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Identifier

000395116

Title

Χημειοενζυμική σύνθεση οπτικώς καθαρών φυσικών προϊόντων και χειρομορφών ενδιάμεσων

Alternative Title

Chemoenzymatic synthesis of optically pure natural products and chiral intermediates

Author

Μπαριωτάκη, Άννα

Thesis advisor

Σμόνου, Ιουλία

Reviewer

Στρατάκης, Μανώλης
Ξενάκης, Αριστοτέλης
Κατερινόπουλος, Χαράλαμπος Ε.
Βασιλικογιαννάκης, Γεώργιος Ε.
Μπουριώτης, Βασίλης
Βελώνια, Κέλλυ

Abstract

In the present thesis the stereoselective enzymatic reductions with NADPHdependent ketoreductases for the synthesis of important chiral intermediates were studied and more specifically for the synthesis of optically pure hydroxy-keto esters,1,3-dihydroxy esters and α- or γ-substituted hydroxy-keto esters. Also, a chemoenzymatic approach for the synthesis of the natural product (R)- Goniothalamin has been accomplished. All products derived from enzymatic reductions were analyzed and characterized and their absolute configuration was determined by NMR spectroscopy. These research projects were accomplished under the Research Program HRAKLEITOS II. In the first part, the enzymatic reduction of tert-butyl 3,5-dioxo-hexanoate for the synthesis of 3,5-dihydroxy esterswas completed, in a two-step, one-pot method in the same reaction vessel, without the isolation of the intermediate. These products were synthesized with excellent optical purity and chemical yield. Ketoreductases proved to be excellent catalysts with high stereoselectivity and chemoselectivity. The next part included the studies for the enzymatic reduction of tert-butyl- 2-methyl-3,5-dioxo-hexanoate for the synthesis of 2-methyl-5-hydroxy-3-keto esters. The products were formed in excellent optical and chemical purity with high enantiomeric and diastereomeric excess. Also, the enzymatic reduction of tert-butyl-4-methyl-3,5-dixo-haxanoate was studied for the synthesis of 4-methyl-5-hydroxy-3-keto esters and 4-methyl-3- hydroxy-5-keto esters with high stereoselectivity and high enantiomeric and diastereomeric excesses. In the next part the chemoenzymatic approach for the synthesis of the natural product (R)-Goniothalamin, an anti-proliferative agent is presented. In the last part the investigation of a new photocatalyst of graphitic Carbon Nitride, for the oxidation of cyclohexanol to cyclohexanone, is described.

Language

Greek

Subject

Biocatalysis

Enzymatic oxidation

Enzymatic reduction

Graphitic Carbon Nitride

Ketoreductases

NADPH

Oxidoreductases

Βιοκατάλυση

Ενζυμική αναγωγή