alpha-ionone and beta-ionone

A toxicologic and dermatologic review of ionone when used as a fragrance ingredient is presented.

Topics: Animals; Consumer Product Safety; Dose-Response Relationship, Drug; Humans; Norisoprenoids; Noxae; Perfume; Risk Assessment; Skin; Skin Absorption; Skin Irritancy Tests; Skin Tests; Toxicity Tests

Apocarotenoids are among the most highly valued fragrance constituents, being also appreciated as synthetic building blocks. This work shows the ability of unspecific peroxygenases (UPOs, EC1.11.2.1) from several fungi, some of them being described recently, to catalyze the oxyfunctionalization of α- and β-ionones and α- and β-damascones. Enzymatic reactions yielded oxygenated products such as hydroxy, oxo, carboxy, and epoxy derivatives that are interesting compounds for the flavor and fragrance and pharmaceutical industries. Although variable regioselectivity was observed depending on the substrate and enzyme, oxygenation was preferentially produced at the allylic position in the ring, being especially evident in the reaction with α-ionone, forming 3-hydroxy-α-ionone and/or 3-oxo-α-ionone. Noteworthy were the reactions with damascones, in the course of which some UPOs oxygenated the terminal position of the side chain, forming oxygenated derivatives (i.e., the corresponding alcohol, aldehyde, and carboxylic acid) at C-10, which were predominant in the

Topics: Catalysis; Fungal Proteins; Fungi; Mixed Function Oxygenases; Norisoprenoids; Substrate Specificity

Carotenoid cleavage dioxygenases (CCDs) drive carotenoid catabolism to produce various apocarotenoids and immediate derivatives with particular developmental, ecological, and agricultural importance. How

Topics: Arabidopsis; beta Carotene; Carotenoids; Dioxygenases; Norisoprenoids; Phosphates; Plant Proteins; Terpenes; Xanthophylls; Zea mays

The identification of aroma composition and key odorants contributing to aroma characteristics of white tea is urgently needed, owing to white tea's charming flavors and significant health benefits. In this study, a total of 238 volatile components were identified in the three subtypes of white teas using headspace solid-phase microextraction (HS-SPME) combined with comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry (GC × GC-TOFMS). The multivariate statistical analysis demonstrated that the contents of 103 volatile compounds showed extremely significant differences, of which 44 compounds presented higher contents in Baihaoyinzhen and Baimudan, while the other 59 compounds exhibited higher contents in Shoumei. The sensory evaluation experiment carried out by gas chromatography-olfactometry/mass spectrometry (GC-O/MS) revealed 44 aroma-active compounds, of which 25 compounds were identified, including 9 alcohols, 6 aldehydes, 5 ketones, and 5 other compounds. These odorants mostly presented green, fresh, floral, fruity, or sweet odors. Multivariate analyses of chemical characterization and sensory evaluation results showed that high proportions of alcohols and aldehydes form the basis of green and fresh aroma characteristic of white teas, and phenylethyl alcohol, γ-Nonalactone, trans-β-ionone, trans-linalool oxide (furanoid), α-ionone, and cis-3-hexenyl butyrate were considered as the key odorants accounting for the different aroma characteristics of the three subtypes of white tea. The results will contribute to in-depth understand chemical and sensory markers associated with different subtypes of white tea, and provide a solid foundation for tea aroma quality control and improvement.

Topics: Acyclic Monoterpenes; Aldehydes; Cyclohexanols; Flavoring Agents; Fruit; Gas Chromatography-Mass Spectrometry; Norisoprenoids; Odorants; Solid Phase Microextraction; Tea; Trityl Compounds; Volatile Organic Compounds

Topics: Carotenoids; Gas Chromatography-Mass Spectrometry; Nicotiana; Norisoprenoids; Oils, Volatile

We investigated the dynamic changes in norisoprenoids and phenylalanine derivatives in off-vine Vidal blanc. Glycosidically bound as well as free-form volatile compounds were identified by GC-MS in two vintages. Thus, off-vine grape exhibited the development of four higher alcohols (viz. linalool oxide, 2-octanol, 1-pentanol, and 1-heptanol), C13-norisoprenoids (α-ionone), phenylalanine-derivates (2-phenylethanol), whereas β-ionone and geranial showed high correlation in on-vine grape. Freeze-thaw cycles and desiccation, two exterior stress affect volatile compound development, resulted in content fluctuations during late harvest. Interestingly, the total content of higher alcohols was higher in on-vine grapes than off-vine grapes in two vintages respectively. Interestingly, the content of higher alcohols was higher in off-vine samples in the 2016 and 2017 vintages. In terms of physicochemical parameters, off-vine Vidal showed results similar to those of on-vine sample. Nevertheless, sensorial impression of the grape juice was influenced by interaction of vintages and vine treatments.

