The synthesis of unnatural pyrrolizidines has been studied using a multicomponent-domino process involving proline or 4-hydroxyproline esters, an aldehyde and a dipolarophile. The formation of the iminium salt promotes the 1,3-dipolar cycloaddition affording highly substituted pyrrolizidines under mild conditions and high regio- and diastereoselectivities.

We report the direct formation of multiwalled carbon nanotubes (MWNT) by ultrasonication of graphite in dimethylformamide (DMF) upon addition of ferrocene aldehyde (Fc-CHO). The tubular structures appear exclusively at the edges of graphene layers and contain Fe clusters. Fc in conjunction with benzyl aldehyde, or other Fc derivatives, does not induce formation of NT. Higher amounts of Fc-CHO a...

A ZnII complex with an aldehyde group hydrolyzed porcine pancreatic elastase under mild conditions, pH 8.0, 50 degrees C, by the Schiff base formation between the ZnII complex and the NH2 group in the protein, suggesting that a ZnII compound can be active toward peptide hydrolysis when it strongly binds to the substrate.

Lysyl oxidase catalyzes the formation of crosslinking aldehydes in collagen and elastin. This report demonstrates that the enzyme has high activity with collagen precipitated as native fibrils, an apparent K(m) of 0.95 muM, and low activity toward either soluble forms such as denatured collagen, isolated alpha chain, or isolated alpha1-CBl peptide, or precipitated collagen fibrils after pepsin ...

It has been demonstrated (1) that the oxidation-reduction of methylglyoxal to lactic acid occurs in two steps. The first step is a condensation of methylglyoxal and reduced glutathione to a thiol ester which is hydrolytically cleaved to lactic acid and reduced glutathione. It was pointed out that such a mechanism might be operative in other aldehyde-oxidizing systems such as glyceraldehyde phos...

2,4,6-triisopropylstryrene was synthesized in a single step via the witting reaction from the corresponding aldehyde. the reaction of three styrene's derivatives, 2,6-dimethylstyrene, 2,4,6-trimethylstyrene, and 2,4,6- triisopropylstyrene with 4-methyl-l,2,4-triazoline-3,5-dion(m etd) was investigated. these reactions are instantaneous at room temperature and lead to the formation of 2: 1 ...

Drosophila alcohol dehydrogenase (Adh) catalyses the oxidation of both alcohols and aldehydes. In the latter case, the oxidation is followed by a reduction of the aldehyde, i.e. a dismutation reaction. At high pH, dismutation is accompanied by a small release of NADH, which is not observed at neutral pH. Previously it has been emphasized that kinetic coefficients obtained by measuring the incre...

The rapid formation of adhesions in suspension by lightly trypsinized BHK21 cells is not dependent on protein synthesis, and only in part on cellular metabolism, although it is completely inhibited by heat- and aldehyde-fixation of the cells. A requirement for protein synthesis becomes evident only if cells are exposed to high levels of trypsin for long periods. Formation of adhesions does not ...

Aldehyde assisted fractionation of biomass produces an acetal-stabilised lignin that is fully upgradeable. We exploit the aldehyde to control lignin's physical properties, producing lignins can be soluble in both polar and apolar solvents.