5524-05-0Relevant articles and documents
Novel reductase participation in the syn-addition of hydrogen to the C=C bond of enones in the cultured cells of Nicotiana tabacum
Shimoda, Kei,Ito, Diana I.,Izumi, Shunsuke,Hirata, Toshifumi
, p. 355 - 358 (1996)
A reductase isolated from cultured cells of Nicotiana tabacum has been characterized and used in the reduction of a C=C bond adjacent to a carbonyl group. The stereochemistry of the latter reaction has been investigated by 2H NMR and mass spectroscopy. It was found that the reductase reduces stereospecifically the C=C bond of verbenone and carvone by syn addition of hydrogen from the re face at the β-position and the re face at the α-position to the carbonyl group; the hydrogen atoms participating in the enzymatic reduction at the α- and β-positions originate from the medium (H2O) and the pro-4S hydrogen of NADPH, respectively.
Asymmetric Reduction of (R)-Carvone through a Thermostable and Organic-Solvent-Tolerant Ene-Reductase
Tischler, Dirk,G?dke, Eric,Eggerichs, Daniel,Gomez Baraibar, Alvaro,Mügge, Carolin,Scholtissek, Anika,Paul, Caroline E.
, p. 1217 - 1225 (2020)
Ene-reductases allow regio- and stereoselective reduction of activated C=C double bonds at the expense of nicotinamide adenine dinucleotide cofactors [NAD(P)H]. Biological NAD(P)H can be replaced by synthetic mimics to facilitate enzyme screening and process optimization. The ene-reductase FOYE-1, originating from an acidophilic iron oxidizer, has been described as a promising candidate and is now being explored for applied biocatalysis. Biological and synthetic nicotinamide cofactors were evaluated to fuel FOYE-1 to produce valuable compounds. A maximum activity of (319.7±3.2) U mg?1 with NADPH or of (206.7±3.4) U mg?1 with 1-benzyl-1,4-dihydronicotinamide (BNAH) for the reduction of N-methylmaleimide was observed at 30 °C. Notably, BNAH was found to be a promising reductant but exhibits poor solubility in water. Different organic solvents were therefore assayed: FOYE-1 showed excellent performance in most systems with up to 20 vol% solvent and at temperatures up to 40 °C. Purification and application strategies were evaluated on a small scale to optimize the process. Finally, a 200 mL biotransformation of 750 mg (R)-carvone afforded 495 mg of (2R,5R)-dihydrocarvone (>95 % ee), demonstrating the simplicity of handling and application of FOYE-1.
Investigating the Structure-Reactivity Relationships Between Nicotinamide Coenzyme Biomimetics and Pentaerythritol Tetranitrate Reductase
Tan, Zhuotao,Han, Yaoying,Fu, Yaping,Zhang, Xiaowang,Xu, Mengjiao,Na, Qi,Zhuang, Wei,Qu, Xudong,Ying, Hanjie,Zhu, Chenjie
, p. 103 - 113 (2021/10/07)
Ene reductases (ERs) are attractive biocatalysts in terms of their high enantioselectivity and expanded substrate scope. Recent works have proved that synthetic nicotinamide coenzyme biomimetics (NCBs) can be used as easily accessible alternatives to natural cofactors in ER-catalyzed reactions. However, the structure-reactivity relationships between NCBs and ERs and influence factors are still poorly understood. In this study, a series of C-5 methyl modified NCBs were synthesized and tested in the PETNR-catalyzed asymmetric reductions. The physicochemical properties of these NCBs including electrochemical properties, stability, and kinetic behavior were studied in detail. The results showed that hydrophobic interaction caused by the introduced methyl group contributed to the stabilization of binding conformation in enzyme active site, resulting in comparable catalytic activity with that of NADPH. Molecular dynamics and steered molecular dynamics simulations were further performed to explain the binding mechanism between PETNR and NCBs, which revealed that stable catalytic conformation, appropriate donor-acceptor distance and angle, as well as free dissociation energy are important factors affecting the activity of NCBs. (Figure presented.).
Total Synthesis of (?)-Rotundone and (?)-epi-Rotundone from Monoterpene Precursors
Rüthi, Fabian,Schr?der, Fridtjof
, (2020/10/30)
The first total synthesis of (?)-rotundone has been accomplished from (+)-(R)-limonene and therefore for the first time from an unrelated monoterpene instead of modifying structurally closely related sesquiterpene precursors such as α-guaiene. Challenges such as intermediates with stereocenters prone to epimerization by enolization were overcome by designing a β-methyl-keto route starting from (+)-(R)-limonene which finally gave (?)-rotundone by Nazarov cyclization of a precursor 13a. Diastereomer (?)-epi-rotundone was separated from (?)-rotundone chromatographically. An alternative route from rac-citronellal provided a diastereomer mixture of racemic Nazarov precursor 13 through a TRIP-catalyzed intramolecular aldolization, thus indicating that the Nazarov cyclization precursor 13a is in principle accessible from (?)-(S)-citronellal. The 11-step synthesis from (+)-(R)-limonene with ca. 1 % overall yield confirmed the absolute configuration of (?)-rotundone and provided samples of good olfactory quality.