Synthesizing Sodium Tungstate and Sodium Molybdate Microcapsules via Bacterial Mineral Excretion.

We present a method, the bacterial mineral excretion (BME), for synthesizing two kinds of microcapsules, sodium tungstate and sodium molybdate, and the two metal oxides' corresponding nanoparticles-the former being as small as 22 nm and the latter 15 nm. We fed two strains of bacteria, Shewanella algae and Pandoraea sp., with various concentrations of tungstate or molybdate ions. The concentrations of tungstate and molybdate were adjusted to make microcapsules of different length-to-diameter ratios. We found that the higher the concentration the smaller the nanoparticles were. The nanoparticles came in with three length-to-diameter ratios: 10:1, 3:1 and 1:1, which were achieved by feeding the bacteria respectively with a low concentration, a medium concentration, and a high concentration. The images of the hollow microcapsules were taken via the scanning electron microsphere (SEM). Their crystal structures were verified by X-ray diffraction (XRD)-the crystal structure of molybdate microcapsules is Na2MoO4 and that of tungstate microcapsules is Na2WO4 with Na2W2O7. These syntheses all were accomplished under a near ambient condition.

Graphene Oxide Nanofiltration Membranes Stabilized by Cationic Porphyrin for High Salt Rejection.

Swelling has great influences on the structure stability and separation performance of graphene oxide laminate membranes (GOLMs) for water desalination and purification. Herein, we report cross-linked GOLMs from GO assembled with cationic tetrakis(1-methyl-pyridinium-4-yl)porphyrin (TMPyP) by a vacuum-assisted strategy. The concave nonoxide regions (G regions) of GO are used as cross-linking sites for the first time to precisely control the channel size for water permeation and salt ion retention. Channels around 1 nm are constructed by modulating the assembly ratio of TMPyP/GO, and these cross-linked GOLMs show high salt rejection.

Highly sensitive INHIBIT and XOR logic gates based on ICT and ACQ emission switching of a porphyrin derivative.

Fluorescence-switch-based logic devices are very sensitive compared with most of the reported devices based on UV/Vis absorption systems. Herein, we demonstrate that a simple molecule, 5,10,15,20-tetra-(4-aminophenyl)porphyrin (TAPP), shows protonation-induced multiple emission switches through intramolecular charge transfer and/or aggregation-caused quenching. Highly sensitive INHIBIT and XOR logic gates can be achieved by combining the intermolecular assembly with the intramolecular photoswitching of diprotonated TAPP (TAPPH2(2+)). In addition, molecular simulations have been performed by DFT for a better understanding of the emission-switching processes.

ß-carboline alkaloids from Stellaria dichotoma var. lanceolata and their anti-inflammatory activity.

The present investigation on the chemical constituents of the roots of Stellaria dichotoma var. lanceolata has resulted in the isolation of 21 ß-carboline alkaloids, including 13 new compounds, dichotomides III-XIV (1-12) and dichotomine E (13), and eight known compounds. The structures of the new compounds were established on the basis of spectroscopic data analysis. Among these isolated alkaloids, five compounds were examined for their anti-inflammatory potential for the inhibition of NO production in LPS-treated RAW 264.7 cells. All compounds tested exhibited significant inhibition of NO production, with IC(50) values in the range of 11.3 to 19.3 µM.

Abietane diterpene alkaloids from Salvia yunnanensis.

Nine new abietane diterpene alkaloids containing an oxazole ring, salviamines A-F (1-6) and isosalviamines C-E (7-9), together with 17 known abietane diterpenes, were isolated and characterized from the roots of Salvia yunnanensis. The structures of 1-9 were elucidated by interpretation of their spectroscopic data.

Cytotoxic and anti-HIV principles from the rhizomes of Begonia nantoensis.

Three new compounds: begonanline (1). nantoamide (2). and methyl (S)-glycerate (3). as well as forty-four known compounds have been isolated and characterized from the rhizomes of Begonia nantoensis. The structures of these compounds were determined by spectral analyses and/or X-ray crystallography. Among them, cucurbitacin B (4). dihydrocucurbitacin B (5). cucurbitacin E (6). dihydrocucurbitacin E (7). cucurbitacin I (8). and (-)-auranamide (9). showed cytotoxicity against four human cancer cell lines. 3beta,22alpha-Dihydroxyolean-12-en-29-oic acid (10), indole-3-carboxylic acid (11), 5,7-dihydroxychromone (12), and (-)-catechin (13) demonstrated significant activity against HIV replication in H9 lymphocyte cells.

New pavine N-oxide alkaloids from the stem bark of Cryptocarya chinensis Hemsl.

Three new pavine N-oxide alkaloids, (-)-isocaryachine-N-oxide B, (+)-caryachine-N-oxide, (-)-caryachine-N-oxide, and a new isoquinoline alkaloid, 6,7-methylenedioxy-N-methylisoquinoline together with 11 known alkaloids were isolated and characterized from the stem bark of Cryptocarya chinensis. The structures of the isolated compounds were determined by spectral methods. The stereochemistry of pavine-N-oxide alkaloids is also discussed.