Deracemizacija (RS)-1-[(4-metilselanil)fenil]etanola i (RS)-1-[(4-etilselanil)fenil]etanola s pomoću sojeva Aspergillus terreus

The fungal strains Aspergillus terreus URM 3371 and A. terreus CCT 4083, isolated in Brazil, catalysed the deracemization of (RS)-1-[(4-methylselanyl)phenyl]ethanol (1) and (RS)-1-[(4-ethylselanyl)phenyl]ethanol (2). Different mass of whole fungal cells (1–5 g), pH values (4 and 7), biotransformation temperature (20 and 32 °C) and additives (ethanol, butanol, propanol and cyclohexanol) were employed in attempt to improve product yield and selectivity. The A. terreus strain URM 3371 transformed (RS)-1 into (+)-(R)-1 with high enantiomeric excess (e.e.≥98 %), good conversion (≥98 %) and acceptable yield (53 %).Sojevi plijesni Aspergillus terreus URM 3371 i A. terreus CCT 4083, izolirani u Brazilu, katalizirali su deracemizaciju (RS)-1-[(4-metilselanil)fenil]etanola (1) i (RS)-1-[(4-etilselanil)fenil]etanola (2). Upotrijebljene su cijele stanice plijesni različite mase (1-5 g), pri različitoj pH-vrijednosti (4 i 7) i temperaturi biotransformacije (20 i 32 °C), uz dodatak raznih aditiva (etanol, butanol, propanol i cikloheksanol) radi poboljšanja prinosa i selektivnosti proizvoda. Soj A. terreus URM 3371 transformirao je (RS)-1 u (+)-(RS)-1 s velikim enantiomernim viškom (≥98 %), dobrom pretvorbom (≥98 %) i prihvatljivim prinosom (53 %)

Biotransformacija supstituiranih feniletanola i acetofenona s pomoću bakterija iz okoliša

Whole cells of hydrocarbon-degrading bacteria, isolated from polluted sediments in the Santos Estuary (Baixada Santista, São Paulo, Brazil), were able to catalyse oxidoreduction reactions with various substituted phenylethanols and acetophenones as substrates. A number of substituted phenylethanols were formed with high (>99 %) enantiomeric excess. The results of microbial oxidation of phenylethanols 2, 3, 5–7 by Acinetobacter sp. 6.4T and the reduction of acetophenones 1a–6a by Serratia marcescens 5.4T showed that the bacteria used as biocatalysts in this study present significant potential for exploitation in biotechnological processes. The reduction of prochiral acetophenones by Serratia marcescens 3.5T yielded optically active alcohols with 90–99 % enantiomeric excess, and Acinetobacter sp. 6.4T is a potential biocatalyst for the oxidation of alcohols.Cijele stanice bakterija koje razgrađuju vodik, izolirane iz onečišćenih sedimenata iz zaljeva Santos (Baixada Santista, São Paulo, Brazil), upotrijebljene su kao katalizatori oksidacije i redukcije raznih supstituiranih feniletanola i acetofenona. Brojni supstituirani feniletanoli nastali su u velikom enantiomernom višku (>99 %). Rezultati mikrobne oksidacije feniletanola 2, 3, 5-7 s pomoću bakterijskog soja Acinetobacter sp. 6,4T i redukcije acetofenona 1a-6a s pomoću soja Serratia marcescens 5,4T pokazali su da postoji velika mogućnost njihove primjene u biotehnološkim procesima. Redukcijom prokiralnih acetofenona s pomoću soja Serratia marcescens 3,5T nastali su optički aktivni alkoholi u enantiomernom višku od 90 do 99 %, te je utvrđeno da je soj Acinetobacter sp. 6,4T jak biokatalizator oksidacije alkohola

Demetilacija N,N-dimetilbenzenamina i N,N,3-trimetilbenzenamina pomoću cijelih stanica plijesni Aspergillus terreus

