Design, synthesis, DFT, molecular modelling studies and biological evaluation of novel 3-substituted (E)-5-(arylidene)-1-methyl-2-thioxoimidazolidin-4-ones with potent cytotoxic activities against breast MCF-7, liver HepG2, and lung A549

Cornulacin: a new isoflavone from Cornulaca monacantha and its isolation, structure elucidation and cytotoxicity through EGFR-mediated apoptosis

Chemical investigation of the methanolic extract of Cornulaca monacantha (Amaranthaceae), an annual wild herb collected from North Sinai, Egypt, yielded a new isoflavone cornulacin 1 and five known compounds: N-trans-feruloyltyramine 2, N-trans-feruloyl-3'-methoxytyramine 3, N-trans-caffeoyl tyramine 4, Cannabisin F 5 and (2aS, 3aS) lyciumamide D 6. Using MTT assay, the isolated compounds were evaluated for their in vitro cytotoxicity against pancreatic (Panc1) and ovarian (A2780) cancer cell lines. Compounds 1, 2, 3, and 4 exhibited promising cytotoxic activity against the tested cells, among which compound 1 (IC50 of 2.1 ± 0.21 μM) was the most active one against A2780 cells, whereas compound 2 (IC50 of 3.4 ± 0.11 μM) was the most effective compound against Panc1 cells. Accordingly, compound 1 was further investigated for its apoptotic induction in A2780 cancer cells using Annexin V/PI staining. Compound 1 significantly stimulated apoptotic ovarian A2780 cancer cells by 45.9-fold and arrested cell proliferation in the S-phase. Such activity was mediated through the upregulation of proapoptotic genes Bax; P53; and caspase 3, 8, and 9 besides the downregulation of the Bcl-2 gene, the anti-apoptotic one. Furthermore, molecular docking investigation demonstrated the strong binding affinity of compound 1 with EGFR active sites, which validated its experimental EGFR enzyme inhibition activity.

Camptothecin structure simplification elaborated new imidazo[2,1-b]quinazoline derivative as a human topoisomerase I inhibitor with efficacy against bone cancer cells and colon adenocarcinoma

Camptothecin is a pentacyclic natural alkaloid that inhibits the hTop1 enzyme involved in DNA transcription and cancer cell growth. Camptothecin structure pitfalls prompted us to design new congeners using a structure simplification strategy to reduce the ring extension number from pentacyclic to tetracyclic while maintaining potential stacking of the new compounds with the DNA base pairs at the Top1-mediated cleavage complex and aqueous solubility, as well as minimizing compound-liver toxicity. The principal axis of this study was the verification of hTop1 inhibiting activity as a possible mechanism of action and the elaboration of new simplified inhibitors with improved pharmacodynamic and pharmacokinetic profiling using three structure panels (A-C) of (isoquinolinoimidazoquinazoline), (imidazoquinazoline), and (imidazoisoquinoline), respectively. DNA relaxation assay identified five compounds as hTop1 inhibitors belonging to the imidazoisoquinolines 3a,b, the imidazoquinazolines 12, and the isoquinolinoimidazoquinazolines 7a,b. In an MTT cytotoxicity assay against different cancer cell lines, compound 12 was the most potent against HOS bone cancer cells (IC50 = 1.47 μM). At the same time, the other inhibitors had no detectable activity against any cancer cell type. Compound (12) demonstrated great penetrating power in the HOS cancer cells' 3D-multicellular tumor spheroid model. Bioinformatics research of the hTop1 gene revealed that the TP53 cell proliferative gene is in the network of hTop1. The finding is confirmed empirically using the gene expression assay that proved the increase in p53 expression. The impact of structure simplification on compound 12 profile, characterized by the absence of acute oral liver toxicity when compared to Doxorubicin as a standard inhibitor, the lethal dose measured on Swiss Albino female mice and reported at LD50 = 250 mg/kg, and therapeutic significance in reducing colon adenocarcinoma tumor volume by 75.36 % after five weeks of treatment with compound 12. The molecular docking solutions of the active CPT-based derivative 12 and the inactive congener 14 into the active site of hTop1 and the activity cliffing of such MMP directed us to recommend the addition of HBD and HBA variables to compound 12 imidazoquinazoline core scaffold to enhance the potency via hydrogen bond formation with the major groove amino acids (Asp533, Lys532) as well as maintaining the hydrogen bond with the minor groove amino acid Arg364.

