivity.

Design, synthesis and in vitro antiproliferative activity of new thiazolidinedione-1,3,4-oxadiazole hybrids as thymidylate synthase inhibitors

Thymidylate synthase (TS) has been an attention-grabbing area of research for the treatment of cancers due to their role in DNA biosynthesis. In the present study, we have synthesised a library of thiazolidinedione-1,3,4-oxadiazole hybrids as TS inhibitors. All the synthesised hybrids followed Lipinski and Veber rules which indicated good drug likeness properties upon oral administration. Among the synthesised hybrids, compound 9 and 10 displayed 4.5 and 4.4 folds activity of 5-Fluorouracil, respectively against MCF-7 cell line whereas 3.1 and 2.5 folds cytotoxicity against HCT-116 cell line. Furthermore, compound 9 and 10 also inhibited TS enzyme with IC50 = 1.67 and 2.21 µM, respectively. Finally, the docking studies of 9 and 10 were found to be consistent with in vitro TS results. From these studies, compound 9 and 10 has the potential to be developed as TS inhibitors.

Barbiturate derivatives for managing multifaceted oncogenic pathways: A mini review

Development and progression of metastasis comprises synchronized erroneous expressions of several composite pathways, which are difficult to manage simultaneously with the representative anticancer molecules. The emergence of the drug resistance and the complex interplay between these pathways further potentiates cancer related complexities. Barbiturates and their derivatives present a commendable anticancer profile by attenuating the cancer manifesting metabolic and enzymatic pathways including, but not limited to matrix metalloproteinases, xanthine oxidase, amino peptidases, histone deacetylases, and Ras/mitogen-activated protein kinase. The derivatization and conjugation of barbiturates with pharmacophores delivers a suitable hybrid profile in containing the anomalous expression of these pathways. The present report presents a succinct collation of the barbiturates and their derivatives in managing the various cancer causing pathways.

Design, synthesis and antiproliferative activity evaluation of fluorine-containing chalcone derivatives

A series of new chalcones containing fluoro atom at B ring have been designed, synthesized, and evaluated to be antiproliferative activity against a panel of human tumor cell lines. Some of the analogs (8, 9, 12, 45, 46 and 48) displayed powerful antiproliferative effects to certain human tumor cells, but all of them were devoid of any cytotoxicity towards the normal HEK 293. Acridine orange staining data supported that the cytotoxic and antiproliferative effects of the synthesized analogs on tumor cells are mediated through apoptosis. The compounds 12 and 46 manifested concentration-dependent antiproliferative activity in human hepatocellular carcinoma cell lines using an xCELLigence assay. The structures and antiproliferative activity relationship were further supported by in silico molecular docking study of the compounds against tubulin protein which suggests our compounds interference to cell division. Communicated by Ramaswamy H. Sarma.

Ultrasound-assisted one-pot green synthesis of new N- substituted-5-arylidene-thiazolidine-2,4-dione-isoxazoline derivatives using NaCl/Oxone/Na3PO4 in aqueous media

A rapid and green method for the synthesis of novel N-thiazolidine-2,4-dione isoxazoline derivatives 5 from N-allyl-5-arylidenethiazolidine-2,4-diones 3 as dipolarophiles with arylnitrile oxides via 1,3-dipolar cycloaddition reaction. The corresponding N-allyl substituted dipolarophiles were prepared by one-pot method from thiazolidine-2,4-dione with aldehydes using Knoevenagel condensation followed by N-allylation of thiazolidine-2,4-dione in NaOH aqueous solution under sonication. In addition, the isoxazoline derivatives 5 were synthesized by regioselective and chemoselective 1,3-dipolar cycloaddition using inexpensive and mild NaCl/Oxone/Na₃PO₄ as a Cl source, oxidant and/or catalyst under ultrasonic irradiation in EtOH/H₂O (v/v, 2:1) as green solvent. All synthesized products are furnished in good yields in the short reaction time, and then their structures were confirmed by NMR, mass spectrometry and X-ray crystallography analysis.

