6-Methoxylated Flavonoids: Jacein, and 3-demethyljacein from Centaurea schmidii with Their Endoplasmic Reticulum Stress and Apoptotic Cell Death in Breast Cancer Cells Along with In-silico Analysis.

In phytochemical analysis, Jacein derivatives: 5,7,4'-trihydroxy-3,6,3'-trimethoxyflavone-7(ß)-D-glucopyranoside (1), and 3-demethyljacein: 3,5,7,4'-tetrahydroxy-6,3'-dimethoxyflavone-7(ß)-D-glucopyranoside (2) were isolated from Campylopus schmidii (C. schmidii) for the first time. The structures were determined by interpretation of NMR, UV, and Mass spectra. To check the roles of ER stress and consequent apoptosis in MCF-7 cell by these compounds, UPR signaling pathway was further examined by analysis of expression of ER stress-related genes. In MTT assay, compounds 1-2 showed cytotoxicity activity against MCF-7 (A) and MDA-MB cells (B) with IC50 values (µM) of 1) 60.04 ± 7.98 (A), and > 200 (B); 2) 42.89 ± 1.91 (A), and 85.31 ± 2.68 (B). The Annexin/PI flow cytometry apoptosis of tested compounds 1-2 was increased significantly in a dose-dependent manner. For example, MCF-7 treatment at the concentration of 100 µM of compounds 1, 2 resulted in total apoptosis (early + late) of 42.04 (18.1 + 24.0), and 66.49 (2.7 + 63.8)%, respectively. Fluorescence microscopy analysis detected an increased protein aggregation, indicating induced ER stress with a marked increase in XBP-1, sXBP-1, ATF-4, and CHoP compared to untreated cells. In-silico characterization, suggested that Adenosine diphosphate site (A-site) and quercetin site (Q-Site) in IRE1a enzyme are both available interacting sites of a target for the investigated ligands but with different strengths of interactions. The results indicated that the ligand∼A-Site complexes are stronger than the ligand∼Q-Site complexes, but the already available ADP ligand in cells does not allow other ligands to interact with the A-Site and cause them to bond in Q-Site.

A new sesquiterpenoid from the shoots of Iranian Daphne mucronata Royle with selective inhibition of STAT3 and Smad3/4 cancer-related signaling pathways.

PURPOSE: Daphne mucronata Royle grown in Iran has shown anticancer activities against different cancer cell lines. Therefore, within this study, we investigate the phytochemical pattern of this plant. METHOD: Phytochemical investigation was done using standard column chromatography system: The structures were recognized by the interpretation of one and two-dimensional nuclear magnetic resonance (NMR) spectra and the help of High-Resolution Electrospray Ionization Mass spectroscopy (HR-ESIMS) and Infrared spectroscopy (IR) data. Stereochemistry was determined using 2D and 3D NOESY, and comparison of coupling constant values with literature. The absolute configuration was determined and confirmed using specific rotation and electronic circular dichroism experiments. Cytotoxicity was done against HeLa cells by standard MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. Luciferase assay was used to check if the compounds can inhibit the activation of cancer-related signaling pathways. Molecular docking simulation was done for biological activity evaluation and to examine the interaction of the ligand with each of the proteins. RESULTS: A new sesquiterpenoid, 4,11(12)-guiadiene-1-ol-3-one (4), together with eight specialized metabolites, betulinic acid (1), coniferyl aldehyde (2), oleanolic acid (3), daphnetoxin (5), apigenin (7), syringin (8), and genkwanol A (9) were isolated and reported for the first time from the shoots of the plant. Compound 4 as an undescribed compound was submitted for cytotoxicity assay and showed moderate activity with the IC50 value of 51.3 ± 4.2 µM against HeLa cancer cells. It showed selective inhibition of Interleukin-6 mediated signal transducer and activator of transcription 3 pathway (STAT-3/ IL-6), and Smad protein / transforming growth factor beta (TGF-ß) transcription factors when screened through an array of cancer signaling pathways. Molecular docking confirmed biological tests and showed the interaction with STAT3 and Smad proteins. CONCLUSION: An undescribed sesquiterpenoid: 4,11(12)-guiadiene-1-ol-3-one in addition to eight known compounds were isolated. The new sesquiterpene was evaluated for the luciferase assay on 14 main cancer-related signaling pathways and showed selective inhibition of STAT3/IL6, and Smad/ TGF-ß transcription factors. Molecular docking simulation showed more interactions with STAT3 than Smad, which confirms better interaction of compound 4 with STAT3 than Smad proteins. Graphical abstract.

