Anisotropy of cell wall polymers in branches of hardwood and softwood: a polarized FTIR study

The mechanical and physical properties of wood fibres are dependent on the organisation of their constituent polymers (cellulose, hemicellulose and lignin). Fourier Transform Infrared (FTIR) microscopy was used to examine the anisotropy of the main wood polymers in isolated cell wall fragments from branches of maple and Serbian spruce. Polarised FTIR measurements indicated an anisotropy, i.e. orientation of the cellulose microfibrils that was more or less parallel to the longitudinal axis of the cell wall. The hemicelluloses, glucomannan and xylan appeared to have a close link to the orientation of the cellulose and, thus, an orientation more parallel to the axis of the cell wall. An important result is that, in both maple and spruce samples, lignin was found to be organised in a parallel way in relation to the longitudinal cell wall axis, as well as to the cellulose. The results show that, despite the different lignin precursors and the different types of hemicelluloses in these two kinds of wood, lignin has a similar orientation, when it comes to the longitudinal axis of the cell wall.     

Synthesis,cytotoxic activity,and fluorescence properties of a set of novel 3-hydroxyquinolin-4(1H)-ones

The targeted solid-phase synthesis of 3-hydroxyquinolin-4(1H)-one derivatives is described. Primary and secondary amines, 3-amino-4-(methoxycarbonyl)benzoic acid and 2-bromo-1-(4-chloro-3-nitrophenyl)ethanone were used as starting materials. The structures of the final compounds were designed in accordance with previous information obtained from structure–activity relationship studies of similar cytotoxic derivatives. Representative prepared compounds were subjected to in vitro screening of cytotoxic activity against various cancer cell lines; the results obtained are discussed. Fluorescence properties of selected compounds were also studied to compare the data with those obtained in analogous derivatives.     

Effect of extraction conditions of paprika oleoresins on their free radical scavenging and anticancer activity

Ground spice paprika was extracted with hexane, by conventional Soxhlet procedure (SX oleoresin), and with supercritical carbon dioxide at three different pressures — 20, 30 and 40 MPa (SF20, SF30 and SF40 oleoresins). The effect of extraction method and conditions on the colour intesity of paprika oleoresins, content of α-tocopherol, as well as antioxidant and antiproliferative activity was examined. Hexane showed highest selectivity for paprika pigments (886.02 ASTA), while α-tocopherol showed highest solubility (3846.9 mg kg^?1) in supercritical carbon dioxide at 20 MPa. All paprika oleoresins exhibited good superoxide anion radical scavenging activity SF30 being the best superoxide anion radical scavenger. Cell growth activity was evaluated in vitro in human cell lines:cervix epitheloid carcinoma (HeLa), breast adenocarcinoma (MCF7) and colon adenocarcinoma (HT-29). The highest antiproliferative activity was exhibited by SX in MCF7 cell line (IC₅₀=14.28 mg mL^?1). Extract SF40 produced significant and selective antiproliferative action towards HeLa cell line. These results suggest that paprika oleoresins, due to high antiradical and tumor cell-inhibiting activity, can be regarded as functional food ingredients.      

Targeting large kinase active site with rigid, bulky octahedral ruthenium complexes

A strategy for targeting protein kinases with large ATP-binding sites by using bulky and rigid octahedral ruthenium complexes as structural scaffolds is presented. A highly potent and selective GSK3 and Pim1 half-sandwich complex NP309 was successfully converted into a PAK1 inhibitor by making use of the large octahedral compounds Lambda-FL172 and Lambda-FL411 in which the cyclopentadienyl moiety of NP309 is replaced by a chloride and sterically demanding diimine ligands. A 1.65 A cocrystal structure of PAK1 with Lambda-FL172 reveals how the large coordination sphere of the ruthenium complex matches the size of the active site and serves as a yardstick to discriminate between otherwise closely related binding sites.