Potential 2,4-dimethyl-1H-pyrrole-3-carboxamide bearing benzimidazole template: Design, synthesis, in vitro anticancer and in silico ADME study

A new series of 2,4-dimethyl-1H-pyrrole-3-carboxamide derivatives bearing benzimidazole moiety was synthesized through a molecular hybridization approach and evaluated for in vitro anticancer activity by NCI-60 on leukemia, melanoma, lung, colon, CNS, ovarian, renal, prostate and breast cancer cell lines at a single dose (10 µM). Among all the synthesized conjugates, some derivatives showed more or less good activity even at such a small dose, while, compound 5-(1H-benzo[d]imidazol-2-yl)-N-(1-cyclohexylethyl)-2,4-dimethyl-1H-pyrrole-3-carboxamide (8f) displayed significant antiproliferative activity specifically against MDA-MB human cancer cell lines. Compound 8f showed promising activity against MDA-MB-435 cell line of melanoma (Growth inhibition: 62.46%) and MDA-MB-468 cell line of breast (Growth inhibition: 40.24%). Computational ADME study qualified its significant physicochemical, pharmacokinetic and drug-likeness properties with good predicted oral bioavailability. Thus this new hybrid molecules would be useful for further anticancer drug development.

Benzoxazole derivatives as new generation of anti-breast cancer agents

New 2-substituted benzoxazole derivatives were synthesized and screened for their in vitro anti-proliferative activities against MCF-7 and MDA-MB-231 cell lines. Compounds 4b, 4d and 11c eliciting the highest activity against MCF-7 cells were further assayed for their cytotoxic activities against A431 and HCC827 cancer cells in addition to their in vitro inhibition of wild and mutated epidermal growth factor receptor (EGFR) enzymes. Compound 11c was the most active against A431 cells and it displayed a potent inhibition of EGFR^WT while compounds 4b and 4d elicited higher potencies than erlotinib against mutated EGFR^L858R. Compounds 4a, 6c and 8a showed the most potent cytotoxic activity against MDA-MB-231 cancer cells where compounds 4a and 6c were slightly less potent aromatase (ARO) inhibitors than letrozole. MCF-7 cells treated with compounds 4b, 4d, 11c and MDA-MB-231 cells treated with compounds 4a, 6c and 8a showed remarkable over-expression of caspase-9 protein level and elicited pre G1 apoptosis and cell cycle arrest at G2/M phase in addition to high annexin V binding affinity indicating significant apoptosis. Chemo-informatic and docking properties were also predicted. Docking results revealed that docked compounds displayed binding modes with EGFR and ARO enzymes comparable to that of the reference ligands. The benzoxazole derivatives 11c and 6c possessing amide and dithiocarbamate moieties respectively were found to be potent apoptosis-inducing anti-breast cancer agents with acceptable physicochemical properties. They exert their activity via inhibition of EGFR and ARO enzymes respectively.

One-Pot Synthesis of Unsymmetrical Bis-Heterocycles: Benzimidazole-, Benzoxazole-, and Benzothiazole-Linked Thiazolidines

A one-pot, three-component synthesis of benzimidazole-linked thiazolidines from 2-cyanomethyl benzimidazole, iso-, isothio-, or isoselenocyanates and 1,2-dichloroethane is reported. Isolation of the key intermediate formed during the course of the reaction validates its mechanistic pathway. Under the same reaction conditions, benzimidazole-linked/fused thiazinanes were obtained when 1,3-dichloropropane or diiodomethane was used.

Recent advances in the pharmacological diversification of quinazoline/quinazolinone hybrids

Due to the pharmacological activities of quinazoline and quinazolinone scaffolds, it has aroused great interest in medicinal chemists for the development of new drugs or drug candidates. The pharmacological activities of quinazoline and its related scaffolds include anti-cancer, anti-microbial, anti-convulsant, and antihyperlipidaemia. Recently, molecular hybridization technology is used for the development of hybrid analogues with improved potency by combining two or more pharmacophores of bioactive scaffolds. The molecular hybridization of various biologically active pharmacophores with quinazoline derivatives resulted in lead compounds with multi-faceted biological activity wherein specific as well as multiple targets were involved. The present review summarizes the advances in lead compounds of quinazoline hybrids and their related heterocycles in medicinal chemistry. Moreover, the review also helps to intensify the drug development process by providing an understanding of the potential role of these hybridized pharmacophoric features in exhibiting various pharmacological activities.

Recent advances in quinazoline/quinazolinone hybrid heterocycles in medicinal chemistry and their pharmacological diversification.

Synthesis and antitumor activity of fluorouracil - oleanolic acid/ursolic acid/glycyrrhetinic acid conjugates

Due to the obvious adverse effects of 5-fluorouracil that limit its clinical usefulness and considering the diverse biological activities of pentacyclic triterpenes, twelve pentacyclic triterpene-5-fluorouracil conjugates were synthesized and their antitumor activities were evaluated. The results indicated that all the single substitution targeted hybrids (7a-12a) possessed much better antiproliferative activities than the double substitution targeted hybrids (7b-12b). Hybrid 12a exhibited good antiproliferative activities against all the tested MDR cell lines. Furthermore, it was revealed that 12a could induce intracellular calcium influx, the generation of ROS, arrest the cell proliferation at the G1 phase, and activate the apoptotic signaling caspase-8, which eventually activates the apoptotic effector caspase-3 and causes the later nuclear apoptosis.

