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Lung cancer remains a leading cause of death in cancer patients, and deregulation of apoptosis is a serious concern in clinical practice, even though therapeutic intervention has been greatly improved. Plants are a versatile source of biologically active compounds for anticancer drug discovery, and aspiletrein A (AA) is a steroidal saponin isolated from Aspidistra letreae that has a potent cytotoxic effect on various cancer cell lines. In this study, we investigated and determined the underlying molecular mechanism by which AA induces apoptosis. AA strongly induced apoptosis in NSCLC cells by mediating ROS generation and thereby activating AMP-activated protein kinase (AMPK) signaling. Consequently, downstream signaling and levels of phosphorylated mTOR and Bcl-2 were significantly decreased. Pretreatment with either an antioxidant, N-acetylcysteine, or an AMPK inhibitor, compound C, could reverse the apoptosis-inducing effect and counteract the effect of AA on the AMPK signaling pathway. Decreased levels of Bcl-2 were due to AA-mediating Bcl-2 degradation via a ROS/AMPK/mTOR axis-dependent proteasomal mechanism. Consistently, the apoptotic-inducing effect of AA was also observed in patient-derived malignant lung cancer cells, and it suppressed an in vitro 3D-tumorigenesis. This study identified the underlying mechanism of AA on lung cancer apoptosis, thereby facilitating potential research and development of this compound for further clinical implications. [ABSTRACT FROM AUTHOR]

[Display omitted] A series of complexes between bis(2-pyridyl)-di(4- n -butylphenyl)ethene (KT4) and bis(2-pyridyl)-di(3-methoxyphenyl)ethene (KT18) with transition metals Co(II), Cu(II), Zn(II), and Cd(II) were synthesized and crystallized. The structures of these compounds were confirmed based on IR, NMR, and MS spectra. Moreover, crystals were obtained for ZnKT18, CoKT18, CuKT18, CdKT18, and CdKT4. Single-crystal X-ray diffraction (XRD) demonstrated the ability of these pyridine-based ligands to coordinate to metal ions via two nitrogen atoms in the aromatic heterocycles. Depending on the central metal, they can form different structures. Zn(II) and Co(II) form mononuclear complexes with KT18 , where the metal coordinates to two N atoms and two chloride ions in a tetrahedral geometry (coordination number 4). The complexes CuKT18 , CdKT18 , and CdKT4 are binuclear complexes with one pendant chloride and two bridging chlorides coordinating with the metal ion (coordination number 5). The cytotoxic properties of free ligands and complexes were tested on four cancer lines, including KB, Hep-G2, Lu, and MCF-7. In general, the free ligands have no cytotoxic activity, while all complexes present strong to medium effects on these cancer lines. Several complexes are comparable in activity to cisplatin, a commercial drug used in the treatment of cancer. Specifically, ZnKT4 selectively inhibits the activities of the KB and Hep-G2 cell lines. CdKT4 has a high impact on Hep-G2 and Lu (IC 50 < 5 μM) while CdKT18 exhibits effective anticancer activity against the KB and MCF-7 cell lines. CuKT18 strongly inhibits the growth progress of the KB cancer cell (IC 50 = 9.52 μM). These IC 50 values are lower than those of cisplatin. [ABSTRACT FROM AUTHOR]

The investigation of the Vietnamese marine sponge Spongia sp. led to the isolation of three new sesquiterpene phenols, langconols A–C ( 1 – 3 ), and one new sesquiterpene hydroxyquinone, langcoquinone C ( 4 ), together with two known meroterpenoids ( 5 and 6 ). Their structures were determined on the basis of spectroscopic analyses and comparisons with published data. Furthermore, the antibacterial assays of the isolates 1 – 6 suggested that 4 and 6 had significant antibacterial activities against Bacillus subtilis and Staphylococcus aureus , with MICs ranging from 6.25 to 25.0 µM, while 1 and 3 possessed significant antibacterial activities against B. subtilis with MICs of 12.5 and 25.0 µM, respectively. In contrast, cytotoxic assays of the isolated compounds 1 – 6 , as well as compounds 7 – 15 previously isolated from this sponge, indicated that 1 and the previously reported anti- B. subtilis and anti- S. aureus sesquiterpene phenol 9 lacked cytotoxic activities against three human cancer cell lines (A549, lung cancer; MCF7, breast cancer; HeLa, cervix cancer) and a human normal cell line (WI-38 fibroblast). [ABSTRACT FROM AUTHOR]

