Lipase-Catalyzed Transesterification of (R,S)-1-Phenylethanol in SC CO[sub]2 and in SC CO[sub]2/Ionic Liquid Systems

Muzafera Paljevac (Avtor), Željko Knez (Avtor), Maja Leitgeb (Avtor)

Povzetek

Commercial immobilized lipase B from Candida antarctica (CALB) was successfully applied to catalyzing the transesterification of (R,S)-1-phenylethanol in supercritical carbon dioxide and in supercritical carbon dioxide/ionic liquid biphasic system. Firstly, the variables affecting the performance of CALB in transesterification reactions in supercritical carbon dioxide, such as CALB concentration, temperature and pressure, were studied. An increase in the conversion and in the reaction rate was observed as the CALB/substrate ratio, temperature and pressure, were increased from 4.3 to 19.9, from 40 °C to 80 °C and from 8 MPa to 10 MPa, respectively. Further increase in temperature from 80 °C to 120 °C and pressure from 10 MPa to 30 MPa resulted in lower conversion and lower initial reaction rate. Furthermore, different vinyl esters were used as acyl donors for CALB-catalyzed transesterification of (R,S)-1-phenylethanol in supercritical carbon dioxide. The highest initial reaction rate was attained with vinyl butyrate, although 50% conversion was attained faster when vinyl acetate was used as acyl donor. Secondly, in transesterification of (R,S)-1-phenylethanol, performed in supercritical carbon dioxide/ionic liquid biphasic system, influence of concentration of 1-butyl-3-methylimidazolium tetrafluoroborate [bmim][BF[sub]4] was studied. The addition of 50 mmol (70% w/w reaction mixture) of [bmim][BF[sub]4] to the reaction system gave the best result in terms of transesterification rate.

Ključne besede

candida antarctica lipase B;transesterification;(R,S)-1-phenylethanol;ionic liquids;vinyl acetate;supercritical carbon dioxide;

Podatki

Jezik:	Angleški jezik
Leto izida:	2009
Tipologija:	1.01 - Izvirni znanstveni članek
Organizacija:	UM FKKT - Fakulteta za kemijo in kemijsko tehnologijo
Založnik:	Slovensko kemijsko društvo
UDK:	544.47
COBISS:	13823766
ISSN:	1318-0207
Št. ogledov:	1858
Št. prenosov:	108
Ocena:	0 (0 glasov)
Metapodatki:

Ostali podatki

Sekundarni jezik:	Slovenski jezik
Sekundarni povzetek:	Komercialno imobilizirano lipazo B iz Candida antarctica (CALB) smo uspešno uporabili kot biokatalizator za encimsko katalizirano transesterifikacijo (R,S)-1-feniletanola v SC $CO_2$ in v dvo-faznem sistemu SC $CO_2$/IL. Najprej smo proučili vpliv različnih reakcijskih parametrov, kot so razmerje CALB/substrati, temperatura in tlak, na aktivnost CALB v SC $CO_2$. Z naraščanjem razmerja CALB/substrati od 4.3 do 19.9, temperature od 40 °C do 80 °C in tlaka od 10 MPa do 30 MPa so naraščale presnove in začetne reakcijske hitrosti. Nadaljnje naraščanje temperature od 80 °C do 120 °C in tlaka od 20 MPa do 30 MPa je povzročilo znižanje tako presnove kot začetne reakcijske hitrosti. Nadalje smo za transesterifikacijo (R,S)-1-feniletanola v SC $CO_2$, katalizirano z imobilizirano CALB, uporabili kot donorje acilne skupine vinil estre z verigami različnih dolžin. Najvišjo začetno reakcijsko hitrost smo dosegli z vinil butiratom, čeprav smo 50% presnovo hitreje dosegli z vinil acetatom. V dvo-faznem sistemu SC $CO_2$/IL smo proučili vpliv koncentracije ionske tekočine 1-butil-3-metilimidazolijevega tetrafluoroborata [bmim][BF$_4$] na potek reakcije. Najvišjo začetno hitrost reakcije smo dosegli, ko smo reakcijo izvedli s 50 mmol (70% w/w reakcijske zmesi) [bmim][BF$_4$].
Sekundarne ključne besede:	lipaza B iz candida antarctica;transesterifikacija;(R;S)-1-feniletanol;ionske tekočine;vinil acetat;superkritični ogljikov dioksid;
URN:	URN:NBN:SI
Vrsta dela (COBISS):	Znanstveno delo
Strani:	str. 815-825
Letnik:	ǂVol. ǂ56
Zvezek:	ǂno. ǂ4
Čas izdaje:	2009
Ključne besede (UDK):	mathematics;natural sciences;naravoslovne vede;matematika;chemistry;crystallography;mineralogy;kemija;physical chemistry;fizikalna kemija;chemical kinetics;catalysis;
ID:	991073