5817-22-1Relevant articles and documents
Scalable and Selective β-Hydroxy-α-Amino Acid Synthesis Catalyzed by Promiscuous l-Threonine Transaldolase ObiH
Doyon, Tyler J.,Kumar, Prasanth,Thein, Sierra,Kim, Maeve,Stitgen, Abigail,Grieger, Abbigail M.,Madigan, Cormac,Willoughby, Patrick H.,Buller, Andrew R.
, (2021/11/23)
Enzymes from secondary metabolic pathways possess broad potential for the selective synthesis of complex bioactive molecules. However, the practical application of these enzymes for organic synthesis is dependent on the development of efficient, economical, operationally simple, and well-characterized systems for preparative scale reactions. We sought to bridge this knowledge gap for the selective biocatalytic synthesis of β-hydroxy-α-amino acids, which are important synthetic building blocks. To achieve this goal, we demonstrated the ability of ObiH, an l-threonine transaldolase, to achieve selective milligram-scale synthesis of a diverse array of non-standard amino acids (nsAAs) using a scalable whole cell platform. We show how the initial selectivity of the catalyst is high and how the diastereomeric ratio of products decreases at high conversion due to product re-entry into the catalytic cycle. ObiH-catalyzed reactions with a variety of aromatic, aliphatic and heterocyclic aldehydes selectively generated a panel of β-hydroxy-α-amino acids possessing broad functional-group diversity. Furthermore, we demonstrated that ObiH-generated β-hydroxy-α-amino acids could be modified through additional transformations to access important motifs, such as β-chloro-α-amino acids and substituted α-keto acids.
L -Threonine Transaldolase Activity Is Enabled by a Persistent Catalytic Intermediate
Kumar, Prasanth,Meza, Anthony,Ellis, Jonathan M.,Carlson, Grace A.,Bingman, Craig A.,Buller, Andrew R.
, p. 86 - 95 (2021/01/09)
l-Threonine transaldolases (lTTAs) are a poorly characterized class of pyridoxal-5′-phosphate (PLP) dependent enzymes responsible for the biosynthesis of diverse β-hydroxy amino acids. Here, we study the catalytic mechanism of ObiH, an lTTA essential for biosynthesis of the β-lactone natural product obafluorin. Heterologously expressed ObiH purifies as a mixture of chemical states including a catalytically inactive form of the PLP cofactor. Photoexcitation of ObiH promotes the conversion of the inactive state of the enzyme to the active form. UV-vis spectroscopic analysis reveals that ObiH catalyzes the retro-aldol cleavage of l-threonine to form a remarkably persistent glycyl quinonoid intermediate, with a half-life of a??3 h. Protonation of this intermediate is kinetically disfavored, enabling on-cycle reactivity with aldehydes to form β-hydroxy amino acids. We demonstrate the synthetic potential of ObiH via the single step synthesis of (2S,3R)-β-hydroxyleucine. To further understand the structural features underpinning this desirable reactivity, we determined the crystal structure of ObiH bound to PLP as the Schiff's base at 1.66 ? resolution. This high-resolution model revealed a unique active site configuration wherein the evolutionarily conserved Asp that traditionally H-bonds to the cofactor is swapped for a neighboring Glu. Molecular dynamics simulations combined with mutagenesis studies indicate that a structural rearrangement is associated with l-threonine entry into the catalytic cycle. Together, these data explain the basis for the unique reactivity of lTTA enzymes and provide a foundation for future engineering and mechanistic analysis.