Topics: Acyclic Monoterpenes; Alcohols; Carotenoids; Cluster Analysis; Cyclohexanols; Female; Gas Chromatography-Mass Spectrometry; Heptanol; Humans; Male; Monoterpenes; Norisoprenoids; Octanols; Pentanols; Phenylalanine; Taste; Trityl Compounds; Vitis; Volatile Organic Compounds; Wine

Apocarotenoids, such as α-, β-ionone, and retinol, have high commercial values in the food and cosmetic industries. The demand for natural ingredients has been increasing dramatically in recent years. However, attempts to overproduce β-ionone in microorganisms have been limited by the complexity of the biosynthetic pathway. Here, an Escherichia coli-based modular system was developed to produce various apocarotenoids. Incorporation of enzyme engineering approaches (N-terminal truncation and protein fusion) into modular metabolic engineering strategy significantly improved α-ionone production from 0.5 mg/L to 30 mg/L in flasks, producing 480 mg/L of α-ionone in fed-batch fermentation. By modifying apocarotenoid genetic module, this platform strain was successfully re-engineered to produce 32 mg/L and 500 mg/L of β-ionone in flask and bioreactor, respectively (>80-fold higher than previously reported). Similarly, 33 mg/L of retinoids was produced in flask by reconstructing apocarotenoid module, demonstrating the versatility of the "plug-n-play" modular system. Collectively, this study highlights the importance of the strategy of simultaneous modular pathway optimization and enzyme engineering to overproduce valuable chemicals in microbes.

Topics: Biosynthetic Pathways; Escherichia coli; Metabolic Engineering; Norisoprenoids; Retinoids

Olfactory receptors are G protein-coupled receptors. Some of them are expressed in tumor cells, such as the OR51E2 receptor overexpressed in LNCaP prostate cancer cells. It is considered a prostate tumor marker. We previously demonstrated that this receptor is able to promote LNCaP cell invasiveness in vitro upon stimulation with its odorant agonist β-ionone, leading to increased generation of metastases in vivo. In the present study, we show that even a relatively short exposure to β-ionone is sufficient to promote metastasis emergence. Moreover, α-ionone, considered an OR51E2 antagonist, in fact promotes prostate tumor growth in vivo. The combination of α-ionone with β-ionone triggers a higher increase in the total tumor burden than each molecule alone. To support the in vivo results, we demonstrate in vitro that α-ionone is a real agonist of OR51E2, mainly sustaining LNCaP cell growth, while β-ionone mainly promotes cell invasiveness. So, while structurally close, α-ionone and β-ionone appear to induce different cellular effects, both leading to increased tumor aggressiveness. This behaviour could be explained by a different coupling to downstream effectors, as it has been reported for the so-called biased ligands of other G protein-coupled receptors.

Topics: Animals; Cell Line, Tumor; Cell Movement; Disease Progression; Humans; Male; Mice; Neoplasm Metastasis; Neoplasm Proteins; Neoplasm Transplantation; Norisoprenoids; Prostatic Neoplasms; Receptors, Odorant; Up-Regulation