Synthesis and characterization of some novel diaryl urea derivatives bearing quinoxalindione moiety.

Diaryl urea derivatives have exhibited a broad spectrum of biochemical effects and pharmaceutical applications. Several diaryl urea derivatives such as sorafenib, regorafenib, linifanib, and tivozanib and lenvatinib are in clinical trial or clinical use. Therefore, development of small molecules within the diaryl urea scaffold with the ability of binding to variety of enzymes and receptors in the biological system are an interesting topic for researchers. Sorafenib as a diaryl urea derivative is a well-known anticancer agent. Corresponding to available information about biological activities of quinoxaline moieties, based on sorafenib scaffold, several structures were designed by replacement of pyridyl carboxamide group of sorafenib with quinoxalindione moiety. A total of 14 novel compounds in 7 synthetic steps were synthesized. Briefly, the amino group of p-aminophenol was first protected followed by O-arylation of 4-acetamidophenol with 5-chloro-2-nitroaniline to provide 5-(4-acetamidophenoxy)-2-nitroaniline. Reduction of the nitro group of 5-(4-acetamidophenoxy)-2-nitroaniline and cyclization of diamine N-(4-(3,4-diaminophenoxy) phenyl) acetamides with oxalic acid afforded compound N-(4-((2,3-dioxo-1,2,3,4-tetrahydroquinoxalin-6-yl)oxy)phenyl) acetamides which on deacetylation gave compounds 6-(4-aminophenoxy) quinoxaline-2,3 (1H, 4H)-diones. Then resultant compounds, 6-(4-aminophenoxy) quinoxaline-2,3 (1H, 4H)-diones were reacted by appropriate isocyanates/ carbamates to give the target compounds 1-(4-((2,3-dioxo-1,2,3,4-tetrahydroquinoxalin-6-yl)oxy)phenyl)-3-phenylureas. The structures of compounds confirmed by proton nuclear magnetic resonance (1H NMR), mass spectrum and Fourier transform infrared (FT-IR).

Synthesis, characterization, cytotoxic screening, and density functional theory studies of new derivatives of quinazolin-4(3H)-one Schiff bases.

A series of novel derivatives of quinazolinone Schiff bases were synthesized from benzoic acid starting material and evaluated for potential cytotoxic activities against the human breast adenocarcinoma (MCF-7) and the human colon adenocarcinoma (HT-29) cell lines. Compared to the reference drug, these compounds showed good cytotoxic activities against studied cell lines especially compounds 4d and 4e. The ground-state geometries of these compounds (4a-g) were optimized at the B3LYP/6-31G* density functional theory (DFT) level. Then maximum absorptions electron affinity, ionization potential, electronegativity (χ), energy gap (Egap), hardness (η), softness (S), electrophilicity (ω), and electrophilicity index (ωi) were calculated and discussed. The quantitative structure-activity relationship (QSAR) properties including the physicochemical parameters were also evaluated and studied. The computed properties of our novel synthesized compounds were compared with erlotinib compound.

Biological evaluation, docking and molecular dynamic simulation of some novel diaryl urea derivatives bearing quinoxalindione moiety.

In this study a series of diarylurea derivatives containing quinoxalindione group were biologically evaluated for their cytotoxic activities using MTT assay against MCF-7 and HepG2 cell lines. Antibacterial activities of these compounds were also evaluated by Microplate Alamar Blue Assay (MABA) against three Gram-negative (Escherichia coli, Pseudomonas aeruginosa and Salmonella typhi), three Gram-positive (Staphylococcus aureus, Bacillus subtilis and Listeria monocitogenes) and one yeast-like fungus (Candida albicans) strain. Furthermore, molecular docking was carried out to study the binding pattern of the compounds to the active site of B-RAF kinase (PDB code: 1UWH). Molecular dynamics simulation was performed on the best ligand (16e) to investigate the ligand binding dynamics in the physiological environment. Cytotoxic evaluation revealed the most prominent cytotoxicity for 6 compounds with IC50 values of 10-18 µM against two mentioned cell lines. None of the synthesized compounds showed significant antimicrobial activity. The obtained results of the molecular docking study showed that all compounds fitted in the binding site of enzyme with binding energy range of -11.22 to -12.69 kcal/mol vs sorafenib binding energy -11.74 kcal/mol as the lead compound. Molecular dynamic simulation indicated that the binding of ligand (16e) was stable in the active site of B-RAF during the simulation.