N,N'-Dibenzyl diketiminate copper isopropanolate, (nacnac(Bn)CuOiPr)(2), polymerizes rac- and S,S-lactide in the presence or absence of isopropanol as a chain-transfer reagent with very high activity (k(2) = 32 M(-1) s(-1)), narrow polydispersities and without evidence of side reactions such as transesterification, epimerization or catalyst decomposition.

[reaction: see text] Aryl coumaryl ethylenes undergo oxidative photocyclization readily to yield helical pyrone-annulated condensed aromatics. The pyrones are conveniently converted to the corresponding photochromic diphenylpyrans/chromenes. Both pyrones and chromenes exhibit helicity-dependent fluorescence efficiency and persistence, respectively.

The use of FeCl(3) resulted in a fast homocoupling of aryllithiums, and this enabled its integration with the halogen-lithium exchange reaction of aryl halides in a flow microreactor. This system allows the homocoupling of two aryl halides bearing electrophilic functional groups, such as CN and NO(2), in under a minute.

Glandular chemical defence relying on the action of salicylaldehyde is characteristic for Chrysomela leaf beetle larvae. The salicylaldehyde precursor salicin, sequestered from salicaceous host plants, is deglucosylated and the aglycon further oxidized by a salicyl alcohol oxidase (SAO) to the respective aldehyde. SAOs, key enzymes in salicin-based glandular chemical defence, were previously id...

Central serotonin dysfunction appears to be related to a subtype of alcoholism with antisocial impulsive features (type II; antisocial alcoholism). The serotonergic deficit may be associated with greater impulsivity, which in turn facilitates both alcohol dependence and antisocial behavior. The present study tested association of antisocial impulsive alcoholism with candidate genes related to s...

1. The distribution of polyphenol oxidase in quinone-tanning systems may be demonstrated in frozen-dried sections by incubation in 0-2 per cent, aqueous catechol at 40 C. for 15-60 minutes. A red colour develops at the enzyme site. 2. The evidence for the view that the egg-shell in trematodes, in certain cestode groups, and in turbellarians, is a quinone-tanned protein secreted by the so-called...

A chemiluminometric flow injection analytical system for the quantitation of L-histidine is described. Histidine oxidase (EC 1.4.3.-) from Brevibacillus borstelensis KAIT-B-022 was immobilized on tresylated poly(vinyl alcohol) beads and packed into a stainless-steel column. The hydrogen peroxide produced was detected chemiluminometrically by a flowthrough sensor containing immobilized peroxidas...

We report the results of x-ray reflectivity measurements of thin films formed by different water-soluble proteins at the air-aqueous solution interface. It is demonstrated that glucose oxidase, alcohol dehydrogenase, and urease molecules denaturate at the air-aqueous solution interface to form 8- to 14-A-thick peptide sheets. X-ray reflectivity data indicate that the spreading of a lipid monola...

Utilizing a simple fluidic structure, we demonstrate the improved performance of oxidase-based enzymatic biosensors. Electrolysis of water is utilized to generate bubbles to manipulate the oxygen microenvironment close to the biosensor in a fluidic channel. For the proper enzyme reactions to occur, a simple mechanical procedure of manipulating bubbles was developed to maximize the oxygen level ...

This laboratory has recently reported that, in a reconstituted enzyme system containing alcohol-induced isozyme 3a of liver microsomal cytochrome P-450, the sum of acetaldehyde generated by the monooxygenation of ethanol and of hydrogen peroxide produced by the NADPH oxidase activity is inadequate to account for the O2 and NADPH consumed. Studies on the stoichiometry have revealed the occurrenc...