Rational design, synthesis and anti-proliferative evaluation of novel 1,4-benzoxazine-[1,2,3]triazole hybrids

New substituted benzoxazine derivatives as potent inducers of membrane permeability and cell death

The search for new agents targeting different forms of cell death is an important research focus for developing new and potent antitumor therapies. As a contribution to this endeavor, we have designed and synthesized a series of new substituted 3,4-dihydro-2H-1,4-benzoxazine derivatives. These compounds have been evaluated for their efficacy against MCF-7 breast cancer and HCT-116 colon cancer cell lines. Overall, substituting this heterocycle led to improved antiproliferative activity compared to the unsubstituted derivative 1. The most active compounds, 2b and 4b, showed IC50 values of 2.27 and 3.26 μM against MCF-7 cells and 4.44 and 7.63 μM against HCT-116 cells, respectively. To investigate the mechanism of action of the target compounds, the inhibition profile of 8 kinases involved in cell signaling was studied highlighting residual activity on HER2 and JNK1 kinases. 2b and 4b showed a consistent binding mode to both receptor kinases, establishing significant interactions with known and catalytically important domains and residues. Compounds 2b and 4b exhibit potent cytotoxic activity by disrupting cell membrane permeability, likely triggering both inflammatory and non-inflammatory cell death mechanisms. This dual capability increases their versatility in the treatment of different stages or types of tumors, providing greater flexibility in clinical applications.

Design and Synthesis of Novel Antioxidant 2-Substituted-5,7,8-Trimethyl-1,4-Benzoxazine Hybrids: Effects on Young and Senescent Fibroblasts

The exponential growth of the aged population worldwide is followed by an increase in the prevalence of age-related disorders. Oxidative stress plays central role in damage accumulation during ageing and cell senescence. Thus, a major target of today's anti-ageing research has been focused on antioxidants counteracting senescence. In the current work, six novel 5,7,8-trimethyl-1,4-benzoxazine/catechol or resorcinol hybrids were synthesized connected through a methoxymethyl-1,2,3-triazolyl or a 1,2,3-triazoly linker. The compounds were evaluated for their antioxidant capacity in a cell-free system and for their ability to reduce intracellular ROS levels in human skin fibroblasts, both young (early-passage) and senescent. The most efficient compounds were further tested in these cells for their ability to induce the expression of the gene heme oxygenase-1 (ho-1), known to regulate redox homeostasis, and cellular glutathione (GSH) levels. Overall, the two catechol derivatives were found to be more potent than the resorcinol analogues. Furthermore, these two derivatives were shown to act coordinately as radical scavengers, ROS inhibitors, ho-1 gene expression inducers, and GSH enhancers. Interestingly, one of the two catechol derivatives was also found to enhance human skin fibroblast viability. The properties of the synthesized compounds support their potential use in cosmetic applications, especially in products targeting skin ageing.

Rational Design, Synthesis, and Anti-Proliferative Evaluation of Novel 4-Aryl-3,4-Dihydro-2H-1,4-Benzoxazines

A synthetic pathway to a novel 4-aryl-3,4-dihydro-2H-1,4-benzoxazine scaffold was developed and a series of compounds based on the scaffold were synthesised as potential anticancer agents. The 4-aryl-substituted compounds were prepared via Buchwald-Hartwig cross-coupling between substituted bromobenzenes and various 1,4-benzoxazines, which in turn were generated from a cascade hydrogenation and reductive amination one-pot reaction. These analogues exhibited moderate to good potency against various cancer cell lines. Structure-activity relationship analysis indicated that the inclusion of hydroxyl groups on ring A and ring B was beneficial to biological activity, while having a para-amino group on ring C significantly enhanced potency. Molecule 14f displayed the most potent anticancer activity (IC50 = 7.84-16.2 µM against PC-3, NHDF, MDA-MB-231, MIA PaCa-2, and U-87 MG cancer cell lines), indicating its potential as a lead compound for further structural optimisation. All the synthesised compounds were fully characterised with NMR, HMRS, and IR. The novel benzoxazine scaffold described in this study holds promise and deserves further in-depth studies.