The identification of a glutathione ( GSH) fumarate conjugate, dicarboxyethyl glutathione, formed during the nonenzymatic succination of GSH by fumarate was confirmed in fumarate hydratase deficient cells using a product ion scan approach followed by hydrophilic interaction liquid chromatography coupled with MS/MS. GSH and its conjugates, including dicarboxyethyl glutathione and glutathione disulfide, were successfully separated on a zwitterionic stationary phase and detected by MS/ MS operated under negative ESI mode. The relative quantitation of the analytes in cell extracts was carried out and a correction model was established to determine correction factors under matrix effects and the response mismatch between the analytes. These factors were calculated and iteratively used to measure all analytes in cell extracts, based on calibration curves constructed in neat solution. The model was a closed-loop calculation, consisting of two sides with each side of the loop presenting a calculation pathway. Deviation of the correction factors obtained from these pathways manifested the model accuracy. The model was evaluated and there was no significant difference between the two pathways. [ABSTRACT FROM AUTHOR]

Twenty compounds including curcuminoids and their pyrazole‐modified analogues were synthesized in a two‐step reaction: (i) condensation between benzaldehyde derivatives and pentane‐2,4‐dione and (ii) pyrazole cyclization of the 1,3‐diketone group in the resulting curcuminoids with hydrazine hydrate. The synthesized compounds were assayed for in vitro anticancer activity against HepG2 cancer cell line by determining their half‐maximal inhibitory concentration (IC50). Pyrazole curcuminoid (1 a, IC50=1.53±0.11 μM) was found to be the most potent molecule against the cancer cells. The pyrazole curcuminoids (1 a–3 a, 5 a) significantly exhibited between 2‐ to 23‐fold higher anticancer activities when compared with their parent structures (1–3, 5). However, the class of fluorinated analogues (7–10; 7 a–10 a) displayed inactivities or activities close to those of respecting compounds (1–6; 1 a–6 a). Structure‐activity relationship analysis indicated that the phenolic motif is responsible for inhibition of cell growth whereas the fluoro/methoxy substituents on the aromatic rings have insignificant contributions to inhibitory activities against HepG2. [ABSTRACT FROM AUTHOR]

A practical strategy for the iodine-promoted synthesis of bis(1-imidazo[1,5-a]pyridyl)arylmethane and its derivatives has been developed. These compounds exhibit high cytotoxicity toward various cancer cell lines and moreover they are promising ligands for the Cu-catalysed synthesis of quinolines. [ABSTRACT FROM AUTHOR]

Cassaine diterpenoids amides from the stem bark of Vietnamese Erythrophleum fordii Oliver were screened for their cytotoxic activity against human cancer cells. The cell proliferation assay results showed that, among the active compounds, 3β-acetyl-nor-erythrophlamide (3AEP) exhibited the most potential cytotoxicity against human leukemia HL-60 and KG cells with IC50 values of 12.0 ± 1.2 and 18.1 ± 2.7 µM, respectively. Treatment of 3AEP resulted in the apoptosis of HL-60 cells via the activation of caspase 3, and poly (ADP-ribose) polymerase (PARP). Molecular docking in silico results showed that the 3AEP can bind to both the procaspase-3 allosteric site and the PARP-1 active site, with binding energies of −7.51 and −9.63 kcal/mol respectively. These results indicated that the stem bark of Vietnamese E. fordii and its cassaine diterpenoid amides may be useful in the apoptosis induction of human leukemia cancer cells. [ABSTRACT FROM AUTHOR]