Due to their bioactive properties as well as their application as precursors in chemical synthesis, hydroxylated isoprenoids and norisoprenoids are very valuable compounds. The efficient hydroxylation of such compounds remains a challenge in organic chemistry caused by the formation of a variety of side products and lack of overall regio- and stereoselectivity. In contrast, cytochromes P450 are known for their selective oxidation under mild conditions. Here, we demonstrate for the first time the ability of myxobacterial CYP260B1 and CYP267B1 from Sorangium cellulosum So ce56 to oxidize such carotenoid-derived aroma compounds. A focused library of 14 substrates such as ionones, damascones, as well as some of their isomers and derivatives was screened in vitro. Both P450s were capable of an efficient oxidation of all tested compounds. CYP260B1-dependent conversions mainly formed multiple products, whereas conversions by CYP267B1 resulted predominantly in a single product. To identify the main products by NMR spectroscopy, an Escherichia coli-based whole-cell system was used. CYP267B1 showed a hydroxylase activity towards the formation of allylic alcohols. Likewise, CYP260B1 performed the allylic hydroxylation of β-damascone [(E)-1-(2,6,6-trimethylcyclohex-1-enyl)but-2-en-1-one] and δ-damascone [(E)-1-(2,6,6-trimethylcyclohex-3-enyl)but-2-en-1-one]. Moreover, CYP260B1 showed an epoxidase activity towards β-ionone [(E)-4-(2,6,6-trimethylcyclohex-1-enyl)but-3-en-2-one] as well as the methyl-substituted α-ionone derivatives raldeine [(E)-1-(2,6,6-trimethylcyclohex-2-enyl)pent-1-en-3-one] and isoraldeine [(E)-3-methyl-4-(2,6,6-trimethylcyclohex-2-enyl)but-3-en-2-one]. In addition, to known products, also novel products such as 2-OH-δ-damascone [(E)-1-(5-hydroxy-2,6,6-trimethylcyclohex-3-enyl)but-2-en-1-one], 3-OH-allyl-α-ionone [(E)-1-(4-hydroxy-2,6,6-trimethylcyclohex-2-enyl)hepta-1,6-dien-3-one], and 4-OH-allyl-β-ionone [(E)-1-(3-hydroxy-2,6,6-trimethylcyclohex-1-enyl)hepta-1,6-dien-3-one] were identified during our studies.

Topics: Bacterial Proteins; Carotenoids; Cytochrome P-450 Enzyme System; Escherichia coli; Hydroxylation; Industrial Microbiology; Magnetic Resonance Spectroscopy; Myxococcales; Norisoprenoids; Odorants; Oxidation-Reduction; Oxidoreductases

Native concentrations of α-ionone, β-ionone, and β-damascenone were studied in various authentic and commercial wines. In addition, the enantiomeric distribution of α-ionone was determined and its merits as a potential marker for aroma adulteration in wine were discussed. For extraction of volatiles, headspace solid-phase microextraction (HS-SPME) was applied, followed by heart-cut multidimensional gas chromatography coupled to tandem mass spectrometric detection for trace-level analysis. The enantioselective analysis of α-ionone was achieved with octakis(2,3-di-O-pentyl-6-O-methyl)-γ-cyclodextrin as the chiral selector in the separation column for gas chromatography (GC). In all the authentic wines studied, α-ionone showed a high enantiomeric ratio in favor of the (R)-enantiomer. Since an illegal addition of α-ionone in a racemic form changes the enantiomeric ratio, this ratio may serve as an adulteration marker. Concentrations varied between

Topics: Gas Chromatography-Mass Spectrometry; Limit of Detection; Norisoprenoids; Odorants; Solid Phase Microextraction; Stereoisomerism; Tandem Mass Spectrometry; Wine

Chemosensory proteins (CSPs) play important roles in chemical communication by insects, as they recognize and transport environmental chemical signals to receptors within sensilla. In this study, we identified HoblCSP1 and HoblCSP2 from a cDNA library of Holotrichia oblita antennae, successfully expressed them in E. coli and purified them by Ni ion affinity chromatography. We then measured the ligand-binding specificities of HoblCSP1 and HoblCSP2 to 50 selected ligands in a competitive binding assay. These results demonstrated that HoblCSP1 and HoblCSP2 have similar ligand-binding spectra. Both proteins displayed the highest affinity for β-ionone, α-ionone and cinnamaldehyde, indicating that they prefer binding to odorants other than sex pheromones. Additionally, immuno-localization revealed that HoblCSP1 is highly concentrated in sensilla basiconica, while HoblCSP2 is specifically localized to sensilla placodea. In conclusion, HoblCSP1 and HoblCSP2 are responsible for binding to general odorants with slightly different specificities due to their different in vivo environments.

