Aliphatic ketone monooxygenase

Although a maj ority of research activities were dedicated to cycloketone converting BVMOs, the recently discovered novel MOs also enable stereoselective oxidation of noncyclic ketones to esters. An aliphatic open-chain monooxygenase (AOCMO) from Pseudomonas Jluorescens DSM 50106 displays stereoselective biooxidation of terminal acyl-groups in proximity to hydroxyls (Scheme 9.23). The biooxidation gives acetic... 

Biological systems overcome the inherent unreactive character of 02 by means of metalloproteins (enzymes) that activate dioxygen for selective reaction with organic substrates. For example, the cytochrome P-450 proteins (thiolated protoporphyrin IX catalytic centers) facihtate the epoxidation of alkenes, the demethylation of Al-methylamines (via formation of formaldehyde), the oxidative cleavage of a-diols to aldehydes and ketones, and the monooxygenation of aliphatic and aromatic hydrocarbons (RH) (equation 104). The methane monooxygenase proteins (MMO, dinuclear nonheme iron centers) catalyze similar oxygenation of saturated hydrocarbons (equation 105). ... 

Aliphatic alcohols can be oxidized to the corresponding carboxylic acid with Acetobacter aceti as long as the amount of substrate is kept below the inhibiting level.162 The Baeyer-Villiger reaction of cyclic ketones can be carried out with monooxygenases from P. putida (9.13) or A. calcoaceticus, the former being preferred, because the latter is pathogenic.163... 

Cytochrome P-450, a monooxygenase enzyme, is one of the major instruments of living systems for eliminating harmful xenobiotics. Typical reactions catalyzed are the conversion of alkylamines to aldehydes, hydroxylation of aromatic and aliphatic hydrocarbons, epoxidation and ketonization of olefins. The term monooxygenase refers to the incorporation (transfer) of one 0-atom of dioxygen into... 

---