Multi-enzymatic synthesis of optically pure β-hydroxy α-amino acids
Hibi, Makoto,Kasahara, Takuya,Kawashima, Takashi,Yajima, Hiroko,Kozono, Shoko,Smirnov, Sergey V.,Kodera, Tomohiro,Sugiyama, Masakazu,Shimizu, Sakayu,Yokozeki, Kenzo,Ogawa, Jun
, p. 767 - 774 (2015/03/18)
A novel enzymatic production system of optically pure β-hydroxy α-amino acids was developed. Two enzymes were used for the system: an N-succinyl L-amino acid β-hydroxylase (SadA) belonging to the iron(II)/α-ketoglutarate-dependent dioxygenase superfamily and an N-succinyl L-amino acid desuccinylase (LasA). The genes encoding the two enzymes are part of a gene set responsible for the biosynthesis of peptidyl compounds found in the Burkholderia ambifaria AMMD genome. SadA stereoselectively hydroxylated several N-succinyl aliphatic L-amino acids and produced N-succinyl β-hydroxy L-amino acids, such as N-succinyl-L-β-hydroxyvaline, N-succinyl-L-threonine, (2S,3R)-N-succinyl-L-β-hydroxyisoleucine, and N-succinyl-L-threo-β-hydroxyleucine. LasA catalyzed the desuccinylation of various N-succinyl-L-amino acids. Surprisingly, LasA is the first amide bond-forming enzyme belonging to the amidohydrolase superfamily, and has succinylation activity towards the amino group of L-leucine. By combining SadA and LasA in a preparative scale production using N-succinyl-L-leucine as substrate, 2.3 mmol of L-threo-β-hydroxyleucine were successfully produced with 93% conversion and over 99% of diastereomeric excess. Consequently, the new production system described in this study has advantages in optical purity and reaction efficiency for application in the mass production of several β-hydroxy α-amino acids.
Total synthesis of the cyclic depsipeptide YM-280193, a platelet aggregation inhibitor
Kaur, Harveen,Harris, Paul W. R.,Little, Peter J.,Brimble, Margaret A.
supporting information, p. 492 - 495 (2015/03/05)
The first total synthesis of YM-280193, a cyclic depsipeptide that inhibits the ADP-induced aggregation of human platelets, is described. The monomer and dipeptide fragments were prepared using conventional chemistry and subsequently assembled by Fmoc-solid-phase peptide synthesis (Fmoc-SPPS). A late-stage novel bis-alkylation-elimination of cysteine on-resin was employed to introduce the unnatural N-methyldehydroalanine moiety. The final step involved execution of a key macrolactamization reaction between the hindered unnatural N,O-dimethylthreonine and ?2-hydroxyleucine residues.
Trichormamides A and B with antiproliferative activity from the cultured freshwater cyanobacterium Trichormus sp. UIC 10339
Luo, Shangwen,Krunic, Aleksej,Kang, Hahk-Soo,Chen, Wei-Lun,Woodard, John L.,Fuchs, James R.,Swanson, Steven M.,Orjala, Jimmy
, p. 1871 - 1880 (2014/10/16)
Two new cyclic lipopeptides, trichormamides A (1) and B (2), were isolated from the cultured freshwater cyanobacterium Trichormus sp. UIC 10339. The strain was obtained from a sample collected in Raven Lake in Northern Wisconsin. The planar structures of trichormamides A (1) and B (2) were determined using a combination of spectroscopic analyses including HRESIMS and 1D and 2D NMR experiments. The absolute configurations of the amino acid residues were assigned by the advanced Marfey's method after acid hydrolysis. Trichormamide A (1) is a cyclic undecapeptide containing two d-amino acid residues (d-Tyr and d-Leu) and one β-amino acid residue (β-aminodecanoic acid). Trichormamide B (2) is a cyclic dodecapeptide characterized by the presence of four nonstandard α-amino acid residues (homoserine, N-methylisoleucine, and two 3-hydroxyleucines) and one β-amino acid residue (β-aminodecanoic acid). Trichormamide B (2) was cytotoxic against MDA-MB-435 and HT-29 cancer cell lines with IC50 values of 0.8 and 1.5 μM, respectively.
DISUBSTITUTED BETA-LACTONES AS INHIBITORS OF N-ACYLETHANOLAMINE ACID AMIDASE (NAAA)
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Paragraph 0384; 0385, (2013/06/06)
The present invention provides compounds and pharmaceutical compositions for inhibiting N-acylethanolamine acid amidase (NAAA). Inhibition of NAAA is contemplated as a method to sustain the levels of palmitoylethanolamide (PEA) and oleylethanolamide (OEA), two substrates of NAAA, in conditions characterized by reduced concentrations of PEA and OEA. The invention also provides methods for treating inflammatory diseases and pain, and other disorders in which decreased levels of PEA and OEA are associated with the disorder.