New tetrazolopyrrolidine-1,2,3-triazole analogues as potent anticancer agents: design, synthesis and molecular docking studies

1,2,3-Triazole and tetrazole derivatives bearing pyrrolidines are found to exhibit notable biological activity and have become useful scaffolds in medicinal chemistry for application in lead discovery and optimization. We report design, synthesis and molecular docking studies of tetrazolyl-1,2,3-triazole derivatives (7a-i) bearing pyrrolidine moiety and evaluating their anticancer activity against four cancer cell lines viz. Hela, MCF-7, HCT-116 and HepG2. The structures of the new compounds were ascertained by spectral means IR, NMR: 1H &13C and Mass spectrum. From the studies compounds7a and 7i exhibited significant anticancer activity against the Hela cell line with IC50 = 0.32 ± 1.00, 1.80 ± 0.22 μM when compared to reference drug Doxorubicin (IC50 = 2.34 ± 0.11 μM), whereas 7h, 7i, and 7b were found to be active against MCF-7, HCT-116 and HepG2 cell lines with IC50 = 3.20 ± 1.40, 1.38 ± 0.06 and 0.97 ± 0.12 μM respectively. Notably 7a exhibited highest conventional hydrogen bondings TyrA:40, SerA:17, LysA:117, AlaA:146, Tyr218 with 3HB4and SerA:17, LysA:117, AlaA:146, TyrA:40 with 6IBZ and docking energy - 10.85, - 8.21 kcal/mol respectively. These compounds were further evaluated for their ADMET and physicochemical properties by using SwissADME. The results of the in vitro and in silico studies suggest that the tetrazole incorporated pyrrolidine-triazoles may possess the ideal structural requirements for further developing new anticancer agents.

A Synthetic Overview of Benzoxazines and Benzoxazepines as Anticancer Agents

Benzoxazines and benzoxazepines are nitrogen and oxygen-containing six and seven-membered benzo-fused heterocyclic scaffolds, respectively. Benzoxazepines and benzoxazines are well-known pharmacophores in pharmaceutical chemistry, which are of significant interest and have been extensively studied because of their promising activity against various diseases including their wide range of anticancer activity. Several reports are known for synthesizing benzoxazine and benzoxazepine-based compounds in the literature. Herein this review provides a critical analysis of synthetic strategies towards benzoxazines and benzoxazepines along with various ranges of anticancer activities based on these molecules that have been reported from 2010 onwards. This review also focuses on the structure-activity relationship of the benzoxazine and benzoxazepine scaffolds containing bioactive compounds and describes how the structural modification affects their anticancer activity.

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.

Synthesis, characterization and cytotoxicity of copper (II) complex containing a 2H-benzo[e][1,3]oxazin derivative

A new cis-dihalo copper(II) complex, [Cu^II(HL^bz)(Cl)₂].CH₃CN (1), where HL^bz = (S)-2-(((2-(2-(pyridin-2-yl)-2H-benzo[e][1,3]oxazin-3(4H)-yl)ethyl)amino)methyl)phenol), was isolated by reacting copper(II) chloride dihydrate and the H₂L ligand (H₂L = 2,2'-((2-(pyridin-2-yl)imidazolidine-1,3-diyl)bis(methylene))diphenol) in a MeOH/CH₃CN (1:3 v/v) mixture. The complex formation occurred via the ligand modification during complexation, producing a unique structure containing 2H-benzo[e][1,3]oxazin, as observed from the single crystal X-ray structure determination. The complex was characterized by elemental analysis, potentiometric titration, spectroscopic techniques (UV-Vis, FT-IR) and conductance measurements. Complex 1 inhibits the growth of myelogenous leukemia cells with an IC₅₀ of 17.3 μmol L^-1.

