scholarly journals FaQR, Required for the Biosynthesis of the Strawberry Flavor Compound 4-Hydroxy-2,5-Dimethyl-3(2H)-Furanone, Encodes an Enone Oxidoreductase

2006 ◽  
Vol 18 (4) ◽  
pp. 1023-1037 ◽  
Author(s):  
Thomas Raab ◽  
Juan Antonio López-Ráez ◽  
Dorothée Klein ◽  
Jose Luis Caballero ◽  
Enriqueta Moyano ◽  
...  
Keyword(s):  
Flavor Compound ◽  
Strawberry Flavor

scholarly journals Glucosylation of 4-Hydroxy-2,5-Dimethyl-3(2H)-Furanone, the Key Strawberry Flavor Compound in Strawberry Fruit

2016 ◽  
Vol 171 (1) ◽  
pp. 139-151 ◽  
Author(s):  
Chuankui Song ◽  
Xiaotong Hong ◽  
Shuai Zhao ◽  
Jingyi Liu ◽  
Katja Schulenburg ◽  
...  
Keyword(s):  
Strawberry Fruit ◽  
Flavor Compound ◽  
Strawberry Flavor

scholarly journals Structural Basis for the Enzymatic Formation of the Key Strawberry Flavor Compound 4-Hydroxy-2,5-dimethyl-3(2H)-furanone

2013 ◽  
Vol 288 (23) ◽  
pp. 16815-16826 ◽  
Author(s):  
André Schiefner ◽  
Quirin Sinz ◽  
Irmgard Neumaier ◽  
Wilfried Schwab ◽  
Arne Skerra
Keyword(s):  
Crystallographic Analysis ◽  
Structural Basis ◽  
Exocyclic Double Bond ◽  
Dependent Manner ◽  
Deuterium Labeling ◽  
Quinone Oxidoreductase ◽  
Chiral Phase ◽  
Flavor Compound ◽  
Substrate Analogs ◽  
Strawberry Flavor

The last step in the biosynthetic route to the key strawberry flavor compound 4-hydroxy-2,5-dimethyl-3(2H)-furanone (HDMF) is catalyzed by Fragaria x ananassa enone oxidoreductase (FaEO), earlier putatively assigned as quinone oxidoreductase (FaQR). The ripening-induced enzyme catalyzes the reduction of the exocyclic double bond of the highly reactive precursor 4-hydroxy-5-methyl-2-methylene-3(2H)-furanone (HMMF) in a NAD(P)H-dependent manner. To elucidate the molecular mechanism of this peculiar reaction, we determined the crystal structure of FaEO in six different states or complexes at resolutions of ≤1.6 Å, including those with HDMF as well as three distinct substrate analogs. Our crystallographic analysis revealed a monomeric enzyme whose active site is largely determined by the bound NAD(P)H cofactor, which is embedded in a Rossmann-fold. Considering that the quasi-symmetric enolic reaction product HDMF is prone to extensive tautomerization, whereas its precursor HMMF is chemically labile in aqueous solution, we used the asymmetric and more stable surrogate product 2-ethyl-4-hydroxy-5-methyl-3(2H)-furanone (EHMF) and the corresponding substrate (2E)-ethylidene-4-hydroxy-5-methyl-3(2H)-furanone (EDHMF) to study their enzyme complexes as well. Together with deuterium-labeling experiments of EDHMF reduction by [4R-2H]NADH and chiral-phase analysis of the reaction product EHMF, our data show that the 4R-hydride of NAD(P)H is transferred to the unsaturated exocyclic C6 carbon of HMMF, resulting in a cyclic achiral enolate intermediate that subsequently becomes protonated, eventually leading to HDMF. Apart from elucidating this important reaction of the plant secondary metabolism our study provides a foundation for protein engineering of enone oxidoreductases and their application in biocatalytic processes.

scholarly journals An ADH toolbox for raspberry ketone production from natural resources via a biocatalytic cascade

2021 ◽  
Author(s):  
Aileen Becker ◽  
Dominique Böttcher ◽  
Werner Katzer ◽  
Karsten Siems ◽  
Lutz Müller-Kuhrt ◽  
...  
Keyword(s):  
Alcohol Dehydrogenase ◽  
Genetically Modified Organisms ◽  
Optical Purity ◽  
High Yield ◽  
Alcohol Dehydrogenases ◽  
Flavor Compound ◽  
Raspberry Ketone ◽  
Cofactor Recycling ◽  
Cosmetic Industry ◽  
Key Points

Abstract Raspberry ketone is a widely used flavor compound in food and cosmetic industry. Several processes for its biocatalytic production have already been described, but either with the use of genetically modified organisms (GMOs) or incomplete conversion of the variety of precursors that are available in nature. Such natural precursors are rhododendrol glycosides with different proportions of (R)- and (S)-rhododendrol depending on the origin. After hydrolysis of these rhododendrol glycosides, the formed rhododendrol enantiomers have to be oxidized to obtain the final product raspberry ketone. To be able to achieve a high conversion with different starting material, we assembled an alcohol dehydrogenase toolbox that can be accessed depending on the optical purity of the intermediate rhododendrol. This is demonstrated by converting racemic rhododendrol using a combination of (R)- and (S)-selective alcohol dehydrogenases together with a universal cofactor recycling system. Furthermore, we conducted a biocatalytic cascade reaction starting from naturally derived rhododendrol glycosides by the use of a glucosidase and an alcohol dehydrogenase to produce raspberry ketone in high yield. Key points • LB-ADH, LK-ADH and LS-ADH oxidize (R)-rhododendrol • RR-ADH and ADH1E oxidize (S)-rhododendrol • Raspberry ketone production via glucosidase and alcohol dehydrogenases from a toolbox Graphical abstract

Understanding the Dynamics of Flavor Compound Release During Food Mastication of Cheese Products in Relation to Perception

2014 ◽  
pp. 493-498
Author(s):  
Elisabeth Guichard ◽  
Claude Yven ◽  
Marie Repoux ◽  
Etienne Sémon ◽  
Hélène Labouré ◽  
...  
Keyword(s):  
Flavor Compound ◽  
Cheese Products

An enzymatic approach to the synthesis of optically pure (3R)- and (3S)-enantiomers of green tea flavor compound 3-hydroxy-3-methylnonane-2,4-dione

2013 ◽  
Vol 85-86 ◽  
pp. 93-98 ◽  
Author(s):  
Olga Bortolini ◽  
Pier Paolo Giovannini ◽  
Silvia Maietti ◽  
Alessandro Massi ◽  
Paola Pedrini ◽  
...  
Keyword(s):  
Green Tea ◽  
Flavor Compound ◽  
Optically Pure
Sign in / Sign up

Export Citation Format

Share Document