Design, synthesis, molecular modelling and antitumor evaluation of S-glucosylated rhodanines through topo II inhibition and DNA intercalation

In the present study, 5-arylidene rhodanine derivatives 3a-f, N-glucosylation rhodanine 6, S-glucosylation rhodanine 7, N-glucoside rhodanine 8 and S-glucosylation 5-arylidene rhodanines 13a-c were synthesised and screened for cytotoxicity against a panel of cancer cells with investigating the effective molecular target and mechanistic cell death. The anomers were separated by flash column chromatography and their configurations were assigned by NMR spectroscopy. The stable structures of the compounds under study were modelled on a molecular level, and DFT calculations were carried out at the B3LYP/6-31 + G (d,p) level to examine their electronic and geometric features. A good correlation between the quantum chemical descriptors and experimental observations was found. Interestingly, compound 6 induced potent cytotoxicity against MCF-7, HepG2 and A549 cells, with IC₅₀ values of 11.7, 0.21, and 1.7 µM, compared to Dox 7.67, 8.28, and 6.62 µM, respectively. For the molecular target, compound 6 exhibited topoisomerase II inhibition and DNA intercalation with IC₅₀ values of 6.9 and 19.6 µM, respectively compared to Dox (IC₅₀ = 9.65 and 31.27 µM). Additionally, compound 6 treatmnet significantly activated apoptotic cell death in HepG2 cells by 80.7-fold, it induced total apoptosis by 34.73% (23.07% for early apoptosis, 11.66% for late apoptosis) compared to the untreated control group (0.43%) arresting the cell population at the S-phase by 49.6% compared to control 39.15%. Finally, compound 6 upregulated the apoptosis-related genes, while it inhibted the Bcl-2 expression. Hence, glucosylated rhodanines may serve as a promising drug candidates against cancer with promising topoisomerase II and DNA intercalation.

Design, Synthesis, Computational Investigations, and Antitumor Evaluation of N-Rhodanine Glycosides Derivatives as Potent DNA Intercalation and Topo II Inhibition against Cancer Cells

Nitrogen and sulfur glycosylation was carried out via the reaction of rhodanine (1) with α-acetobromoglucose 3 under basic conditions. Deacetylation of the protected nitrogen nucleoside 4 was performed with CH₃ONa in CH₃OH without cleavage of the rhodanine ring to afford the deprotected nitrogen nucleoside 6. Further, deacetylation of the protected sulfur nucleoside 5 was performed with CH₃ONa in CH₃OH with the cleavage of the rhodanine ring to give the hydrolysis product 7. The protected nitrogen nucleosides 11a-f were produced by condensing the protected nitrogen nucleoside 4 with the aromatic aldehydes 10a-f in C₂H₅OH while using morpholine as a secondary amine catalyst. Deacetylation of the protected nitrogen nucleosides 11a-f was performed with NaOCH₃/CH₃OH without cleavage of the rhodanine ring to afford the deprotected nitrogen nucleosides 12a-f. NMR spectroscopy was used to designate the anomers' configurations. To examine the electrical and geometric properties derived from the stable structure of the examined compounds, molecular modeling and DFT calculations using the B3LYP/6-31+G (d,p) level were carried out. The quantum chemical descriptors and experimental findings showed a strong connection. The IC₅₀ values for most compounds were very encouraging when evaluated against MCF-7, HepG2, and A549 cancer cells. Interestingly, IC₅₀ values for 11a, 12b, and 12f were much lower than those for Doxorubicin (7.67, 8.28, 6.62 μM): (3.7, 8.2, 9.8 μM), (3.1, 13.7, 21.8 μM), and (7.17, 2.2, 4.5 μM), respectively. Against Topo II inhibition and DNA intercalation, when compared to Dox (IC₅₀ = 9.65 and 31.27 μM), compound 12f showed IC₅₀ values of 7.3 and 18.2 μM, respectively. In addition, compound 12f induced a 65.6-fold increase in the rate of apoptotic cell death in HepG2 cells, with the cell cycle being arrested in the G2/M phase as a result. Additionally, it upregulated the apoptosis-mediated genes of P53, Bax, and caspase-3,8,9 by 9.53, 8.9, 4.16, 1.13, and 8.4-fold change, while it downregulated the Bcl-2 expression by 0.13-fold. Therefore, glucosylated Rhodanines may be useful as potential therapeutic candidates against cancer because of their topoisomerase II and DNA intercalation activity.