Gold(I)-Catalyzed Synthesis of 4H-Benzo[d][1,3]oxazines and Biological Evaluation of Activity in Breast Cancer Cells

The first gold(I)-catalyzed cycloisomerization procedure applied to the synthesis of substituted 4H-benzo[d][1,3]oxazines has been developed starting from N-(2-alkynyl)aryl benzamides. The chemoselective oxygen cyclization via the 6-exo-dig pathway yielded the observed heterocycles in modest to good chemical yields under very mild reaction conditions. The obtained oxazines were assayed on the breast cancer (BC)-derived cell lines MCF-7 and HCC1954 with differential biological activity. The newly synthesized 4H-benzo[d][1,3]oxazine compounds showed several degrees of cell proliferation inhibition with a remarkable effect for those compounds having a substituted aryl at C-2 of the molecules. The 4H-benzo[d][1,3]oxazines showed an IC₅₀ ranking from 3.1 to 95 μM in MCF-7 and HCC1954 cells. These compounds represent potential drug candidates for BC treatment. However, additional assays are needed to elucidate their complete effect over the cellular and molecular hallmarks of cancer.

Developments in the Application of 1,2,3-Triazoles in Cancer Treatment

BACKGROUND

The impact of cancer on modern society cannot be emphasized enough in terms of both economic and human costs. Cancer treatments are known, unfortunately, for their side effects - frequently numerous and severe. Drug resistance is another issue medical professionals have to tackle when dealing with neoplastic illnesses. Cancer rates are rising worldwide due to various factors - low-quality nutrition, air and water pollution, tobacco use, etc. For those and many other reasons, drug discovery in the field of oncology is a top priority in modern medical science.

OBJECTIVE

To present the reader with the latest in cancer drug discovery with regard to 1,2,3-triazole- containing molecules in a clear, concise way so as to make the present review a useful tool for researchers.

METHODS

Available information present on the role of 1,2,3-triazoles in cancer treatment was collected. Data was collected from scientific literature, as well as from patents.

RESULTS

A vast number of triazole-containing molecules with antiproliferative properties have been proposed, synthesized and tested for anticancer activity both in vitro and in vivo. The substances vary greatly when considering molecular structure, proposed mechanisms of action and affected cancer cell types.

CONCLUSION

Triazole-containing molecules with anticancer activity are being widely synthesized and extensively tested. They vary significantly in terms of both structure and mechanism of action. The methods for their preparation and administration are well established and with proven reproducibility. These facts suggest that triazoles may play an important role in the discovery of novel antiproliferative medications with improved effectiveness and safety profile.

Histopathological evaluation of Senecio rhizomatus Rusby in 7,12-dimethylbenz(α) anthracene-induced breast cancer in female rats

Background and Aim:

Senecio rhizomatus Rusby (SrR) is a medicinal plant of the Asteraceae family and traditionally consumed as infusion in the Andean region from Peru for inflammatory disorders. This study aimed to determine the histopathological changes afforded by SrR in 7, 12-dimethylbenz[a]anthracene (DMBA)-induced breast cancer (BC) in rats.

Materials and Methods:

An ethanolic extract of SrR aerial parts was prepared by maceration with 96% ethanol, and the chemical components were identified by gas chromatography coupled to mass spectrometry; the antioxidant activity was determined by 1,1-diphenyl-2-picril-hidrazil (DPPH) assay; and the acute toxicity was assessed according to the OCED 423 guidelines. In a pharmacological study, 30 female Holztman rats were distributed randomly into five groups, as follows. Group I: Negative control (physiological serum, 2 mL/kg); Group II. DMBA (80 mg/Kg body weight); and Groups III, IV, and V: DMBA + ethanol extract of SrR at doses of 10, 100, and 200 mg/kg, respectively.

