Electrochemical Oxidative Difunctionalization of Diazo Compounds with Diselenides and Nucleophiles.

An electrochemical oxidative difunctionalization of diazo compounds with diselenides and nucleophiles has been developed. This innovative approach yields a diverse array of selenium-containing pyrazole esters and alkoxy esters, overcoming the limitations of traditional synthesis methods. Remarkably, various nucleophiles, including acids, alcohols, and pyrazoles, can be seamlessly incorporated. Notably, this protocol boasts high atom efficiency, excellent functional group tolerance, and good efficiency and operates under transition metal- and oxidant-free conditions, distinguishing it in the field.

Design, docking optimization, and evaluation of biotin-PEG4-1,8-naphthalimide as a potent and safe antitumor agent with dual targeting of ferroptosis and DNA.

A set of biotin-polyethylene glycol (PEG)-naphthalimide derivatives 4a-4h with dual targeting of ferroptosis and DNA were designed and optimized using docking simulation as antitumor agents. Docking simulation optimization results indicated that biotin-PEG4-piperazine-1,8-naphthalimide 4d should be the best candidate among these designed compounds 4a-4h, and therefore, we synthesized and evaluated it as a novel antitumor agent. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay and MGC-803 and U251 xenograft models identified 4d as a good candidate antitumor agent with potent efficacy and safety profiles, compared with amonafide and temozolomide. The findings of the docking simulations, fluorescence intercalator displacement (FID), western blot, comet, 5-ethynyl-2'-deoxyuridine (EdU), flow cytometry, transmission electron microscopy, and BODIPY-581/591-C11, FerroOrange, and dihydroethidium (DHE) fluorescent probe assays revealed that 4d could induce DNA damage, affect DNA synthesis, and cause cell cycle arrest in the S phase in MGC-803 cells. Also, it could induce lipid peroxidation and thus lead to ferroptosis in MGC-803 cells, indicating that it mainly exerted antitumor effects through dual targeting of ferroptosis and DNA. These results suggested that it was feasible to design, optimize using docking simulation, and evaluate the potency and safety of biotin-PEG-1,8-naphthalimide as a antitumor agent with dual targeting of ferroptosis and DNA, based on a multi-target drug strategy.

Synthesis and Biological Evaluation of Novel 2-Amino-1,4-Naphthoquinone Amide-Oxime Derivatives as Potent IDO1/STAT3 Dual Inhibitors with Prospective Antitumor Effects.

Indoleamine-2,3-dioxygenase 1 (IDO1) and signal transducer and activator of transcription 3 (STAT3) have emerged as significant targets in the tumor microenvironment for cancer therapy. In this study, we synthesized three novel 2-amino-1,4-naphthoquinone amide-oxime derivatives and identified them as dual inhibitors of IDO1 and STAT3. The representative compound NK3 demonstrated effective binding to IDO1 and exhibited good inhibitory activity (hIDO1 IC50 = 0.06 µM), leading to its selection for further investigation. The direct interactions between compound NK3 and IDO1 and STAT3 proteins were confirmed through surface plasmon resonance analysis. A molecular docking study of compound NK3 revealed key interactions between NK3 and IDO1, with the naphthoquinone-oxime moiety coordinating with the heme iron. In the in vitro anticancer assay, compound NK3 displayed potent antitumor activity against selected cancer cell lines and effectively suppressed nuclear translocation of STAT3. Moreover, in vivo assays conducted on CT26 tumor-bearing Balb/c mice and an athymic HepG2 xenograft model revealed that compound NK3 exhibited potent antitumor activity with low toxicity relative to 1-methyl-L-tryptophan (1-MT) and doxorubicin (DOX). Overall, these findings provided evidence that the dual inhibitors of IDO1 and STAT3 may offer a promising avenue for the development of highly effective drug candidates for cancer therapy.

Discovery of novel sulfonamide chromone-oxime derivatives as potent indoleamine 2,3-dioxygenase 1 inhibitors.

