1
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Miles SA, Nillama JA, Hunter L. Tinker, Tailor, Soldier, Spy: The Diverse Roles That Fluorine Can Play within Amino Acid Side Chains. Molecules 2023; 28:6192. [PMID: 37687021 PMCID: PMC10489206 DOI: 10.3390/molecules28176192] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Revised: 08/17/2023] [Accepted: 08/17/2023] [Indexed: 09/10/2023] Open
Abstract
Side chain-fluorinated amino acids are useful tools in medicinal chemistry and protein science. In this review, we outline some general strategies for incorporating fluorine atom(s) into amino acid side chains and for elaborating such building blocks into more complex fluorinated peptides and proteins. We then describe the diverse benefits that fluorine can offer when located within amino acid side chains, including enabling 19F NMR and 18F PET imaging applications, enhancing pharmacokinetic properties, controlling molecular conformation, and optimizing target-binding.
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Affiliation(s)
| | | | - Luke Hunter
- School of Chemistry, The University of New South Wales (UNSW), Sydney 2052, Australia
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2
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de Dios SMR, Hass JL, Graham DL, Kumar N, Antony AE, Morton MD, Berkowitz DB. Information-Rich, Dual-Function 13C/ 2H-Isotopic Crosstalk NMR Assay for Human Serine Racemase (hSR) Provides a PLP-Enzyme "Partitioning Fingerprint" and Reveals Disparate Chemotypes for hSR Inhibition. J Am Chem Soc 2023; 145:3158-3174. [PMID: 36696670 PMCID: PMC11103274 DOI: 10.1021/jacs.2c12774] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The first dual-function assay for human serine racemase (hSR), the only bona fide racemase in human biology, is reported. The hSR racemization function is essential for neuronal signaling, as the product, d-serine (d-Ser), is a potent N-methyl d-aspartate (NMDA) coagonist, important for learning and memory, with dysfunctional d-Ser-signaling being observed in some neuronal disorders. The second hSR function is β-elimination and gives pyruvate; this activity is elevated in colorectal cancer. This new NMR-based assay allows one to monitor both α-proton-exchange chemistry and β-elimination using only the native l-Ser substrate and hSR and is the most sensitive such assay. The assay judiciously employs segregated dual 13C-labeling and 13C/2H crosstalk, exploiting both the splitting and shielding effects of deuterium. The assay is deployed to screen a 1020-compound library and identifies an indolo-chroman-2,4-dione inhibitor family that displays allosteric site binding behavior (noncompetitive inhibition vs l-Ser substrate; competitive inhibition vs adenosine 5'-triphosphate (ATP)). This assay also reveals important mechanistic information for hSR; namely, that H/D exchange is ∼13-fold faster than racemization, implying that K56 protonates the carbanionic intermediate on the si-face much faster than does S84 on the re-face. Moreover, the 13C NMR peak pattern seen is suggestive of internal return, pointing to K56 as the likely enamine-protonating residue for β-elimination. The 13C/2H-isotopic crosstalk assay has also been applied to the enzyme tryptophan synthase and reveals a dramatically different partition ratio in this active site (β-replacement: si-face protonation ∼6:1 vs β-elimination: si-face protonation ∼1:3.6 for hSR), highlighting the value of this approach for fingerprinting the pyridoxal phosphate (PLP) enzyme mechanism.
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Affiliation(s)
| | | | | | - Nivesh Kumar
- Department of Chemistry, University of Nebraska, Lincoln, NE 68588 USA
| | - Aina E. Antony
- Department of Chemistry, University of Nebraska, Lincoln, NE 68588 USA
| | - Martha D. Morton
- Department of Chemistry, University of Nebraska, Lincoln, NE 68588 USA
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3
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Ramos De Dios SM, Tiwari VK, McCune CD, Dhokale RA, Berkowitz DB. Biomacromolecule-Assisted Screening for Reaction Discovery and Catalyst Optimization. Chem Rev 2022; 122:13800-13880. [PMID: 35904776 DOI: 10.1021/acs.chemrev.2c00213] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Reaction discovery and catalyst screening lie at the heart of synthetic organic chemistry. While there are efforts at de novo catalyst design using computation/artificial intelligence, at its core, synthetic chemistry is an experimental science. This review overviews biomacromolecule-assisted screening methods and the follow-on elaboration of chemistry so discovered. All three types of biomacromolecules discussed─enzymes, antibodies, and nucleic acids─have been used as "sensors" to provide a readout on product chirality exploiting their native chirality. Enzymatic sensing methods yield both UV-spectrophotometric and visible, colorimetric readouts. Antibody sensors provide direct fluorescent readout upon analyte binding in some cases or provide for cat-ELISA (Enzyme-Linked ImmunoSorbent Assay)-type readouts. DNA biomacromolecule-assisted screening allows for templation to facilitate reaction discovery, driving bimolecular reactions into a pseudo-unimolecular format. In addition, the ability to use DNA-encoded libraries permits the barcoding of reactants. All three types of biomacromolecule-based screens afford high sensitivity and selectivity. Among the chemical transformations discovered by enzymatic screening methods are the first Ni(0)-mediated asymmetric allylic amination and a new thiocyanopalladation/carbocyclization transformation in which both C-SCN and C-C bonds are fashioned sequentially. Cat-ELISA screening has identified new classes of sydnone-alkyne cycloadditions, and DNA-encoded screening has been exploited to uncover interesting oxidative Pd-mediated amido-alkyne/alkene coupling reactions.
