The purification and characterization of three enzymes involved in ethanol formation from acetyl-CoA in Thermoanaerobacter ethanolicus 39E (formerly Clostridium thermohydrosulfuricum 39E) is described. The secondary-alcohol dehydrogenase (20 Adh) was determined to be a homotetramer of 40 kDa subunits (SDS/PAGE) with a molecular mass of 160 kDa. The 20 Adh had a lower catalytic efficiency for th...

The scope of the triphenylsilyl perrhennate (O3ReOSiPh3, 1) catalyzed 1,3-isomerization of allylic alcohols has been thoroughly explored. It was found to be effective for a wide variety of secondary and tertiary allylic alcohol substrates bearing aryl, alkyl, and cyano substituents. Two general reaction types were found which gave high levels of product selectivity: those driven by formation of...

Reversible covalent bonding is often used for the creation of novel supramolecular structures, multi-component assemblies and sensing ensembles. Despite the remarkable success of dynamic covalent systems, the reversible binding of a mono-alcohol with high strength is challenging. Here, we show that a strategy of carbonyl activation and hemiaminal ether stabilization can be embodied in a four-co...

The helical stability of poly-L-glutamic acid and poly-Lornithine in aqueous alcohol solutions was studied by optical rotatory dispersion and potentiometric titration determinations. It was found that aliphatic alcohols enhance the stability of the helix according to the series methanol < ethanol < I-propanol < I-butanol. The role of secondary and tertiary alcohols was also investigated. Thermo...

The reaction of secondary alcohols 1 with chlorodimethylsilane (HSiMe(2)Cl) proceeded in the presence of a catalytic amount of GaCl(3)/diethyl tartrate to give the corresponding organic chlorides 3. In the catalytic cycle, the reaction of diethyl tartrate 4a with HSiMe(2)Cl 2 gives the chlorosilyl ether 5 with generation of H(2). Alcohol-exchange between the formed chlorosilyl ether 5 and the s...

Several 2-alkanols (2-propanol, 2-butanol, 2-pentanol, etc.) were examined as substrates for ADP-ribosylation in the NAD/NADase enzymatic system. Even though these secondary alcohols have hydroxy groups that are subject to the steric influence of a methyl group, they were shown to be efficiently ADP-ribosylated. However, in the case of 3-alkanol (3-butanol), only slight ADP-ribosylation was obs...

Three dehydrogenases – (R)-alcohol dehydrogenase from L. kefir, (S)-aromatic alcohol dehydrogenase from T. sp. and (S)-alcohol dehydrogenase from T. brockii – were tested for the preparation of enantiopure hydroxyl metabolites of pentoxifylline (PTX), propentofylline (PPT) and denbufylline (DBF). These metabolites have an important pharmacological significance. The experimental conditions were ...

We report the cross-dehydrative reaction of two alcohols to form unsymmetrical ethers using NHC–gold(I) complexes (NHC = N-heterocyclic carbene). Our progress in developing this reaction into a straightforward procedure is discussed in detail. The optimised methodology proceeds under mild reaction conditions and produces water as the sole by-product. The synthetic utility of this environmentall...

3. The enzyme system could be concentrated from growth media, though with some loss, by ammonium sulphate precipitation. 4. Of the substances tested, all the primary aromatic alcohols, which included fi-naphthylcarbinol, benzyl alcohol and seven other ringsubstituted benzyl alcohols, were oxidized, but three secondary I-phenylethanols were not. Glucose, ethanol, butanol and the L-amino acids te...