A series of chromone-oxime derivatives containing piperazine sulfonamide moieties were designed, synthesized and evaluated for their inhibitory activities against IDO1. These compounds displayed moderate to good inhibitory activity against IDO1 with IC50 values in low micromolar range. Among them, compound 10m bound effectively to IDO1 with good inhibitory activities (hIDO1 IC50 = 0.64 µM, HeLa IDO1 IC50 = 1.04 µM) and were selected for further investigation. Surface plasmon resonance analysis confirmed the direct interaction between compound 10m and IDO1 protein. Molecular docking study of the most active compound 10m revealed key interactions between 10m and IDO1 in which the chromone-oxime moiety coordinated to the heme iron and formed several hydrogen bonds with the porphyrin ring of heme and ALA264, consistent with the observation by UV-visible spectra that 10m induced a Soret peak shift from 403 to 421 nm. Moreover, compound 10m exhibited no cytotoxicity at its effective concentration in MTT assay. Consistently, in vivo assays results demonstrated that 10m displayed potent antitumor activity with low toxicity in CT26 tumor-bearing Balb/c mice, in comparison with 1-methyl-l-tryptophan (1-MT) and 4-amino-N-(3-chloro-4-fluorophenyl)-N'-hydroxy-1,2,5-oxadiazole-3-carboximidamide (IDO5L). In brief, the results suggested that chromone-oxime derivatives containing sulfonamide moieties might serve as IDO1 inhibitors for the development of new antitumor agents.

Ursolic acid-piperazine-dithiocarbamate ruthenium(II) polypyridyl complexes induced necroptosis in MGC-803 cells.

Three ursolic acid-piperazine-dithiocarbamate ruthenium(II) polypyridyl complexes Ru1-Ru3 were designed and synthesized for evaluating antitumor activity. All the complexes exhibited high in vitro cytotoxicity against MGC-803, T24, HepG2, CNE2, MDA-MB-231, MCF-7, A549, and A549/DDP cell lines. Ru1, Ru2, and Ru3 were 11, 8 and 10 times, respectively, more active than cisplatin against A549/DDP. An in vivo study on MGC-803 xenograft mouse models demonstrated that representative Ru2 exhibited an effective inhibitory effect on tumor growth, showing stronger antitumor activity than cisplatin. Biological investigations suggested that Ru2 entered MGC-803 cells by a clathrin-mediated endocytic pathway, initially localizing in the lysosomes and subsequently escaping and localizing in the mitochondria. Mitochondrial swelling resulted in vacuolization, which induced vacuolation-associated cell death and necroptosis with the formation of necrosomes (RIP1-RIP3) and the uptake of propidium iodide. These results demonstrate that the potential of Ru2 as a chemotherapeutic agent to kill cancer cells via a dual mechanism represents an alternative way to eradicate apoptosis-resistant forms of cancer.

Visible-Light-Promoted Selenylative Spirocyclization of Indolyl-ynones toward the Formation of 3-Selenospiroindolenine Anticancer Agents.

A metal-free and efficient visible-light-induced spirocyclization of indolyl-ynones with diselenides at room temperature under air atmosphere to prepare 3-selenospiroindolenines in moderate to good yields has been developed. The resulting products were tested for in vitro anticancer activity by MTT assay, and compounds 3 c and 3 e showed potent cancer cell-growth inhibition activities.

Design, synthesis and biological evaluation of 3-nitro-1,8-naphthalimides as potential antitumor agents.

