- Enantioselective hydrolysis of racemic and meso -epoxides with recombinant escherichia coli expressing epoxide hydrolase from Sphingomonas sp. HXN-200: Preparation of epoxides and vicinal diols in high ee and high concentration
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A unique epoxide hydrolase (SpEH) from Sphingomonas sp. HXN-200 was identified and cloned based on genome sequencing and expressed in Escherichia coli. The engineered E. coli (SpEH) showed the same selectivity and substrate specificity as the wild type strain and 172 times higher activity than Sphingomonas sp. HXN-200 for the hydrolysis of styrene oxide 1. Hydrolysis of racemic styrene oxide 1, substituted styrene oxides 3, 5-7, and N-phenoxycarbonyl-3,4-epoxypiperidine 8 (200-100 mM) with resting cells of E. coli (SpEH) gave (S)-epoxides 1, 3, 5-7 and (-)-8 in 98.0-99.5% enantiomeric excess (ee) and 37.6-46.5% yield. Hydrolysis of cyclopentene oxide 9, cyclohexene oxide 10, and N-benzyloxycarbonyl-3,4-epoxypyrrolidine 11 (100 mM) afforded the corresponding (R, R)-vicinal trans-diols 12-14 in 86-93% ee and 90-99% yield. The ee of (1R, 2R)-cyclohexane-1,2-diol 13 was improved to 99% by simple crystallization. These biotransformations showed high specific activity (0.28-4.3 U/mg cdw), product concentration, product/cells ratio, and cell-based productivity. Hydrolysis at even higher substrate concentration was also achieved: (S)-1 was obtained in 430 mM (51 g/Lorg) and 43% yield; (1R, 2R)-13 was obtained in 500 mM (58 g/L) and >99% yield. Gram-scale preparation of epoxides (S)-1, (S)-3, (S)-6 and diols (1R, 2R)-12, (1R, 2R)-13, (3R, 4R)-14 were also demonstrated. E. coli (SpEH) cells showed the highest enantioselectivity to produce (S)-1 (E of 39) among all known EHs in the form of whole cells or free enzymes and the highest enantioselectivities to produce (S)-3, 5, 6, 7, (-)-8, and (R, R)-14 (E of 36, 35, 28, 57, 22, and 28) among all known EHs. The easily available and highly active E. coli (SpEH) cells are the best biocatalysts known thus far for the practical preparation of these useful and valuable enantiopure epoxides and vicinal diols via hydrolysis.
- Wu, Shuke,Li, Aitao,Chin, Yit Siang,Li, Zhi
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p. 752 - 759
(2013/06/05)
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- Asymmetric trans-dihydroxylation of cyclic olefins by enzymatic or chemo-enzymatic sequential epoxidation and hydrolysis in one-pot
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Novel and efficient one-pot enzymatic and chemo-enzymatic synthetic methods are developed for the asymmetric trans-dihydroxylations of cyclic olefins 1a and 1bvia sequential epoxidation and hydrolysis. The Novozym 435 -mediated epoxidation of cyclohexene 1a and subsequent hydrolysis of the intermediate cyclohexene oxide 2a with resting cells of Sphingomonas sp. HXN-200 in one-pot gave (1R,2R)-cyclohexane diol 3a in 84% ee and 95% conversion. trans-Dihydroxylation of N-benzyloxycarbonyl 3-pyrroline 1b with the same enzymatic system gave the corresponding (3R,4R)-N- benzyloxycarbonyl-3,4-dihydroxy-pyrrolidine 3b in 93% ee and 94% conversion. In the one-pot chemo-enzymatic system, epoxidation of N-benzyloxycarbonyl 3-pyrroline 1b by m-CPBA and subsequent hydrolysis of epoxide intermediate 2b with resting cells of Sphingomonas sp. HXN-200 gave the trans-diol (3R,4R)-3b in 92% ee and 94-97% conversion. While the trans-dihydroxylation of cyclohexene 1a to (1R,2R)-cyclohexane diol 3a is reported for the first time, the trans-dihydroxylation of N-benzyloxycarbonyl 3-pyrroline 1b to (3R,4R)-3b with such an enzymatic or chemo-enzymatic system afforded a much higher product concentration than the same reaction with the system using a microorganism containing the two necessary enzymes. The developed one-pot enzymatic and chemo-enzymatic systems for the asymmetric trans-dihydroxylation of olefins are new, easy to prepare, adjust and operate, are high yielding, complementary to Sharpless asymmetric dihydroxylation and particularly useful for the asymmetric synthesis of cyclic trans-diols.
- Xu, Yi,Li, Aitao,Jia, Xin,Li, Zhi
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scheme or table
p. 2452 - 2458
(2011/10/13)
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- Biocatalytic preparation of chiral 3,4-dihydroxypyrrolidines
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Enzymatic acylations and alcoxycarbonylations of cis- and trans-3,4-dihydroxypyrrolidines and hydrolysis of their diacylated or dialcoxycarbonylated derivatives have been studied. High enantioselectivity is obtained using Candida antarctica lipase B as catalyst in the hydrolysis of the trans-diacetyl derivative, while for the desymmetrization of the cis-3,4-dihydroxypyrrolidines the best results are obtained in the acylation process catalyzed by C. antarctica lipase A.