Results:

The antioxidant activity of the SrR extract against DPPH was 92.50% at 200 mg/mL. The oral administration of SrR at doses of 50, 300, 2000, and 5000 mg/kg did not show any clinical evidence of toxicity or occurrence of death. The groups that received SrR presented a lower frequency of tumors and acumulative tumor volume compared with the DMBA group (p<0.05); the DMBA group exhibited a higher incidence of necrosis and moderate mitosis, up to 66.67% and 100.00%, respectively. Finally, infiltrating carcinoma with extensive tumor necrosis was evidenced.

Conclusion:

In experimental conditions, the ethanolic extract of SrR had a protective effect in DMBA-induced BC in female rats. Furthermore, the antioxidant activity of its main phytochemicals could be responsible for the effect observed, and SrR seems to be a safe extract in the preclinical phase.

Synthesis of 3-methyl-4H-benzo[b][1,4]thiazine-2-carboxylates using CAN as a catalyst and its conversion into guanidines

Background:

1,4-benzothiazine carboxylates show wide application in the field of medicinal chemistry. Therefore, we have designed convenient and efficient method for the synthesis of 1,4-benzothiazine carboxylates.

Objective:

Synthesis of 1,4-benzothiazine carboxylates and its guanidines by simple and facile method using efficient catalyst.

Method:

Derivatives of 1,4-benzothiazine carboxylates were synthesized by cyclocondensing β-keto esters with 2- aminobenzenethiols using CAN as a catalyst at room temperature. 1,4-benzothiazine caboxylate,condensed with guanidine hydrochloride in the presence of sodium methoxide in DMF to obtained new 3-substituted-l-4Hbenzo[b][1,4]thiazine-2-carboxyguanidines (88-91%).

Results:

All the products were obtained with good to excellent yields within 40 min. Here, CAN oxidizes aminothiophenol into disulfide and then nucleophilic attack of enolic form of β-ketoesters on the disulphide and 1, 4-benzothiazine acetates, were obtained with good yields.

Conclusion:

We have designed convenient and efficient method for the synthesis of 1,4-benzothiazine carboxylates. Most remarkable features of this cyclocondensation such as use of efficient catalyst and non-volatile solvent under mild reaction condition to obtained excellent yield.

Computational investigations and molecular dynamics simulations envisioned for potent antioxidant and anticancer drugs using indole-chalcone-triazole hybrids

Cancer, also called malignancy, is a disease which is closely related with the oxidative stress instigated by the overproduction of vulnerable oxygen and nitrogen species. Available drugs are relatively painful and toxic and so are trailing their captivation. Keeping this in mind, we have attempted to reach a novel anti-cancer drug by taking a set of nineteen ligands which are hybrids of Indole-chalcone and triazole. These ligands were allowed to interact with the DNA dodecamer 5'(CGCGAATTCGCG)3' one by one using various docking protocols of Glide. Better docked complexes screened through docking scores and reported activity data were selected and exposed to molecular dynamics run of 20 ns. The dynamical pathways were investigated for each complex comparing the pre- and post- dynamics run. The outcome of the work is discussed in this paper. Among the better hybrids of this series, one of the molecules has shown interesting features, confirming its non-toxic nature and working as intercalator as well minor groove binder, perhaps making it suitable as a potent drug for further pharmacological use.

Synthesis, in vitro COX-1/COX-2 inhibition testing and molecular docking study of novel 1,4-benzoxazine derivatives

The present work deals with an efficient and straightforward synthesis, biological activity and molecular docking study of novel 1,4-benzoxazine derivatives.

Copper fluorapatite assisted synthesis of new 1,2,3-triazoles bearing a benzothiazolyl moiety and their antibacterial and anticancer activities

New 1,2,3-triazoles with a benzothiazolyl scaffold have been synthesized for the first time using copper fluorapatite as a catalyst and their antibacterial and anticancer activities are reported.

