10326-41-7Relevant articles and documents
Bridging racemic lactate esters with stereoselective polylactic acid using commercial lipase catalysis
Van Wouwe, Pieter,Dusselier, Michiel,Basic, Aurelie,Sels, Bert F.
, p. 2817 - 2824 (2013)
A productive and enantioselective hydrolysis of racemic mixtures of lactate esters with commercial Candida rugosa lipase was performed. This step contributes to a novel envisioned route for stereoselective PLA production by combining recent chemocatalytic developments with this biocatalytic contribution, foreseeing two separate l- and d-lactate enantiomer streams. A study of the hydrolysis kinetics identified an unexpected rate determining step at the origin of an unprecedented ester reactivity order.
Structures, chemotaxonomic significance, cytotoxic and Na+,K+-ATPase inhibitory activities of new cardenolides from Asclepias curassavica
Zhang, Rong-Rong,Tian, Hai-Yan,Tan, Ya-Fang,Chung, Tse-Yu,Sun, Xiao-Hui,Xia, Xue,Ye, Wen-Cai,Middleton, David A.,Fedosova, Natalya,Esmann, Mikael,Tzen, Jason T. C.,Jiang, Ren-Wang
, p. 8919 - 8929 (2014)
Five new cardenolide lactates (1-5) and one new dioxane double linked cardenolide glycoside (17) along with 15 known compounds (6-16 and 18-21) were isolated from the ornamental milkweed Asclepias curassavica. Their structures were elucidated by extensive spectroscopic methods (IR, UV, MS, 1D- and 2D-NMR). The molecular structures and absolute configurations of 1-3 and 17 were further confirmed by single-crystal X-ray diffraction analysis. Simultaneous isolation of dioxane double linked cardenolide glycosides (17-21) and cardenolide lactates (1-5) provided unique chemotaxonomic markers for this genus. Compounds 1-21 were evaluated for the inhibitory activities against DU145 prostate cancer cells. The dioxane double linked cardenolide glycosides showed the most potent cytotoxic effect followed by normal cardenolides and cardenolide lactates, while the C21 steroids were non-cytotoxic. Enzymatic assay established a correlation between the cytotoxic effects in DU145 cancer cells and the Ki for the inhibition of Na+,K+-ATPase. Molecular docking analysis revealed relatively strong H-bond interactions between the bottom of the binding cavity and compounds 18 or 20, and explained why the dioxane double linked cardenolide glycosides possessed higher inhibitory potency on Na+,K+-ATPase than the cardenolide lactate. This journal is
Use of wastewater sludge as a raw material for production of L-lactic acid
Nakasaki, Kiyohiko,Akakura, Naoki,Adachi, Tomohiko,Akiyama, Tetsuo
, p. 198 - 200 (1999)
This study utilizes wastewater sludges to produce L-lactic acid, a precursor of biodegradable plastic. The high concentrations of cellulose contained in the sludge, derived from a paper manufacturing facility, have been found to be convertible to L-lactic acid at a rate as high as 6.91 g/L. To achieve such a high conversion rate, the sludge must be pretreated with cellulase. This pretreatment includes inoculation of the sludge with lactic acid bacteria, strain LA1, after the sludge has been subjected to enzymatic hydrolysis. This study utilizes wastewater sludges to produce L-lactic acid, a precursor of biodegradable plastic. The high concentrations of cellulose contained in the sludge, derived from a paper manufacturing facility, have been found to be convertible to L-lactic acid at a rate as high as 6.91 g/L. To achieve such a high conversion rate, the sludge must be pretreated with cellulase. This pretreatment includes inoculation of the sludge with lactic acid bacteria, strain LA1, after the sludge has been subjected to enzymatic hydrolysis.
Site-Specific, covalent immobilization of dehalogenase ST2570 catalyzed by formylglycine-generating enzymes and its application in batch and semi-continuous flow reactors
Jian, Hui,Wang, Yingwu,Bai, Yan,Li, Rong,Gao, Renjun
, (2016)
Formylglycine-generating enzymes can selectively recognize and oxidize cysteine residues within the sulfatase sub motif at the terminus of proteins to form aldehyde-bearing formylglycine (FGly) residues, and are normally used in protein labeling. In this study, an aldehyde tag was introduced to proteins using formylglycine-generating enzymes encoded by a reconstructed set of the pET28a plasmid system for enzyme immobilization. The haloacid dehalogenase ST2570 from Sulfolobus tokodaii was used as a model enzyme. The C-terminal aldehyde-tagged ST2570 (ST2570CQ) exhibited significant enzymological properties, such as new free aldehyde groups, a high level of protein expression and improved enzyme activity. SBA-15 has widely been used as an immobilization support for its large surface and excellent thermal and chemical stability. It was functionalized with amino groups by aminopropyltriethoxysilane. The C-terminal aldehyde-tagged ST2570 was immobilized to SBA-15 by covalent binding. The site-specific immobilization of ST2570 avoided the chemical denaturation that occurs in general covalent immobilization and resulted in better fastening compared to physical adsorption. The site-specific immobilized ST2570 showed 3-fold higher thermal stability, 1.2-fold higher catalytic ability and improved operational stability than free ST2570. The site-specific immobilized ST2570 retained 60% of its original activity after seven cycles of batch operation, and it was superior to the ST2570 immobilized to SBA-15 by physical adsorption, which loses 40% of its original activity when used for the second time. It is remarkable that the site-specific immobilized ST2570 still retained 100% of its original activity after 10 cycles of reuse in the semi-continuous flow reactor. Overall, these results provide support for the industrial-scale production and application of site-specific, covalently immobilized ST2570.