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Affiliation(s)
| | - Virendra K Tiwari
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, United States
| | - Christopher D McCune
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, United States
| | - Ranjeet A Dhokale
- Higuchi Biosciences Center, University of Kansas, Lawrence, Kansas 66047, United States
| | - David B Berkowitz
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, United States
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4
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Loro C, Sala R, Penso M, Foschi F. DBU Catalysed Enantioselective Degradative Rearrangement: a Way to Tetrasubstituted 2‐Aryl‐2‐Amino Esters. Adv Synth Catal 2021. [DOI: 10.1002/adsc.202100493] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Camilla Loro
- Dipartimento di Scienza e Alta Tecnologia Università degli Studi dell'Insubria Via Valleggio 9 IT-20100 Como Italy
| | - Roberto Sala
- Dipartimento di Scienza e Alta Tecnologia Università degli Studi dell'Insubria Via Valleggio 9 IT-20100 Como Italy
| | - Michele Penso
- CNR-Istituto di Scienze e Tecnologie Chimiche “Giulio Natta” (SCITEC) Via Golgi 19 IT-20133 Milano Italy
| | - Francesca Foschi
- Dipartimento di Scienza e Alta Tecnologia Università degli Studi dell'Insubria Via Valleggio 9 IT-20100 Como Italy
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5
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Copper-Catalyzed Regioselective Synthesis of ( E)-β-Fluorovinyl Sulfones. Molecules 2019; 24:molecules24081569. [PMID: 31009999 PMCID: PMC6514952 DOI: 10.3390/molecules24081569] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Revised: 04/17/2019] [Accepted: 04/19/2019] [Indexed: 11/30/2022] Open
Abstract
Organofluorine compounds are finding increasing application in a variety of fields such as pharmaceutical, agrochemical, and material sciences. However, given the scarcity of fluorine-containing natural products, advancement in this area depends almost entirely on the development of new synthetic methodologies. In this article, we present the synthesis of a series of previously undescribed (E)-β-fluorovinyl sulfones via a simple copper-catalyzed addition of hydrogen fluoride to alkynyl sulfone starting materials in varying yields and E/Z selectivities. The hydrogenation of these products was also explored and compared with the hydrogenation of the related Z isomers. These new products may find interesting applications, given the versatility of vinyl sulfones in chemical synthesis and the unique properties of vinyl fluorides in biological settings.
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6
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Graham DL, Beio ML, Nelson DL, Berkowitz DB. Human Serine Racemase: Key Residues/Active Site Motifs and Their Relation to Enzyme Function. Front Mol Biosci 2019; 6:8. [PMID: 30918891 PMCID: PMC6424897 DOI: 10.3389/fmolb.2019.00008] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Accepted: 02/12/2019] [Indexed: 01/06/2023] Open
Abstract
Serine racemase (SR) is the first racemase enzyme to be identified in human biology and converts L-serine to D-serine, an important neuronal signaling molecule that serves as a co-agonist of the NMDA (N-methyl-D-aspartate) receptor. This overview describes key molecular features of the enzyme, focusing on the side chains and binding motifs that control PLP (pyridoxal phosphate) cofactor binding as well as activity modulation through the binding of both divalent cations and ATP, the latter showing allosteric modulation. Discussed are catalytically important residues in the active site including K56 and S84—the si- and re-face bases, respectively,—and R135, a residue that appears to play a critical role in the binding of both negatively charged alternative substrates and inhibitors. The interesting bifurcated mechanism followed by this enzyme whereby substrate L-serine can be channeled either into D-serine (racemization pathway) or into pyruvate (β-elimination pathway) is discussed extensively, as are studies that focus on a key loop region (the so-called “triple serine loop”), the modification of which can be used to invert the normal in vitro preference of this enzyme for the latter pathway over the former. The possible cross-talk between the PLP enzymes hSR and hCBS (human cystathionine β-synthase) is discussed, as the former produces D-serine and the latter produces H2S, both of which stimulate the NMDAR and both of which have been implicated in neuronal infarction pursuant to ischemic stroke. Efforts to gain a more complete mechanistic understanding of these PLP enzymes are expected to provide valuable insights for the development of specific small molecule modulators of these enzymes as tools to study their roles in neuronal signaling and in modulation of NMDAR function.
