14901-07-6Relevant articles and documents
Enzymatic carotenoid cleavage in star fruit (Averrhoa carambola)
Fleischmann, Peter,Watanabe, Naoharu,Winterhalter, Peter
, p. 131 - 137 (2003)
This paper presents the first description of an enzyme fraction exhibiting carotenoid cleavage activity isolated from fruit skin of Averrhoa carambola. Partial purification of the enzyme could be achieved by acetone precipitation, ultrafiltration (300 kDa
An unexpected generation of magnetically separable Se/Fe3O4 for catalytic degradation of polyene contaminants with molecular oxygen
Chen, Xingyu,Mao, Jingfei,Liu, Chuang,Chen, Chao,Cao, Hongen,Yu, Lei
, p. 3205 - 3208 (2020)
Selenization of Fe2O3 with NaHSe led to Se/Fe3O4. The unexpected generation of Fe3O4 attributed to the reduction conditions of the reaction, and the resulted magnetic features of the materi
Effect of cis/trans isomerism of β-carotene on the ratios of volatile compounds produced during oxidative degradation
Wache, Yves,Bosser-DeRatuld, Aurelie,Lhuguenot, Jean-Claude,Belin, Jean-Marc
, p. 1984 - 1987 (2003)
β-Carotene is, when cleaved, an important source of flavor and aroma compounds in fruits and flowers. Among these aroma compounds, the main degradation products are β-ionone, 5,6-epoxy-β-ionone, and dihydroactinidiolide (DHA), which are associated by flavorists and perfumers with fruity, floral, and woody notes. These three species can be produced by degradation of β-carotene through an attack by enzyme-generated free radicals and a cleavage at the C9-C10 bond. This study investigated the influence of cis/trans isomerism at the C9-C10 bond on the production of β-carotene degradation compounds, first with a predictive approach and then experimentally with different isomer mixtures. β-Carotene solutions containing high ratios of 9-cis-isomers produced more DHA, suggesting a different pathway than for the transformation of all-trans-β-carotene to ionone and DHA. These results are important in the search for financially viable processes to produce natural carotene-derived aroma compounds.
Carotenoid-cleavage activities of crude enzymes from pandanous amryllifolius
Ningrum, Andriati,Schreiner, Matthias
, p. 1871 - 1881 (2014)
Carotenoid degradation products, known as norisoprenoids, are aroma-impact compounds in several plants. Pandan wangi is a common name of the shrub Pandanus amaryllifolius. The genus name Pandanus is derived from the Indonesian name of the tree, pandan. In Indonesia, the leaves from the plant are used for several purposes, e.g., as natural colorants and flavor, and as traditional treatments. The aim of this study was to determine the cleavage of β-carotene and β-apo-8-carotenal by carotenoidcleavage enzymes isolated from pandan leaves, to investigate dependencies of the enzymatic activities on temperature and pH, to determine the enzymatic reaction products by using Headspace Solid Phase Microextraction Gas Chromatography/Mass Spectrophotometry (HS-SPME GC/MS), and to investigate the influence of heat treatment and addition of crude enzyme on formation of norisoprenoids. Crude enzymes from pandan leaves showed higher activity against β-carotene than β-apo-8-carotenal. The optimum temperature of crude enzymes was 70°, while the optimum pH value was 6.We identified bionone as the major volatile reaction product from the incubations of two different carotenoid substrates, β-carotene and β-apo-8-carotenal. Several treatments, e.g., heat treatment and addition of crude enzymes in pandan leaves contributed to the norisoprenoid content. Our findings revealed that the crude enzymes from pandan leaves with carotenoid-cleavage activity might provide a potential application, especially for biocatalysis, in natural-flavor industry.
PQQ-dependent Dehydrogenase Enables One-pot Bi-enzymatic Enantio-convergent Biocatalytic Amination of Racemic sec-Allylic Alcohols
Gandomkar, Somayyeh,Rocha, Raquel,Sorgenfrei, Frieda A.,Montero, Lía Martínez,Fuchs, Michael,Kroutil, Wolfgang
, p. 1290 - 1293 (2020/12/23)
The asymmetric amination of secondary racemic allylic alcohols bears several challenges like the reactivity of the bi-functional substrate/product as well as of the α,β-unsaturated ketone intermediate in an oxidation-reductive amination sequence. Heading for a biocatalytic amination cascade with a minimal number of enzymes, an oxidation step was implemented relying on a single PQQ-dependent dehydrogenase with low enantioselectivity. This enzyme allowed the oxidation of both enantiomers at the expense of iron(III) as oxidant. The stereoselective amination of the α,β-unsaturated ketone intermediate was achieved with transaminases using 1-phenylethylamine as formal reducing agent as well as nitrogen source. Choosing an appropriate transaminase, either the (R)- or (S)-enantiomer was obtained in optically pure form (>98 % ee). The enantio-convergent amination of the racemic allylic alcohols to one single allylic amine enantiomer was achieved in one pot in a sequential cascade.
