Influence of deep eutectic solvents on reactions catalyzed by alcohol dehydrogenase

Autor: Martinuš, Tihana
Přispěvatelé: Cvjetko Bubalo, Marina
Jazyk: chorvatština
Rok vydání: 2020
Předmět:
Popis: Porastom ekološke svijesti i interesa za vođenjem biokatalitičkih procesa koji rezultiraju većom produktivnošću i smanjenom količinom štetnog otpada, znanstvenici se okreću razvoju eutektičkih otapala kao nove generacije ekološki prihvatljivih otapala. U ovome radu ispitana je aktivnost enzima alkohol dehidrogenaze u eutektičkim otapalima na bazi kolin-klorida i betaina te promjene u konformaciji istog. Otapala s betainom kao akceptorom vodika pokazala su najmanje konformacijske promjene enzima u odnosu na pufer kao referentno otapalo, a ista otapala pokazala su se povoljnima i za njegovu aktivnost. Zbog potrebe enzima za koenzimom, u istim otapalima ispitana je i stabilnost koenzima NADH i NAD+ nakon čega je potvrđen stabilizirajući utjecaj eutektičkih otapala na bazi kolin-klorida sa ureom i etilen glikolom kao donorima vodika. Kako bi se provjerila mogućnost odvijanja reakcije redukcije katalizirane cijelim stanicama, provedena je asimetrična redukcija 2-klor-1-(3,4-difluoro-fenil)etanona katalizirana stanicama kvasca Saccharomyces cerevisiae. Reakcija je provedena u eutektičkom otapalu betain:etilen-glikol (u molarnom omjeru 1:2) koji se pokazao kao povoljno eutektičko otapalo u kojemu nastaje (S)-2-klor-1-(3,4-difluorofenil)etanol, vrijedan farmaceutski proizvod važan u sintezi antitrombotika Brilique koji se koristi za potrebe liječenja koronarnog sindroma. Because of increased environmental awareness and interest in biocatalytic processes with higher productivity and reduced amounts of hazardous waste, scientists work hard to develop deep eutectic solvents (DES) as a new generation of ecology acceptable solvents. In this study, the activity of ADH and changes in its conformation in DES based on betaine and choline chloride were investigated. DES with betaine as a hydrogen acceptor showed the least conformational changes of the enzyme compared to the buffer and the same solvents proved to be favorable for its activity. Due to the need of the enzyme for coenzyme, the stability of coenzymes NADH and NAD+ was examined in DES with betaine and choline chloride and the stabilizing effect of DES based on choline chloride with urea and ethylene glycol as hydrogen donors was confirmed. An asymmetric reduction of 2-chloro-1-(3,4-difluoro-phenyl)ethanone catalyzed by Saccharomyces cerevisiae was also performed to see if whole cells could catalyse this reaction. The reaction was carried out in DES betaine ethylene glycol (molar ratio of 1:2) which have been shown to be preferred choice for this reduction. As a product, (S)-2-chloro-1-(3,4-difluorophenyl)ethanol, a valuable pharmaceutical product was formed.
Databáze: OpenAIRE