Guido Galliani

Metabolism of ferulic acid by a facultatively anaerobic strain of Pseudomonas cepacia

Summary A facultatively anaerobic strain of Pseudomonas cepacia capable of utilizing aerobically ferulic acid as the only carbon and energy source was isolated. From the anaerobic Pseudomonas cultures supplied with ferulic acid and yeast extract, we isolated and identified 3-methoxy-4-hydroxystyrene and 3-methoxy-4-hydroxyphenylpropionic acid. These substances were not further metabolized. Aerobically growing cells completely metabolized ferulic acid through the intermediary formation of 3-methoxy-4-hydroxystyrene and 3-methoxy-4-hydroxyphenylpropionic acid.

Structure reactivity relationships in the microsomal oxidation of tertiary amines

SummaryApparent kinetic parameters Vmax and KM have been measured for the oxidative N-demethylation of twelve para-substituted N, N-dimethylanilines catalysed by rat liver microsomes. Vmax was enhanced by pretreatment of the rats with phénobarbital, whereas pretreatment with β-naphthoflavone gave no appreciable enhancement. In the case of phénobarbital pretreatment the kinetic parameters could be expressed in terms of lipophilic and electronic effect of the substituents. Kinetic parameters from control and β-naphthoflavone microsomes gave no statistically meaningful correlation.

Aromatic hydroxylation of benzylamides by potassium superoxide

Abstract N-benzylamides react with potassium superoxide in benzene in presence of 18-crown-6 ether to give ortho and para hydroxylated products. A mechanism is proposed for this reaction, involving the nucleophilic attack of superoxide anion to amide carbonyl and hydrogen abstraction from benzyle methylene by the substrate-superoxide adduct.

Demethylation and Nitration of Aryldimethilamines with Cerium (IV) Ammonium Nitrate

Abstract Studies about the oxidation of organic molecules with Ce (IV) have been performed by many groups and are summarised in two reviews1. This oxidant has a particular behaviour when the salt cerium (IV) ammonium nitrate (CAN), soluble in organic solvents, is used. In previous papers2 we explored the reactivity of some aromatic trinuclear compounds with CAN. The results reported in this paper indicate that the oxidation of aromatic amines with CAN differs from the behaviour of other metal oxidants as acetates with these substrates3.

Electronic factors and lipophilicity in the horseradish peroxidase-catalyzed oxidation of N, N-dialkylanilines with hydrogen peroxide and oxygen

Abstract Initial rates of N -dealkylation of 15 N, N -dialkylanilines with hydrogen peroxide and oxygen in the presence of the enzyme horseradish peroxidase are interpreted mainly in terms of electron availability on nitrogen. In these cases a mechanism similar to that postulated in the chemical oxidation of these substrates is suggested, and involves the formation of a cation radical. Lipophilicity acts as a limiting factor in the reaction, and highly hydrophilic and hydrophobic substrates deviate from the reactivity suggested by electronic factors toward higher and lower reactivity, respectively.

Horseradish peroxidase-catalysed oxidation of aromatic tertiary amines with hydrogen peroxide

The horseradish peroxidase-catalysed oxidation of aromatic tertiary amines with hydrogen peroxide leads to a secondary amine and an aldehyde. With alkylmethylanilines demethylation is preferred to dealkylation. Evidence is given for the coexistence of the usual peroxidation reaction and a free radical chain reaction which depends upon oxygen concentration.

Bis(salicylaldehyde)ethylenedi-iminecobalt(II)-catalysed oxidation of aromatic amines with oxygen

N-n-Butylanilines undergo N-dealkylation to give a primary amine and butyraldehyde by oxidation with oxygen in the presence of bis(salicylaldehyde)ethylenedi-iminecobalt(II)(CoIIsalen) as catalyst. High conversions are obtained with high catalyst concentrations and low [substrate]/[catalyst] ratios (r). Inspection of the effect of catalyst and substrate concentrations on initial reaction rates (vin) shows poor sensitivity to the electronic effect of the nuclear substituent. Some anilines give azo derivatives at a lower rate in the same conditions.

Facile Synthesis of 3-Alkyl-5-methyloxazolidine-2,4-diones and N-Lactoyl-N,N′-dialkylureas

Abstract The reaction between aliphatic amines and propylene carbonate can be performed in solventless conditions under microwave irradiation, becoming nearly complete within 15 min of irradiation. Oxidation of the formed mixture of 2-hydroxyethylcarbamates gives 3,5-methylalkyl-oxazolidine-2,4-diones. These compounds can react further with aliphatic primary amines to give N-lactoylureas.

Formation of superoxide radical anion in the horseradish peroxidase-catalysed oxidation of three aromatic tertiary amines with hydrogen peroxide

The horseradish peroxidase-catalysed oxidation of aromatic tertiary amines with hydrogen peroxide to give a secondary amine and an aldehyde occurs through the co-occurrence of the usual reaction with H2O2 and a free radical chain reaction which depends upon oxygen concentration. The intervention of superoxide radical anion is demonstrated by the reduction of cytochrome CIII and the dismutation catalysed by superoxide dismutase.

The Oxidation of Some Aryldialkylamines with Thallium (III) Nitrate (TTN) in Various Solvents

Abstract The oxidation of organic substrates with thallium (III) nitrate (TTN) has been summarised in a recent review1. No systematic study is available using aromatic tertiary amines as substrates. We showed in two previous reports2,3 that these compounds undergo oxidative dealkylation and nitration when oxidised with cerium (IV) ammonium nitrate (CAN).