Izolacija bioaktivnih flavonoida iz biljke Jacaranda obtusifolia H. B. K. ssp. rhombifolia (G. F. W. Meijer) Gentry

The paper describes the bioassay-guided isolation, structure elucidation and anticancer evaluation of five flavonoids ()-liquiritigenin (1), ()-neoliquiritin (2), isoliquiritigenin (3), isoliquiritin (4) and formononetin (5) from the twigs of Jacaranda obtusifolia H. B. K. ssp. rhombifolia (G. F. W. Meijer) Gentry. The structures were elucidated based on 1H, 13C NMR, comprehensive 2D NMR, MS analyses and comparison with previously reported spectral data. Compounds 1 and 3 were demonstrated to be inhibitory in vitro against NCI-H187 (small cell lung cancer) with IC50 values of 30.1 and 16.6 µg mL1, respectively. The isolates were non-cytotoxic to Vero cells (African green monkey kidney).U radu je opisana izolacija, određivanje strukture i antitumorsko djelovanje pet flavonoida: ()-likviritigenina (1), ()-neolikviritina (2), izolikviritigenina (3), izolikviritina (4) i formononetina (5) iz plodova biljke Jacaranda obtusifolia H. B. K. ssp. rhombifolia (G. F. W. Meijer) Gentry. Strukture su određene na temelju 1H, 13C NMR, 2D NMR, MS i usporedbom s ranije objavljenim spektroskopskim podacima. Spojevi 1 i 3 imaju inhibitorni učinak in vitro na tumorsku staničnu liniju raka pluća NCI-H187 (IC50 vrijednost 30,1, odnosno 16,6 µg mL1). Izolirani flavonoidi nisu citotoksični za Vero stanice (bubrežne stanice afričkog zelenog majmuna)

Analytical aspects of molecular emission and sorption

SIGLEAvailable from British Library Document Supply Centre- DSC:D35947/81 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Analytical aspects of molecular emission and sorption

SIGLEAvailable from British Library Document Supply Centre- DSC:D35947/81 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Simultaneous determination of neomycin sulfate and polymyxin B sulfate by capillary electrophoresis with indirect UV detection

A simple and rapid capillary electrophoresis method, with indirect UV detection, for the simultaneous determination of neomycin sulfate and polymyxin B sulfate in pharmaceutical formulations was developed. Critical parameters such as pH, buffer composition and concentration, voltage and injection time have been studied to evaluate, how they affect responses, such as resolution and migration times. Separation was performed on a fused silica capillary with 50 μm i.d. and 27 cm total length at an applied voltage of 6 kV with a 15 mM phosphate run buffer (pH 5.0) containing 40 mM N-(4-hydroxy-phenyl)acetamide and 50 mM tetradecylammonium bromide (TTAB). The detection wavelength was set at 280 nm. Quantitative analysis was validated by testing the reproducibility of the method, giving a relative standard deviation less than 0.4 and 2.4% for the repeatability of migration time and corrected peak area, respectively. Accuracy was tested by spiking eye–ear formulations with standards and the recoveries of neomycin sulfate and polymyxin B sulfate were found to be between 97.44–103.18% and 96.85–101.68%, respectively. Linearity of neomycin sulfate and polymyxin B sulfate were obtained in the ranges of 17–682 and 24–608 μg/mL, respectively, with r2 values above 0.999. The established TLC–densitometric method was applied to evaluate the proposed CE method, and comparable results were obtained by using CE with much shorter analysis time and a small quantity of solvents consumed. The developed method is also the first report on the simultaneous determination of neomycin sulfate and polymyxin B sulfate in pharmaceutical preparations by CE

Synthesis of castanospermine

The diastereoselective synthesis of castanospermine is described in 11 synthetic steps from L-xylose. The borono-Mannich reaction between L-xylose, allylamine and (E)-styrene boronic acid gives a tetrahydroxy amine with the desired configurations for C-6, C-7, C-8 and C-8a in the target molecule. A novel pyrrolo[1,2-c]oxazol-3-one precursor was employed to allow for the control of pi-facial diastereoselectivity in an osmium(VIII)-catalysed syn-dihydroxylation (DH) reaction. A regioselective ring-opening of the cyclic sulfate derivative of the resulting diol then secured the C-1 hydroxyl group of castanospermine with the correct configuration. A Mitsunobu cyclization then provided di-O-benzyl castanospermine and ultimately the final target alkaloid

Extrusion printed polymer structures: a facile and versatile approach to tailored drug delivery platforms

A novel extrusion printing system was used to create drug delivery structures wherein dexamethasone- 21-phosphate disodium salt (Dex21P) was encapsulated within a biodegradable polymer (PLGA) and water soluble poly(vinyl alcohol) (PVA) configurations. The ability to control the drug release profile through the spatial distribution of drug within the printed 3-dimensional structures is demonstrated. The fabricated configurations were characterised by optical microscopy and SEM to evaluate surface morphology. The results clearly demonstrate the successful encapsulation of dexamethasone within a laminated PLGA:PVA structure. The resulting drug release profiles from the structures show a two stage release profile with distinctly different release rates and minimal initial burst release observed. Dexamethasone release was monitored over a 4-month period. This approach clearly demonstrates that the extrusion printing technique provides a facile and versatile approach to fabrication of novel drug delivery platforms

Extrusion printed polymer structures: a facile and versatile approach to tailored drug delivery platforms

A novel extrusion printing system was used to create drug delivery structures wherein dexamethasone-21-phosphate disodium salt (Dex21P) was encapsulated within a biodegradable polymer (PLGA) and water soluble poly(vinyl alcohol) (PVA) configurations. The ability to control the drug release profile through the spatial distribution of drug within the printed 3-dimensional structures is demonstrated. The fabricated configurations were characterised by optical microscopy and SEM to evaluate surface morphology. The results clearly demonstrate the successful encapsulation of dexamethasone within a laminated PLGA:PVA structure. The resulting drug release profiles from the structures show a two stage release profile with distinctly different release rates and minimal initial burst release observed. Dexamethasone release was monitored over a 4-month period. This approach clearly demonstrates that the extrusion printing technique provides a facile and versatile approach to fabrication of novel drug delivery platforms