3480-87-3Relevant academic research and scientific papers
Expanding the repertoire of nitrilases with broad substrate specificity and high substrate tolerance for biocatalytic applications
Rayavarapu, Pratima,Shah, Shikha,Sunder, Avinash Vellore,Wangikar, Pramod P.
, p. 289 - 296 (2020/05/18)
Enzymatic conversion of nitriles to carboxylic acids by nitrilases has gained significance in the green synthesis of several pharmaceutical precursors and fine chemicals. Although nitrilases from several sources have been characterized, there exists a scope for identifying broad spectrum nitrilases exhibiting higher substrate tolerance and better thermostability to develop industrially relevant biocatalytic processes. Through genome mining, we have identified nine novel nitrilase sequences from bacteria and evaluated their activity on a broad spectrum of 23 industrially relevant nitrile substrates. Nitrilases from Zobellia galactanivorans, Achromobacter insolitus and Cupriavidus necator were highly active on varying classes of nitriles and applied as whole cell biocatalysts in lab scale processes. Z. galactanivorans nitrilase could convert 4-cyanopyridine to achieve yields of 1.79 M isonicotinic acid within 3 h via fed-batch substrate addition. The nitrilase from A. insolitus could hydrolyze 630 mM iminodiacetonitrile at a fast rate, effecting 86 % conversion to iminodiacetic acid within 1 h. The arylaliphatic nitrilase from C. necator catalysed enantioselective hydrolysis of 740 mM mandelonitrile to (R)-mandelic acid in 4 h. Significantly high product yields suggest that these enzymes would be promising additions to the suite of nitrilases for upscale biocatalytic application.
Degradation of bisphenol A and acute toxicity reduction by different thermo-tolerant ascomycete strains isolated from arid soils
Mtibaà, Rim,Olicón-Hernández, Dario Rafael,Pozo, Clementina,Nasri, Moncef,Mechichi, Tahar,González, Jesus,Aranda, Elisabet
, p. 87 - 96 (2018/03/21)
Four different laccase-producing strains were isolated from arid soils and used for bisphenol A (BPA) degradation. These strains were identified as Chaetomium strumarium G5I, Thielavia arenaria CH9, Thielavia arenaria HJ22 and Thielavia arenaria SM1(III) by internal transcribed spacer 5.8 S rDNA analysis. Residual BPA was evaluated by HPLC analysis during 48 h of incubation. A complete removal of BPA was observed by the whole cell fungal cultures within different times, depending on each strain. C. strumarium G5I was the most efficient degrader, showing 100% of removal within 8 h of incubation. The degradation of BPA was accompanied by the production of laccase and dye decolorizing peroxidase (DyP) under degradation conditions. The presence of aminobenzotriazole (ABT) as an inhibitor of cytochrome P450s monooxygenases (CYP) demonstrated a slight decrease in BPA removal rate, suggesting the effective contribution of CYP in the conversion. The great involvement of laccase in BPA transformation together with cell-associated enzymes, such as CYP, was supported by the identification of hydroxylated metabolites by ultra-high performance liquid chromatography-mass spectroscopy (UHPLC-MS). The metabolic pathway of BPA transformation was proposed based on the detected metabolites. The acute toxicity of BPA and its products was investigated and showed a significant reduction, except for T. arenaria SM1(III) that did not caused reduction of toxicity (IC50 8%), possibly due to the presence of toxic metabolites. The results of the present study point out the potential application of the isolated ascomycetes in pollutant removal processes, especially C. strumarium G5I as an efficient degrader of BPA.
Homoserine lactone derivatives, preparation method thereof and pharmaceutical composition for prevention or treatment of the periodontal diseases containing the same as an active ingredient
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, (2017/04/14)
The present invention relates to homoserine lactone derivatives, optical isomers of the same, or pharmaceutically acceptable salts of the same. The homoserine lactone derivatives in the present invention have excellent properties as a quorum sensing antagonist which hinders communications among bacteria. According to the present invention, the homoserine lactone derivatives can hinder gene expressions of bacteria while effectively blocking formation of biofilm which is known to raise resistance against antibiotics, and suppress propagation of bacteria, thereby being useful as a pharmaceutical composition for preventing or treating periodontal diseases.
Ligand-Promoted, Boron-Mediated Chemoselective Carboxylic Acid Aldol Reaction
Nagai, Hideoki,Morita, Yuya,Shimizu, Yohei,Kanai, Motomu
supporting information, p. 2276 - 2279 (2016/06/01)
The first carboxylic acid selective aldol reaction mediated by boron compounds and a mild organic base (DBU) was developed. Inclusion of electron-withdrawing groups in the amino acid derivative ligands reacted with BH3·SMe2 forms a boron promoter with increased Lewis acidity at the boron atom and facilitated the carboxylic acid selective enolate formation, even in the presence of other carbonyl groups such as amides, esters, ketones, or aliphatic aldehydes. The remarkable ligand effect led to the broad substrate scope including biologically relevant compounds.