Development of a Novel Biocatalyst for the Resolution of rac-Pantolactone
Kesseler, Maria,Friedrich, Thomas,Hoeffken, Hans Wolfgang,Hauer, Bernhard
, p. 1103 - 1110 (2002)
A novel L-pantolactone hydrolase, Lph, from Agrobacterium tumefaciens Lu681 was characterized, which stereospecifically hydrolyses L-pantolactone to L-pantoic acid yielding D-pantolactone with > 95% enantiomeric excess. The enzyme was found to be a 30 kDa-Zn2+-hydrolase with a Km for L-pantolactone of 7 mM and a Vmax of 30 U/mg. The corresponding lph gene was identified as an 807 bp ORF and cloned into E. coli. It was overexpressed under control of Ptac and Prha yielding enzyme activities of up to 600 U/g dry weight. Resolution of D,L-pantolactone in repeated batches with isolated Lph and enzyme recovery by membrane filtration gave D-pantolactone with 50% yield and 90-95% ee over 6 days. Covalent immobilization to EupergitC led to a stable biocatalyst easy to handle in a repeated batch production of D-pantolactone. Further improvements in the activity of Lph were achieved by directed evolution of the enzyme. Activities of mutants F62S, K197D and F100L were increased 2.3, 1.7, and 1.5 fold, respectively.
Novel urushiols with human immunodeficiency virus type 1 reverse transcriptase inhibitory activity from the leaves of Rhus verniciflua
Kadokura, Kazunari,Suruga, Kohei,Tomita, Tsuyoshi,Hiruma, Wataru,Yamada, Motoyuki,Kobayashi, Akio,Takatsuki, Akira,Nishio, Toshiyuki,Oku, Tadatake,Sekino, Yoshihiro
, p. 148 - 153 (2014)
Two novel urushiols, 1 and 2, and two known urushiols, 3 and 4, were isolated from the leaves of Rhus verniciflua and were examined for their human immunodeficiency virus type 1 (HIV-1) reverse transcriptase (RT) inhibitory activity. The novel urushiols were found to be 1,2-dihydroxyphenyl-3-[7(E),9(Z),11(Z)-pentadecatrienyl]-14-ol (1) and 1,2-dihydroxyphenyl-3-[8(Z),10(E),12(E)-pentadecatrienyl]-14-ol (2) by spectroscopic analyses. The absolute configuration at C-14 in 1 and 2 was determined to be a racemic mixture of (R) and (S) isomers by ozonolysis. Compound 2 (IC50: 12.6 μM) showed the highest HIV-1 RT inhibitory activity among the four urushiols, being 2.5-fold more potent than the positive control, adriamycin (IC50: 31.9 μM). Although the known urushiols were isolated from the sap and leaves of R. verniciflua, 1 was exclusively present in the leaves, and higher amounts of 2 were found in the leaves than in the sap. Present findings indicate that the leaves of R. verniciflua represent a new biological resource from which novel and known urushiols may be prepared, and the possible use of novel urushiols as bioactive products.
Asymmetric hydrolysis of 2-hydroxy-carboxylic esters using recombinant Escherichia coli
Nakagawa, Atsushi,Kato, Ko,Shinmyo, Atsuhiko,Suzuki, Toshio
, p. 2394 - 2398 (2007)
Optically active 2-hydroxy-carboxylates are important compounds for their use as intermediates in the synthesis of pharmaceuticals and stereoblock polymers. Enterobacter sp. DS-S-75 and the recombinant Escherichia coli harbouring the 4-chloro-3-hydroxybutyrate (CHB) hydrolase gene from the strain DS-S-75 showed asymmetric hydrolytic activity towards 2-hydroxy-carboxylates, as well as towards CHB. It was discussed that the hydroxyl group in the substrate was particularly important for the asymmetric hydrolytic activity of the CHB hydrolase, and as such, it was re-designated to EnHCH (hydroxy-carboxylic ester hydrolase derived from Enterobacter sp.). Using the recombinant cell, both the reaction rate and the concentration of the substrates were significantly improved upon when compared to that of DS-S-75. Optically active 2-hydroxy-carboxylates could be synthesized on a practical basis for industrial production in this report.