Topics: Acrolein; Amino Acid Sequence; Animals; Arthropod Antennae; Binding, Competitive; Coleoptera; Escherichia coli; Female; Gene Expression; Insect Proteins; Ligands; Male; Molecular Sequence Data; Neurons, Afferent; Norisoprenoids; Odorants; Phylogeny; Protein Binding; Receptors, Odorant; Recombinant Proteins; Sensilla

Taking application of some isolation and purification technologies, such as solvent extraction, preliminary solvent isolation, column chromatographies over silica gel and Sephadex LH-20 gel and preparative HPLC, 10 compounds were obtained from Gynura nepalensis cultivated in the suburban area of Beijing. Their structures were identified by spectroscopic methods and comparison with literature as (3R) -3-hydroxy-β-ionone (1), (3S,5R, 6S, 7E) -5, 6-epoxy-3-hydroxy-7-megastigmen-9-one (2), (+) -boscialin (3), 3, 6-trans-3-hydroxy-α-ionone (4), 3, 6-cis-3-hydroxy-α-ionone (5), 3, 4-cis-3, 4-dihydroxy-β-ionone (6), ethyl caffeate (7), loliolide (8), 1H-indole-3-carbaldehyde (9), and 3-(hydroxyacetyl)indole (10), respectively. All compounds were isolated from the title plant for the first time, and with compounds 1, 2, 4-7, 9 and 10 being isolated from Gynura species for the first time. Structurally, the above compounds 1-6 belong to C13 nor-sesquiterpenoids, sharing the same carbon skeleton of megastigmane. According to this study, they are one of major kinds of chemical constituents of Gynura nepalensis and have important reference value for the investigation on phytotaxonomy of this species.

Topics: Asteraceae; Caffeic Acids; Cyclohexanones; Drugs, Chinese Herbal; Glucosides; Indoles; Mass Spectrometry; Molecular Structure; Norisoprenoids

Many terpenes and terpenoid compounds are known as bioactive substances with desirable fragrance and medicinal activities. Modification of such compounds to yield new derivatives with desired properties is particularly attractive. Cytochrome P450 monooxygenases are potential enzymes for these reactions due to their capability of performing different reactions on a variety of substrates. We report here the characterization of CYP264B1 from Sorangium cellulosum So ce56 as a novel sesquiterpene hydroxylase. CYP264B1 was able to convert various sesquiterpenes including nootkatone and norisoprenoids (α-ionone and β-ionone). Nootkatone, an important grapefruit aromatic sesquiterpenoid, was hydroxylated mainly at position C-13. The product has been shown to have the highest antiproliferative activity compared with other nootkatone derivatives. In addition, CYP264B1 was found to hydroxylate α- and β-ionone, important aroma compounds of floral scents, regioselectively at position C-3. The products, 3-hydroxy-β-ionone and 13-hydroxy-nootkatone, were confirmed by (1)H and (13)C NMR. The kinetics of the product formation was analyzed by high-performance liquid chromatography, and the K ( m ) and k (cat) values were calculated. The results of docking α-/β-ionone and nootkatone into a homology model of CYP264B1 revealed insights into the structural basis of these selective hydroxylations.

Topics: Biotechnology; Cytochrome P-450 Enzyme System; Kinetics; Mixed Function Oxygenases; Models, Molecular; Myxococcales; Norisoprenoids; Polycyclic Sesquiterpenes; Sesquiterpenes

Carotenoid derived volatiles are important fragrance compounds, which contribute to the scents of flowers from diverse taxa. A famous example is represented by the flowers of Osmanthus fragrans where apocarotenoids account for more than 20% of all volatiles. In the recent years, bio-degradation of carotenoids has been shown to be an important route for apocarotenoids formation. Here, we report on the contribution the O. fragrans carotenoid cleavage dioxygenase 1 to the synthesis of the two predominant C(13)-apocarotenoids, α- and β-ionone, derived from α-and β-carotene, respectively.