Design, synthesis, structural characterization and in vitro evaluation of new 1,4-disubstituted-1,2,3-triazole derivatives against glioblastoma cells

A new series of 1,4-disubstituted-1,2,3-triazole derivatives were synthesized through the copper-catalyzed azide-alkyne 1,3-dipolar cycloaddition (Click chemistry) and their inhibitory activities were evaluated against different human glioblastoma (GBM) cell lines, including highly drug-resistant human cell lines GBM02, GBM95. The most effective compounds were 9d, containing the methylenoxy moiety linked to triazole and the tosyl-hydrazone group, and the symmetrical bis-triazole 10a, also containing methylenoxy moiety linked to triazole. Single crystal X-ray diffraction analysis was employed for structural elucidation of compound 9d. In silico analyses of physicochemical, pharmacokinetic, and toxicological properties suggest that compounds 8a, 8b, 8c, 9d, and 10a are potential candidates for central nervous system-acting drugs.

Semi-synthesis, structural modification and biological evaluation of 5-arylbenzofuran neolignans

5-Arylbenzofuran neolignans, a newfound class of natural products, were semi-synthesized, and a series of derivatives were designed, synthesized and evaluated for cytotoxicity.

FeCl3-Mediated Domino Reaction of Benzoxazinones with Aroylmethylidene Malonates: Synthesis to Functionalized Pyrrolobenzoxazines

An efficient domino approach for the synthesis of pyrrolobenzoxazine derivatives is described. The FeCl₃-promoted domino reaction between aroylmethylidene malonates and benzoxazinones has been successfully established to afford the title compounds in good to excellent yield under mild reaction conditions. The domino protocol provides a concise and straightforward access to highly substituted pyrrolobenzoxazines with high efficiency and excellent functional group tolerance.

A novel piperazine linked β-amino alcohols bearing a benzosuberone scaffolds as anti-proliferative agents

A new series of 1-((9-chloro-2,3-dimethyl-6,7-dihydro-5H-benzo[7]annulen-8-yl)methoxy)-3-(4-phenylpiperzin-1-yl) propan-2-ols (6a-k) have been designed, synthesized and their structures were established by spectroscopic data (FT-IR, ¹H NMR, ¹³C NMR, HRMS) and further confirmed by X-ray analysis. The newly synthesized compounds 6a-k were evaluated for their in vitro anti-proliferative activity against four cancer cell lines such as HeLa (cervical), MDA-MB-231 (breast), A549 (lung) and MIAPACA (pancreatic). Among the compounds tested, the compound 6e displayed most potent activity against four cancer cell lines with GI₅₀ values ranging from 0.010 to 0.097μM. The structure and anti-proliferative activity relationship was further supported by in silico molecular docking study of the active compounds against Colchicine binding site of β-tubulin.

Small hybrid heteroaromatics: resourceful biological tools in cancer research

Nowadays, hybrid drugs containing two or more covalently linked known potential pharmacophores are designed to simultaneously modulate multiple targets of multifactorial diseases to overcome the side effects associated with a single drug.

Synthesis, Characterization, and Antibacterial Activity of Diethyl 1-((4-Methyl-2-phenyl-4,5-dihydrooxazol-4-yl)methyl)-1H-1,2,3-triazole-4,5-dicarboxylate

The compound, diethyl 1-((4-methyl-2-phenyl-4,5-dihydrooxazol-4-yl)methyl)-1H-1,2,3-triazole-4,5-dicarboxylate 2, was synthesized in high yield, through 1,3-dipolar cycloaddition reaction of 4-(azidomethyl)-4-methyl-2-phenyl-4,5-dihydrooxazole and diethyl but-2-ynedioate in the absence of a solvent. The structure of the synthesized compound was established on the basis of NMR spectroscopy (1H, 13C), X-ray crystallography, and MS data. The prepared compound was also tested in vitro for its antibacterial activity against Gram-positive bacteria (Staphylococcus aureus) and Gram-negative bacteria (Escherichia coli). The calculation of MBC/MIC ratio showed that this triazole derivative 2 had a bactericidal effect on the two strains tested.