Glyoxalase; the role of the components.
CROOK,LAW
, p. 492 - 499 (1952)
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Au/Pt/TiO2 catalysts prepared by redox method for the chemoselective 1,2-propanediol oxidation to lactic acid and an NMR spectroscopy approach for analyzing the product mixture
Redina, Elena,Greish, Alexander,Novikov, Roman,Strelkova, Anastasiya,Kirichenko, Olga,Tkachenko, Olga,Kapustin, Gennady,Sinev, Ilya,Kustov, Leonid
, p. 170 - 183 (2015)
1,2-propanediol obtained from the waste glycerol is the most prominent substrate to produce lactic acid (LA) through the sustainable green catalytic oxidative route. We showed that bimetallic Au/Pt/TiO2 catalysts that could be easily prepared by the redox reaction with preadsorbed hydrogen possessed a high activity in the formation of lactic acid from 1,2-propanediol through selective primary hydroxyl group oxidation by an oxygen-air mixture or an air. The most efficient catalyst with the highest TON value was the sample with the lowest Au content. Even the addition of 0.025 wt.% of gold to the 1%Pt/TiO2 catalyst by the redox method resulted in the enhanced 1,2-propanediol conversion up to 96% with the 91% selectivity to LA. The high oxidation activity of the Au/Pt/TiO2 catalysts was ascribed to the strong interaction between the two metals in Au/Pt bimetallic particles and between the bimetallic particles and the support, which was proved by X-ray photoelectron spectroscopy (XPS) analysis, Fourier transform infrared spectroscopy of adsorbed CO (DRIFTS) technique, and temperature programmed reduction method (TPR-H2). The reaction products were identified and analyzed with the use of 1D and 2D nuclear magnetic resonance spectroscopy (NMR) methods, which also allowed suggesting a plausible up-to-date scheme of 1,2-propanediol catalytic oxidation.
Pan,Petersen,Johnson
, p. 709 (1940)
From lignocellulosic biomass to lactic- and glycolic-acid oligomers: A gram-scale microwave-assisted protocol
Carnaroglio, Diego,Tabasso, Silvia,Kwasek, Beata,Bogdal, Dariusz,Gaudino, Emanuela Calcio,Cravotto, Giancarlo
, p. 1342 - 1349 (2015)
The conversion of lignocellulosic biomass into platform chemicals is the key step in the valorization of agricultural waste. Of the biomass-derived platform chemicals currently produced, lactic acid plays a particularly pivotal role in modern biorefineries as it is a versatile commodity chemical and building block for the synthesis of biodegradable polymers. Microwave-assisted processes that furnish lactic acid avoid harsh depolymerization conditions while cutting down reaction time and energy consumption. We herein report a flash catalytic conversion (2 min) of lignocellulosic biomass into lactic and glycolic acids under microwave irradiation. The batch procedure was successfully adapted to a microwave-assisted flow process (35 mL min-1), with the aim of designing a scalable process with higher productivity. The C2 and C4 units recovered from the depolymerization were directly used as the starting material for a solvent and catalyst-free microwave-assisted polycondensation that afforded oligomers in good yields.
Maclay et al.
, p. 1660,1663 (1939)
Valeur
, (1921)
Promoting effect of solvent on Cu/CoO catalyst for selective glycerol oxidation under alkaline conditions
Dodekatos, Georgios,Ternieden, Jan,Schünemann, Stefan,Weidenthaler, Claudia,Tüysüz, Harun
, p. 4891 - 4899 (2018)
Cu/CoO catalysts were employed for the selective oxidation of glycerol in the aqueous phase under basic conditions. The effect of the solvent on the catalytic performance was investigated and the impact on the catalyst was thoroughly elucidated. Detailed characterization of the catalysts by HR-TEM, XRD, and XPS analysis before and after the reaction revealed that the addition of co-solvents (ethanol, n-propanol, or tert-butanol) drastically altered the catalyst properties. In particular, the amount of the catalytically active CoO(OH) phase generated during the reaction depends on the co-solvent used. Generally, the co-solvent has a beneficial effect on the catalytic activity and improves the glycerol conversion by a factor of up to 1.8, which could be linearly correlated to the ET(30) solvent polarity.