Silver Nanoparticles Formulation of Flower Head’s Polyphenols of Cynara scolymus L.: A Promising Candidate against Prostate (PC-3) Cancer Cell Line through Apoptosis Activation

Cynara scolymus L. (Family: Compositae) or artichoke is a nutritious edible plant widely used for its hepatoprotective effect. Crude extracts of flower, bract, and stem were prepared and evaluated for their in vitro antioxidant activity and phenolic content. The flower crude extract exhibited the highest phenolic content (74.29 mg GAE/gm) as well as the best in vitro antioxidant activity using total antioxidant capacity (TAC), ferric reducing antioxidant power (FEAP), and 1,1-diphenyl-2-picrylhyazyl (DPPH) scavenging assays compared with ascorbic acid. Phenolic fractions of the crude extracts of different parts were separated and identified using high-performance liquid chromatography HPLC-DAD analysis. The silver nanoparticles of these phenolic fractions were established and tested for their cytotoxicity and apoptotic activity. Results showed that silver nanoparticles of a polyphenolic fraction of flower extract (Nano-TP/Flowers) exhibited potent cytotoxicity against prostate (PC-3) and lung (A549) cancer cell lines with IC₅₀ values of 0.85 μg/mL and 0.94 μg/mL, respectively, compared with doxorubicin as a standard. For apoptosis-induction, Nano-TP/Flowers exhibited apoptosis in PC-3 with a higher ratio than in A549 cells. It induced total prostate apoptotic cell death by 227-fold change while it induced apoptosis in A549 cells by 15.6-fold change. Nano-TP/Flowers upregulated both pro-apoptotic markers and downregulated the antiapoptotic genes using RT-PCR. Hence, this extract may serve as a promising source for anti-prostate cancer candidates.

Evaluation of 2-Thioxoimadazolidin-4-one Derivatives as Potent Anti-Cancer Agents through Apoptosis Induction and Antioxidant Activation: In Vitro and In Vivo Approaches

BACKGROUND

Hepatocellular carcinoma (HCC) is one of the most widespread malignancies and is reported as the fourth most prevalent cause of cancer deaths worldwide. Therefore, we aimed to investigate the probable mechanistic cytotoxic effect of the promising 2-thioxoimidazolidin-4-one derivative on liver cancer cells using in vitro and in vivo approaches. The compounds were tested for the in vitro cytotoxic activity using MTT assay, and the promising compound was tested in colony forming unit assay, flow cytometric analysis, RT-PCR, Western blotting, in vivo using SEC-carcinoma and in silico to highlight the virtual mechanism of action. Both compounds 4 and 2 performed cytotoxic effects against HepG2 cells with IC50 values of 0.017 and 0.18 μM, respectively, compared to Staurosporine and 5-Fu as reference drugs with IC50 values of 5.07 and 5.18 µM, respectively. Compound 4 treatment revealed apoptosis induction by 19.35-fold (11.42% compared to 0.59% in control), arresting the cell cycle at G2/M phase. Moreover, studying gene expression that plays critical roles in cell cycle and apoptosis by RT-PCR demonstrated that compound 4 enhances the expression of the pro-apoptotic genes p53, PUMA, and Caspase 3, 8, and 9, and impedes the anti-apoptotic Bcl-2 gene in the HepG2 cells. It can also inhibit the PI3K/AKT pathway at both gene and protein levels, which was reinforced by the in silico predictions of the molecular docking simulations towards the PI3K/AKT proteins. Finally, in vivo study verified that compound 4 has a promising anti-cancer activity through activating antioxidant levels (CAT, SOD and GSH) and ameliorating hematological, biochemical, and histopathological findings.

Synthesis, antiviral, DFT and molecular docking studies of some novel 1,2,4-triazine nucleosides as potential bioactive compounds

A novel series of nucleosides with potential antiviral activity have been synthesized and characterized using IR, MS, 1D NMR and 2D NMR data. The antiviral activity of the synthesized compounds was assessed against the Coxsackie B virus and Hepatitis A virus (HAV-10). The results revealed that compound 6 is equipotent to the standard drug Ribavirin against HAV-10. Also, some computational studies, such as the prediction of pharmacokinetic properties, toxicity, and bioactivity, have been done.