scholarly journals Efficient Synthesis of New Fluorinated β-Amino Acid Enantiomers through Lipase-Catalyzed Hydrolysis

Molecules ◽  
2020 ◽  
Vol 25 (24) ◽  
pp. 5990
Author(s):  
Sayeh Shahmohammadi ◽  
Ferenc Fülöp ◽  
Enikő Forró

An efficient and novel enzymatic method has been developed for the synthesis of β-fluorophenyl-substituted β-amino acid enantiomers through lipase PSIM (Burkholderia cepasia) catalyzed hydrolysis of racemic β-amino carboxylic ester hydrochloride salts 3a–e in iPr2O at 45 °C in the presence of Et3N and H2O. Adequate analytical methods were developed for the enantio-separation of racemic β-amino carboxylic ester hydrochlorides 3a–e and β-amino acids 2a–e. Preparative-scale resolutions furnished unreacted amino esters (R)-4a–e and product amino acids (S)-5a–e with excellent ee values (≥99%) and good chemical yields (>48%).

2008 ◽  
Vol 19 (17) ◽  
pp. 2072-2077 ◽  
Author(s):  
Gábor Tasnádi ◽  
Enikő Forró ◽  
Ferenc Fülöp

2011 ◽  
Vol 47 (2) ◽  
pp. 193-201
Author(s):  
N. E. Borisova ◽  
F. E. Zhurkin ◽  
T. G. Gulevich ◽  
K. K. Babievskii ◽  
M. D. Reshetova ◽  
...  

2007 ◽  
Vol 73 (16) ◽  
pp. 5370-5373 ◽  
Author(s):  
Shigenori Yamaguchi ◽  
Hidenobu Komeda ◽  
Yasuhisa Asano

ABSTRACT d- and l-amino acids were produced from l- and d-amino acid amides by d-aminopeptidase from Ochrobactrum anthropi C1-38 and l-amino acid amidase from Pseudomonas azotoformans IAM 1603, respectively, in the presence of α-amino-ε-caprolactam racemase from Achromobacter obae as the catalyst by dynamic kinetic resolution of amino acid amides.


1956 ◽  
Vol 104 (2) ◽  
pp. 183-191 ◽  
Author(s):  
Kenneth E. Lentz ◽  
Leonard T. Skeggs ◽  
Kenneth R. Woods ◽  
Joseph R. Kahn ◽  
Norman P. Shumway

Preparations of hypertensin II, obtained from the treatment of hypertensin I by the action of the hypertensin converting enzyme of plasma and purified by countercurrent distribution, were quantitatively analyzed for their amino acid content. Chromatography on ion exchange columns showed the presence of equimolar amounts of aspartic acid, proline, valine, isoleucine, tyrosine, phenylalanine, histidine, and arginine. Hypertensin I was found to contain one mole of leucine and one mole of histidine in addition to the amino acids of hypertensin II. These two amino acids were isolated from the conversion products of hypertensin I and identified as the peptide histidylleucine. Carboxypeptidase digestion of hypertensin I showed the carboxyl terminal sequence of amino acids to be residue-phenylalanyl-histidylleucine. Similar studies of hypertensin II demonstrated residue-phenylalanine. It was concluded that the conversion of hypertensin I by the plasma hypertensin converting enzyme involved hydrolysis of the phenylalanyl-histidine bond to form hypertensin II and histidylleucine. The further removal by carboxypeptidase of phenylalanine from hypertensin II destroyed all of the vasoconstrictor activity.


Some time ago, two of the authors of the present communication, in seeking a method for the separation of the amino-acids from the carbohydrates, found that under certain conditions the former could be readily separated in the form of the barium salts of their carbamates, a class of compounds originally described by Siegfried. As these carbamates, on heating with water, are readily decomposed into barium carbonate and the free amino-acid, it was suggested that a convenient method might be evolved, using the formation of these compounds as a basis, for the separation of the hydrolysis products of the proteins.* This suggestion was followed up, and a method was subsequently elaborated and applied to the separation of the hydrolysis products of gelatin by one of the authors in conjunction with Miss H. L. Kingston. Since the publication of the two papers just quoted, the researches on the use of the “carbamate method,” as it may be conveniently called, have been continued, and promise results, which may ultimately lead to a satisfactory separation of most of the hydrolysis products of the proteins when only relatively small amounts of material are available for investigation. During the course of this work the base, which is the chief subject discussed in this paper, was discovered.


Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 1704-1704
Author(s):  
Kenneth W. Jackson ◽  
Victoria J. Christiansen ◽  
Kyung N. Lee ◽  
Christina F. Mason ◽  
Patrick A. McKee

Abstract Antiplasmin cleaving enzyme (APCE) is a proteinase that specifically, but slowly cleaves the Pro-Asn bond in long-form α2-antiplasmin (Met-α2AP) in human plasma. This slow cleavage produces a steady-state plasma mixture of Met-α2AP and an N-terminally shortened form of antiplasmin, Asn-α2AP. The Asn-α2AP form crosslinks to fibrin ~13-fold faster than Met-α2AP. A faster crosslink rate causes a greater number of antiplasmin molecules to become bound during fibrin formation, thereby enhancing resistance to fibrinolysis. Inhibition of plasma APCE may decrease the number of antiplasmin molecules crosslinked and result in clots that are more easily removed during fibrinolysis. Therefore, an inhibitor specific for APCE could potentially be used to regulate fibrinolysis. Human Met-α2AP exists in two polymorphic forms at position six in the mature sequence, with arginine predominant, and tryptophan accounting for a lesser percentage. We have determined the relative cleavage rates of synthetic peptides from a peptide library that span the cleavage site. The peptides contained all common amino acids except cysteine in the polymorphic position (P7 position). Arg was the optimal amino acid in this position with a relative cleavage rate ~5–10-fold faster than other amino acids except Lys, which was ~70% of the Arg rate. The P7 position Arg enhancement was also observed when Arg was in the P6 or P5 position, but no enhancement was observed when Arg was moved to positions P8, P4, P3 or P2. It was also determined that APCE is preferentially an endoproteinase rather than an aminodipeptidase, with a 10-fold greater rate of hydrolysis of the internal Pro-Asn bond in the Met-α2AP 1–17 peptide sequence MEPLGRQLTSGP-NQEQV over the Pro-Asn bond penultimate to the amino-terminal bond in the Met-α2AP 11–27 peptide sequence GP-NQEQVSPLTLLKLGN in peptide hydrolysis experiments. We conclude that APCE inhibitors designed with a positive charge placed upstream of the Pro-X scissile bond equivalent to five to seven amino acid residues may prove to be highly potent and specific. In addition, such inhibitors should also prove useful for blocking the activity of the closely related enzyme fibroblast activation protein. This work was supported by NIH grant HL072995.


2004 ◽  
Vol 380 (1) ◽  
pp. 211-218 ◽  
Author(s):  
Chi-Wah TSEUNG ◽  
Laura G. McMAHON ◽  
Jorge VÁZQUEZ ◽  
Jan POHL ◽  
Jesse F. GREGORY

We have previously identified and purified a novel β-glucosidase, designated PNGH (pyridoxine-5´-β-d-glucoside hydrolase), from the cytosolic fraction of pig intestinal mucosal. PNGH catalyses the hydrolysis of PNG (pyridoxine-5´-β-d-glucoside), a plant derivative of vitamin B6 that exhibits partial nutritional bioavailability in humans and animals. Preliminary amino acid sequence analysis indicated regions of close similarity of PNGH to the precursor form of LPH (lactase–phlorizin hydrolase), the β-glucosidase localized to the brush-border membrane. We report in the present study amino acid sequence data for PNGH and results of Northern blot analyses, upon which we propose a common genomic origin of PNGH and LPH. Internal Edman sequencing of the PNGH band isolated by SDS/PAGE yielded data for 16 peptides, averaging 10.8 amino acids in length. These peptides from PNGH (approx. 140 kDa) were highly similar to sequences existing over most of the length of the >200 kDa precursor of rabbit LPH; however, we found no PNGH sequences that corresponded to approx. 350 amino acids between positions 463 and 812 of the LPH precursor, a region encoded by exon 7 of the LPH precursor gene (amino acids 568–784), and no sequences that corresponded to regions near the N-terminus. MS analysis of tryptic peptides yielded 25 peptides, averaging 15 amino acids, with masses that matched segments of the rabbit LPH precursor. Northern blot analysis of pig and human small intestinal polyadenylated mRNA using a non-specific LPH cDNA probe showed an expected approx. 6 kb transcript of the LPH precursor, but also an approx. 4 kb transcript that was consistent with the size predicted from the PNGH protein mass. Using a probe specific to the region encoded by exon 7, hybridization occurred only with the 6 kb transcript. Based on these observations, we propose that both PNGH and LPH enzymes have the same genomic origin, but differ in transcriptional and, possibly, post-translational processing.


1971 ◽  
Vol 24 (4) ◽  
pp. 1235 ◽  
Author(s):  
AS Inglis ◽  
PW Nicholls ◽  
CM Roxburgh

Reaction of hydriodic acid with peptides and proteins has been studied. At the boiling point, hydrolysis of the peptide bond, particularly stable bonds linking valine and isoleucine residues, is facile. Several amino acids react with constantboiling hydriodic acid but the only reactions detrimental to the amino acid analysis are the reduction of serine with concomitant formation of alanine, and the destruction of tryptophan. Gentler conditions of hydrolysis with diluted hydriodic acid are required for analysis of serine. Good results for analysis of proteins for amino acids may be obtained after a 6-hr hydrolysis period.


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