- An engineered old yellow enzyme that enables efficient synthesis of (4R,6R)-actinol in a one-pot reduction system
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(4R,6R)-Actinol can be stereo-selectively synthesized from ketoisophorone by a two-step conversion using a mixture of two enzymes: Candida macedoniensis old yellow enzyme (CmOYE) and Corynebacterium aquaticum (6R)-levodione reductase. However, (4S)-phorenol, an intermediate, accumulates because of the limited substrate range of CmOYE. To address this issue, we solved crystal structures of CmOYE in the presence and absence of a substrate analogue p-HBA, and introduced point mutations into the substrate-recognition loop. The most effective mutant (P295G) showed two- and 12-fold higher catalytic activities toward ketoisophorone and (4S)-phorenol, respectively, than the wild-type, and improved the yield of the two-step conversion from 67.2 to 90.1%. Our results demonstrate that the substrate range of an enzyme can be changed by introducing mutation(s) into a substrate-recognition loop. This method can be applied to the development of other favorable OYEs with different substrate preferences.
- Horita, Shoichiro,Kataoka, Michihiko,Kitamura, Nahoko,Nakagawa, Takuya,Miyakawa, Takuya,Ohtsuka, Jun,Nagata, Koji,Shimizu, Sakayu,Tanokura, Masaru
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p. 440 - 445
(2015/03/05)
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- METHODS FOR SYNTHESIS OF CHIRAL INTERMEDIATES OF CAROTENOIDS, CAROTENOID ANALOGS, AND CAROTENOID DERIVATIVES
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A method used for synthesizing intermediates for use in the synthesis of carotenoids and carotenoid analogs, and/or carotenoid derivatives. In some embodiments, the invention includes methods for synthesizing optically active intermediates useful for the synthesis of optically active carotenoids.
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Page/Page column 40-41
(2010/10/20)
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- β-hydroxysulfoxides as chiral cyclic ketone equivalents: Enantioselective synthesis of polysubstituted cyclohexanones, cyclohexenones and cyclohexenediones
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The β-hydroxysulfoxide moiety, after oxidation to sulfone, acts as a masked carbonyl group in a cyclic system, opening an easy access to differently substituted enantiomerically pure cyclic ketones by means of aluminium-mediated conjugate additions, stereoselective reductions and elimination by retrocondensation in basic medium.
- Carreno, M. Carmen,Perez-Gonzalez, Manuel,Ribagorda, Maria,Somoza, Alvaro,Urbano, Antonio
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p. 3052 - 3053
(2007/10/03)
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- Synthesis of (R)- and (S)-4-hydroxyisophorone by ruthenium-catalyzed asymmetric transfer hydrogenation of ketoisophorone
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The first synthesis of (R)- and (S)-4-hydroxyisophorone by catalytic transfer hydrogenation of ketoisophorone is reported. Ruthenium catalysts containing commercially available chiral amino alcohols afforded 4-hydroxyisophorone in up to 97% selectivity an
- Hennig, Michael,Puentener, Kurt,Scalone, Michelangelo
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p. 1849 - 1858
(2007/10/03)
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- Hydrolase-catalyzed preparation of (R)- and (S)-4-hydroxy-2,6,6- trimethyl-2-cyclohexen-1-ones (phorenols), the key synthetic intermediates for abscisic acid
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Preparation of both the enantiomers of 4-hydroxy-2,6,6-trimethyl-2- cyclohexen-1-one (phorenol), which are versatile synthetic intermediates for abscisic acid and carotenoids, was achieved by hydrolase-catalyzed hydrolysis of the corresponding chloroaceta
- Kiyota, Hiromasa,Nakabayashi, Miho,Oritani, Takayuki
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p. 3811 - 3817
(2007/10/03)
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- Total synthesis of C31-methyl ketone apocarotenoids 3. On the structure of hopkinsiaxanthin: First total synthesis of (all-E)-(3S)- and (9Z)-(3S)-7′-apohopkinsiaxanthin
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Optically active (all-E)-(3S)-7′-apohopkinsiaxanthin, previously known as F1, and (9Z)-(3S)-7′-apohopkinsiaxanthin have been prepared by total synthesis for the first time in ca. 1% combined overall yield, including two unidentified geometrical isomers, in sixteen linear steps from (4R,6R)-actinol, (2E)-3-methyl-2-penten-4-yn-1-ol, (7-formyl-2-methyl-2,4,6-octatrienyl)triphenylphosphonium bromide, (3-formyl-2-butenyl)triphenylphosphonium bromide and methyllithium, by use of a C15+C10+C5+C1 approach. By an alternative route from (2Z)-5-[((4S)-4-hydroxy-2,6,6-trimethyl-3-oxo-1-cyclohexenyl)-3-methyl-2-penten- 4-ynyl]triphenylphosphonium bromide, (7-formyl-2-methyl-2,4,6-octatrienyl)triphenylphosphonium bromide and (2E)-3-methyl-4-oxo-2-pentenal, the same target compounds were obtained in a combined overall yield of >61%, including four unidentified geometrical isomers, over two steps, by use of a C15+C16 approach. A hypothetical structure for hopkinsiaxanthin is discussed, based on present and previously reported spectroscopic and chemical data for (all-E)-(3S)- and (9Z)-(3S)-7′-apohopkinsiaxanthin and on data previously reported for hopkinsiaxanthin itself. Acta Chemica Scandinavica 1997.