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Affiliation(s)
- Danielle L Graham
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, NE, United States
| | - Matthew L Beio
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, NE, United States
| | - David L Nelson
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, NE, United States
| | - David B Berkowitz
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, NE, United States
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7
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Uraguchi D, Kawai Y, Sasaki H, Yamada K, Ooi T. Allenedicarboxylate as a Stereochemically Labile Electrophile for Chiral Organic Base-catalyzed Stereoselective Michael Addition. CHEM LETT 2018. [DOI: 10.1246/cl.180031] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Daisuke Uraguchi
- Institute of Transformative Bio-Molecules (WPI-ITbM) and Department of Molecular and Macromolecular Chemistry, Graduate School of Engineering, Nagoya University, Furo-cho D2-1, Chikusa, Nagoya, Aichi 464-8601, Japan
| | - Yasutaka Kawai
- Institute of Transformative Bio-Molecules (WPI-ITbM) and Department of Molecular and Macromolecular Chemistry, Graduate School of Engineering, Nagoya University, Furo-cho D2-1, Chikusa, Nagoya, Aichi 464-8601, Japan
| | - Hitoshi Sasaki
- Institute of Transformative Bio-Molecules (WPI-ITbM) and Department of Molecular and Macromolecular Chemistry, Graduate School of Engineering, Nagoya University, Furo-cho D2-1, Chikusa, Nagoya, Aichi 464-8601, Japan
| | - Kohei Yamada
- Institute of Transformative Bio-Molecules (WPI-ITbM) and Department of Molecular and Macromolecular Chemistry, Graduate School of Engineering, Nagoya University, Furo-cho D2-1, Chikusa, Nagoya, Aichi 464-8601, Japan
| | - Takashi Ooi
- Institute of Transformative Bio-Molecules (WPI-ITbM) and Department of Molecular and Macromolecular Chemistry, Graduate School of Engineering, Nagoya University, Furo-cho D2-1, Chikusa, Nagoya, Aichi 464-8601, Japan
- CREST, Japan Science and Technology Agency (JST), Nagoya University, Nagoya, Aichi 464-8601, Japan
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8
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Malik G, Swyka RA, Tiwari VK, Fei X, Applegate GA, Berkowitz DB. A thiocyanopalladation/carbocyclization transformation identified through enzymatic screening: stereocontrolled tandem C-SCN and C-C bond formation. Chem Sci 2017; 8:8050-8060. [PMID: 29568453 PMCID: PMC5855125 DOI: 10.1039/c7sc04083k] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Accepted: 09/29/2017] [Indexed: 12/31/2022] Open
Abstract
Herein we describe a formal thiocyanopalladation/carbocyclization transformation and its parametrization and optimization using a new elevated temperature plate-based version of our visual colorimetric enzymatic screening method for reaction discovery. The carbocyclization step leads to C-SCN bond formation in tandem with C-C bond construction and is highly stereoselective, showing nearly absolute 1,2-anti-stereoinduction (5 examples) for substrates bearing allylic substitution, and nearly absolute 1,3-syn-stereoinduction (16 examples) for substrates bearing propargylic substitution. Based upon these high levels of stereoinduction, the dependence of the 1,2-stereoinduction upon cyclization substrate geometry, and the generally high preference for the transoid vinyl thiocyanate alkene geometry, a mechanistic model is proposed, involving (i) Pd(ii)-enyne coordination, (ii) thiocyanopalladation, (iii) migratory insertion and (iv) β-elimination. Examples of transition metal-mediated C-SCN bond formation that proceed smoothly on unactivated substrates and allow for preservation of the SCN moiety are lacking. Yet, the thiocyanate functionality is of great value for biophysical chemistry (vibrational Stark effect) and medicinal chemistry (S,N-heterocycle construction). The title transformation accommodates C-, O-, N- and S-bridged substrates (6 examples), thereby providing the corresponding carbocyclic or heterocyclic scaffolds. The reaction is also shown to be compatible with a significant range of substituents, varying in steric and electronic demand, including a wide range of substituted aromatics, fused bicyclic and heterocyclic systems, and even biaryl systems. Combination of this new transformation with asymmetric allylation and Grubbs ring-closing metathesis provides for a streamlined enantio- and diastereoselective entry into the oxabicyclo[3.2.1]octyl core of the natural products massarilactone and annuionone A, as also evidenced by low temperature X-ray crystal structure determination. Utilizing this bicyclic scaffold, we demonstrate the versatility of the thiocyanate moiety for structural diversification post-cyclization. Thus, the bridging vinyl thiocyanate moiety is smoothly elaborated into a range of derivative functionalities utilizing transformations that cleave the S-CN bond, add the elements of RS-CN across a π-system and exploit the SCN moiety as a cycloaddition partner (7 diverse examples). Among the new functionalities thereby generated are thiotetrazole and sulfonyl tetrazole heterocycles that serve as carboxylate and phosphate surrogates, respectively, highlighting the potential of this approach for future applications in medicinal chemistry or chemical biology.
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Affiliation(s)
- G Malik
- Department of Chemistry , University of Nebraska , Lincoln , NE 68588 , USA .
| | - R A Swyka
- Department of Chemistry , University of Nebraska , Lincoln , NE 68588 , USA .
| | - V K Tiwari
- Department of Chemistry , University of Nebraska , Lincoln , NE 68588 , USA .
| | - X Fei
- Department of Chemistry , University of Nebraska , Lincoln , NE 68588 , USA .
| | - G A Applegate
- Department of Chemistry , University of Nebraska , Lincoln , NE 68588 , USA .
| | - D B Berkowitz
- Department of Chemistry , University of Nebraska , Lincoln , NE 68588 , USA .
