Improvement of some pharmaceutical properties of nocloprost by β- and γ-Cyclodextrin Complexation

Inclusion complexation of nocloprost, a potent antiulcer prostaglandin derivative, with -, -, and -cyclodextrins (CyDs) in aqueous solutions has been studied by the solubility method and¹³C-NMR spectroscopy. The steric requirement of host-guest interaction was reflected in the magnitude of the stability constants and the thermodynamic parameters of the inclusion complexes. Solid complexes of nocloprost with - and -CyDs in a molar ratio of 1 : 2 were obtained on the basis of aBs-type phase solubility diagram. The X-ray diffraction data suggested that nocloprost is included in the cylindrical channel formed by coaxial alignment of -CyD molecules to give a channel type structure. Release and thermal behavior of the solid complexes was examined and compared with nocloprost itself. The results indicated that the -CyD complex may have great utility among the three CyDs, being a rapid dissolving form of nocloprost with improved thermal stability.     

Adsorption characteristics of bisphenol A onto carbonaceous materials produced from wood chips as organic waste

A single-chain amphiphile containing a rigid Schiff base segment, 3-cyano-N-benzylidene hexadecylamine (CNBHB) in the polar head group was synthesized and studied for its vesicle-forming properties. The dependence of the aggregation behavior of the vesicles as such and in the presence of manganese ions were studied as a function of temperature using differential scanning calorimetry and turbidity measurements. Transmission electron microscopy (TEM) was used to analyze the morphology of the vesicles, showed interesting features with fusion of regular structures, and were quite stable. In the presence of manganese ions, fusion of vesicles takes place. This could be due to the metal ions that are bound to the surface of the vesicles that cause a partial destruction of the hydration shell on the surface of the vesicles. The reduction in the hydration force could thus be responsible for the fusion.     

Cyclopolycondensations

Fully aromatic polyquinazolinediones of high molecular weight were prepared by the cyclopolycondensation reaction of 4,4′-diamino-3,3′-biphenyldicarboxylic acid with aromatic diisocyanates. The poly(phosphoric acid) solution polymerization techniques yielded tractable poly(urea acid), which was converted to polyquinazolinediones by thermal cyclodehydration at 300–400°C. under reduced pressure. The polyquinazolinediones thus obtained have excellent thermal stability both in nitrogen and in air. The poly(urea acid) is soluble in dimethyl sulfoxide, and films can be cast from the polymer solution of poly(urea acid) (η_inh = 0.8 to 1.8). The films are made tough by being heated in nitrogen or under reduced pressure at 300–400°C. The polymerization mechanism of the cyclopolycondensation reaction was studied, and it was established that the polymerization proceeded through the formation of tractable poly(urea acid), Structure (I), of high molecular weight, followed by cyclodehydration, yielding poly(1,2-dihydro-2-imino-4H-3,1-benzoxazin-4-one), Structure (II). On subsequently being heated this undergoes intramolecular rearrangement along the polymer chain, giving the thermodynamically stable polyquinazolinedione, Structure (III).     

Determination of 4-hydroxy-2-nonenal in primary rat hepatocyte cultures by liquid chromatography with laser induced fluorescence detection

An HPLC (high performance liquid chromatography) method with laser induced fluorescence (LIF) detection is described for the determination of 4-hydroxy-2-nonenal (HNE) formed from lipid peroxidation in rat hepatocytes. Carbonyl compounds were fluorescently labelled by incubating the hepatocyte samples with a tagging reagent, 4-(2-carbazoylpyrrolidin-1-yl)-7-nitro-2,1,3-benzoxadiazole (NBD-ProCZ), at 60 degrees C for 10 min. The hydrazone derivatives were extracted with a C18 solid phase extraction (SPE) cartridge and separated on a reversed-phase HPLC column. The detection limit was 2.5 fmol or 0.5 nM (5 microL injection) of HNE in the cell homogenate. Method precision (C.V.) was 5% at the 5 nM level. The method has been used to determine free HNE in rat hepatocyte samples treated with several pro-oxidant toxins. A significant HNE increase (from 4 to 27.6 pmol/10(6) cells) was observed with the samples treated by allyl alcohol. The results were in accordance with those for malondialdehyde formation as measured by a thiobarbituric acid (TBA) assay.     

Ageladine A: an antiangiogenic matrixmetalloproteinase inhibitor from the marine sponge Agelas nakamurai

A novel MMP inhibitor, ageladine A (1) with antiangiogenic activity was isolated from a marine sponge Agelas nakamurai. Structure 1 was determined by a combination of spectroscopic and chemical methods to be an unprecedented structure of 4-(4,5-dibromo-1H-pyrrol-2-yl)]-1H-imidazo[4,5-c]pyridin-2-amine.