N,N-dimethylbenzenamine and N,N,3-trimethylbenzenamine were N-demethylated through enzymatic reactions mediated by whole cells of Aspergillus terreus strains SSP 1498, URM 3371 and URM 3571. The respective products, N-methylbenzenamine and N,3-dimethylbenzenamine, were obtained in high conversions under both neutral and basic conditions. The oxidative N-demethylation of tertiary aromatic amines by A. terreus was not enhanced by the presence of the oxidant tert-butylperoxide, although further demethylation of N,N-dimethylbenzenamine to aniline was observed. The strains of the investigated A. terreus were unable to perform the dealkylation of N,N-diethylbenzenamine.N,N-dimetilbenzenamin i N,N,3-trimetilbenzenamin demetilirani su enzimskim reakcijama kataliziranim pomoću cijelih stanica sojeva Aspergillus terreus SSP 1498, URM 3371 i URM 3571. U kiseloj i lužnatoj sredini dobiveni su veliki udjeli proizvoda, tj. N-metilbenzenamina i N,3-dimetilbenzenamina. Dodatak oksidansa tert-butilnog peroksida nije pospješio oksidativnu N-demetilaciju tercijarnih aromatskih amina, kataliziranu pomoću plijesni A. terreus, ali je doveo do daljnje demetilacije N,N-dimetilbenzenamina u anilin. Ispitani sojevi A. terreus nisu pospješili dealkilaciju N,N-dietilbenzenamina

Demetilacija N,N-dimetilbenzenamina i N,N,3-trimetilbenzenamina pomoću cijelih stanica plijesni Aspergillus terreus

N,N-dimethylbenzenamine and N,N,3-trimethylbenzenamine were N-demethylated through enzymatic reactions mediated by whole cells of Aspergillus terreus strains SSP 1498, URM 3371 and URM 3571. The respective products, N-methylbenzenamine and N,3-dimethylbenzenamine, were obtained in high conversions under both neutral and basic conditions. The oxidative N-demethylation of tertiary aromatic amines by A. terreus was not enhanced by the presence of the oxidant tert-butylperoxide, although further demethylation of N,N-dimethylbenzenamine to aniline was observed. The strains of the investigated A. terreus were unable to perform the dealkylation of N,N-diethylbenzenamine.N,N-dimetilbenzenamin i N,N,3-trimetilbenzenamin demetilirani su enzimskim reakcijama kataliziranim pomoću cijelih stanica sojeva Aspergillus terreus SSP 1498, URM 3371 i URM 3571. U kiseloj i lužnatoj sredini dobiveni su veliki udjeli proizvoda, tj. N-metilbenzenamina i N,3-dimetilbenzenamina. Dodatak oksidansa tert-butilnog peroksida nije pospješio oksidativnu N-demetilaciju tercijarnih aromatskih amina, kataliziranu pomoću plijesni A. terreus, ali je doveo do daljnje demetilacije N,N-dimetilbenzenamina u anilin. Ispitani sojevi A. terreus nisu pospješili dealkilaciju N,N-dietilbenzenamina

Biotransformations of Substituted Phenylethanols and Acetophenones by Environmental Bacteria

Whole cells of hydrocarbon-degrading bacteria, isolated from polluted sediments in the Santos Estuary (Baixada Santista, São Paulo, Brazil), were able to catalyse oxidoreduction reactions with various substituted phenylethanols and acetophenones as substrates. A number of substituted phenylethanols were formed with high (>99 %) enantiomeric excess. The results of microbial oxidation of phenylethanols 2, 3, 5–7 by Acinetobacter sp. 6.4T and the reduction of acetophenones 1a–6a by Serratia marcescens 5.4T showed that the bacteria used as biocatalysts in this study present significant potential for exploitation in biotechnological processes. The reduction of prochiral acetophenones by Serratia marcescens 3.5T yielded optically active alcohols with 90–99 % enantiomeric excess, and Acinetobacter sp. 6.4T is a potential biocatalyst for the oxidation of alcohols

Deracemization of (RS)-1-[(4-Methylselanyl)Phenyl]Ethanol and (RS)-1-[(4-Ethylselanyl)Phenyl]Ethanol by Strains of Aspergillus terreus

The fungal strains Aspergillus terreus URM 3371 and A. terreus CCT 4083, isolated in Brazil, catalysed the deracemization of (RS)-1-[(4-methylselanyl)phenyl]ethanol (1) and (RS)-1-[(4-ethylselanyl)phenyl]ethanol (2). Different mass of whole fungal cells (1–5 g), pH values (4 and 7), biotransformation temperature (20 and 32 °C) and additives (ethanol, butanol, propanol and cyclohexanol) were employed in attempt to improve product yield and selectivity. The A. terreus strain URM 3371 transformed (RS)-1 into (+)-(R)-1 with high enantiomeric excess (e.e.≥98 %), good conversion (≥98 %) and acceptable yield (53 %)