Acridone Derivatives from Atalantia monophyla Inhibited Cancer Cell Proliferation through ERK Pathway

The present study aimed to investigate the effect of acridone alkaloids on cancer cell lines and elucidate the underlying molecular mechanisms. The ten acridone alkaloids from Atalantia monophyla were screened for cytotoxicity against LNCaP cell lines by a WST-8 assay. Then, the most potential acridone, buxifoliadine E, was evaluated on four types of cancer cells, namely prostate cancer (LNCaP), neuroblastoma (SH SY5Y), hepatoblastoma (HepG2), and colorectal cancer (HT29). The results showed that buxifoliadine E was able to significantly inhibit the proliferation of all four types of cancer cells, having the most potent cytotoxicity against the HepG2 cell line. Western blotting analysis was performed to assess the expression of signaling proteins in the cancer cells. In HepG2 cells, buxifoliadine E induced changes in the levels of Bid as well as cleaved caspase-3 and Bax through MAPKs, including Erk and p38. Moreover, the binding interaction between buxifoliadine E and Erk was investigated by using the Autodock 4.2.6 and Discovery Studio programs. The result showed that buxifoliadine E bound at the ATP-binding site, located at the interface between the N- and C-terminal lobes of Erk2. The results of this study indicate that buxifoliadine E suppressed cancer cell proliferation by inhibiting the Erk pathway.     

Dynamically adaptive tree grid modeling for simulation and visualization of rainwater overland flow

Modeling and visualization of a rainwater overland flow is an important tool for a risk assessment, preparation, evacuation planning, and real‐time forecasting of flood warning. The objective of this research is to develop a numerical software to visualize the rainwater overland flow based on a finite volume method for shallow water equations and in combination with the dynamically adaptive tree grid technique and the dynamic domain‐defining method. The obtained simulations for several experiments were tested and compared with results in literature, both theoretical and experimental results. The comparisons with non‐adaptive grids show that the developed algorithm for simulation is very efficient and has a potential for practical usages, in terms of computational times and accuracy. Copyright © 2015 John Wiley & Sons, Ltd.     

Bis[1‐(pyridin‐2‐yl)­ethano­ne‐κN 4‐phenyl­thio­semicarbazonato‐κ2N4,S]­manganese(II)

One half of the mol­ecule of the title complex, [Mn(C₁₄H₁₃N₄S)₂], is related to the other half by a twofold axis passing through the Mn atom. This high‐spin Mn atom is six‐coordinated, in an octahedral geometry, by the azomethine N, the pyridyl N and the thiol­ate S atom of two planar 1‐­(pyridin‐2‐yl)­ethanone N(4)‐phenyl­thio­semicarbazone lig­ands. In the crystal, the mol­ecules are interconnected by N—­H?S and C—H?N interactions, forming a three‐dimensional network.     

11‐Methyl‐12a‐phenyl‐9a,12a‐dihydrophenanthro[9′,10′:5,6][1,4]dioxino[2,3‐d]oxazole and 9a‐(10‐hydroxyphenanthren‐9‐yl)‐11,12a‐diphenyl‐9a,12a‐dihydrophenanthro[9′,10′:5,6][1,4]dioxino[2,3‐d]oxazole

In the title compounds, C₂₄H₁₇NO₃, (I), and C₄₃H₂₇NO₅, (II), the dioxine ring is not planar and tends toward a boat conformation. The oxazoline ring adopts a twisted conformation in mol­ecule (I) but is essentially planar in mol­ecule (II). The configuration of the dioxine–oxazoline system is determined by the sp³ state of the two shared atoms. The phenanthrene moiety is nearly coplanar with the dioxine ring, while the phenyl ring is perpendicular to the attached oxazole ring. The triclinic unit cell of (II) contains two crystallographically independent mol­ecules related by a pseudo‐inversion centre.     