Evaluation of a new protocol for enzymatic dynamic kinetic resolution of 3-hydroxy-3-(aryl)propanoic acids
Koszelewski, Dominik,Zysk, Malgorzata,Brodzka, Anna,Zadlo, Anna,Paprocki, Daniel,Ostaszewski, Ryszard
, p. 11014 - 11020 (2015/11/24)
The application of tandem metal-enzyme dynamic kinetic resolution (DKR) is a powerful tool for the manufacture of high-value chemical commodities. A new protocol of kinetic resolution based on irreversible enzymatic esterification of carboxylic acids with orthoesters was introduced to obtain optically active β-hydroxy esters. This procedure was combined with metal catalyzed racemization of the target substrate providing both (R) and (S) enantiomers of ethyl 3-hydroxy-3-(4-nitrophenyl)propanoate with a high yield of 89% at 40°C. A substantial influence of the enzyme type, organic co-solvent, and metal catalyst on the conversion and enantioselectivity of the enzymatic dynamic kinetic resolution was noted.
A high throughput screening strategy for the assessment of nitrile-hydrolyzing activity towards the production of enantiopure β-hydroxy acids
Coady, Tracey M.,Coffey, Lee V.,O'Reilly, Catherine,Owens, Erica B.,Lennon, Claire M.
, p. 150 - 155 (2013/10/01)
Nitrile hydrolysing enzymes have found wide use in the pharmaceutical industry for the production of fine chemicals. This work presents a strategy that facilitates the rapid identification of bacterial isolates demonstrating nitrile hydrolysing activity. The strategy incorporates toxicity, starvation and induction studies along with subsequent colorimetric screening for activity, further focusing the assessment towards the substrates of interest. This high-throughput strategy uses a 96 well plate system, and has enabled the rapid biocatalytic screening of 256 novel bacterial isolates towards β-hydroxynitriles. Results demonstrate the strategy's potential to rapidly assess a variety of β-hydroxynitriles including aliphatic, aromatic and dinitriles. A whole cell catalyst Rhodococcus erythropolis SET1 was identified and found to catalyse the hydrolysis of 3-hydroxybutyronitrile with remarkably high enantioselectivity under mild conditions, to afford (S)-3-hydroxybutyric acid in 42% yield and >99.9% ee. The biocatalytic capability of this strain including the variation of parameters such as temperature and time were further investigated and all results indicate the presence of a highly enantioselective if not enantiospecific nitrilase enzyme within the microbial whole cell.
Synthesis and antitumour activity of β-hydroxyisovalerylshikonin analogues
Rao, Zhen,Liu, Xin,Zhou, Wen,Yi, Jing,Li, Shao-Shun
experimental part, p. 3934 - 3941 (2011/11/12)
A series of novel β-hydroxyisovalerylshikonin analogues bearing oxygen-containing substituents at the side-chain hydroxyl of shikonin were designed and synthesized. The cytotoxicities of these compounds were evaluated in vitro against multi-drug resistant (MDR) cell lines DU-145 and HeLa. Most compounds exhibited significant inhibitory activity on both cell lines. The structure-activity relationship showed the analogues with ether substituents displayed the most potent antitumour activity and selective cytotoxicity towards DU-145. Among the compounds with ether substituents, increasing the steric hindrance in the carbon bearing β-hydroxyl or replace the β-hydroxyl with acetoxy or methoxy would lead to the decline of cytotoxicity.
Acetic acid aldol reactions in the presence of trimethylsilyl trifluoromethanesulfonate
Downey, C. Wade,Johnson, Miles W.,Lawrence, Daniel H.,Fleisher, Alan S.,Tracy, Kathryn J.
supporting information; experimental part, p. 5351 - 5354 (2010/10/20)
(Figure presented) In the presence of TMSOTf and a trialkylamine base, acetic acid undergoes aldol addition to non-enolizable aldehydes under exceptionally mild conditions. Acidic workup yields the β-hydroxy carboxylic acid. The reaction appears to procee
Rhenium-catalyzed reaction of carbonyl compounds with ketene silyl acetals
Nishiyama, Yutaka,Kaiba, Kenta,Umeda, Rui
experimental part, p. 793 - 795 (2010/03/24)
It was found that rhenium complex is an effective catalyst for the reaction of carbonyl compounds with ketene silyl acetals. A wide range of β-silyloxy esters is obtained by the treatment of carbonyl compounds with ketene silyl acetals in the presence of
Highly anti-selective catalytic aldol reactions of amides with aldehydes
Saito, Susumu,Kobayashi, Shu
, p. 8704 - 8705 (2007/10/03)
Barium phenoxide-catalyzed, highly anti-selective direct-type aldol reactions of amides with aldehydes have been developed. In the presence of a slight excess amount of an amide, the desired reactions proceeded smoothly under mild conditions, and a wide r
