Jenis ragi Baker II telah digunakan dalam kajian ini sebagai biopemangkin untuk mengkaji penurunan 2, 6, 6-trimethylcyclohex - 2-ene-1,4-dione (ketoisophorone) kepada perantara kiral yang berguna dan meghasilkan produk yang bernilai tinggi iaitu (4R, 6R) -4-hidroksi-2,6,6-trimethylcyclohexanone atau nama ringkasnya (4R, 6R) -actinol. Lima substrat ketoisophorone yang berbeza telah diperkenalkan pada kultur yang berbeza untuk menyiasat kesan regenerasi kofaktor dan kursus masa ketoisophorone untuk menghasilkan perantara yang sepadan dengan 2,6,6-trimethylcyclohexane-1,4-dione [(6R) - levodione] dan 4-hydroxy-2,6,6-trimethylcyclohex-2-ene-1-one [(4S) -phorenol] dan produk utama (R)-hydroxy-2,2,6-trimethylcycloheanone [(4R, 6R) -actinol] di seluruh sel Saccharomyces cerevisiae. Ketersediaan dan kestabilan kofaktor telah dikaji dengan menggunakan spekta penyerapan ultraviolet-yang boleh dilihat. dan didapati bahawa pada 2.0 g / L konsentrasi substrat ketersediaan kofaktor adalah yang paling rendah disebabkan pembekuan nutrien glukosa. Tiada kesan kepekatan substrat terhadap perencatan sel dari 0.2 g / L hingga 2.0 g / L. Kromatografi gas digunakan untuk menganalisis substrat, perantara; (6R) -levodione dan (4S) -phorenol dan produk utama (4R, 6R) -actinol. Kepekatan (6R) -levodione mempunyai kepekatan yang lebih tinggi berbanding dengan (4S) -phorenol kerana persaingan koenzim dan kadar pengurangan bon karbon-karbon yang lebih tinggi berbanding dengan kadar tindak balas pengurangan karbon.
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Baker’s yeast type II has been utilized in this study as a biocatalyst to investigate the reduction of 2, 6, 6-trimethylcyclohex--2-ENE-1,4-Dione (ketoisophorone) into a useful chiral intermediates as well as for its valuable product that is (4R,6R) -4-hydroxy-2,6,6-trimethylcyclohexanone or in short (4R, 6R) -actinol. Five different substrate of ketoisophorone has been introduced at different culture in order to investigate the effect of the cofactor regeneration and the time courses of ketoisophorone to produce corresponding intermediates of 2,6,6-trimethylcyclohexane-1,4-dione [(6R)-levodione] and 4-hydroxy-2,6,6-trimethylcyclohex-2-ene-1-one [(4S)-phorenol] and the main product (R)-hydroxy-2,2,6-trimethylcycloheanone [(4R,6R)-actinol] on the whole- cell Saccharomyces cerevisiae. The cofactor availability and stability has been investigated by using ultraviolet-visible and it was found that at 2.0 g/L of substrate concentration the cofactor availability is the lowest as the nutrient-limiting of glucose. There is no effect of substrate concentration towards cell inhibition from 0.2 g/L to 2.0 g/L. Gas chromatography was used to analyse the substrate, intermediates; (6R)-levodione and (4S)-phorenol and main product (4R, 6R)-actinol. The concentration of (6R)-levodione has higher concentration compared to (4S)-phorenol due to the competition of coenzymes and higher rate of carbon-carbon double bond reduction compared to the reaction rate of carbonyl reduction.
On the whole-cell cell saccharomyces cerevisiae biotransformation of ketoisophorone at different substrate concentrations / Illya Syafiqah Mohd Razif