Topics: Carotenoids; Flowers; Norisoprenoids; Odorants; Oleaceae

In addition to the already available information on the authenticity of alpha- (1) and beta-ionone (2) from plant tissues, there is an interest in the stable isotope data of 1 and 2 available by synthesis from citral and acetone, as European Union regulations, in contrast to the United States and other countries, do not allow a product to be declared as 'natural' that has been chemically synthesized (e.g., by using a natural catalyst) from natural educts. Analyses performed by on-line capillary gas chromatography-isotope ratio mass spectrometry in the combustion and pyrolysis modes (HRGC-C/P-IRMS) as well as by elemental analyzers (EA-C/P-IRMS) measuring delta(13)C(V)-PDB and delta(2)H(V)-SMOW values provide for the first time isotope data of such 'natural' 1 and 2 as well as of synthetic and 'ex plant' alpha-ionol (3). The isotope data recorded for synthesized 1 and 2 reflected the influence of the origin of the used citral, whereas that of acetone was less remarkable. For instance, 'natural' 1 ex citral from lemongrass showed, as expected for a C4 plant, an enriched delta(13)C(V)-PDB value of -18.5 per thousand. In addition, the use of synthetic citral resulted in an enriched delta(2)H(V)-SMOW value of -43 per thousand, whereas with citral ex Litsea cubeba and ex lemongrass values of -242 and -232 per thousand, respectively, were recorded. IRMS analyses of 'natural' 2 revealed delta(13)C(V)-PDB and delta(2)H(V)-SMOW values that were nearly identical to that recorded for 'natural' 1. As to both 1 and 2, variations of synthesis conditions led to distinct changes in the delta(13)C(V)-PDB but not the delta(2)H(V)-SMOW values. Synthetic 3 showed delta(13)C(V)-PDB and delta(2)H(V)-SMOW values of -24.5 and -184 per thousand, respectively. These data differed from those found in raspberry fruit under study (n = 8), that is, ranging from -33.6 to -36.6 per thousand for delta(13)C(V)-PDB and from -200 to -225 per thousand for delta(2)H(V)-SMOW. The values determined additionally for 1 and 2 in raspberry fruit samples ranged from -30.3 to -35.1 per thousand and from -176 to -221 per thousand for delta(13)C(V)-PDB and delta(2)H(V)-SMOW, respectively, and thus corresponded to the already known literature information.

Topics: Butylated Hydroxytoluene; Fruit; Gas Chromatography-Mass Spectrometry; Norisoprenoids; Rosaceae; Taste

A new coupling system of GC-GC, connected via a Multi Column Switching Device MCS2 for measuring isotope ratios, is introduced. By means of several standard substances the precise and accurate measurement of isotopic values is proved. First applications concerning the authentication of raspberry aroma compounds are established. Consequently, the combination of constant flow multidimensional gas chromatography-combustion/pyrolysis-isotope ratio mass spectrometry (MDGC-C/P-IRMS) is applied to the authenticity assessment of (E)-alpha(beta)-ionone from six different raspberry cultivars. Furthermore, 12 commercially available raspberry products and samples of (E)-alpha(beta)-ionone, some declared to be natural, are investigated. delta(2)Eta(V)(-)(SMOW) and delta(13)C(V)(-)(PDB) values of (E)-alpha(beta)-ionone are determined, and characteristic authenticity ranges were concluded from raspberries by correlation of both delta(2)Eta(V)(-)(SMOW) and delta(13)C( V)(-)(PDB) values. The results are correlated with the determination of enantiomeric purities of (E)-alpha-ionone, using stir bar sorptive extraction enantio-multidimensional gas chromatography mass spectrometry (SBSE-enantio-MDGC-MS).

Topics: Food Analysis; Fruit; Gas Chromatography-Mass Spectrometry; Norisoprenoids; Rosaceae

The hydroxylation of alpha-ionone 1 and beta-ionone 2 to their corresponding mono-hydroxylated derivatives has been examined using a recombinant E. coli whole cell system, in which cytochromes P450 SU1 and SU2, and P450 SOY were over-expressed with their cognate ferrodoxins. Both substrates are hydroxylated with a high degree of regioselectivity and for alpha-ionone 1 the reaction is highly diastereoselective yielding the anti-isomer.

Topics: Actinobacteria; Biotransformation; Catalysis; Cytochrome P-450 Enzyme System; Hydroxylation; Norisoprenoids; Stereoisomerism

Diffusion-based NMR techniques were employed to study effects of pH on beta-lactoglobulin (BLG) conformation and binding affinity to alpha- and beta-ionone. In the first part of the study, the influence of pH on the diffusion coefficient of BLG in D(2)O solution was investigated using a stimulated-echo NMR experiment. The diffusion coefficient of BLG decreased with increasing pH values. A significant decrease in the diffusion coefficient observed at pH 11 may be due to total unfolding (denaturation) of the protein, resulting in hydrophobically driven self-aggregation. A diffusion-based NOE pumping technique was then applied to determine the relative binding affinities between alpha- and beta-ionones and BLG at pH values varying from 3 to 11. An increase in signal intensities for beta-ionone with increasing molar concentration ratios between beta-ionone and BLG was observed at all pH ranges studied. The increased signal intensities reflect increased relative binding affinity. The greatest binding affinity occurred at pH 9 and the lowest at pH 11. alpha-Ionone showed binding evidence only at pH 9, and the binding was significantly weaker than that obtained for beta-ionone at the same pH. The high affinity observed for both aroma compounds at pH 9 may be due to a flexible conformation of BLG at this pH so that the flavor ligand accessibility increases. Conversely, alkaline denaturation occurring at pH 11 gives rise to relatively lower binding affinity compared to that observed at the other pH values.