- Haugan, Jarle Andre,Lobkovsky, Emil,Liaaen-Jensen, Synnove
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p. 1201 - 1216
(2007/10/03)
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- The Synthesis of Optically Active Enriched (+)-(6R)-α-Ionone
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Starting with the readily available (-)-(S)-4-hydroxy-2,6,6-trimethylcyclohex-2-en-1-one (2) an optically active enriched sample of (+)-(6R)-α-ionone (1) (85percent enantiomeric excess) was synthesized.
- Pfander, Hanspeter,Semadeni, Pascal A.
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p. 145 - 151
(2007/10/02)
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- Microbial Conversion of 4-Oxoisophorone by Thermophile, Thermomonospora curvata
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Thermomonospora curvata IFO 12384 was selected from many thermophiles tested as a strain capable of converting 2,6,6-trimethyl-2-cyclohexene-1,4-dione (4-oxoisophorone) into (6R)-2,2,6-trimethyl-1,4-cyclohexadione ((3R)-dihydro-4-oxoisophorone) efficiently.The other conversion products were also isolated and identified by spectrometry.Based on the results of experiments with a degradation sequence, a conversion pathway for 4-oxoisophorone by this thermophile is proposed.The effects of nutritional conditions, temperature, initial pH and the concentration of the substrate on the conversion were examined.Under the optimal conditions, the conversion ratio of 4-oxoisophorone to (3R)-dihydro-4-oxoisophorone was over 95percent.The production rate of (3R)-dihydro-4-oxoisophorone was 86 mg per 1 g of dry cells per hr.
- Hori, Nobuaki,Hieda, Tadaharu,Mikami, Yoichi
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p. 123 - 130
(2007/10/02)
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- Technische Verfahren zur Synthese von Carotinoiden und verwandten Verbindungen aus Oxo-isophoron. I. Modifizierung der Kienzle-Mayer-Synthese von (3S,3'S)-Astaxanthin
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An efficient synthesis of (3S,3'S)-astaxanthin (1a) in high yield and optical purity starting from (4R,6R)-4-hydroxy-2,2,6-trimethylcyclohexanone (4) is reported.The absolute configuration of 1a, previously derived from ORD. data, has been confirmed by X-ray analysis of 5, a derivate of 6-oxo-isophorone (2).The key features of the improved synthesis are the two-step conversion of 4 to the key intermediate (4S)-2,6,6-trimethyl-4-hydroxy-2-cyclohexen-1-one (14), a new method for the partial reduction of the sterically hindered triple bond of (S)-6-hydroxy-3-(5-hydroxy-3-methyl-3-penten-1-ynyl)-2,4,4-trimethyl-2-cyclohexen-1-one (32), and Wittig olefination of the dialdehyde 1,6-dimethyl-1,3,5-octatrienedial (38) using phosphonium salt 37 with a free hydroxyl group.
- Widmer, Erich,Zell, Reinhard,Lukac, Teodor,Casadei, Marco,Schoenholzer, Peter,Broger, Emil A.
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p. 2405 - 2418
(2007/10/02)
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