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9
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McCune CD, Beio ML, Sturdivant JM, de la Salud-Bea R, Darnell BM, Berkowitz DB. Synthesis and Deployment of an Elusive Fluorovinyl Cation Equivalent: Access to Quaternary α-(1'-Fluoro)vinyl Amino Acids as Potential PLP Enzyme Inactivators. J Am Chem Soc 2017; 139:14077-14089. [PMID: 28906111 PMCID: PMC6052324 DOI: 10.1021/jacs.7b04690] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Developing specific chemical functionalities to deploy in biological environments for targeted enzyme inactivation lies at the heart of mechanism-based inhibitor development but also is central to other protein-tagging methods in modern chemical biology including activity-based protein profiling and proteolysis-targeting chimeras. We describe here a previously unknown class of potential PLP enzyme inactivators; namely, a family of quaternary, α-(1'-fluoro)vinyl amino acids, bearing the side chains of the cognate amino acids. These are obtained by the capture of suitably protected amino acid enolates with β,β-difluorovinyl phenyl sulfone, a new (1'-fluoro)vinyl cation equivalent, and an electrophile that previously eluded synthesis, capture and characterization. A significant variety of biologically relevant AA side chains are tolerated including those for alanine, valine, leucine, methionine, lysine, phenylalanine, tyrosine, and tryptophan. Following addition/elimination, the resulting transoid α-(1'-fluoro)-β-(phenylsulfonyl)vinyl AA-esters undergo smooth sulfone-stannane interchange to stereoselectively give the corresponding transoid α-(1'-fluoro)-β-(tributylstannyl)vinyl AA-esters. Protodestannylation and global deprotection then yield these sterically encumbered and densely functionalized quaternary amino acids. The α-(1'-fluoro)vinyl trigger, a potential allene-generating functionality originally proposed by Abeles, is now available in a quaternary AA context for the first time. In an initial test of this new inhibitor class, α-(1'-fluoro)vinyllysine is seen to act as a time-dependent, irreversible inactivator of lysine decarboxylase from Hafnia alvei. The enantiomers of the inhibitor could be resolved, and each is seen to give time-dependent inactivation with this enzyme. Kitz-Wilson analysis reveals similar inactivation parameters for the two antipodes, L-α-(1'-fluoro)vinyllysine (Ki = 630 ± 20 μM; t1/2 = 2.8 min) and D-α-(1'-fluoro)vinyllysine (Ki = 470 ± 30 μM; t1/2 = 3.6 min). The stage is now set for exploration of the efficacy of this trigger in other PLP-enzyme active sites.
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Affiliation(s)
| | | | | | | | - Brendan M. Darnell
- Department of Chemistry, University of Nebraska, Lincoln, NE, 68588-0304
| | - David B. Berkowitz
- Department of Chemistry, University of Nebraska, Lincoln, NE, 68588-0304
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10
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Nelson DL, Applegate GA, Beio ML, Graham DL, Berkowitz DB. Human serine racemase structure/activity relationship studies provide mechanistic insight and point to position 84 as a hot spot for β-elimination function. J Biol Chem 2017; 292:13986-14002. [PMID: 28696262 DOI: 10.1074/jbc.m117.777904] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Revised: 06/26/2017] [Indexed: 11/06/2022] Open
Abstract
There is currently great interest in human serine racemase, the enzyme responsible for producing the NMDA co-agonist d-serine. Reported correlation of d-serine levels with disorders including Alzheimer's disease, ALS, and ischemic brain damage (elevated d-serine) and schizophrenia (reduced d-serine) has further piqued this interest. Reported here is a structure/activity relationship study of position Ser84, the putative re-face base. In the most extreme case of functional reprogramming, the S84D mutant displays a dramatic reversal of β-elimination substrate specificity in favor of l-serine over the normally preferred l-serine-O-sulfate (∼1200-fold change in kcat/Km ratios) and l (l-THA; ∼5000-fold change in kcat/Km ratios) alternative substrates. On the other hand, the S84T (which performs l-Ser racemization activity), S84A (good kcat but high Km for l-THA elimination), and S84N mutants (nearly WT efficiency for l-Ser elimination) displayed intermediate activity, all showing a preference for the anionic substrates, but generally attenuated compared with the native enzyme. Inhibition studies with l-erythro-β-hydroxyaspartate follow this trend, with both WT serine racemase and the S84N mutant being competitively inhibited, with Ki = 31 ± 1.5 μm and 1.5 ± 0.1 mm, respectively, and the S84D being inert to inhibition. Computational modeling pointed to a key role for residue Arg-135 in binding and properly positioning the l-THA and l-serine-O-sulfate substrates and the l-erythro-β-hydroxyaspartate inhibitor. Examination of available sequence data suggests that Arg-135 may have originated for l-THA-like β-elimination function in earlier evolutionary variants, and examination of available structural data suggests that a Ser84-H2O-Lys114 hydrogen-bonding network in human serine racemase lowers the pKa of the Ser84re-face base.
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Affiliation(s)
- David L Nelson
- From the Department of Chemistry, University of Nebraska, Lincoln, Nebraska 68588
| | - Greg A Applegate
- From the Department of Chemistry, University of Nebraska, Lincoln, Nebraska 68588
| | - Matthew L Beio
- From the Department of Chemistry, University of Nebraska, Lincoln, Nebraska 68588
| | - Danielle L Graham
- From the Department of Chemistry, University of Nebraska, Lincoln, Nebraska 68588
| | - David B Berkowitz
- From the Department of Chemistry, University of Nebraska, Lincoln, Nebraska 68588.
