Screening, substrate specificity and stereoselectivity of yeast strains, which reduce sterically hindered isopropyl ketones

Hiraoka, Chihiro; Matsuda, Masaaki; Suzuki, Yuya; Fujieda, Shigeo; Tomita, Mina; Fuhshuku, Ken‐ichi; Obata, Rika; Nishiyama, Shigeru; Sugai, Takeshi

doi:10.1016/j.tetasy.2006.12.013

Cited by 22 publications

(3 citation statements)

References 34 publications

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“…Later, Matori et al (1991) [4] determined the positional specificity of more than 30 microbial lipases with the position specificity parameter (PSI), which provide us with a good tool to determine the specificities of lipases. Over the past decades, the substrate specificities of lipases have not only been studied in detail in aqueous media [5][6][7][8], but also in organic solvents [9][10][11][12][13]. Recently, Mateos et al [14] gave the map of substrate selectivity of lipases from thermophilic fungi, which gives us more useful knowledge about the specificities of lipases.…”

Section: Introductionmentioning

confidence: 99%

Studies of substrate specificities of lipases from different sources

Song

Hao

et al. 2008

Euro J Lipid Sci & Tech

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Although lipases are widely applied in a wide variety of reactions, available information on the factors that are responsible for the substrate specificities of lipases from different sources is scarce. In this paper, nine lipase-producing microorganism strains were isolated from oil-containing samples. The properties of these enzymes, including pH optima, temperature optima, thermal stability, and pH stability, vary significantly with the different sources from which these lipases were isolated. The substrate specificities of the nine lipases, including fatty acid and positional specificities, were also studied. The fatty acid specificities of the nine lipases were observably different toward 15 substrates with different carbon chain lengths, different saturation degrees and different side chains. The lipases from S 3 Penicillium citrinum (PCL), MJ 1 Aspergillus niger (ANL), MJ 2 Aspergillus oryzae (AOL), YM Bacillus coughing (BCL), S 9 Geotrichum candidum (GCL), and S 11 Candida lypolytica (CLL) showed the strongest specificities to short-chain esters, and the other lipases showed strong selectivity for medium-or long-chain and branched esters. The positional specificities were examined by analyzing the hydrolytic products of triolein catalyzed by the nine lipases, using TLC. The lipases can be mainly classified into two groups by their specificities for the ester bond at position 2 of triglycerides; one group can selectively hydrolyze the ester bond at position 2 of the triglycerides, the other group cannot. All these nine lipases were divided into four groups by hierarchical clustering analysis on the basis of the results of fatty acid and positional specificities.

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Section: Introductionmentioning

confidence: 99%

Studies of substrate specificities of lipases from different sources

Song

Hao

et al. 2008

Euro J Lipid Sci & Tech

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“…Their 0.45-mol scale reaction took 3 days in a flow reactor without tri(pyrrolidin-1-yl)phosphine oxide ( 13 ). The Sugai group treated arenes with lithium and ethylenediamine in tetrahydrofuran (THF) or Et 2 O but did not isolate 1,4-cyclohexadiene products ( 25 , 26 ) and indicated that THF might be a ligand for a lithium ion ( 25 ).…”

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confidence: 99%

Scalable Birch reduction with lithium and ethylenediamine in tetrahydrofuran

Burrows

Kamo

Koide

2021

Science

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Easy aryl reductions The Birch reduction has been widely used for more than half a century to achieve partial reduction of aryl rings by alkali metals at just two diametrically opposed carbon sites. However, the conditions require condensation of caustic gaseous ammonia. A variation developed soon afterward by Benkeser used safer liquid ethylene diamine but was prone to overreduction. By diluting ethylene diamine in tetrahydrofuran solvent, Burrows et al . now obtain selectivities comparable to Birch conditions but without the need for condensed ammonia. —JSY

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“…We applied set of incubated microorganisms involving yeasts and fungi, which had been used for the reduction of ketone 6 with an aromatic ring [21] (Scheme 3). In our hand, out of six strains which showed a certain progress of the reduction, two exhibited the desired enantiofacial selectivity as shown in Table 1.…”

Section: Resultsmentioning

confidence: 99%