Design, Synthesis and Cancer Cell Growth Inhibition Evaluation of New Aminoquinone Hybrid Molecules

Molecular hybridization has proven to be a successful multi-target strategy in the design and development of new antitumor agents. Based on this rational approach, we have planned hybrid molecules containing covalently linked pharmacophoric units, present individually in compounds acting as inhibitors of the cancer protein targets tubulin, human topoisomerase II and ROCK1. Seven new molecules, selected by docking calculation of the complexes with each of the proteins taken into consideration, have been efficiently synthesized starting from 2,3-dichloro-1,4-naphtoquinone or 6,7-dichloro-5,8-quinolinquinone. By screening the full National Cancer Institute (NCI) panel, including 60 human cancer cell lines, four molecules displayed good and sometimes better growth inhibition GI₅₀ than the ROCK inhibitor Y-27632, the Topo II inhibitor podophyllotoxin and the tubulin inhibitor combretastatin A-4. The relative position of N,N heteroatoms in the structures of the tested compounds was crucial in affecting bioactivity and selectivity. Furthermore, compound 3 (2-(4-(2-hydroxyethyl)piperazin-1-yl)-3-(3,4,5-trimethoxyphenoxy)naphthalene-1,4-dione) emerged as the most active in the series, showing a potent and selective inhibition of breast cancer BT-549 cells (GI₅₀ < 10 nM).

Phenylpropanoid-based sulfonamide promotes cyclin D1 and cyclin E down-regulation and induces cell cycle arrest at G1/S transition in estrogen positive MCF-7 cell line

Cancer is one of the most critical problems of public health in the world and one of the main challenges for medicine. Different biological effects have been reported for sulfonamide-based compounds including antibacterial, antifungal, and antitumor activities. Herein, a series of phenylpropanoid-based sulfonamides (4a, 4a', 4b, 4b', 5a, 5a', 5b and 5b') were synthesized and their cytotoxic activity was evaluated against four cell lines derived from human tumours (A549 - lung, MCF-7 - breast, Hep G2 - hepatocellular carcinoma, and HT-144-melanoma). Cell viability was significantly reduced in the MCF-7 cell line when compounds 4b, 4b' and 5a were used; IC₅₀ values were lower than those found for their precursors (eugenol and dihydroeugenol) and sulfanilamide. We observed that 4b induced cell cycle arrest at G1/S transition. This is probably due to its ability to reduce cyclin D1 and cyclin E expression. Moreover, 4b also induced apoptosis in MCF-7 cells as demonstrated by an increase in the cell population positive for annexin V in treated cultures in comparison to the control group. Taken together, the data showed that 4b is a promising antitumor agent and it should be considered for further in vivo studies.

Combretastatin A4-camptothecin micelles as combination therapy for effective anticancer activity

Cancer is a major worldwide health problem, for which chemotherapy is a common treatment option. However drug toxicity and the development of resistance to chemotherapy are two main challenges associated with the traditional anticancer drugs. Combined pharmacological therapy based on different mechanisms might be an effective strategy in cancer treatment, and could exhibit a synergistic therapeutic efficacy. Herein, we aim to combine combretastatin A4 (CA4) and camptothecin (Cpt) chemically into a codrug through two hydrophilic linkers utilizing click chemistry to improve their water solubility and anticancer activity. The synthesized amphiphilic structure could self-assemble into a micelle structure as confirmed by atomic force microscopy (AFM) and dynamic light scattering (DLS), which showed a high stability and improved water solubility at pH 7.4, with a low critical micelle concentration (CMC) value of 0.9 mM. Moreover, in vitro hydrolysis was observed upon incubation of the hybrid compound with an esterase enzyme, which suggested a complete disassembly into the starting active drugs. Finally, cytotoxicity studies on HeLa cancer cells showed that the codrug demonstrated an enhanced (five fold) cytotoxicity as compared with the free drugs. In addition the combination index (CI) was <1, which suggests a synergistic activity for the codrug. Moreover, the tested concentrations of the codrug were not significantly cytotoxic to a noncancerous fibroblast cell line. The imaging of HeLa cells treated with FITC-loaded micelles showed a rapid internalization. In conclusion, the codrug of CA4 and Cpt might be a potential novel anticancer drug as it demonstrated a synergistic cytotoxic activity that might spare noncancerous cells.