- Rodríguez-Rodríguez, Jesús A.,Brieva, Rosario,Gotor, Vicente
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scheme or table
p. 6789 - 6796
(2010/10/03)
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- Fluoropyrrolidine amides as dipeptidyl peptidase IV inhibitors
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Amides derived from fluorinated pyrrolidines and 4-substituted cyclohexylglycine analogues have been prepared and evaluated as inhibitors of dipeptidyl dipeptidase IV (DP-IV). Analogues which incorporated (S)-3-fluoropyrrolidine showed good selectivity for DP-IV over quiescent cell proline dipeptidase (QPP). Compound 48 had good pharmacokinetic properties and was orally active in an oral glucose tolerance test in lean mice.
- Caldwell, Charles G.,Chen, Ping,He, Jiafang,Parmee, Emma R.,Leiting, Barbara,Marsilio, Frank,Patel, Reshma A.,Wu, Joseph K.,Eiermann, George J.,Petrov, Aleksandr,He, Huaibing,Lyons, Kathryn A.,Thornberry, Nancy A.,Weber, Ann E.
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p. 1265 - 1268
(2007/10/03)
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- Epoxide hydrolase-catalyzed enantioselective synthesis of chiral 1,2-diols via desymmetrization of meso-epoxides
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The discovery, from nature, of a diverse set of microbial epoxide hydrolases is reported. The utility of a library of epoxide hydrolases in the synthesis of chiral 1,2-diols via desymmetrization of a wide range of meso-epoxides, including cyclic as well as acyclic alkyl- and aryl-substituted substrates, is demonstrated. The chiral (R,R)-diols were furnished with high ee's and yields. The discovery of the first microbial epoxide hydrolases providing access to complementary (S,S)-diols is also described. Copyright
- Zhao, Lishan,Han, Bin,Huang, Zilin,Miller, Mark,Huang, Hongjun,Malashock, Dan S.,Zhu, Zuolin,Milan, Aileen,Robertson, Dan E.,Weiner, David P.,Burk, Mark J.
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p. 11156 - 11157
(2007/10/03)
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- Enantioselective Trans Dihydroxylation of Nonactivated C-C Double Bonds of Aliphatic Heterocycles with Sphingomonas sp. HXN-200
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The bacterial strain Sphingomonas sp. HXN-200 was used to catalyze the trans dihydroxylation of N-substituted 1,2,5,6-tetrahydropyridines 1 and 3-pyrrolines 4 giving the corresponding 3,4-dihydroxypiperidines 3 and 3,4-dihydroxypyrrolidines 6, respectivel
- Chang, Dongliang,Heringa, Maarten F.,Witholt, Bernard,Li, Zhi
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p. 8599 - 8606
(2007/10/03)
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- Highly enantioselective hydrolysis of alicyclic meso-epoxides with a bacterial epoxide hydrolase from Sphingomonas sp. HXN-200: Simple syntheses of alicyclic vicinal trans-diols
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Hydrolysis of N-benzyloxycarbonyl-3,4-epoxy-pyrrolidine and cyclohexene oxide with the epoxide hydrolase of Sphingomonas sp. HXN-200, respectively, gave the corresponding vicinal trans-diols in high ee and yield, representing the first example of enantioselective hydrolysis of a meso-epoxide with a bacterial epoxide hydrolase.
- Chang, Dongliang,Wang, Zunsheng,Heringa, Maarten F.,Wirthner, Renato,Witholt, Bernard,Li, Zhi
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p. 960 - 961
(2007/10/03)
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- Synthesis of biologically active sialyl Lewis X mimetics
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The design and synthesis of two sialyl Lewis X (SLe(x)) mimetics are described. In the design of mimetic 1, an ethylene glycol linkage is used to bridge the fucose and galactose moiety, and a carboxymethyl group is placed in the 3-OH position of the galactose residue to provide the negative charge which is believed to be essential for binding to (E)-selectin. In the design of mimetic 2, a D-tartaric acid derivative is used to provide the trans-dihydroxyl groups originally from the glucosamine moiety for the linkage of the fucose and the carboxypentyl groups. At a concentration of 1.5 mM, 1 inhibits 50% of the binding of SLe(x) glycoconjugate to immobilized recombinant (E)-selectin, while 2 has an IC50 of 10 mM. Mimetic 1 is also found to be stable toward α-L-fucosidase. Results from the ROESY and COSY experiments indicate that compound 1 is conformationally flexible, which may explain its relatively weak activity compared to SLe(x) (IC50 = 0.8 mM).
- Huang,Wong
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p. 3100 - 3106
(2007/10/02)
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