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11
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Serra M, Bernardi E, Marrubini G, Colombo L. One-Pot Vinylation of Azlactones: Fast Access to Enantioenriched α-Vinyl Quaternary Amino Acids. European J Org Chem 2017. [DOI: 10.1002/ejoc.201700353] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Massimo Serra
- Department of Drug Sciences; Medicinal Chemistry and Pharmaceutical Technology Section; University of Pavia; Viale Taramelli 12 27100 Pavia Italy
| | - Eric Bernardi
- Department of Drug Sciences; Medicinal Chemistry and Pharmaceutical Technology Section; University of Pavia; Viale Taramelli 12 27100 Pavia Italy
| | - Giorgio Marrubini
- Department of Drug Sciences; Medicinal Chemistry and Pharmaceutical Technology Section; University of Pavia; Viale Taramelli 12 27100 Pavia Italy
| | - Lino Colombo
- Department of Drug Sciences; Medicinal Chemistry and Pharmaceutical Technology Section; University of Pavia; Viale Taramelli 12 27100 Pavia Italy
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12
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Boibessot T, Bénimélis D, Meffre P, Benfodda Z. Advances in the synthesis of α-quaternary α-ethynyl α-amino acids. Amino Acids 2016; 48:2081-101. [DOI: 10.1007/s00726-016-2276-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Accepted: 06/08/2016] [Indexed: 11/24/2022]
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13
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McCune C, Chan SJ, Beio ML, Shen W, Chung WJ, Szczesniak LM, Chai C, Koh SQ, Wong PTH, Berkowitz DB. "Zipped Synthesis" by Cross-Metathesis Provides a Cystathionine β-Synthase Inhibitor that Attenuates Cellular H2S Levels and Reduces Neuronal Infarction in a Rat Ischemic Stroke Model. ACS CENTRAL SCIENCE 2016; 2:242-52. [PMID: 27163055 PMCID: PMC4850510 DOI: 10.1021/acscentsci.6b00019] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2016] [Indexed: 05/08/2023]
Abstract
The gaseous neuromodulator H2S is associated with neuronal cell death pursuant to cerebral ischemia. As cystathionine β-synthase (CBS) is the primary mediator of H2S biogenesis in the brain, it has emerged as a potential target for the treatment of stroke. Herein, a "zipped" approach by alkene cross-metathesis into CBS inhibitor candidate synthesis is demonstrated. The inhibitors are modeled after the pseudo-C 2-symmetric CBS product (l,l)-cystathionine. The "zipped" concept means only half of the inhibitor needs be constructed; the two halves are then fused by olefin cross-metathesis. Inhibitor design is also mechanism-based, exploiting the favorable kinetics associated with hydrazine-imine interchange as opposed to the usual imine-imine interchange. It is demonstrated that the most potent "zipped" inhibitor 6S reduces H2S production in SH-SY5Y cells overexpressing CBS, thereby reducing cell death. Most importantly, CBS inhibitor 6S dramatically reduces infarct volume (1 h post-stroke treatment; ∼70% reduction) in a rat transient middle cerebral artery occlusion model for ischemia.
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Affiliation(s)
- Christopher
D. McCune
- Department
of Chemistry, University of Nebraska, Lincoln, Nebraska 68588, United States
| | - Su Jing Chan
- Department
of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117597
| | - Matthew L. Beio
- Department
of Chemistry, University of Nebraska, Lincoln, Nebraska 68588, United States
| | - Weijun Shen
- Department
of Chemistry, University of Nebraska, Lincoln, Nebraska 68588, United States
| | - Woo Jin Chung
- Department
of Chemistry, University of Nebraska, Lincoln, Nebraska 68588, United States
| | - Laura M. Szczesniak
- Department
of Chemistry, University of Nebraska, Lincoln, Nebraska 68588, United States
| | - Chou Chai
- Neurodegeneration
Research Laboratory, National Neuroscience
Institute, Singapore 308433
| | - Shu Qing Koh
- Department
of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117597
| | - Peter T.-H. Wong
- Department
of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117597
- (P.T.-H.W.) E-mail:
| | - David B. Berkowitz
- Department
of Chemistry, University of Nebraska, Lincoln, Nebraska 68588, United States
- (D.B.D.) E-mail:
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14
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Uraguchi D, Yamada K, Ooi T. HighlyE-Selective and Enantioselective Michael Addition to Electron-Deficient Internal Alkynes Under Chiral Iminophosphorane Catalysis. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201503928] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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15
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Uraguchi D, Yamada K, Ooi T. Highly
E
‐Selective and Enantioselective Michael Addition to Electron‐Deficient Internal Alkynes Under Chiral Iminophosphorane Catalysis. Angew Chem Int Ed Engl 2015; 54:9954-7. [DOI: 10.1002/anie.201503928] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2015] [Indexed: 11/12/2022]
Affiliation(s)
- Daisuke Uraguchi
- Institute of Transformative Bio‐Molecules (WPI‐ITbM) and Department of Applied Chemistry, Graduate School of Engineering, Nagoya University, Nagoya 464‐8603 (Japan)
| | - Kohei Yamada
- Institute of Transformative Bio‐Molecules (WPI‐ITbM) and Department of Applied Chemistry, Graduate School of Engineering, Nagoya University, Nagoya 464‐8603 (Japan)
| | - Takashi Ooi
- Institute of Transformative Bio‐Molecules (WPI‐ITbM) and Department of Applied Chemistry, Graduate School of Engineering, Nagoya University, Nagoya 464‐8603 (Japan)
- CREST, Japan Science and Technology Agency (JST), Nagoya University, Nagoya 464‐8603 (Japan)
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16
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Abstract
Described are the synthesis and application of α-t-butyldimethylsilyl-α-methoxyacetaldehyde as a formal methoxyvinyl cation equivalent. Addition of Grignard reagents to the title aldehyde, followed by treatment of the intermediate β-hydroxysilanes with KH, gives good yields of large Z-methoxyvinylated products. Assuming a Peterson-like elimination mechanism, one can infer that the Grignard addition proceeds with high syn selectivity. These results are consistent with a chelation control model involving coordination to the α-methoxy group in the title aldehyde rather than an alternative stereoelectronic Felkin-Anh-type model. It must be noted that a steric Felkin-Anh model also accounts for the observed stereochemistry. All told, the title reagent can be employed to efficiently append a Z-configured methoxyvinyl group to an appropriate R-M species, in two steps.