A series of 3-nitro-naphthalimides 1(1a-1h) were designed and synthesized as antitumor agents. MTT assay results showed that all these compounds exhibited obvious antiproliferative activity against SKOV3, HepG2, A549, T-24 and SMMC-7721 cancer cell lines, while compound 1a displayed the best antiproliferative activity against HepG2 and T-24 cell lines in comparison with mitonafide, with IC50 of 9.2 ± 1.8 and 4.133 ± 0.9 µM, respectively. In vivo antiproliferative activity assay results showed that compound 1a exhibited good antiproliferative activity in the HepG2 and T-24 models, compared with mitonafide. Action mechanism results showed that compound 1a could induced the damage of DNA and the inhibition topo I, accompanying by inducing the G2-stage arresting and the apoptosis of T-24 cancer cells through up-regulating expression levels of cyclin B1, cdc 2-pTy, Wee1, γH2AX, p21, Bax and cytochrome c and down-regulating expression of Bcl-2.

Synthesis and Antiproliferative Evaluation of Novel Hybrids of Dehydroabietic Acid Bearing 1,2,3-Triazole Moiety.

To discover novel potent cytotoxic diterpenoids, a series of hybrids of dehydroabietic acid containing 1,2,3-triazole moiety were designed and synthesized. The target compounds were characterized by means of FT-IR, 1H NMR, 13C NMR, ESI-MS and elemental analysis techniques. The in vitro cytotoxicity of these compounds was evaluated by standard MTT (methyl thiazolytetrazolium) assay against CNE-2 (nasopharynx), HepG2 (liver), HeLa (epithelial cervical), BEL-7402 (liver) human carcinoma cell lines and human normal liver cell (HL-7702). The screening results revealed that most of the hybrids showed significantly improved cytotoxicity over parent compound DHAA. Among them, [1-(3-fluorobenzyl)-1H-1,2,3-triazole-4-yl]dehydroabietic acid methyl ester (3c), and [1-(2-nitrobenzyl)-1H-1,2,3-triazole-4-yl]dehydroabietic acid methyl ester (3k) displayed better antiproliferative activity with IC50 (50% inhibitory concentration) values of 5.90 ± 0.41 and 6.25 ± 0.37 µM toward HepG2 cells compared to cisplatin, while they exhibited lower cytotoxicity against HL-7702. Therefore, the 1,2,3-triazole-hybrids could be a promising strategy for the synthesis of antitumor diterpenoids and it also proved the essential role of 1,2,3-triazole moiety of DHAA in the biological activity.

Synthesis and Biological Evaluation of Novel Dehydroabietic Acid-Oxazolidinone Hybrids for Antitumor Properties.

Novel representatives of the important group of biologically-active, dehydroabietic acid-bearing oxazolidinone moiety were synthesized to explore more efficacious and less toxic antitumor agents. Structures of all the newly target molecules were confirmed by IR, ¹H-NMR, 13C-NMR, and HR-MS. The inhibitory activities of these compounds against different human cancer cell lines (MGC-803, CNE-2, SK-OV-3, NCI-H460) and human normal liver cell line LO2 were evaluated and compared with the commercial anticancer drug cisplatin, using standard MTT (methyl thiazolytetrazolium) assay in vitro. The pharmacological screening results revealed that most of the hybrids showed significantly improved antiproliferative activities over dehydroabietic acid and that some displayed better inhibitory activities compared to cisplatin. In particular, compound 4j exhibited promising cytotoxicity with IC50 values ranging from 3.82 to 17.76 µM against all the test cell lines and displayed very weak cytotoxicity (IC50 > 100 µM) on normal cells, showing good selectivity between normal and malignant cells. Furthermore, the action mechanism of the representative compound 4j was preliminarily investigated by Annexin-V/PI dual staining, Hoechst 33258 staining, which indicated that the compound can induce cell apoptosis in MGC-803 cells in a dose-dependent manner and arrest the cell cycle in G1 phase. Therefore, 4j may be further exploited as a novel pharmacophore model for the development of anticancer agents.

Copper-Catalyzed Decarboxylative/Click Cascade Reaction: Regioselective Assembly of 5-Selenotriazole Anticancer Agents.