Method for preparing beta-ionone through cyclization
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Paragraph 0024-0080, (2020/06/02)
The invention discloses a method for preparing beta-ionone through cyclization. The method comprises the following steps: with pseudoionone as a raw material, performing cyclization on the pseudoionone through a catalyst, namely concentrated sulfuric acid
Iodine/water-mediated deprotective oxidation of allylic ethers to access α,β-unsaturated ketones and aldehydes
Chen, Weifeng,Jiang, Kezhi,Xue, Yuntian,Yan, Yaolong,Yang, Lei
, p. 14720 - 14724 (2020/04/27)
The first iodine/water-mediated deprotective oxidation of allylic ethers to access α,β-unsaturated ketones and aldehydes was achieved. The reaction tolerates a wide range of functionalities. Furthermore, this protocol was found to be applicable to the oxidative transformation of allylic acetates. The proposed mechanism involves an oxygen transfer from solvent water to the carbonyl products.
Scalable synthesis of the aroma compounds d6-β-ionone and d6-β-cyclocitral for use as internal standards in stable isotope dilution assays
Mosaferi, Shabnam,Jelley, Rebecca E.,Fedrizzi, Bruno,Barker, David
, (2020/12/02)
C13 Norisoprenoids are important aroma compounds in wine, giving positive attributes to the overall wine aroma even when found at very low levels. β-Ionone is considered one of the most important aroma compounds giving violet, woody and raspberry aromas to wine, fruits and vegetables in which it is found. Due to its potent aroma at low levels, precise analytical methods are desired for its quantification. Stable isotope dilution assay (SIDA) is one of the most important of these methods but requires the use of isotopically labelled standards. Herein, we describe the scalable synthesis of d6-β-ionone and d6-β-cyclocitral, another aroma compound with smokey and fruity notes, starting from the relatively inexpensive deuterated starting material d6-acetone.
Transfer-dehydrogenation of secondary alcohols catalyzed by manganese NNN-pincer complexes
Budweg, Svenja,Junge, Kathrin,Beller, Matthias
supporting information, p. 14143 - 14146 (2019/12/02)
Novel catalytic systems based on pentacarbonylmanganese bromide and stable NNN-pincer ligands are presented for the transfer-dehydrogenation of secondary alcohols to give the corresponding ketones in good to excellent isolated yields. Best results are obtained using di-picolylamine derivatives as ligands and acetone as an inexpensive hydrogen acceptor. Besides high activity for benzylic substrates, aliphatic alcohols, as well as steroid derivatives, are readily oxidized in the presence of the optimal phosphorus-free catalyst.
Biocatalytic Enantioselective Oxidation of Sec-Allylic Alcohols with Flavin-Dependent Oxidases
Gandomkar, Somayyeh,Jost, Etta,Loidolt, Doris,Swoboda, Alexander,Pickl, Mathias,Elaily, Wael,Daniel, Bastian,Fraaije, Marco W.,Macheroux, Peter,Kroutil, Wolfgang
, p. 5264 - 5271 (2019/11/13)
The oxidation of allylic alcohols is challenging to perform in a chemo- as well as stereo-selective fashion at the expense of molecular oxygen using conventional chemical protocols. Here, we report the identification of a library of flavin-dependent oxidases including variants of the berberine bridge enzyme (BBE) analogue from Arabidopsis thaliana (AtBBE15) and the 5-(hydroxymethyl)furfural oxidase (HMFO) and its variants (V465T, V465S, V465T/W466H and V367R/W466F) for the enantioselective oxidation of sec-allylic alcohols. While primary and benzylic alcohols as well as certain sugars are well known to be transformed by flavin-dependent oxidases, sec-allylic alcohols have not been studied yet except in a single report. The model substrates investigated were oxidized enantioselectively in a kinetic resolution with an E-value of up to >200. For instance HMFO V465S/T oxidized the (S)-enantiomer of (E)-oct-3-en-2-ol (1 a) and (E)-4-phenylbut-3-en-2-ol with E>200 giving the remaining (R)-alcohol with ee>99% at 50% conversion. The enantioselectivity could be decreased if required by medium engineering by the addition of cosolvents (e. g. dimethyl sulfoxide).