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17
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Synthesis, resolution, and determination of absolute configuration of protected α-ethynylphenylalanine enantiomers. Amino Acids 2015; 47:899-907. [DOI: 10.1007/s00726-015-1917-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2014] [Accepted: 01/07/2015] [Indexed: 10/24/2022]
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18
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Ni C, Hu M, Hu J. Good partnership between sulfur and fluorine: sulfur-based fluorination and fluoroalkylation reagents for organic synthesis. Chem Rev 2014; 115:765-825. [PMID: 25144886 DOI: 10.1021/cr5002386] [Citation(s) in RCA: 928] [Impact Index Per Article: 92.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- Chuanfa Ni
- Key Laboratory of Organofluorine Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences , 345 Ling-Ling Road, Shanghai City, Shanghai 200032, China
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19
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Yan XW, Zhang Q, Wei W, Ji JX. Simple and convenient synthesis of fluoroalkenes via direct coupling of alcohols, alkynes and fluoroboric acid under metal-free conditions. Tetrahedron Lett 2014. [DOI: 10.1016/j.tetlet.2014.05.069] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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20
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Finkbeiner P, Weckenmann NM, Nachtsheim BJ. Alkynyliodonium Salt Mediated Alkynylation of Azlactones: Fast Access to Cα-Tetrasubstituted α-Amino Acid Derivatives. Org Lett 2014; 16:1326-9. [DOI: 10.1021/ol500053c] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Affiliation(s)
- Peter Finkbeiner
- Institut für Organische
Chemie, Eberhard Karls Universität Tübingen, Auf
der Morgenstelle 18, 72076 Tübingen, Germany
| | - Nicole M. Weckenmann
- Institut für Organische
Chemie, Eberhard Karls Universität Tübingen, Auf
der Morgenstelle 18, 72076 Tübingen, Germany
| | - Boris J. Nachtsheim
- Institut für Organische
Chemie, Eberhard Karls Universität Tübingen, Auf
der Morgenstelle 18, 72076 Tübingen, Germany
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21
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Opekar S, Pohl R, Eigner V, Beier P. Conjugate Addition of Diethyl 1-Fluoro-1-phenylsulfonylmethanephosphonate to α,β-Unsaturated Compounds. J Org Chem 2013; 78:4573-9. [DOI: 10.1021/jo400297f] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Stanislav Opekar
- Institute of Organic Chemistry
and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo nám. 2, 166 10 Prague, Czech Republic
| | - Radek Pohl
- Institute of Organic Chemistry
and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo nám. 2, 166 10 Prague, Czech Republic
| | - Václav Eigner
- Department of Solid State Chemistry, Institute of Chemical Technology, Technická
5, 166 28, Prague, Czech Republic
| | - Petr Beier
- Institute of Organic Chemistry
and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo nám. 2, 166 10 Prague, Czech Republic
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22
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Sparr C, Salamanova E, Schweizer WB, Senn HM, Gilmour R. Theoretical and X-ray crystallographic evidence of a fluorine-imine gauche effect: an addendum to Dunathan's stereoelectronic hypothesis. Chemistry 2011; 17:8850-7. [PMID: 21732444 DOI: 10.1002/chem.201100644] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2011] [Indexed: 11/07/2022]
Abstract
The preference of β-fluoroimines to adopt a gauche conformation has been studied by single-crystal X-ray diffraction analysis and DFT methods. Empirical and theoretical evidence for a preferential gauche arrangement around the NCCF torsion angle (φ) is presented ((E)-2-fluoro-N-(4-nitrobenzylidene)ethanamine: φ(NCCF) =70.0°). In the context of this study, the analysis of a pyridoxal-derived β-fluoroaldimine was performed, a species that is implicated in the inhibition of pyridoxal phosphate (PLP)-dependent enzymes by β-fluoroamine derivatives. The gauche preference of the internal aldimine (=NCH(2)CH(2)F) that can be rationalized by stereoelectronic arguments does not hold for the corresponding external system (N=CHCH(2)F) (E(min) when φ(NCCF) =120°). Moreover, the C-F bond is lengthened by more than 0.02 Å at φ(NCCF) =±90°, when it is exactly antiperiplanar to the conjugated imine. This activation of the C-F σ bond by an adjacent π system constitutes an addendum to Dunathan's stereoelectronic hypothesis.
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Affiliation(s)
- Christof Sparr
- Swiss Federal Institute of Technology (ETH) Zürich, Laboratory for Organic Chemistry, Department of Chemistry and Applied Biosciences, Zürich, Switzerland
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23
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Landelle G, Bergeron M, Turcotte-Savard MO, Paquin JF. Synthetic approaches to monofluoroalkenes. Chem Soc Rev 2011; 40:2867-908. [DOI: 10.1039/c0cs00201a] [Citation(s) in RCA: 243] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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24
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Wnuk SF, Sacasa PR, Restrepo J. Application of germyldesulfonylation reactions to the synthesis of germanium-containing nucleoside analogues. NUCLEOSIDES NUCLEOTIDES & NUCLEIC ACIDS 2010; 28:537-49. [PMID: 20183601 DOI: 10.1080/15257770903054340] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Treatment of the protected (E)-5'-deoxy-5'-[(p-toluenesulfonyl)methylene]uridine and adenosine derivatives with tributyl- or triphenylgermane hydride (AIBN/toluene/Delta) effected radical-mediated germyldesulfonylations to give 5'-(tributyl- or triphenylgermyl)methylene-5'-deoxyuridine and adenosine derivatives as single (E)-isomers. Analogous treatment of 2'-deoxy-2'-[(phenylsulfonyl)methylene]uridine with Ph(3)GeH afforded the corresponding vinyl triphenylgermane product. Stereoselective halodegermylation of the (E)-5'-(tributylgermyl)methylene-5'-deoxy nucleosides with N-iodosuccinimide or N-bromosuccinimide provided the Wittig-type (E)-5'-deoxy-5'-(halomethylene) nucleosides quantitatively, while no halodegermylations was observed with the 5'-deoxy-5'-(triphenylgermyl)methylene counterparts. Treatment of the vinyl trialkylgermanes with aqueous trifluoroacetic acid effected protiodegermylation, while vinyl triarylgermanes were stable under the acidic conditions.