Green synthesis and anticancer potential of chalcone linked-1,2,3-triazoles

A series of chalcone linked-1,2,3-triazoles was synthesized via cellulose supported copper nanoparticle catalyzed click reaction in water. The structures of all the compounds were analyzed by IR, NMR and Mass spectral techniques. All the synthesized products were subjected to 3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium bromide (MTT) cytotoxicity assay against a panel of four human cancer cell lines (MCF-7, MIA-Pa-Ca-2, A549, HepG2) to check their anticancer potential. Compound 6h was found to be most active against all the tested cancer cell lines with IC₅₀ values in the range of 4-11 μM and showed better or comparable activity to the reference drug against all the tested cell lines. Cell cycle analysis revealed that compound 6h induces apoptosis and G2/S arrest in MIA-Pa-Ca-2 cells. Compound 6h triggers mitochondrial potential loss in pancreatic cancer MIA-Pa-Ca-2 cells. Further, Compound 6h also triggers caspase-3 and PARP-1 cleavage, which increases in dose dependent manner.

Synthesis of newer 1,2,3-triazole linked chalcone and flavone hybrid compounds and evaluation of their antimicrobial and cytotoxic activities

The present study was carried out in an attempt to synthesize a new class of antimicrobial and antiplasmodial agents by copper catalyzed click chemistry to afford 25 compounds 10-14(a-e) of 1,4-disubstituted-1,2,3-triazole derivatives of chalcones and flavones. The structures of the newly synthesized compounds were established by elemental analysis, IR, (1)H NMR, (13)C NMR and Mass spectral data. The newly synthesized compounds were evaluated for their antibacterial activity against Gram positive bacteria (Staphylococcus aureus, Enterococcus faecalis), Gram negative bacteria (Escherichia coli, Pseudomonas aeruginosa, Shigella boydii, Klebsiella pneumoniae) and antifungal activity against (Candida albicans, Candida tropicalis, Candida parapsilosis, Cryptococcus neoformans, Dermatophyte) as well as molds (Aspergillus niger, Aspergillus fumigatus). The antiplasmodial and cytotoxic activities of these compounds were also evaluated against human malaria parasite Plasmodium falciparum strain 3D7 and human hepato-cellular carcinoma cells (Huh-7), respectively. Compounds 10a, 10c, 10d, 12c and 14e showed promising antibacterial activity while compounds 10e, 11d, 11e, 12c, 13a, 13b, 13e, 14a and 14d showed good antifungal activity as compared to the corresponding standard drugs. Compound 10b was found to be the most active against Plasmodium falciparum while the remaining compounds showed moderate to weak antiplasmodial activity. However, cytotoxic activities of all compounds were found ineffective against Huh-7 cells.

An overview of molecular hybrids in drug discovery

INTRODUCTION

The hybridization of biologically active molecules is a powerful tool for drug discovery used to target a variety of diseases. It offers the prospect of better drugs for the treatment of a number of illnesses including cancer, malaria, tuberculosis and AIDS. Hybrid drugs can provide combination therapies in a single multi-functional agent and, by doing so, be more specific and powerful than conventional classic treatments. This research field is in great expansion and attracts many researchers worldwide.

AREA COVERED

This review covers the main research published between early 2013 to mid-2015 and takes into account several previous reviews on the subject. Its intention is to showcase the most recent advances reported towards the development of molecular hybrids in drug discovery. Particular attention is given to anticancer hybrids throughout the review.

EXPERT OPINION

Current advances show that molecular hybrids of biologically active molecules can lead to powerful therapeutics. Natural products play a key role in this field. It is also believed that toxin hybrids present a great opportunity for future progress and should be further explored. Furthermore, the synthesis of hybrid organometallics should be systematically studied as it can lead to potent drugs. The crucial requirement for growth still remains the efficacy of synthesis. Hence, the development of efficient synthetic methods allowing rapid access to diverse series of hybrids must be further investigated by researchers.