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A dichapetalin-type triterpenoid and a dibenzylbutyrolactone-type lignan, together with five known lignans, a known aromatic diterpenoid, and a known acylated phytosterol, were isolated from the aerial parts of Phyllanthus songboiensis, collected in Vietnam. Their structures were determined by interpretation of the spectroscopic data, and the inhibitory activity toward HT-29 human colon cancer cells of all isolates was evaluated by a cytotoxicity assay. The known arylnaphthalene lignan, (+)-acutissimalignan A, was highly cytotoxic toward HT-29 cells, with an IC50 value of 19 nM, but this compound was inactive as a DNA topoisomerase IIα (topo IIα) poison. The known phytosterol, (-)-β-sitosterol-3-O-β-D-(6-O-palmitoyl)glucopyranoside, was found to stimulate natural killer (NK) cells at a concentration of 10μM in the presence of interleukin 12 (IL-12)., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Solubilized sterol C24-methyltransferase (24-SMT) was purified to homogeneity from a cell extract of the yeast Candida albicans (Ca) by anion exchange chromatography, gel permeation chromatography and fast performance liquid chromatography using a Mono Q column. The purified enzyme has an apparent molecular mass of 178 kDa on gel permeation chromatography and 43 kDa on SDS/PAGE, indicating that it is composed of four identical subunits. The substrate requirement of the native enzyme has an optimal specificity for zymosterol with associated kinetic constants of K(m) 50 μM and k(cat) of 0.01 s⁻¹. The product of the enzyme incubated with zymosterol was fecosterol. Inhibition of the catalyst was observed with substrate analogs designed as transition state analogs (25-azalanosterol, K(i)=54 nM and 24 (R,S),25-epiminolanosterol, K(i)=11 nM) or as mechanism-based inactivators (26,27-dehydrozymosterol, K(i) 9 μM) and k(inact)=0.03 min⁻¹) of the C24-methylation reaction. Product analogs ergosterol and fecosterol, but neither cholesterol nor sitosterol, inhibited activity affording K(i) values of 20 and 72 μM, respectively. Ammonium and thia analogs of the intermediates of the sterol C24-methyl reaction sequence were effective growth inhibitors exhibiting IC(50) values that ranged from 3 to 20 μM., (Copyright © 2010 Elsevier Inc. All rights reserved.)

Uninhibited access to the unstructured information distributed across the web and in scientific literature databases continues to be beyond the reach of scientists and health professionals. To address this challenge we have developed a literature driven, ontology-centric navigation infrastructure consisting of a content acquisition engine, a domain-specific ontology (in OWL-DL) and an ontology instantiation pipeline delivering sentences derived by domain-specific text mining. A visual query tool for reasoning over A-box instances in the populated ontology is presented and used to build conceptual queries that can be issued to the knowledgebase. We have deployed this generic infrastructure to facilitate data integration and knowledge sharing in the domain of dengue, which is one of the most prevalent viral diseases that continue to infect millions of people in the tropical and subtropical regions annually. Using our unique methodology we illustrate simplified search and discovery on dengue information derived from distributed resources and aggregated according to dengue ontology. Furthermore we apply data mining to the instantiated ontology to elucidate trends in the mentions of dengue serotypes in scientific abstracts since 1974.