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Affiliation(s)
- Stanislaw F Wnuk
- Department of Chemistry & Biochemistry, Florida International University, Miami, Florida, USA.
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25
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Berkowitz DB, Karukurichi KR, de la Salud-Bea R, Nelson DL, McCune CD. Use of Fluorinated Functionality in Enzyme Inhibitor Development: Mechanistic and Analytical Advantages. J Fluor Chem 2008; 129:731-742. [PMID: 19727327 PMCID: PMC2598403 DOI: 10.1016/j.jfluchem.2008.05.016] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
On the one hand, owing to its electronegativity, relatively small size, and notable leaving group ability from anionic intermediates, fluorine offers unique opportunities for mechanism-based enzyme inhibitor design. On the other, the "bio-orthogonal" and NMR-active 19-fluorine nucleus allows the bioorganic chemist to follow the mechanistic fate of fluorinated substrate analogues or inhibitors as they are enzymatically processed. This article takes an overview of the field, highlighting key developments along these lines. It begins by highlighting new screening methodologies for drug discovery that involve appropriate tagging of either substrate or the target protein itself with (19)F-markers, that then report back on turnover and binding, respectively, via an the NMR screen. Taking this one step further, substrate-tagging with fluorine can be done is such a manner as to provide stereochemical information on enzyme mechanism. For example, substitution of one of the terminal hydrogens in phosphoenolpyruvate, provides insight into the, otherwise latent, facial selectivity of C-C bond formation in KDO synthase. Perhaps, most importantly, from the point of view of this discussion, appropriately tailored fluorinated functionality can be used to form to stabilized "transition state analogue" complexes with a target enzymes. Thus, 5-fluorinated pyrimidines, alpha-fluorinated ketones, and 2-fluoro-2-deoxysugars each lead to covalent adduction of catalytic active site residues in thymidylate synthase, serine protease and glycosidase enzymes, respectively. In all such cases, (19)F NMR allows the bioorganic chemist to spectrally follow "transition state analogue" formation. Finally, the use of specific fluorinated functionality to engineer "suicide substrates" is highlighted in a discussion of the development of the alpha-(2'Z-fluoro)vinyl trigger for amino acid decarboxylase inactivation. Here (19)F NMR allows the bioorganic chemist to glean useful partition ratio data directly out of the NMR tube.
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Affiliation(s)
- David B Berkowitz
- Department of Chemistry, University of Nebraska, Lincoln, NE 68588-0304
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26
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He M, Ghosh AK, Zajc B. Julia Olefination as a General Route to Phenyl (alpha-Fluoro)vinyl Sulfones. Synlett 2008; 2008:999-1004. [PMID: 19888442 PMCID: PMC2771386 DOI: 10.1055/s-2008-1072513] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Mild and efficient synthesis of phenyl (alpha-fluoro)vinyl sulfones via condensation of aldehydes and a ketone with a novel benzothiazolyl based bis-sulfone reagent is reported and this proceeds with moderate to good Z-stereoselectivity.
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Affiliation(s)
| | | | - Barbara Zajc
- Department of Chemistry, The City College and The City University of New York, 160 Convent Avenue, New York, NY 10031, USA
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27
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Wnuk SF, Lalama J, Garmendia CA, Robert J, Zhu J, Pei D. S-Ribosylhomocysteine analogues with the carbon-5 and sulfur atoms replaced by a vinyl or (fluoro)vinyl unit. Bioorg Med Chem 2008; 16:5090-102. [PMID: 18375129 DOI: 10.1016/j.bmc.2008.03.028] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2008] [Revised: 03/05/2008] [Accepted: 03/10/2008] [Indexed: 11/28/2022]
Abstract
Treatment of the protected ribose or xylose 5-aldehyde with sulfonyl-stabilized fluorophosphonate gave (fluoro)vinyl sulfones. Stannyldesulfonylation followed by iododestannylation afforded 5,6-dideoxy-6-fluoro-6-iodo-d-ribo or xylo-hex-5-enofuranoses. Coupling of the hexenofuranoses with alkylzinc bromides gave 10-carbon ribosyl- and xylosylhomocysteine analogues incorporating a fluoroalkene. The fluoroalkenyl and alkenyl analogues were evaluated for inhibition of Bacillus subtilis S-ribosylhomocysteinase (LuxS). One of the compounds, 3,5,6-trideoxy-6-fluoro-d-erythro-hex-5-enofuranose, acted as a competitive inhibitor of moderate potency (K(I)=96microM).