Creation of an enantioselective hydrolase by engineered substrate-assisted catalysis [10]
Magnusson,Hult,Holmquist
, p. 4354 - 4355 (2001)
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Chiron approach towards optically pure γ-valerolactone from alanine
Datrika, Rajender,Kallam, Srinivasa Reddy,Katta, Rambabu,Siddaiah, Vidavalur,Pratap
, p. 2801 - 2808 (2018)
A concise synthesis of both enantiomers of γ-valerolactone has been developed from commercially available Alanine. The key steps in the synthesis of these γ-Lactones are DIBAL-H reduction of ester (9) followed by in situ Wittig reaction with EtO2CCH = PPh3 ylide (13) (Z/E = 1: 3.5) and one pot lactonization triggered by deprotection of O-TBS ether (14).
Linfuranones B and C, Furanone-Containing Polyketides from a Plant-Associated Sphaerimonospora mesophila
Akiyama, Hirofumi,Indananda, Chantra,Thamchaipenet, Arinthip,Motojima, Atsuko,Oikawa, Tsutomu,Komaki, Hisayuki,Hosoyama, Akira,Kimura, Akane,Oku, Naoya,Igarashi, Yasuhiro
, p. 1561 - 1569 (2018)
Two new furanone-containing polyketides, linfuranones B and C, were isolated from a plant-associated actinomycete of the genus Sphaerimonospora. Their structures were determined by NMR and MS spectroscopic analyses, and the absolute configurations were established by anisotropic methods and chemical degradation approaches. In silico analysis of biosynthetic genes suggested that linfuranone B is generated from linfuranone C by oxidative cleavage of the polyketide chain. Linfuranones B and C induced preadipocyte differentiation into matured adipocytes at 20-40 μM without showing cytotoxicity.
Hayashi et al.
, p. 4351 (1976)
Coenzyme B12-dependent glycerol dehydratase deficiency in Klebsiella pneumoniae
Zheng, Zong-Ming,Wang, Ti-Peng,Xu, Yun-Zhen,Liu, De-Hua
, p. 7323 - 7326 (2013)
The physiology and fermentation properties of coenzyme B12-dependent glycerol dehydratase deficient mutant Klebsiella pneumoniae B1.9131 were investigated. Compared with that of wild type strain, glycerol dehydratase activity decreased by 80 %. Activities of dha regulon coded two enzymes are influenced by inactivation of GDHt. 1,3-Propanediol oxidoreductase activity decreased by 62 % while glycerol dehydrogenase activity increased by 36 %. Fed-batch fermentation showed that more of the metabolic flux of glycerol was directed to lactate and ethanol in the mutant. Instead, lactate other than 1,3-propanediol was the main product and its final concentration increased from 41 to 76 g L-1 with mutant isolate. The concentration of 1,3-propanediol decreased from 91 to 40 g L-1. The results demonstrate that GDHt is not indispensable in glycerol metabolism but is crucial for the efficient synthesis of 1,3-propanediol.
Nicotinamide adenine dinucleotide analog, and synthesis method and application thereof
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Paragraph 0106-0110, (2019/07/04)
The invention discloses a nicotinamide adenine dinucleotide (NAD) analogue, and a synthesis method and an application thereof. The structural formula of the NAD analogue is shown in the description; and in the formula, a carboxyl group is used as 1-position carbon, the spatial configuration of the chiral center of the 2-position carbon atom of the analog is S, the substituent R is a C1-C5 alkyl group or an alkyl group formed by substituting H in the C1-C5 alkyl group with one of -OH, -COOH, -CONH2, -SCH3 and other six groups shown in the description, and the substitution group is a carbon atom at the end or the secondary end. The NAD analogue is synthesized from 1-(2',4'-dinitrophenyl)-3-carbamoylpyridine and L-alpha-amino acid under the catalysis of an alkali; and the NAD analog can be used as NAD(P)-dependent oxidoreductase coenzyme. The method has the advantages of mild reaction conditions during synthesis of the NAD analogue, and simple and easily available raw materials, and allows the reaction product to completely reserve the stereostructure of the raw material L-alpha-amino acid without racemization. The NAD analog obtained in the present invention can beused in biocatalysis, bioanalytical chemistry, metabolic engineering and synthetic biology researches.
Functional Models of the Nickel Pincer Nucleotide Cofactor of Lactate Racemase
Shi, Renyi,Wodrich, Matthew D.,Pan, Hui-Jie,Tirani, Farzaneh Fadaei,Hu, Xile
supporting information, p. 16869 - 16872 (2019/11/13)
A novel nickel pincer cofactor was recently discovered in lactate racemase. Reported here are three synthetic nickel pincer complexes that are both structural and functional models of the pincer cofactor in lactate racemase. DFT computations suggest the ipso-carbon atom of the pyridinium pincer ligands act as a hydride acceptor for lactate isomerization, whereas an organometallic pathway involving nickel-mediated β-hydride elimination is less favored.