Organic spin clusters. A dendritic-macrocyclic poly(arylmethyl) polyradical with very high spin of S = 10 and its derivatives: synthesis, magnetic studies, and small-angle neutron scattering

Synthesis and characterization of organic spin clusters, high-spin poly(arylmethyl) polyradicals with 24 and 8 triarylmethyls, are described. Polyether precursors to the polyradicals are prepared via modular, multistep syntheses, culminating in Negishi cross-couplings between four monofunctional branch (dendritic) modules and the tetrafunctional calix[4]arene-based macrocyclic core. The corresponding carbopolyanions are prepared and oxidized to polyradicals in tetrahydrofuran-d(8). The measured values of S, from numerical fits of magnetization vs magnetic field data to Brillouin functions at low temperatures (T = 1.8-5 K), are S = 10 and S = 3.6-3.8 for polyradicals with 24 and 8 triarylmethyls, respectively. Magnetizations at saturation (M(sat)) indicate that 60-80% of unpaired electrons are present at T = 1.8-5 K. Low-resolution shape reconstructions from the small-angle neutron scattering (SANS) data indicate that both the polyradical with 24 triarylmethyls and its derivatives have dumbbell-like shapes with overall dimensions 2 x 3 x 4 nm, in agreement with the molecular shapes of the lowest energy conformations obtained from Monte Carlo conformational searches. On the basis of these shapes, the size of the magnetic anisotropy barrier in the polyradical, originating in magnetic shape anisotropy, is estimated to be in the milliKelvin range, consistent with the observed paramagnetic behavior at T >or= 1.8 K. For macromolecular polyradicals, with the elongated shape and the spin density similar to the polyradical with 24 triarylmethyls, it is predicted that the values of S on the order of 1000 or higher may be required for "single-molecule-magnet" behavior, i.e., superparamagnetic blocking (via coherent rotation of magnetization) at the readily accessible temperatures T > 2 K.     

(Dibenzyl sulfoxide‐κO)bis(1,3‐diphenylpropane‐1,3‐dionato‐κ2O,O′)dioxouranium(VI)

In the title compound, [UO₂(C₁₅H₁₁O₂)₂(C₁₄H₁₄OS)], the U^VI atom is coordinated by seven O atoms in a distorted pentagonal–bipyramidal geometry. Both di­phenyl­propane‐1,3‐dionate systems are nearly planar. The sulfoxide moiety is in a distorted tetrahedral geometry, while its two aromatic rings are nearly orthogonal to one another. The crystal packing is stabilized by two bifurcated hydrogen‐bonding interactions involving both uranyl O atoms.     

Triplet ground state (S= 1) pegylated bis(aminoxyl) diradical: synthesis and the effect of water on magnetic properties

The synthesis and magnetic characterization of pegylated bis(aminoxyl) diradical with an S= 1 ground state are presented, revealing water-induced changes in the molecular conformation and magnetic properties.     

A 1:1 adduct of hexa­methylene­tetramine and 4‐hydroxy‐3‐methoxy­benz­aldehyde

In the title complex, C₆H₁₂N₄·C₈H₈O₃, the hexa­methyl­ene­tetramine mol­ecule accepts a single intermolecular O—H?N hydrogen bond from the hydroxy group of the 4‐hydroxy‐3‐methoxy­benz­aldehyde moiety. The non‐centrosymmetric crystal structure is built from alternating molecular sheets of 4‐hydroxy‐3‐methoxy­benz­aldehyde and hexa­methyl­ene­tetramine mol­ecules, and is stabilized by intermolecular O—H?N, C—H?O and C—H?π interactions.     

1,1′‐Di­acetyl‐3‐hydroxy‐2,2′,3,3′‐tetra­hydro‐3,3′‐bi(1H‐indole)‐2,2′‐dione

In the title compound, C₂₀H₁₆N₂O₅, both of the 1‐acetyl­isatin (1‐acetyl‐1H‐indole‐2,3‐dione) moieties are planar and form a dihedral angle of 74.1 (1)°. Weak intermolecular hydrogen bonds and C—H?π interactions stabilize the packing in the crystal.     

1,3-Alternate calix[4]arene nitronyl nitroxide tetraradical and diradical: synthesis, X-ray crystallography, paramagnetic NMR spectroscopy, EPR spectroscopy, and magnetic studies

Calix[4]arenes constrained to 1,3-alternate conformation and functionalized at the upper rim with four and two nitronyl nitroxides have been synthesized, and characterized by X-ray crystallography, magnetic resonance (EPR and ¹H NMR) spectroscopy, and magnetic studies. Such calix[4]arene tetraradicals and diradicals provide scaffolds for through-bond and through-space intramolecular exchange couplings.