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Affiliation(s)
- Stanislaw F Wnuk
- Department of Chemistry & Biochemistry, Florida International University, Miami, FL 33199, USA.
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28
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Ting A, Schaus SE. Organocatalytic Asymmetric Mannich Reactions: New Methodology, Catalyst Design, and Synthetic Applications. European J Org Chem 2007. [DOI: 10.1002/ejoc.200700409] [Citation(s) in RCA: 413] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Amal Ting
- Department of Chemistry, Boston University, Life Science and Engineering Building, 24 Cummington Street, Boston, MA 02215, U. S. A., Fax: +1‐617‐353‐6466
| | - Scott E. Schaus
- Department of Chemistry, Boston University, Life Science and Engineering Building, 24 Cummington Street, Boston, MA 02215, U. S. A., Fax: +1‐617‐353‐6466
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29
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Karukurichi KR, de la Salud-Bea R, Jahng WJ, Berkowitz DB. Examination of the new alpha-(2'Z-fluoro)vinyl trigger with lysine decarboxylase: the absolute stereochemistry dictates the reaction course. J Am Chem Soc 2007; 129:258-9. [PMID: 17212389 PMCID: PMC2562574 DOI: 10.1021/ja067240k] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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30
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Li G, van der Donk WA. Efficient synthesis of suitably protected beta-difluoroalanine and gamma-difluorothreonine from L-ascorbic acid. Org Lett 2007; 9:41-4. [PMID: 17192080 PMCID: PMC2593874 DOI: 10.1021/ol062401a] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
[reaction: see text] Fluorinated amino acids are useful building blocks for the preparation of biologically active peptides and peptidomimetics with increased metabolic stability. We report here the synthesis of two fluorinated amino acids, beta-difluoroalanine and gamma-difluorothreonine, as analogues of Ser and Thr, respectively. These compounds were suitably protected for Fmoc-based solid-phase peptide synthesis. Once incorporated into peptides, they may serve as alternative substrates or inhibitors of lantibiotic synthetases that posttranslationally dehydrate Ser and Thr residues to dehydroalanine and dehydrobutyrine, respectively.
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31
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Berkowitz DB, Wu B, Li H. A formal [3,3]-sigmatropic rearrangement route to quaternary alpha-vinyl amino acids: use of allylic N-PMP trifluoroacetimidates. Org Lett 2006; 8:971-4. [PMID: 16494487 PMCID: PMC2504469 DOI: 10.1021/ol060019s] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Pd(II)-mediated rearrangement of allylic N-PMP (p-methoxyphenyl) trifluoroacetimidates provides the first formal sigmatropic route to quaternary, alpha-vinylic amino acids, potential suicide substrates for PLP enzymes. The amino acid side chains enter via transition-metal-mediated C-C bond constructions, including (i) Cu(I)-mediated conjugate addition (Ala); (ii) Pd(0)/AsPh3-mediated Stille coupling (allyl-Gly, Phe, DOPA, m-Tyr); and (iii) Pd(0)/Pt-Bu3-mediated Negishi coupling (Leu). In the synthesis of the DOPA decarboxylase inactivator, alpha-vinyl-m-tyrosine, the new N-PMP trifluoroacetimidate rearranges much more efficiently than the corresponding trichloroacetimidate.
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Affiliation(s)
- David B Berkowitz
- Department of Chemistry, University of Nebraska, Lincoln, Nebraska 68588-0304, USA.
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32
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Ting A, Lou S, Schaus SE. Highly Diastereoselective Asymmetric Mannich Reactions of 1,3-Dicarbonyls with Acyl Imines. Org Lett 2006; 8:2003-6. [PMID: 16671767 DOI: 10.1021/ol060304b] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
[reaction: see text] The cinchona alkaloids catalyze direct asymmetric Mannich reactions of cyclic 1,3-dicarbonyl compounds with acyl imines to afford alpha-quaternary carbon-bearing reaction products in yields of up to 98%, a diastereomeric excess of 90% or greater, and enantioselectivities up to 99% ee. A model is proposed that accounts for both the observed diastereoselectivities and the enantioselectivities for the reactions.
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Affiliation(s)
- Amal Ting
- Department of Chemistry, Center for Chemical Methodology and Library Development at Boston University, Massachusetts 02215, USA
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33
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Berkowitz DB, Charette BD, Karukurichi KR, McFadden JM. α-Vinylic Amino Acids: Occurrence, Asymmetric Synthesis and Biochemical Mechanisms. TETRAHEDRON, ASYMMETRY 2006; 17:869-882. [PMID: 29977107 PMCID: PMC6029878 DOI: 10.1016/j.tetasy.2006.02.026] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
This report presents an overview of the family of naturally occurring 'vinylic' amino acids, namely those that feature a C-C double bond directly attached to the α-carbon, along the side chain. Strategies that have been brought to bear on the stereocontrolled synthesis of these olefinic amino acids are surveyed. The mechanistic diversity by which such 'vinylic triggers' can be actuated in a PLP (pyridoxal phosphate) enzyme active site is then highlighted by discussions of vinylglycine (VG), its substituted congeners, particularly AVG [4E-(2'-aminoethoxy)vinylglycine], and a naturally occurring VG-progenitor, SMM (S-methylmethionine).
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Affiliation(s)
- David B Berkowitz
- Department of Chemistry, University of Nebraska, Lincoln, NE 68588-0304
| | | | | | - Jill M McFadden
- Department of Chemistry, University of Nebraska, Lincoln, NE 68588-0304
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