Topics: Diffusion; Hydrogen-Ion Concentration; Lactoglobulins; Magnetic Resonance Spectroscopy; Norisoprenoids; Protein Conformation; Terpenes

Beta-lonone has been reported to induce the cytochrome P450 (P450) 281 in rats. In this study, the effects of beta-ionone and an isomer, alpha-ionone, on liver P450 1A and 2B expression in Sprague Dawley rats were investigated. Subcutaneous administration of alpha- and beta-ionone 72 and 48 hr prior to sacrificing the animals induced the liver microsomal P450 1A and 2B proteins. P450 2B1 induction was associated with the accumulation of its corresponding mRNA. Induction by beta-ionone was much higher than that by a-ionone in both the mRNA and protein levels. When the route of administration was compared, P450 2B was induced more strongly after oral administration compared to that after subcutaneous injection. A single oral dose of 100, 300 and 600 mg/kg of alpha- and beta-ionone for 24 h induced P450 2B1-selective pentoxyresorufin O-depentylase activity comparably in a dose-dependent manner. In addition, alpha- and beta-ionone induced the P450 1A and 2B proteins. These results suggest that alpha- and beta-ionone might be potent P450 281 inducers in rats, and that both ionones may be useful for examining the role of metabolic activation in chemical-induced toxicity where metabolic activation is required.

Topics: Animals; Cytochrome P-450 CYP1A1; Cytochrome P-450 CYP2B1; Enzyme Induction; Male; Norisoprenoids; Rats; Rats, Sprague-Dawley; RNA, Messenger; Terpenes

Apparent binding constants of aroma compounds limonene, alpha- and beta-ionone, and terpenyl acetate, with beta-lactoglobulin (BLG), were determined, using dynamic coupled column liquid chromatography, for pH values varying from 3 to 11. K(a) values varied from 2.61 to 3.21 x 10(3) M(-1) for limonene, indicating a strong interaction with BLG. Similarly, significant and close apparent binding constants were obtained for alpha- and beta-ionone, 1.7 x 10(2) and 4.5 to 5.4 x 10(2) M(-1), respectively. These data indicated that a similar mechanism is involved for the binding of these two molecules. The weaker values obtained at low pH, for alpha-ionone relative to beta-ionone, can be explained by the existence of steric hindrance. An increase of the apparent binding constant was observed, for all the compounds studied, when the pH was increased from 3 to 9. At this pH, an apparent binding constant was obtained for terpenyl acetate (1.04 x 10(2) M(-1)), whereas this determination was not possible at pH 3 and 6. The apparent binding constant increase was in agreement with the decrease of aroma compound relative activity coefficient in the presence of BLG, previously observed at this pH. It indicated a best accessibility to the same binding site. The binding constants of all the aroma compounds studied decreased at pH 11 as a result of the important release of the BLG structure previously reported.

Topics: Chromatography, High Pressure Liquid; Chromatography, Liquid; Cyclohexenes; Hydrogen-Ion Concentration; Kinetics; Lactoglobulins; Limonene; Norisoprenoids; Odorants; Terpenes

Immobilized cells of Nicotiana tabacum reduced the carbon-carbon double bond adjacent to the carbonyl group and then the carbonyl group itself of the dienone compounds, alpha-ionone and beta-ionone. In addition, the selectivity for the reduction of the double bond adjacent to the carbonyl group could be enhanced by performing the biotransformation in medium with a pH near the optimal pH of the enone reductase which specifically catalyses the reduction of the alpha, beta-unsaturated double bond of s-trans-enones.

Topics: Biotransformation; Catalysis; Cells, Cultured; Chromatography, Gas; Chromatography, Thin Layer; Hydrogen-Ion Concentration; Magnetic Resonance Spectroscopy; Nicotiana; Norisoprenoids; Oxidation-Reduction; Plants, Toxic; Terpenes