Diversity-oriented synthesis of novel benzimidazole linked indolo-benzodiazepine/quinoxaline ring systems using poly(ethylene glycol) as soluble polymer support is described. Commercially available 4-fluoro-3-nitrobenzoic acid and indoline were utilized for the construction of these annulated biheterocyclic compound libraries having multiple privileged structures with three-point structural div...

For the polymer-solvent system poly(pheny1enc oxide) in toluenc the mechanism and kinet~cs of crystallization have bccn studied w i f h the Pulsc lnduccd Critical Scattering technique. I t was found that aftcr a dclay-time r the growth mechanism was diffusion controlled. The delay-timc is thought to be conncctcd with the nucleation of thc crystallites and it disappeared in the "sceded" crystall...

In this work, a series of novel paraffin inhibitor, polyaminoamide (PAA), was designed and prepared by aminolysis and poly-condensation using soybean oil and canola oil as the raw material. The property of the PAAs as paraffin inhibitor was investigated, the results show several PAA samples are potent in paraffin inhibition, and PPC-2 is the most effective one. Besides, the paraffin crystal mor...

We hereby report a mild and efficient coupling reaction between alkyl aldehydes and aryl diamines. In the presence of a Cu(2+) or a Zn(2+) ion, oxygen (O2) in air is able to promote the oxidative condensation of the two readily preparable functional groups, forming stable benzimidazole linkages in neutral aqueous solution at room temperature (RT). We demonstrated that the reaction could be util...

Pyrazolidinones were prepared in a two-step sequence starting from α-hydrazonocarboxylic acids. After a four-component Ugi coupling, the resulting hydrazone was engaged in a copper triggered [3 + 2] cycloaddition/aerobic oxidation cascade.

Differences in the interaction of poly-L-histidine with DNA of various base composition have been demonstrated using melting and CD measurements. The two types of complexes formed with DNA at pH values below the pK of 5.9 and in the region of pH 6.5 are very different in their CD spectral properties. The binding effects with highly protonated poly-L-histidine are AT-dependent as reflected by la...

A metal-free catalytic approach to tryptanthrins has been achieved for the first time. The unique process is realized by an organocatalytic and indole and anthranilic acid substrate co-catalyzed photochemical oxidative condensation with visible light and O2. The truly environmentally friendly reaction conditions enable various reactants to participate in the process to deliver structurally dive...

The present paper describes the biosynthesis of the thiamin thiazole in Bacillus subtilis and Saccharomyces cerevisiae. The two pathways are quite different: in B. subtilis, the thiazole is formed by an oxidative condensation of glycine, deoxy-D-xylulose 5-phosphate and a protein thiocarboxylate, whereas, in S. cerevisiae, the thiazole is assembled from glycine, NAD and Cys205 of the thiazole s...

The first enantiospecific synthesis of akaol A, a marine sesquiterpene quinol, has been achieved. Key steps of the synthetic sequence are the oxidative degradation of (-)-sclareol to a dinorlabdane ketoester, mediated by the ozone-lead(IV) acetate system, the diastereoselective α-methylation of a ketoaldehyde, followed by an intramolecular aldol condensation and the further Diels-Alder cycloadd...

Vascular remodeling during chronic hypertension may impair the supply of tissues with oxygen, glucose and other compounds, potentially unleashing deleterious effects. In this study, we used Spontaneously Hypertensive Rats and normotensive Wistar-Kyoto rats with or without pharmacological inhibition of poly(ADP-ribose)polymerase-1 by an experimental compound L-2286, to evaluate carotid artery re...