[Anthraquinones and triterpenoids from roots of Knoxia roxburghii].

Nine compounds were isolated from an ethanol extract of the roots of K. roxburghii by using a combination of various chromatographic techniques including column chromatography over silica gel, MCI gel, Sephadex LH-20, and reversed-phase HPLC. On the basis of physical-chemical properties and spectroscopic data analysis, their structures were identified as munjistin (1), 1-methoxy-3,6-dihydroxy-2-hydroxymethyl-9,10-anthraquinone (2), 1,2,3-trihydroxy-9,10-anthraquinone (3), arjunolic acid (4), hyptatic acid-A (5), hyptatic acid-B (6), 2α,3ß,24-trihydroxyurs-12-en-28-oic acid (7), 2α,3ß,23-trihydroxyurs-12-en-28-oic acid (8), and daucosterol (9). Compounds 1-9 were obtained from this genus for the first time.

Self-assembled polymeric nanoparticles based on oleic acid-grafted chitosan oligosaccharide: biocompatibility, protein adsorption and cellular uptake.

Oleic acid-grafted chitosan oligosaccharide (OA-g-CSO) was synthesized to prepare self-assembled nanoparticles by sonication at physiological pH value (7.4). The nanoparticles appeared to be spherical in shape with a diameter of 158.1 ± 64.3 nm. The biocompatibility of OA-g-CSO nanoparticles was evaluated in vitro via MTT assay and hemolysis test. The nanoparticles showed no cytotoxicity to mouse embryo fibroblasts and the hemolysis rates came well within permissible limits (<2 %) in the tested conditions. When incubated with bovine calf serum, the protein adsorption on the surface of OA-g-CSO nanoparticles was concentration-dependent, and the amount of bovine serum albumin was in the highest proportion of the total amount of adsorbed proteins. Cellular uptake rate was evaluated by incubating fluorescence labeled OA-g-CSO nanoparticles with human lung carcinoma cells (A549). OA-g-CSO nanoparticles could be taken up by A549 cells, and the uptake rates increased with incubation time and particle concentration.

1-Benzyl-3,5-bis-(4-methyl-benzyl-idene)-4-oxopiperidin-1-ium chloride acetic acid monosolvate.

In the title solvated mol-ecular salt, C(28)H(28)NO(+)·Cl(-)·C(2)H(4)O(2), the central piperidinium ring of the cation adopts an envelope conformation with the N atom displaced by 0.798 (2) Šfrom the mean plane of the five C atoms. In the crystal, the components are linked by N-H⋯Cl and O-H⋯Cl hydrogen bonds into trimeric assemblies. C-H⋯Cl and C-H⋯π inter-actions further consolidate the packing.

Identification of the Peptides that Bind to Tyrosine Kinase Receptor EphB2 by Phage Display.

The gene encoding the Ig-like domain of tyrosine protein kinase receptor EphB2 was cloned into the expressing vector pET28a. Under induction with IPTG, the positive strain expressed the fusion protein with a hexahistidine tail on the N-terminal. The protein was purified under denaturing conditions using metal chelate chromatography. The purity was up to 94%. The purified-protein-coated ELISA plate was used as target to screen recombinant phages able to bind onto it, and after three rounds of affinity screening, 19 phages that could bind specifically with EphB2 were isolated from a random phage-displayed seven-peptide library. The peptide sequences of the positive phage clones were analyzed.

Surface modification of magnetite nanoparticles using gluconic acid and their application in immobilized lipase.

Superparamagnetic magnetite nanoparticles (SMN) were surface-modified with gluconic acid (GLA) to improve their hydrophilicity and bio-affinity. Gluconic acid was successfully coated on the surface of magnetite nanoparticles and characterized using Fourier transform infrared spectroscopy (FT-IR). With water-soluble carbodiimide (EDC) as the coupling reagent, lipase was successfully immobilized onto the hydroxyl-functionalized magnetic nanoparticles. The immobilized lipase had better resistance to temperature and pH inactivation in comparison to the free form and hence widened the reaction pH and temperature range. Thermostability and storage stability of the enzyme improved upon covalent immobilization. Immobilized lipase showed higher activity after recycling when compared to the free one and could be recovered by magnetic separation.