Efficient total synthesis of manzacidin B
Shinada, Tetsuro,Oe, Kentaro,Ohfune, Yasufumi
supporting information; experimental part, p. 3250 - 3253 (2012/07/31)
The highly diastereoselective synthesis of the marine natural product, (-)-manzacidin B, is described. A novel copper-catalyzed aldol reaction of the α-methylserine-derived aldehyde with an isocyanoacetate possessing (1R)-camphorsultam as the chiral auxiliary proceeded in a highly diastereoselective manner to give the (4R,5R,6R)-adduct, which was converted into manzacidin B in a few steps.
Total structure and inhibition of tumor cell proliferation of laxaphycins
Bonnard, Isabelle,Rolland, Marc,Salmon, Jean-Marie,Debiton, Eric,Barthomeuf, Chantal,Banaigs, Bernard
, p. 1266 - 1279 (2007/10/03)
From a mixed assemblage of Lyngbya majuscula rich marine cyanobacteria, we isolated a series of cell growth inhibitory cyclic peptides, The structures of the two major components, laxaphycins A (1) and B (2), and of two minor peptides, laxaphycins B2 (3) and B3 (4), were determined by spectroscopic methods and degradative analysis. Absolute configurations of natural and nonproteinogenic amino acids were determined by a combination of hydrolysis, synthesis of noncommercial residues, chemical derivatization, and HPLC analysis. The organism producing the laxaphycins was identified as the cyanobacterium Anabaena torulosa. The antiproliferative activity of laxaphycins was investigated on a panel of solid and lymphoblastic cancer cells. Our results demonstrate that in contrast to laxaphycin A, laxaphycin B inhibits the proliferation of sensitive and resistant human cancer cell lines and that this activity is strongly increased in the presence of laxaphycin A. This effect appears to be due to an unusual biological synergism.
Synthesis of γ-halogenated and long-chain β-hydroxy-α-amino acids and 2-amino-1,3-diols using threonine aldolases
Steinreiber, Johannes,Fesko, Kateryna,Mayer, Clemens,Reisinger, Christoph,Schürmann, Martin,Griengl, Herfried
, p. 8088 - 8093 (2008/02/08)
The l- and d-threonine aldolase catalyzed formation of γ-halogenated and long-chain l- and d-3-alkylserine-derivatives 1-12, respectively, was shown starting from glycine and halogenated C2- or C4-C12 aldehydes. lTA from Pseudomonas putida accepted all tested aldehydes with strongly varying diastereoselectivity (de up to 93%). Only aldehydes smaller than decanal were converted by dTA from Alcaligenes xylosoxidans with good selectivities (de up to 73%). Utilizing isobutanal enantio- and diastereopure d-syn-2-amino-3-hydroxy-4-methylpentanoic acid was obtained (ee>99%, de>95%), which was converted to the corresponding 2-amino-1,3-diol.
DIRECT ORGANOCATALYTIC ASYMMETRIC REACTIONS OF ENOLIZABLE α-AMINO ALDEHYDES OR KETONES TO FORM HIGHLY ENANTIOMERICALLY ENRICHED AMINE PRODUCTS
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Page/Page column 42, (2010/10/20)
A method for asymmetrically forming a (diprotectedamino)-product having a chiral center and in which one enantiomer is in excess over the other is disclosed. The method comprises reacting an enolizable alpha- (diprotectedamino)-aldehyde or -ketone donor molecule with an excess of an unsaturated acceptor molecule that has one or no hydrogen atoms bonded to a carbon atom alpha to the carbon of the unsaturation. The donor and acceptor molecules are dissolved or dispersed in a liquid solvent and are in the presence of a chiral amine catalyst to form an addition product reaction medium. The reaction medium is maintained for a time sufficient to form an α-(diprotectedamino)-aldehyde or -ketone product having a chiral center formed at a carbon atom bonded to the α-(diprotectedamino) group and in which one enantiomer is in excess over the other.