A simple and efficient Cu-catalyzed decarboxylative/click reaction for the preparation of 1,4-disubstituted 5-arylselanyl-1,2,3-triazoles from propiolic acids, diselenides, and azides has been developed. The mechanistic study revealed that the intermolecular AAC reaction of an alkynyl selenium intermediate occurred. The resulting multisubstituted 5-seleno-1,2,3-triazoles were tested for in vitro anticancer activity by MTT assay, and compounds 4f, 4h, and 4p showed potent cancer cell-growth inhibition activities.

Design, synthesis and pharmacological evaluation of novel 2-chloro-3-(1H-benzo[d]imidazol-2-yl)quinoline derivatives as antitumor agents: in vitro and in vivo antitumor activity, cell cycle arrest and apoptotic response.

A series of novel 2-chloro-3-(1H-benzo[d]imidazol-2-yl)quinoline derivatives (3a1-3d6) were designed and synthesized as antitumor agents. In vitro antitumor assay results showed that some compounds exhibited moderate to high inhibitory activities against HepG2, SK-OV-3, NCI-H460 and BEL-7404 tumor cell lines, and most compounds exhibited much lower cytotoxicities against HL-7702 normal cell line compared to 5-FU and cisplatin. In vivo antitumor assay results showed that the representative compound 3a1 exhibited effective inhibition on tumor growth in the HepG2 xenograft mouse model. Mechanistic studies suggested that 3a1 may exert antitumor activity by the up-regulation of Bax, intracellular Ca2+ release, ROS generation, p21, p27 and p53, downregulation of Bcl-2, activation of caspase-9 and caspase-3 and subsequent cleavage of PARP, and inhibition of CDK activity.

Catalyst-Free Synthesis of Pyrrolo[1,2-a]quinolines via Dehydration/[3 + 2] Cycloaddition Directly from 2-Methylquinolines, Aldehydes, and Alkynoates.

A simple and efficient catalyst-free synthesis of pyrrolo[1,2-a]quinoline derivatives from 2-methylquinolines, aldehydes, and alkynoates via dehydration/[3 + 2] cycloaddition has been developed. The reaction conditions are tolerant to air, and H2O is the only byproduct of this transformation, thus offering an environmentally benign process with a wide range of potential applications in organic synthesis and medicinal chemistry.

Atom-Economic Synthesis of 4-Pyrones from Diynones and Water.

Transition-metal-free synthesis of 4-pyrones via TfOH-promoted nucleophilic addition/cyclization of diynones and water has been developed. This transformation is simple, atom economical and environmentally benign, providing rapid and efficient access to substituted 4-pyrones.

Design, synthesis and pharmacological evaluation of new 2-oxo-quinoline derivatives containing α-aminophosphonates as potential antitumor agents.

A series of novel 2-oxo-quinoline derivatives containing α-aminophosphonates were designed and synthesized as antitumor agents. MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay results demonstrated that some compounds exhibited moderate to high inhibitory activity against HepG2, SK-OV-3 and NCI-H460 tumor cell lines, and most compounds showed much lower cytotoxicity against HL-7702 normal cells than 5-FU and cisplatin. The action mechanism of representative compound 5b was investigated by fluorescence staining assay, flow cytometric analysis and western blot (WB) assay, which indicated that this compound induced apoptosis and G2/M phase arrest accompanied by an increase in the production of intracellular Ca2+ and reactive oxygen species (ROS) and affecting associated enzymes and genes.

rac-(1R,2S,6R,7R)-4-{[(1E)-(2-Chloro-phen-yl)methyl-idene]amino}-1-isopropyl-7-methyl-4-aza-tricyclo-[5.2.2.0]undec-8-ene-3,5-dione.

The title compound, C(21)H(23)ClN(2)O(2), was synthesized from N-amino-α-terpinene maleimide and 2-chloro-benzaldehyde. There are two independent mol-ecules in the asymmetric unit which are linked via an inter-molecular C-H⋯O hydrogen bond. The crystal studied was found to be a partial merohedral twin, with a 0.74 (7):0.26 (7) domain ratio.